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Tuesday 30 September 2008

Successful Re-Entry Marks Bright Future For ATV

Europe's first Automated Transfer Vehicle (ATV) Jules Verne successfully completed its six-month ISS logistics mission with its controlled destructive re-entry over a completely uninhabited area of the South Pacific.

Following a final deorbit burn at 14:58 CEST which slowed its velocity by 70 m/s, the ATV entered the upper atmosphere at an altitude of 120 km at 15:31 CEST. It broke up at an altitude of 75 km with the remaining fragments falling into the Pacific some 12 minutes later.

The ATV has proved what a key ISS logistics vehicle it is. Following its 9 March launch on an Ariane 5 rocket from Europe's Spaceport in French Guiana, the ATV delivered 6 tonnes of cargo to the International Space Station, to which it remained docked for five months.

This included ISS reboost and refuelling propellants, water, oxygen and 1.3 tonnes of dry cargo including food, clothing, spares and other items. During its mission, the ATV displayed the full range of its capabilities, including automatic rendezvous and docking, four ISS reboosts to a higher orbital altitude to offset atmospheric drag, ISS attitude control, performing a collision-avoidance manoeuvre when fragments of an old satellite came within the Station's vicinity, and on its final journey offloading tonnes of waste.

"This mission is a fantastic accomplishment which caps a great year of human spaceflight for the European Space Agency", said Simonetta Di Pippo, ESA's Director of Human Spaceflight. "Together with the Columbus laboratory, the ATV has really shown how far European capabilities have developed in building, launching and controlling space infrastructure.

Europe has now taken a further step towards its capability of being able to transport and return cargo and astronauts to and from space and helping to define the global picture for human spaceflight from the ISS to future exploration activities."

Following its undocking on 5 September, the ATV had spent 23 days carrying out "rephrasing" manoeuvres to bring it to the correct position behind and underneath the ISS.

This predefined position allowed the re-entry to be viewed and recorded from the Station itself, as well as from two specially-equipped observation planes located in the vicinity of the ATV's flight path in the skies above the South Pacific. This observation campaign will serve to determine whether the vehicle's break-up matched the computer modelling.

"Credit has to go to everyone involved in such a flawless mission" said John Ellwood, ESA's ATV Project Manager.

"Not only to the ESA and industrial teams that brought the project to fruition, but also to the teams at the ATV Control Centre and around the world who have done a superb job while the spacecraft has been in orbit. This is truly a wonderful spacecraft, and vital to the continued service of the ISS following Shuttle retirement in 2010. I look forward to the launch of the next ATV, which is currently under production at EADS Astrium in Bremen, Germany."

BBC NEWS | Science & Environment | Freighter now back down in a fireball

Europe's biggest, most sophisticated spaceship is about to bring its six-month mission to an end by plunging into the Pacific in a ball of flames.
The "Jules Verne" freighter undocked from the space station three weeks ago packed with rubbish and will take its unwanted cargo into a destructive dive.
Most of the vehicle is expected to burn up in the atmosphere; only fragments will make it down to the ocean water.
Two engine firings should bring the ship out of the sky on Monday.
Events will be overseen from the European Space Agency's (Esa) freighter control centre in Toulouse, France.
 
Mike Steinkopf, the mission director for re-entry, says a "safety zone" has been drawn in the south Pacific some 2,700km long by 200km wide.
"We will see what appears to be a very bright meteor"
 
Jason Hatton
Esa-Nasa re-entry observing team
"We issue a notification to the air traffic and maritime authorities to make sure there are no planes or boats going through that zone during our re-entry time," he told BBC News.
 
Astronauts on the overflying International Space Station (ISS) and scientists in two chase planes will take pictures as the disintegrating mass of metal streaks through the morning Pacific darkness.
 
"Visually, we will see what appears to be a very bright meteor," explained Jason Hatton from the chase team set by Esa and the US space agency (Nasa). "It will start as a point of light with a trail, and then as it comes apart, we will see fragments."

 
Jules Verne - also known by the generic name Automated Transfer Vehicle (ATV) - cost about 1.3bn euros to develop.
Although Esa has produced many complex scientific satellites, none match the scale of the freighter.
After launch, the space truck can work out where it needs to go in space, and then makes a fully automatic docking once it arrives at its destination.

JULES VERNE - THE FIRSTS

The ATV is the first completely automated rendezvous and docking ship to go to the ISS
The ATV is the largest and most powerful space tug going to the ISS over its mission life
It provides the largest refuelling and waste elimination capability for the space station
It is the only vehicle on the current timeline able to de-orbit the ISS when it is retired

It was developed as part of Esa's ISS membership agreement, to haul cargo, propellant, water and oxygen to the space station; and also to provide propulsion capacity at the station.
But such has been the performance of Jules Verne that Esa officials and industry chiefs are already talking about upgrading the ship's design - potentially to carry astronauts.
The first step, however, would be to develop technologies that enable the safe return of cargo to Earth.
European space ministers will discuss the issue at their meeting in The Hague in November.
 
Jules Verne is currently orbiting the Earth just below the space station at an altitude of about 330km.
Taking the freighter out of the sky involves turning it to face the direction of flight so that its rear engines are then facing forward and can be fired to slow the ship's velocity.

The first burn, which will be initiated at about 1000 GMT and last roughly six minutes, will put the 13.5-tonne spacecraft on a sharp elliptical orbit.

Cost: Total bill was 1.3bn euros (at least 4 more ATVs will be built)
Total cargo capacity: 7.6 tonnes, but first mission flew lighter
Mass at launch: About 20 tonnes depending on cargo manifest
Dimensions: 10.3m long and 4.5m wide - the size of a large bus
Solar panels: Once unfolded, the solar wings span 22.3m
Engine power: 4x 490-Newton thrusters; and 28x 220N thrusters
Mission timeline: Launch - 9 March; Docking - 3 April;
Undocking - 5 September; De-orbit - 29 September

Approximately two hours later, the engines will be fired again, this time for some 15 minutes. This should take the ATV on its final trajectory and a steep dive towards the Pacific.
The freighter is expected to be moving at some 7.6km/s as it meets significant atmosphere at 120km. As the plunge continues and temperatures rise, Jules Verne will be torn part.

"We expect the solar panels to break just two-and-a-half-minutes after the entry into the atmosphere; and then we will have fragmentation of the docking adaptor, protective shields and other structural elements," explained Mr Steinkopf.

"Nevertheless, statistically speaking, there will be about 30% of the overall vehicle that may reach the ocean, but only in bits and pieces."

The final moments will be witnessed in the Pacific by two chase planes. The jets, a Gulfstream-V and a DC8, will carry an observation team equipped with a range of spectroscopic imagers and conventional video and stills cameras.

The team wants to establish in detail how the different components of Jules Verne, such as its fuel tanks, come apart.

The information will inform the computer models used by space agencies to plan the safe re-entries of future spacecraft.

"We expect to see signatures associated with the fuel in the wake of the vehicle because you have this trail behind it," Mr Hatton told BBC News from the team's campaign base in Tahiti.

"That's where the spectroscopy comes in. You have a range of different spectrograph's all the way from the near-ultraviolet, through the visible to the near-infra-red. In the different colours, we'll probably see what materials are being released from the vehicle, maybe what some of the fragments are - aluminium, for example."

Under the agreement Esa has with its international partners, at least four more ATVs will be flown to the space station in the coming years. The next is due to launch in 2010.

And, ultimately, it is likely that an ATV will be tasked with destroying the space station when the partners have decided the platform is beyond servicing, perhaps towards the end of the next decade.

A freighter will be commanded to drive the whole structure into a similar region of the south Pacific.

Fireball over the South Pacific

Space Weather News for Sept. 29, 2008
http://spaceweather.com

GOODBYE, JULES VERNE:  Earlier today, European mission controllers commanded the robotic cargo carrier Jules Verne to re-enter Earth's atmosphere over the south Pacific Ocean. The disintegrating spacecraft made a spectacular fireball observed by at least one NASA aircraft and possibly the International Space Station. First pictures are coming in now and may be found at http://spaceweather.com

GREAT PROMINENCE:  Sunspot counts remain very low, but solar activity is not zero.  For the third day in a row, astronomers are monitoring one of the best solar prominences in years. The plume of hot gas, twisted into complex shapes by solar magnetic fields, is nearly 10 times taller than Earth and an easy target for safely-filtered backyard telescopes.  Visit http://spaceweather.com for photos and movies.

Fireball over the South Pacific

The Jules Verne ATV (Advanced Transport Vehicle) disintrigrates over the South Pacific Ocean.....



Saturday 27 September 2008

Countdown to the Final Burn: ATV Jules Verne will Undock on September 5th | Universe Today

The ATV on approach to the station in April. Mission will end next month (ESA/NASA)
The Automated Transfer Vehicle (ATV) Jules Verne will undock from the International Space Station (ISS) on September 5th to begin three weeks of autonomous flight, setting it up for a suicidal re-entry on September 29th. The ATV has been loaded with refuse and unwanted equipment from the ISS set to burn up in the Earth's upper atmosphere marking the end of the life of Europe's most advanced space vehicle. To record the event, both NASA and the European Space Agency will be photographing and videoing the descent…

The Russian Federal Space Agency Roscosmos announced the date for the end of the Jules Verne mission to the ISS on Thursday. This news comes after a highly successful period for the European ATV, proving the ATV can be used for extensive re-supply tasks and provide the station with a valuable re-boost and space debris avoidance options.


This first ATV, also known as "Jules Verne" (as it delivered two original manuscripts written by the 19th Century author to the station), was launched from French Guiana in South America on board an Ariane-5 heavy-lift rocket on March 5th. During this busy time for the Space Station, the ATV had to remain in a "parking orbit" for nearly a month before delivering supplies to the ISS crew on April 3th. Only when Space Shuttle Endeavour (STS-123) had undocked and landed on March 26th could the ATV approach and dock.

Since then, the ATV has proven to be a valuable addition to the station, surpassing all expectations. The ISS crew will miss Jules Verne as the roomy temporary supply vessel has provided a great area for the crew to sleep and wash, plus one of its empty tanks has been used to store 110 litres of condensation water. These extra (unexpected) uses prompted mission control to extend the life of the mission for an extra month.

But all good things come to an end and the ATV will undock on September 5th to begin its journey back to Earth as a fireball at the end of September. The ATV will be dropping up to six tonnes of unwanted equipment and waste from the station into a pre-designated area of the Pacific Ocean. But ESA and NASA will be watching, photographing and videoing Jules Verne's final service to the ISS crew…
 
Comments:

10 Responses to "Countdown to the Final Burn: ATV Jules Verne will Undock on September 5th"

Dominion Says:
August 29th, 2008 at 6:20 pm
what a waste.
 
Tyler Durden Says:
August 29th, 2008 at 7:47 pm
^ Agreed. You want to dispose of space trash, send it down with the astronauts, or just give it a shove in the right direction so it burns up in the atmosphere. No use destroying a perfectly good vehicle that could have been reused as such, or added to the space station as extra usable space.
 
Keith Says:
August 29th, 2008 at 11:27 pm
The current Russian supply modules also go exactly the same way. There will be further ATV launches in the future, it's just that it was not designed to be a reusable vehicle.

However there are plans to adapt the ATV basic design into a cargo return vessel and even a man rated vehicle.
 
Jon Hanford Says:
August 30th, 2008 at 3:38 am
As Keith points out, ESA & NASA are already studying the Jules Verne as a manned ferry for astronauts to & from the ISS. With the impending Shuttle fleet retirement & political problems with the Russians, I would seriously increase funding to make this option materialize ASAP. This ATV's near flawless mission (including an autonomous docking withe the ISS), increased payload capabilities (for supplies, propellant & equipment) and using the ESAs' own heavy lift rocket would make this an ideal transport vehicle to and from the station. As I understand the situation, the ATV is already man-rated, so only a crew capsule must be fabricated & tested, then integrated with the ATV. Might be easier said than done, but examine the alternatives. NASA & ESA would both benefit greatly & I believe this could be accomplished in only a couple of years. They've developed a great ATV so now let's fully utilize its' potential.
 
Sili Says:
August 30th, 2008 at 3:45 am
Wait. They're going to jettison 110 l of water?
Why?!
 
Chuck Lam Says:
August 30th, 2008 at 5:56 am
Why contaminate the atmosphere with ISS crap? Why not simply jetson the trash outbound in a simple container with an obsolete mini-rocket. Thus sparing an already troubled atmoshpere with more of the same. Also, why waste an ATV vehicle? There must be useful serviceable hardware beneficial to the ISS joke. Damn! What are these morons spending our tax dollars thinking?
 
Dominion Says:
August 30th, 2008 at 7:21 am
"unwanted equipment"? just what are they throwing away? If we are ever going to have an orbital construction facility to create bigger ships then we will need all the equipment and resources we can get. There are plans to build a base on the moon. Why can't this thing be sent there? Going to need and want some equipment on the moon. And water too. Just seems such a waste to burn it all up just cause it can't be used right now. And the ATV is supposed to drop six tons of stuff into the ocean!?! I thought we were going to be thinking green now. Can anyone say pollution? Does the ATV have any remaining fuel in it? Wouldn't that be a toxic hazard? And we are just going to throw it in with the fish? We wonder why there are so many dead zones in the ocean now. Maybe cause we throw garbage and toxic waste in it all the time. I think it is time Nasa and Esa were made to be accountable for their actions. They do use tax dollars to fund their operations after all.
 
David Says:
August 30th, 2008 at 2:41 pm
As someone who lives near the pacific, NZ, I wonder if NASA has consent to drop this POLLUTION into OUR oceans.
 
I agree with Dominion above, lets keep it up there once we get it there. Push the wee dear into a better , safer orbit and leave it there. It could be a life boat a place to go to if things go wrong, a storeroom of old stuff, in the future this may be used in another project or maybe for museums?
 
Mir too should have been left up there.

There is far too much pollution of the atmosphere as these things launch, so we dont need any more dliberate pollutionn like this.
If NASA dont stop this NZ will take its space needs elswhere.( joke)

Does any one know if there has been permission given to NASA and the USA to polute our waters in this way?

Maybe its time to show us the real space ships with the reverse engineered ships from area 51?

DaViD
 
trux Says:
August 30th, 2008 at 2:43 pm
Can't they just bring all the junk back to the Earth and sell it on eBay?! It could help financing the next flight. I bet that even the broken toilet would sell on eBay for an astronomic amount.
 
Paul Says:
August 30th, 2008 at 9:19 pm
Didn"t they just use it to steer the station away from some serious space junk.
It sounds pretty handy to me.

Thursday 25 September 2008

NASA - Target Launch Date Reset

Target Launch Date Reset

09.24.08
image from an animation of the Hubble being released from the shuttle
WASHINGTON -- The target launch date for space shuttle Atlantis' STS-125 mission to service the Hubble Space Telescope has been reset to Oct. 14 at 10:19 p.m. EDT. A news conference is scheduled for Friday, Oct. 3, at NASA's Kennedy Space Center in Florida to announce an official launch date.

With the delay of Atlantis' launch from Oct. 10 to Oct. 14, shuttle Endeavour's STS-126 supply mission to the International Space Station, also will move from Nov. 12 to Nov. 16 at 7:07 p.m. EST. The target launch date adjustments were made Wednesday during the Space Shuttle Program's Flight Readiness Review, which concludes Thursday.

+ Read full Press Release

Wednesday 24 September 2008

Slip likely for Atlantis launch to Hubble / Sea Launch orbits satellite

 
      NEWSALERT: Wednesday, September 24, 2008 @ 1658 GMT
---------------------------------------------------------------------
          The latest news from Spaceflight Now


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access" to software demonstrations, user presentations, hands-on training,
technical seminars, subject matter experts, and keynote speakers Brig Gen
(ret) Duane Deal and NASA Astronaut Capt. A lan Bean. Download the event
guide for a detailed conference agenda and secure your space at
www.agiuc.com.
+++


COMMANDER SAYS CREW NEEDS TO MAKE UP TRAINING
---------------------------------------------
Atlantis commander Scott Altman said Tuesday his crew lost a week of
training time because of Hurricane Ike, "so you come to the question of
either slipping the launch or cutting out events."

 http://spaceflightnow.com/shuttle/sts125/080923tcdt/


SEA LAUNCH DEPLOYS NEW GALAXY FOR NORTH AMERICA
-----------------------------------------------
A communications satellite that will broadcast a range of international
television channels to North America was sent into space today to replace
the aging spacecraft currently doing that job.

 http://spaceflightnow.com/sealaunch/galaxy19/


ULYSSES REVEALS SUN IS BLOWING WEAKER SOLAR WIND
------------------------------------------------
Surprising data from NASA's Ulysses spacecraft show that the solar wind --
the continuous outflow of plasma and magnetic fields from the Sun's
atmosphere into interplanetary space -- is only about three fourths as
strong as it was a decade ago, during the last interval of low solar
activity.

 http://spaceflightnow.com/news/n0809/23ulysses/


COSMIC "DARK FLOW" DETECTED ACROSS BILLIONS OF LIGHT YEARS
----------------------------------------------------------
Using data from NASA's Wilkinson Microwave Anisotropy Probe, scientists
have identified an unexpected motion in distant galaxy clusters. The
cause, they suggest, is the gravitational attraction of matter that lies
beyond the observable universe.

 http://spaceflightnow.com/news/n0809/23darkflow/


OPPORTUNITY ROVER TO HEAD TOWARD GIANT CRATER
---------------------------------------------
NASA's Mars Rover Opportunity is setting its sights on a crater more than
20 times larger than its home for the past two years. To reach the crater
the rover team calls Endeavour, Opportunity would need to drive
approximately 7 miles to the southeast, matching the total distance it has
traveled since landing on Mars in early 2004.

 http://spaceflightnow.com/news/n0809/22opportunity/


A SPECIAL SHUTTLE SIGHT
-----------------------
For a few hours on Saturday morning, a true rarity occurred for NASA's
space shuttle program as both Atlantis and Endeavour were fully visible on
their Kennedy Space Center launch pads with the rotating service gantries
open.

Panoramas and photos:
 http://spaceflightnow.com/shuttle/sts126/080920twoshuttles/

High-definition video:
 http://www.spaceflightnowplus.com/hd/

NASA to Preview Next Space Station Expedition

HOUSTON -- The work of the next International Space Station residents will be previewed in a briefing broadcast on NASA Television at 1 p.m. CDT Thursday, Sept. 25, from NASA's Johnson Space Center. Reporters at participating NASA centers may ask questions.

Expedition 18 Commander Mike Fincke, Flight Engineer and Soyuz Commander Yuri Lonchakov and U.S. spaceflight participant Richard Garriott are scheduled to launch in a Soyuz spacecraft Oct. 12 from the Baikonur Cosmodrome in Kazakhstan. They will arrive at the station Oct. 14. Garriott will return home with the two Russian members of the Expedition 17 crew on Oct. 24. Fincke and Lonchakov will join NASA astronaut Greg Chamitoff, who has been on board the orbiting complex since June.

The briefers who will preview Expedition 18 are:

-- Michael Suffredini, International Space Station Program manager
-- Susan Brand, Expedition 18 increment manager
-- Ron Spencer, Expedition 18 lead flight director
-- Julie Robinson, International Space Station Program scientist

For NASA TV downlink information, schedules and links to streaming video, visit: http://www.nasa.gov/ntv
 
For more information about the International Space Station and its crews, visit: http://www.nasa.gov/station 
 
- end -

NASA - NASA Announces New Target Launch Dates, Status News Conference

WASHINGTON -- The target launch date for space shuttle Atlantis' STS-125 mission to service the Hubble Space Telescope has been reset to Oct. 14 at 10:19 p.m. EDT. A news conference is scheduled for Friday, Oct. 3, at NASA's Kennedy Space Center in Florida to announce an official launch date.

With the delay of Atlantis' launch from Oct. 10 to Oct. 14, shuttle Endeavour's STS-126 supply mission to the International Space Station, also will move from Nov. 12 to Nov. 16 at 7:07 p.m. EST. The target launch date adjustments were made Wednesday during the Space Shuttle Program's Flight Readiness Review, which concludes Thursday.

Detailed assessments were presented Wednesday by Mission Operations, Flight Crew Operations, and training divisions affected by the closure of the NASA's Johnson Space Center in Houston, as a result of Hurricane Ike. While vehicle processing at Kennedy continues on schedule, the lost week of training and mission preparation due to the impacts of the storm led to the decision to slip the dates.

The Oct. 3 news conference will follow the Flight Readiness Review, a meeting to assess preparations for the STS-125 mission to Hubble, and will begin no earlier than 4 p.m. EDT.

The briefing participants are:
- Associate Administrator for Space Operations Bill Gerstenmaier
- Deputy Associate Administrator for Programs, Science Mission Directorate Mike Luther
- Space Shuttle Program Manager John Shannon
- STS-125 Launch Director Ed Mango

NASA Television and the agency's Web site will broadcast the briefing live. Media may ask questions from participating NASA locations. Reporters should contact their preferred NASA center to confirm its participation.

For NASA TV streaming video, downlink and schedulling information visit: http://www.nasa.gov/ntv

For more about the two remaining Shuttle missions of 2008 visit: http://www.nasa.gov/shuttle


- end -

Asteroidal Occultation Tonight

Damn those Grey clouds are in the way again tonight blocking it all out........

***********************************
The SOCIETY for POPULAR ASTRONOMY
***********************************
======================================================
Special Electronic News Bulletin 2008 September 24
======================================================


ASTEROIDAL OCCULTATION ON WEDNESDAY 24 SEPTEMBER
By Jon Harper
Occultation Section Director

Asteroidal Occultation of TYC 0633-01047-1 by (56) Melete on Wednesday
24 September at around 22h 36m UT in UK: an interesting event of
reasonable length. The m(v) 10.9 star lies just inside Aries near its
boundary with Cetus and Pisces, at
R.A. 2h 5m 38s.9, decl +10d 59' 31".2 (2000)
Altitude at time of occultation about 32 degrees, azimuth around 120
degrees (ESE/SE).

Melete will be at m(v) 11.8 and may be detected before and after the
occultation in the vicinity of the star. The duration of the
occultation at the central line is estimated to be around 14 seconds,
but will of course be less the further you are from the centre line.
Observers should expect to see a drop in the combined light of the
asteroid and star of around 1.3 magnitudes.

The wide occultation path crosses the UK from north-eastern England to
the south coast, crossing the country between 22:36 and 22:37 UT.
You should set up in good time and find the star. It is a good idea
to start watching the star for any occultation a couple of minutes
before the predicted time. If you would like to observe the event,
and require a star chart of the area, please drop me an e-mail.
I will be happy to send one by return as an attachment for you to
print out. I also have the most up-to-date occultation path generated
by Occult Watcher and Google Earth available too, again please
request. (jonvran@aol.com)

If you intend to do a timing please download a report form from the
SPA Occultation Section's web site :

http://www.popastro.com/sections/occ/occ_templates.htm

You will find examples of how to fill the forms in on the same page.
If you require any further help please ask. Please let me know how
you get on, and if you do attempt a timing I will be happy to receive
your results.

The SPA Electronic News Bulletins are sponsored by the Open University.


Bulletin compiled by Clive Down

(c) 2008 the Society for Popular Astronomy

Tuesday 23 September 2008

Catch A Shooting Star On Mars

The detections were made using predictions of when meteor showers should occur as the orbit of Mars intersects with debris from comet 79P/du Toit-Hartley.  These predictions were cross-referenced with observations of activity in the Martian ionosphere by NASA's Mars Global Surveyor (MGS) satellite.
Dr Apostolos Christou, who is presenting the results at the RAS National Astronomy Meeting in Belfast on Wednesday  2nd April, said, "Just as we can predict meteor outbursts at Earth, such as the Leonids, we can also predict when meteor showers are going to occur at Mars and Venus.   We believe that shooting stars should appear at Venus and Mars with a similar brightness to those we see at Earth. However, as we are not in a position to watch them in the Martian sky directly, we have to sift through satellite data to look for evidence of particles burning up in the upper atmosphere."
Observations of meteor showers, caused when a planet passes through the dusty trail left by a comet as it moves along its orbital path, give insights into the age, size and composition of particles ejected from the comet's nucleus, the ejection velocity, as well as general information about the structure and history of the comet itself.  Roughly four times more comets approach the orbit of Mars than the Earth's and a high proportion of these are Jupiter Family Comets.  Mars therefore offers a significant opportunity to improve our understanding of meteor showers and Jupiter Family Comets.
When meteor particles burn up in a planet's atmosphere, metals contained within them are ionised to form a layer of plasma.  On Earth, this layer has an altitude of approximately 95-100 kilometres and on Mars the layer is predicted to be around 80-95 kilometres above the Martian surface.  Meteor showers leave a narrow layer of plasma superimposed on top of the main plasma layer, caused by meteors that are general debris from the Solar System. 
Christou and his colleagues developed a model to predict meteor showers caused by the intersection of Mars with dust trails from comet 79P/du Toit-Hartley.  From the model, the team identified six predicted meteor showers since the MGS satellite entered into orbit around Mars in 1997.  Although the metallic ions cannot be observed directly by MGS instruments, evidence for the plasma layer can be inferred by monitoring electron density in the Martian atmosphere using the spacecraft's radio communication system.
Out of the six predicted showers, ionospheric data from MGS was only available for the outbursts in April 2003 and March 2005.
In the April 2003 data, the team found that an ionospheric disturbance appeared at the exact time of the predicted meteor outburst.  The height of the disturbance corresponded with the predicted altitude for the formation of the metallic ion layer and its width and multi-peaked shape were similar to structures observed in the Earth's ionosphere linked to the Perseid meteor shower.
For the 2005 data, no features were observed near or immediately after the predicted meteor shower.  Dr Christou says, "We speculate that we don't see anything in the 2005 data because the meteors burned up deeper in the atmosphere where their ionisation is less efficient. If we are going to get a clear picture of what is going on, we need more optical and ionospheric observations of meteor showers at both the Earth and Mars so we can establish a definitive link between cause and effect.  Equally importantly, we need further observations of Martian meteor showers, either from orbit or from the planet's surface, to confirm our predictions. Finally, we need to improve our prediction model by tracking more comets that might cause meteor showers on Mars."
Dr Christou is now investigating the possibilities of making observations with Europe's ExoMars mission, which is due to land on Mars in 2015.
________________________________
 
Adapted from materials provided by Royal Astronomical Society.

Monday 22 September 2008

Astronomy Picture of the Day

Astronomy Picture of the Day





Astronomy Picture of the Day


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.


2008 September 21



Egging On the Autumnal Equinox
Credit: Phil Plait (Bad Astronomy & Blog)


Explanation: Tomorrow is the autumnal equinox -- should eggs be able to stand on end? This long-standing myth loses much of its mystique after a demonstration that eggs can be made to stand on end during any day of the year. Pictured above, Dr. Phil Plait, acting as the Bad Astronomer balanced three raw eggs on end in late October 1998. Later, more modestly, his wife balanced five more. The little-appreciated fact that most eggshells have small bumps on them makes this seemingly impossible task achievable. Although, during an equinox, every place on Earth experiences an equal length day and night (12 hours each), this fact has no practical effect on egg stability.



Tomorrow's picture: equal night




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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
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A service of: ASD at NASA / GSFC
& Michigan Tech. U.

Saturday 20 September 2008

Thursday 18 September 2008

Doomed Spacecraft to fly over US and Europe

Space Weather News for Sept. 18, 2008
http://spaceweather.com

DOOMED SPACECRAFT:  Jules Verne is about to become a fireball. On Sept. 29th, with NASA aircraft looking on, the 22-ton European spacecraft will plunge into Earth's atmosphere over the south Pacific Ocean and harmlessly disintegrate. Jules Verne recently spent five months docked to the space station where it delivered supplies, used its engines help the station avoid a piece of space junk, and served as an impromptu bedroom for the ISS crew. Mission accomplished, the doomed spacecraft is now making its final orbits around Earth glowing about as brightly as Polaris (the North Star).  US and European observers are favored with flybys this weekend. If you'd like to see Jules Verne, check the Simple Satellite Tracker for viewing times: http://spaceweather.com/flybys/

POLAR CROWN PROMINENCES: Colossal dark tadpoles. Fiery "plasma falls."  Van Gogh vortices.  These are a few of the strange things Japan's Hinode spacecraft has found inside polar crown prominences on the sun. Visit http://spaceweather.com for must-see movies.

Water Hit With Young Star's Best Shot

Feature

September 18, 2008

Water Hit With Young Star's Best Shot

Water is being blasted to pieces by a young star's laser-like jets, according to new
observations from NASA's Spitzer Space Telescope.

The discovery provides a better understanding of how water -- an essential ingredient for
life as we know it -- is processed in emerging solar systems.

"This is a truly unique observation that will provide important information about the
chemistry occurring in planet-forming regions, and may give us insights into the
chemical reactions that made water and even life possible in our own solar system," said
Achim Tappe, of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.

A young star forms out of a thick, rotating cloud of gas and dust. Like the two ends of a
spinning top, powerful jets of gas emerge from the top and bottom of the dusty cloud. As
the cloud shrinks more and more under its own gravity, its star eventually ignites and the
remaining dust and gas flatten into a pancake-like disk, from which planets will later
form. By the time the star ignites and stops accumulating material from its cloud, the jets
will have died out.

Tappe and his colleagues used Spitzer's infrared eyes to cut through the dust surrounding
a nascent star, called HH 211-mm, and get a better look at its jets. These particular jets
are exceptionally young at 1,000 years old, and they are some of the most collimated, or
focused, known. An instrument on Spitzer called a spectrometer analyzed light from one
of the jets, revealing information about its molecules.

To the astronomers' surprise, Spitzer picked up the signature of rapidly spinning
fragments of water molecules, called hydroxyl, or OH. In fact, the hydroxyl molecules
have absorbed so much energy (through a process called excitation) that they are rotating
around with energies equivalent to 28,000 Kelvin (27,700 degrees Celsius). This far
exceeds normal expectations for gas streaming out of a stellar jet. Water, which is
abbreviated H2O, is made up of two oxygen atoms and one hydrogen; hydroxyl, or OH,
contains one oxygen and one hydrogen atom.

The results reveal that the jet is ramming its head into a wall of material, vaporizing ice
right off the dust grains it normally coats. The jet is hitting the material so fast and hard
that a shock wave is also being produced.

"The shock from colliding atoms and molecules generates ultraviolet radiation, which
will break up water molecules, leaving extremely hot hydroxyl molecules," said Tappe.

Tappe said this same process of ice being vaporized off dust occurs in our own solar
system, when the sun vaporizes ice in approaching comets. In addition, the water that
now coats our world is thought to have come from icy comets that vaporized as they
rained down on a young Earth.

Tappe is the lead author of a paper on this topic, which was published in a recent issue of
the Astrophysical Journal. Co-authors on the paper include Charlie Lada, and August
Muench, also of the Harvard-Smithsonian Center for Astrophysics; and J. H. Black, of
the Chalmers University of Technology, in Onsala, Sweden.

-end-

Wednesday 17 September 2008

New Mars mission picked / First image of planet around a Sun-like star


      NEWSALERT: Wednesday, September 17, 2008 @ 1125 GMT
---------------------------------------------------------------------
          The latest news from Spaceflight Now


NEW MARS MISSION PICKED TO STUDY PLANET'S ATMOSPHERE
----------------------------------------------------
NASA has selected a Mars robotic mission that will provide information
about the Red Planet's atmosphere, climate history and potential
habitability in greater detail than ever before. The MAVEN spacecraft will
be launched in late 2013.

 http://spaceflightnow.com/news/n0809/16maven/


LIKELY PLANET IMAGES AROUND A SUN-LIKE STAR
-------------------------------------------
Astronomers have unveiled what is likely the first picture of a planet
around a normal star similar to the Sun. The images show the young star,
which lies about 500 light-years from Earth, and a companion with a mass
about eight times that of Jupiter.

 http://spaceflightnow.com/news/n0809/15planet/


HUBBLE SPACE TELESCOPE SEES OVERLAPPING GALAXIES
------------------------------------------------
NASA's Hubble Space Telescope has captured a rare alignment between two
spiral galaxies. The outer rim of a small, foreground galaxy is
silhouetted in front of a larger background galaxy. Skeletal tentacles of
dust can be seen extending beyond the small galaxy's disk of starlight.

 http://spaceflightnow.com/news/n0809/16hubble/


MINOTAUR 4 PATHFINDER COMPLETED AT VANDENBERG
---------------------------------------------
Orbital Sciences has completed the full-scale "pathfinder" ground
operations of the Minotaur 4 space launch vehicle in preparation for its
inaugural flight that is currently scheduled to take place in early 2009.

 http://spaceflightnow.com/news/n0809/16minotaur4/


OUR STAR COULD BE FAR FROM WHERE IT STARTED
-------------------------------------------
A long-standing scientific belief holds that stars tend to hang out in the
same general part of a galaxy where they originally formed. Some
astrophysicists have recently questioned whether that is true, and now new
simulations show that, at least in galaxies similar to our own Milky Way,
stars such as the sun can migrate great distances.

 http://spaceflightnow.com/news/n0809/15immigrant/


1843 STELLAR ERUPTION MAY BE NEW TYPE OF EXPLOSION
--------------------------------------------------
Scientists have shown that the outbursts of Eta Carinae, the Milky Way's
biggest, brightest and perhaps most studied star after the Sun, could be
driven by an entirely new type of stellar explosion that is fainter than a
typical supernova.

 http://astronomynow.com/etacarinaeseruptionsamultistageprocess.html

Tuesday 16 September 2008

Mission control appears to escape major damage from Hurricane Ike


      NEWSALERT: Saturday, September 13, 2008 @ 2014 GMT
---------------------------------------------------------------------
          The latest news from Spaceflight Now


MISSION CONTROL APPEARS TO ESCAPE MAJOR DAMAGE
----------------------------------------------
A rideout team at the Johnson Space Center endured a virtual direct hit
from Hurricane Ike early Saturday, firing up generators to keep sensitive
computer and communications gear in mission control on line when power was
lost. A detailed assessment is not yet available, but officials said no
injuries were reported and the space center appeared to escape major
damage.

 http://spaceflightnow.com/news/n0809/13hurricaneike/


PHOENIX LANDER SEES, FEELS MARTIAN WHIRLWINDS IN ACTION
-------------------------------------------------------
After three months of performing experiments in the north polar regions of
Mars, NASA's Phoenix Lander has finally seen dust devils, and sensed a dip
in air pressure as one passed nearby.

 http://www.astronomynow.com/080912DustdevilspayvisittoPhoenix.html


NEW GEAR FOR HUBBLE READIED FOR LAUNCH PAD
------------------------------------------
After an intense summer of long hours and tight schedules, ground
technicians packing the new science instruments and equipment for launch
to the Hubble Space Telescope are nearing the finish line.

 http://spaceflightnow.com/shuttle/sts125/status.html#080911


ENDEAVOUR MOVED FROM HANGAR TO ASSEMBLY BUILDING
------------------------------------------------
In preparation for its role as a standby rescue craft during next month's
Hubble Space Telescope servicing mission and the scheduled November
logistics run to the international space station, shuttle Endeavour was
moved to the Vehicle Assembly Building on Thursday morning.

 http://spaceflightnow.com/shuttle/sts126/status.html

Friday 12 September 2008

Harvest Moon and Aurora Watch

Space Weather News for Sept. 12, 2008
http://spaceweather.com

HARVEST MOON:  This weekend's full Moon has a special name--the Harvest Moon. It's the full Moon closest to the northern autumnal equinox. In years past, farmers depended on the light of the Harvest Moon to gather ripening crops late into the night. Post-Edison, we appreciate it mainly for its beauty. Be alert in the nights ahead for Harvest Moon halos, coronas and 'dogs. Visit http://spaceweather.com for example and more information.
 
AURORA WATCH:  Around the Arctic Circle, moonlight will compete with Northern Lights.  A solar wind stream flowing from a coronal hole on the sun is due to touch Earth on Sept. 13th or 14th, possibly triggering high-latitude geomagnetic storms.  Sky watchers from Alaska to Scandinavia should be alert for these magnificent sightly auroras-not so much will be seen further South.

September 2008 Aurora Gallery:   http://spaceweather.com/aurora/gallery_01sep08.htm

Wednesday 10 September 2008

COMET REPORT AND UPCOMING EVENTS FOR AUTUMN 2008

Comets in 2008 this year so far and upcoming ones: Comet 17/P Holmes was good one to see at the beginning of 2008 and into the new year but was fading into the background sky after its cataclysmic outburst in late 2007 a good comet overall and well placed for Northern observers to see even in small Binoculars the nebulous round expanding shape that made the constellation of Perseus look out of shape for a short while-a good one although it has now faded into the background of the sky as it has spread out so much although the B.A.A Comet section page on the website still puts it at magnitude 6 but its trend is to fade, It is now in the Constellation of cancer close to M44 Praesepe.
 
Since then the skies have been pretty much devoid of Comets with 8/P Tuttle only being around for a few nights before fading rapidly and moving quickly across the sky-only got about one glimpse of it overall for a short time-other Comets around were for the professional observers to glance at between magnitudes 10 to 14 which were a little beyond the boundaries of observing for us amature astronomers to see.
 
COMET BOATTINI 2007 W1 was seen in the late evening twilight in may but was sharply lost in the Western Evening twilight and until the Summer Solstice had past to appear in the early morning skies of July at magnitude 6 to 7 although now august has past and Autumn is almost upon us now this one is also fading from view now attaining a good magnitude of around 7.5 to 8 and into September fading to 9 or 10th Magnitude
 
COMET LULIN (2007 N3) should become a Binocular visible object during late December at magnitude 7 and into January of the new year but this is mainly a Comet for the early part of 2009 during late February when it should attain a good Magnitude 4 so that will certainly be one to look out for next year and I will keep you all informed about this one.
 
Astronomical Events in 2008 and upcoming events: No more Eclipses are scheduled for the rest of 2008 although there is the Orionids around the 20th October and the Taurid and Geminid Meteor showers to look out for in November and December, there is also an Occultation of Venus with the Moon during the early evening on December 1st.
 
The Planets for the rest of 2008: Mercury: will be best seen in the Western Evening skies during December as it will reach magnitude -0.7
Venus: will also be best seen in the December evening and morning skies at magnitude 4.1
Mars: will be lost to the Evening skies and won't appear in the morning skies until December but will mainly stay in the twilight of the suns glare.
Jupiter: will gradually edge to the South West during the rest of the year and set during December.
Saturn: will return to the morning skies to be a winter object and into 2009.
Uranus and Neptune: will be on view for most of this period.
 
Future NASA Missions including the I.S.S and Hubble Space Telescope upgrade Mission: At this time of writing the space shuttle has been held back from being rolled out onto the launch pad due to storm warnings-it will be blasting off for a HST upgrade service mission and this will be one of the last 10 Space Shuttle missions-1 more shuttle flight is planned for this year during November, Five in 2009 and the final Three Missions during 2010 to bring the space shuttle program to a close-over 20 rocket launches worldwide are planned before the end of 2008
 
Lighting up times for the rest of 2008:
September 1st 20.15 BST
September  15th 19.43 BST
October 1st 19.07 BST
October 15th 18.36 BST
 
Clocks back one hour on October 26th at 02.00 Hours
 
November 1st 17.02 G.M.A.T
November 15th 16.40 G.M.A.T
December 1st 16.25 G.M.A.T
December 31st 16.31 G.M.A.T
 
Looking forward to 2009: 5 space shuttle launches are scheduled for this year and also sees the return of several Comets to observe and 3 that may become within Binocular range-N3 Lulin may reach 4 to 6 Magnitude during February-the best one predicted so far for 2009, P/Christensen (2003 K2) may reach Magnitude 9 or less, 22P/Kopff may reach around Magnitude 9, 88P/Howell to reach around Magnitude 9 during the year although unpredictable, so there are some good ones to look out for in 2009.
 
2009 will also be the International year of Astronomy so perhaps people can think of something to do for the Society as I am planning to do something and moreover perhaps during Moon week which will be 20th to 26th July to celebrate the 40th anniversary of the Apollo Moon landings.

CERN Press Release

Geneva, 10 September 2008. The first beam in the Large Hadron Collider at CERN1 was successfully steered around the full 27 kilometres of the world's most powerful particle accelerator at 10h28 this morning. This historic event marks a key moment in the transition from over two decades of preparation to a new era of scientific discovery.

"It's a fantastic moment," said LHC project leader Lyn Evans, "we can now look forward to a new era of understanding about the origins and evolution of the universe."

Starting up a major new particle accelerator takes much more than flipping a switch. Thousands of individual elements have to work in harmony, timings have to be synchronized to under a billionth of a second, and beams finer than a human hair have to be brought into head-on collision. Today's success puts a tick next to the first of those steps, and over the next few weeks, as the LHC's operators gain experience and confidence with the new machine, the machine's acceleration systems will be brought into play, and the beams will be brought into collision to allow the research programme to begin.

Once colliding beams have been established, there will be a period of measurement and calibration for the LHC's four major experiments, and new results could start to appear in around a year. Experiments at the LHC will allow physicists to complete a journey that started with Newton's description of gravity. Gravity acts on mass, but so far science is unable to explain the mechanism that generates mass. Experiments at the LHC will provide the answer. LHC experiments will also try to probe the mysterious dark matter of the universe – visible matter seems to account for just 5% of what must exist, while about a quarter is believed to be dark matter. They will investigate the reason for nature's preference for matter over antimatter, and they will probe matter as it existed at the very beginning of time.

"The LHC is a discovery machine," said CERN Director General Robert Aymar, "its research programme has the potential to change our view of the Universe profoundly, continuing a tradition of human curiosity that's as old as mankind itself."

Tributes have been coming in from laboratories around the world that have contributed to today's success.

"The completion of the LHC marks the start of a revolution in particle physics," said Pier Oddone, Director of the US Fermilab. "We commend CERN and its member countries for creating the foundation for many nations to come together in this magnificent enterprise. We appreciate the support that DOE and NSF have provided throughout the LHC's construction. We in the US are proud to have contributed to the accelerator and detectors at the LHC, together with thousands of colleagues around the world with whom we share this quest."

"I congratulate you on the start-up of the Large Hadron Collider," said Atsuto Suzuki, Director of Japan's KEK laboratory, "This is a historical moment."

"It has been a fascinating and rewarding experience for us," said Vinod  C. Sahni, Director of India's Raja Ramanna Centre for Advanced Technology, "I extend our best wishes to CERN for a productive run with the LHC machine in the years to come."

"As some might say: 'One short trip for a proton, but one giant leap for mankind!' TRIUMF, and indeed all of Canada, is delighted to bear witness to this amazing feat," said Nigel S. Lockyer, Director of Canada's TRIUMF laboratory. "Everyone has been involved but CERN is to be especially congratulated for bringing the world together to embark on such an incredible adventure."

In a visit to CERN shortly before the LHC's start-up United Nations Secretary General, Ban Ki-moon said: "I am very honored to visit CERN, an invaluable scientific institution and a shining example what international community can achieve through joint efforts and contribution. I convey my deepest admiration to all the scientists and wish them all the success for their research for peaceful development of scientific progress."

1 CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.

Copyright CERN 2008 - Press Office, DSU-CO

Wednesday 3 September 2008

Complilation of things for the Lyra Magazine for Richard Chilvers......

2008 An Astronomical year in Space: This year so far has been a very good year in space with 3 successful missions to the I.S.S delivering the kibo space laboratory as well as the European Columbus laboratory and a new cargo freighter called Jules Verne which successfully docked with the I.S.S to deliver 10.000 pounds of supplies to the complex-the system worked very successfully after a month of testing, on April 3 Cosmanauts took off for the I.S.S from Baikonur Cosmadrome in Kazakhstan riding on a Soyus space rocket bound for the I.S.S and successfully docked although their return back to Earth was a little shaky when their descent back to Earth was a little steeper than planned and landed almost 300 or so miles from where they intended to in Kazakhstan-however they all survived the descent although the media had a story to tell that many of us got to hear about.

Comets in 2008 this year so far and upcoming ones: Comet 17/P Holmes was good one to see at the begginning of 2008 and into the new year but was fading into the background sky after its cataclismic outburst in late 2007 a good comet overall and well placed for Northern observers to see even in small Binoculars the nebulus round shape that made the constellation of Perseus look out of shape for a while-good one, since then the skies were much devoid of Comets with 8/P Tuttle only being around for a few nights before fading rapidly-only got about one glimpse of it overall other Comets around were for the professional observers to glance at, Comet Boattinni 2007 W1 was seen in the late evening twilight in may but was sharply lost until the Summer Solsice had past to appear in the early morning skies of July although now august has past and Autumn is almost upon us now this one is also fading from view now attaining a good magnitude of around 7.5 to 8
Comet lulin should become a Binocular object during mid November and into December of the latter part of this year but is mainly a Comet for the early part of 2009 during late Feburary when it shoul attain a good Magnitude 4 so that will certainly be one to look out for next year.
Astronomical Events in 2008 and upcoming events: No more Eclipses are schedualed for the rest of 2008 although there is the Taurid and Geminid Meteor showers to look out for in December, an Occultation of Venus during the early evening on December 1st.
The Planets for the rest of 2008: Mercury: will be best seen in the Evening skies during December as it will reach magnitude -0.7
Venus: will also be in the December evening and morning skies at magnitude 4.1
Mars: will be lost to the Evening skies and won't appear in the morning skies until December but will mainly stay in the twilight of the suns glare.
Jupiter; will gradually edge to the South West during the rest of the year and set during December.
saturn will return to the morning skies to be a winter object and into 2009.
Uranus and Neptune will be on view for most of this period.
Future NASA Missions including the I.S.S and Hubble Space Telescope upgrade Mission: At this time of writing the space shuttle has been held back from being rolled out onto the launch pad due to storm warnings-it will be blasting off for a HST upgrade service mission and this will be one of the last 10 Space Shuttle missions-1 more shuttle flight is planned for this year during November, Five in 2009 and the final Three Missions during 2010 to bring the space shuttle program to a close-over 20 rocket launches worldwide are planned before the end of 2008
Lighting up times for the rest of 2008:
September 1st 20.15 BST
September 15th 19.43 BST
October 1st 19.07 BST
October 15th 18.36 BST
Clocks back one hour on October 26th at 02.00 Hours
November 1st 17.02 G.M.A.T
November 15th 16.40 G.M.A.T
December 1st 16.25 G.M.A.T
December 31st 16.31 G.M.A.T
Looking forward to 2009: 5 space shuttle launches are schedualed for this year and also sees the return of several Comets to observe and 3 that may become within Binocular range-N3 Lulin may reach 4 to 6 Magnitude-the best one predicted so far for 2009, P/Christensen (2003 K2) may reach Magnitude 9 or less, 22P/Kopff may reach around Magnitude 9, 88P/Howell to reach around Magnitude 9 next year so there are some good ones to look out for in 2009.
Artistic Launch^
The I.S.S Diagram^
The I.S.S^
Lunar Eclipse^
Comet Holmes^

Tuesday 2 September 2008

Astronomy For Kids.....

Can we make astronomy for children an easy subject?

What is astronomy?
 
Children ask this question while we say something about space or physics. Astronomy is a branch of physics. It studies about the celestial bodies. Most of the children love to learn this science because it induces the curiosity. A good teacher can use astronomy for kids to teach them how to read and understand science; perhaps astronomy can be considered as the window to the world of science. Stars, comets, satellite, solar system etc. always finds a place in the imagination of a kid.

Most of the kids may wonder when they realize the 'size' of the universe. Astronomy for kids starts from an answer to the question; what is space? U.F.O. are lots of definitions available for the term 'space'. However, anything that is beyond the atmosphere of our planet, earth, is considered as space.

A kid is interested in astronomy definitely raises a question, how big our universe is. Because, children are very much interested in colours, size, number etc. The answer is crucial for kids in order to stimulate the interest with the subject astronomy. Actually, scientists have put forward lots of theories about the size of the universe. We can explain to the children about the infinity theory and big bang theory to make astronomy for kids interesting. So, we are sure in one thing that we do not know the size of the universe. The most extreme object that we see with the naked eye is about 2,000,000 light years distant. We can gently ask the child to find out how big the universe is. It really sharpens the curiosity of the child about the universe and makes astronomy for kids something enjoyable.

Does the universe have an end? Or being it eternal? Ask such questions to the kid, and encouraging them to find the answer is definitely useful. There are hundreds of books available in the market about astronomy for kids. Providing these books to kids is useful. There are lots of softwares available in the market to teach astronomy. If children are getting in touch with such softwares, they would be able to visualize the universe with the help of pictures and videos included in the software.

Explaining astronomy to a child is obviously a tough task. The elders must include interesting stories and poems while explaining astronomy for kids. They can explain about the stars, black hole, a comet, and so on. Showing pictures, telling some stories from mythology etc. helps the child to grasp the nuances of astronomy.

SPA ENB No. 251


                ***********************************
                 The SOCIETY for POPULAR ASTRONOMY
                ***********************************
        ====================================================
         Electronic News Bulletin No. 251    2008 August 31
        ====================================================


Here is the latest round-up of news from the Society for Popular
Astronomy.  The SPA is Britain's liveliest astronomical society, with
members all over the world.  We accept subscription payments online
at our secure site and can take credit and debit cards. You can join
or renew via a secure server or just see how much we have to offer by
visiting  http://tinyurl.com/kogyx


PERSEIDS 2008 PRELIMINARY REPORT
By Alastair McBeath, SPA Meteor Section Director

The unexpectedly late Perseid maximum on August 12-13 reported last
time has continued to attract most attention. Visual Zenithal Hourly
Rates (ZHRs) in the International Meteor Organization's (IMO's)
preliminary online overview from this maximum have gradually
decreased as more results have come through, and seem now to have
stabilized somewhat at between 110-130 from about 01:00-02:30 UT
on August 13. There may have been submaxima within this interval, with
ZHRs peaking at ~120-130 around 01:00, 01:30 and 02:00 UT within
that band, but the 30-minute "periodicity" these might suggest could
have been an artefact of the analysis, rather than a genuine effect. There
is little evidence now for an IMO visual results' peak on August 11-12
that could have been due to the predicted, early, strong maximum near
05:30 UT on August 12. However, ZHRs of 60+ were present from
roughly 01:00 UT on August 12 till at least 06:30 UT on August 13. The
"normal" maximum time on August 12, due between 11:30-14:00 UT,
was not well-observed, though ZHRs around then were ~80.

Poor weather over the British Isles has led to disappointing amounts of
usable visual data coming through to the Section, but the following
people have contributed something between helpful notes through to
fully-detailed observing reports from the Perseids to us so far,
including those on the SPA Forums, and the UK Weather World's
Space Weather Forum (address via the SPA Observing Forum's
"Perseids 2008" topic, at http://snipurl.com/3lisu  ): "Aristarchus"
(Greece), Andy Ball (Worcestershire), "blobrana" (no location given),
Jeff Brower (British Columbia, Canada; radio results), Willy Camps
(Belgium; radio results), "coldfieldboundary" (Belgium), Assistant
Meteor Director David Entwistle (Lancashire; radio results), Dave
Hancox (East Ayrshire), "Maddie" (Cornwall), Tony Markham
(Staffordshire), Conor McDonald (Co. Derry), Martin McKenna (Co.
Derry), Matthew Phipps (Hertfordshire), "Pro]v[etheus" (Surrey or
Derbyshire), Jonathan Shanklin (Cambridgeshire), Enrico Stomeo
(Italy; video results), Rich Taibi (Maryland, USA), and the Director
(Northumberland).  Most grateful thanks are due to all these people for
their efforts in observing and providing their results to us so quickly.
Naturally anyone else who still has data to submit is most welcome to
do so.

David Entwistle's assessment of the three sets of radio reports in now
has indicated a more likely strong, main peak between roughly 01:50-
02:05 UT on August 13. The graphs were often rather spiky, which could
suggest short-lived bursts of meteors from time to time, an effect which
lasted from maybe 01:00 or 01:30 UT through to 04:00 UT or a little
after, also on August 13. The possible minor early maximum around
05:20 UT on August 12, identified last time, still awaits confirmation.

From the SPA's visual results, Perseid ZHRs were between 15 to 30
from August 3-4 till 10-11, which concurred with the IMO details for the
same period, gradually rising with time. The limited data from August
11-12 and 12-13 though suggest ZHRs were between 60-75 on both
nights in what our observers recorded, and may actually have been a
little better overall on August 11-12. There were too few results for these
to be at all definitive, however. The sole set of video data was made
under trying conditions on August 12-13 especially, but things were far
from perfect even on August 11-12. After adjusting for sky conditions,
the Perseid video rate was overall somewhat higher on August 12-13,
and may have peaked especially around 01:51-01:56 UT, though this
is difficult to be sure of. Four of a hundred video Perseids were fireballs
on August 11-12, compared to none of 47 on 12-13, which could
suggest the Perseids were less bright overall on 12-13. While the early
casual reports reaching us suggested a visually bright showing of
Perseids on August 12-13, what full visual observations are available
now do not support this, aside from the video data. Perseid magnitudes
were no different on August 12-13 than other dates during the shower
in the details submitted now, with overall mean magnitudes corrected
to a limiting magnitude +6.5 sky for the Perseids and sporadics
respectively having fairly normal values of +2.6 and +3.5, with a
reasonably average 32% of Perseids leaving persistent trains.

Thus apart from the oddly late, strong maximum, the Perseids appear
to have been quite similar to what we would usually expect. Why there
was such a peak on August 12-13 remains a mystery. The timing, if not
the strength, was not far from when the "tertiary peak", seen only in IMO
data from 1997-1999, might have recurred. The theoretical timing for
this peak would have been approximately 3 to 4 hours before the
August 12-13 peak, at ~21:30 UT on August 12. Professional
meteoricist Jeremie Vaubaillon, currently at the California Institute of
Technology, has recently indicated the unanticipated maximum may
have resulted from material that had spread unusually far from a
meteoroid stream laid down at parent comet 109P/Swift-Tuttle's 441
AD perihelion passage (as also reported in IAU Electronic Telegram
1480 of August 26; my thanks to SPA Vice-President Robin Scagell for
forwarding a copy). The Earth was expected to miss this trail, albeit
not by too great a distance, around 23:34 UT on August 12. This is not
an especially close match to what was observed, but no more
convincing candidate dust trails have been suggested as yet.
Investigations continue.


RECENT FIREBALLS
By Alastair McBeath, SPA Meteor Section Director

Two fresh fireball sightings have come through since ENB 250, an
event in daylight on August 19-20 at about 19:10 UT, probably of at
least magnitude -9 as spotted from just off the Hampshire coast, and
another at 21:08 UT on August 22-23, of roughly magnitude -4/-5, seen
from Cornwall. As ever, sightings of fireballs made from the UK or
nearby are always welcomed by the Section. Information on what to
record was given last time (see: http://snipurl.com/3litt ).


METEORITE--ASTEROID LINK SOLVED
MIT

For the last few years, it has seemed puzzling that the vast majority
of asteroids that come near the Earth are of a type that matches only
a tiny fraction of meteorites.  Since meteorites are supposed mostly
to be pieces of asteroids, that discrepancy was hard to explain, but a
solution has now been suggested.  The smaller rocks that most often
fall to Earth, it seems, come straight in from the main asteroid belt
between Mars and Jupiter, rather than from the 'near-Earth asteroid'
population.

In the main belt, the population is much more varied, and approximates
to the mix of types that is found among meteorites.  But why would the
things that most frequently hit us match that distant population
better than they match the objects that are right in our neighbourhood?
That's where the idea emerged of a fast track all the way from the
main belt to landing on the Earth's surface.  The fast track, it turns
out, is caused by a process called the Yarkovsky effect, which was
discovered long ago but whose significance has only recently been
recognized.

The Yarkovsky effect causes asteroids to change their orbits as a
result of absorbing the Sun's heat on one side and radiating it in a
different direction owing to their rotation.  That produces a small
thrust that operates continuously in one direction and can in time
alter the object's path.  Because the surface area of an object is
proportional to the square of its size whereas its mass goes as the
cube, the effect acts most strongly on the smallest objects.  Thus,
for rocks of boulder size and smaller, typical of meteorites, the
Yarkovsky effect can play a major role, moving them from anywhere in
the asteroid belt on to paths that can intersect the Earth.  For
larger asteroids a kilometre or so across, about which some people
have taken to worrying as potential threats to the Earth, the effect
is too weak to alter their orbits at all quickly.


'INNER OORT CLOUD' OBJECT?
Sloan Digital Sky Survey

A minor planet with the prosaic name 2006 SQ372 was discovered by the
Sloan Digital Sky Survey (SDSS) through the application of a searching
algorithm to data that were actually taken to look for supernovae --
an area of sky of about 200 square degrees was observed every clear
night in the autumns of 2005, 2006, and 2007.  2006 SQ372 has an
unusual orbit, an ellipse that is four times longer than it is wide;
the object is presently slightly closer to us than Neptune but is
beginning the outward leg of a 22,500-year journey that will take it
to a distance of something like 1600 times the distance from the Earth
to the Sun.  The only known object with a comparable orbit is Sedna --
a distant, Pluto-like dwarf planet discovered in 2003 -- but 2006
SQ372's orbit takes it more than half as far again from the Sun, and
its orbital period is nearly twice as long.

The new object is much smaller than Sedna, probably 30-60 miles across
instead of nearly 1,000.  It may be cometary in nature, but it never
gets close enough to the Sun to develop a long, bright tail of
evaporated gas and dust.  Even at its most distant turning point, 2006
SQ372 will be ten times closer to the Sun than the supposed main body
of the supposed Oort Cloud.  The existence of an 'inner' Oort cloud
has been suggested for many years, but SQ372 and perhaps Sedna are the
first objects found that could be deemed to have originated there.
2006 SQ372 was bright enough to find with the SDSS only because it is
near its closest approach to the Sun.  Since the SDSS survey observed
less than 1% of the sky, there could well be many similar objects to
be discovered.


XMM-NEWTON FINDS MASSIVE CLUSTER OF GALAXIES
ESA

The orbiting X-ray observatory XMM-Newton has discovered a very
massive cluster of galaxies in the distant Universe.  The newly
discovered cluster, called 2XMM J083026+524133, is estimated to
contain as much mass as a thousand large galaxies; much of it is in
the form of 100-million-degree gas.  It was first observed by chance
as XMM-Newton was studying another celestial object, and was placed
in a catalogue for a future follow-up.  Astronomers discovered the
cluster as they were analysing the catalogue, which is based on 3,500
X-ray images which together cover about 1% of the sky, and contains
more than 190,000 individual X-ray sources.  The team was looking for
extended patches of X-rays that could either be nearby galaxies or
distant clusters of galaxies.  J083026+524133 stood out because it was
so bright.  Images made in visible light by the Sloan Digital Sky
Survey did not show any obvious nearby galaxy in that location, but
when the team obtained a deep exposure with the Large Binocular
Telescope in Arizona they found a cluster of galaxies calculated to be
at a distance of 7.7 billion light-years.


DO GALAXIES HAVE A MINIMUM MASS?
New Scientist

The Milky Way's galactic companions all seem to have much the same
amount of mass in their cores.  A collection of at least 22 dwarf
galaxies orbits the Milky Way; the brightnesses range over a factor of
10,000.  Astronomers analysed the motions of stars in the innermost
1000 light-years, where they might expect common properties to emerge
if any existed, in 18 of the dwarf galaxies.  They measured the
velocities of hundreds of stars in orbit around the galaxies' centres,
which allowed them to calculate the masses of the galaxies' cores.
Surprisingly, the masses all came out about the same -- roughly 10
million solar masses.  What the 'New Scientist' is claiming is that
most of the mass is dark matter, and that the dimmest galaxies had
10,000 times more dark matter than visible matter.  It says that that
is an unusual ratio, and by way of an example says that the Milky Way,
for example, contains only roughly 10 times as much dark matter as
ordinary matter.  The similarity of the masses hints that the dwarf
galaxies must have at least that much mass in order to form.

The 'New Scientist' article goes on to speculate about the nature of
dark matter and to draw various conclusions that do not necessarily
follow from the observational facts.  There is a misunderstanding
whereby differences in the ratio of the mass to the luminosity between
different objects are assigned (as they are in the paragraph above) to
ratios of 'dark matter' to 'visible matter'.  A (normally unspoken)
assumption is that the proper ratio of mass to light is that exhibited
by the Sun.  If the Milky Way has ten times as much total mass in
relation to its total brightness it is said to have ten times as much
dark matter as visible matter.  But that is not a sensible way of
describing the situation.  A star of early-M spectral type is about
five magnitudes (a factor of 100) fainter than the Sun but has about
half as much mass, so it has a mass-to-light ratio of 50 in solar
units.  It does not seem helpful to conclude, as by analogy with the
assertions above one would be obliged to do, that an early-M star has
fifty times as much dark matter as visible matter, or that there is
anything mysterious about the former.


FIRST LIGHT FOR THE FERMI SPACE TELESCOPE
NASA

NASA has announced that its new gamma-ray telescope, formerly known as
GLAST, has passed its orbital checks and has been formally renamed the
'Fermi Gamma-ray Space Telescope' in honour of Prof. Enrico Fermi
(1901-1954), a pioneer in high-energy physics.  Scientists expect
Fermi, by observing gamma-rays, to make many discoveries involving
highly energetic sources such as pulsars and black holes.  Since the
spacecraft's launch on June 11, scientists have tested and calibrated
its two instruments, the Large-Area Telescope (LAT) and the GLAST
Burst Monitor (GBM).

The large-area telescope has obtained in four days an all-sky image
similar to the one that the now-defunct Compton gamma-ray observatory
took years of observations to produce.  It scans the entire sky every
three hours when operating in survey mode, which will occupy most of
the telescope's observing time during the first year of operations, to
allow scientists to monitor rapid changes.  The telescope is sensitive
to photons with energies ranging from 20 MeV (million electron volts)
to over 300,000 MeV. The high end of the range, which corresponds to
energies more than 5 million times greater than dental X-rays, is
little explored.  The spacecraft's secondary instrument, the GBM,
detected 31 explosions of the sort known as gamma-ray bursts in its
first month of operations.  The GBM is sensitive to less-energetic
gamma-rays than the LAT, giving it a complementary view of the broad
gamma-ray spectrum.


The SPA Electronic News Bulletins are sponsored by the Open University.

Bulletin compiled by Clive Down


(c) 2008 the Society for Popular Astronomy