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Life after death in the
Crab Nebula

...a team of scientists has detected polarized gamma-ray emission from the vicinity of the Crab Nebula, providing insight into the processes that bring a dead star to life...

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Getting closer to the Milky Way’s black hole

...astronomers have stared deep into the heart of the supermassive black hole that is thought to lurk at the centre of our own Milky Way Galaxy...

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Comets disguised as asteroids

...between five and ten percent of Near Earth Objects could be comets impersonating asteroids...

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Video archive

STS-120 day 2 highlights

Flight Day 2 of Discovery's mission focused on heat shield inspections. This movie shows the day's highlights.


STS-120 day 1 highlights

The highlights from shuttle Discovery's launch day are packaged into this movie.


STS-118: Highlights

The STS-118 crew, including Barbara Morgan, narrates its mission highlights film and answers questions in this post-flight presentation.

 Full presentation
 Mission film

STS-120: Rollout to pad

Space shuttle Discovery rolls out of the Vehicle Assembly Building and travels to launch pad 39A for its STS-120 mission.


Dawn leaves Earth

NASA's Dawn space probe launches aboard a Delta 2-Heavy rocket from Cape Canaveral to explore two worlds in the asteroid belt.

 Full coverage

Dawn: Launch preview

These briefings preview the launch and science objectives of NASA's Dawn asteroid orbiter.

 Launch | Science

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More video

All eyes on Rosetta for

Steins fly-by

Posted: September 04, 2008

The Rosetta control room is buzzing with anticipation as ESA’s comet-chasing spacecraft makes its final preparations for a fly-by of asteroid (2867) Steins on the evening of 5 September.

Artist impression of Rosetta as it swoops towards asteroid (2867) Steins. Closest approach is scheduled for 20:58 Central European Summer Time. Image: ESA/C. Carreau.

Just prior to closest approach the spacecraft will be flipped, and switched into a specially designed asteroid fly-by mode, providing optimal observation and tracking conditions. Science observations will be at their best thanks to good illumination conditions from the Sun. At the time of closest approach Rosetta will skim past the asteroid at a distance of 800 kilometres and a speed of 8.6 kilometres per second relative to Steins. At this time, communications between the Earth and the satellite will take 20 minutes each way.

Rosetta's stop-off at Steins is extremely important, since asteroids represent samples of Solar System material at different stages of evolution, allowing planetary scientists to put together the jigsaw puzzle of Solar System evolution and finding the Earth's place amongst the chaos.

After the call-in on Steins, Rosetta will make one more fly-by of the Earth in November 2009 before being placed back into deep space hibernation for three years prior to reaching its final destination of Comet 67P/Churymov-Gerasimenko in 2014.

A time line of fly-by events are scheduled as follows (all times in CEST, Central European Summer Time):

4 September  
1320-1820 Last opportunity to acquire images for optical navigation
5 September  
0720-1020 Slot for possible trajectory correction manoeuvre
1020 Navigation cameras switch to tracking mode
1100 Uplink fly-by commands for asteroid fly-by mode
2018-2038 Spacecraft flip over
2039 Spacecraft switches automatically to asteroid fly-by mode
2056 Sun illuminates Rosetta from the back and the asteroid fully
2058 Closest approach, at a planned distance of 800 km from the asteroid
2227 First post-fly-by acquisition of signal
telemetry received via NASA's Goldstone ground station
2230 Start of science data download via Goldstone
6 September  
1200 Live streaming of Rosetta Steins fly-by press conference from the European Space Operations Centre begins
1300 Images from fly-by published on ESA web
1500 End of press conference streaming
1601 End of reception of first set of science data

A Rosetta blog and expanded timeline of events is available at: and images from the fly-by will be streamed on the ESA website.

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