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Recipe for giant lunar telescopes

...simply take a pinch of carbon, a handful of epoxy, and a generous helping of lunar dust...

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Second supernovae points to quark stars ...three of the most luminous supernova explosions ever observed could be the signatures of weird pseudo-stellar objects known as quark stars...

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Contact with ET may be sooner than we think ...a new study suggests we have been looking in the wrong place all along...

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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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EPOXI checks out super-Earth planet

Posted: June 5 2008

The innovative Deep Impact spacecraft, which sent a coffee-table sized penetrator slamming into comet Tempel-1 almost three years ago, has now begun its new job as “super-Earth” planet hunter “EPOXI”.

Artist impression of the Deep Impact flyby spacecraft releasing its impactor towards comet Tempel-1 in July 2005. The flyby spacecraft has been re-christened EPOXI and will begin its new assignment to hunt for super-Earth exoplanets. Image: NASA.

EPOXI is a combination of two separate science investigations, one consisting of the Extrasolar Planet Observations and Characterisation (EPOCh) and the other of the flyby of comet Hartley-2, planned for 2010, called the Deep Impact eXtended Investigation (DIXI), which follows in the footsteps of the hugely successful Deep Impact mission in July 2005 which revealed in unprecedented detail the surface of a comet and the effects of impact into such a finely powdered surface.

For the majority of May, EPOXI was trained on the red dwarf star GJ436, 32 light years from Earth. This star has a Neptune sized planet circling it every 20 to 30 days in an unusually eccentric orbit.

“Tidal forces from the star should have made the orbit circular, unless there is another planet whose gravitational tug pulls the orbit into an oval shape,” says Drake Deming, EPOXI’s Deputy Principal Investigator.  “If that second planet lies in the same orbital plane as the Neptune-sized planet then we should see it transit. The transit would be too shallow to be spotted by ground-based telescopes, and EPOXI is the only space mission that can look at GJ436 nearly continuously for several weeks." Deming and his team are in the process of analysing the results of these data.

In addition to targeting the red dwarf star, EPOXI imaged the Earth over three 24-hour periods, measuring its rotational light curve at visible wavelengths from the ultraviolet to the near-infrared. These observations will help to calibrate future observations of Earthlike exoplanets. EPOXI obtained a particularly interesting view of the Earth on May 29, when the Moon passed in front of the Earth as viewed from the spacecraft.  Transit events such as this will help planetary scientists to deduce the nature and composition of exoplanetary systems.

Deep Impact captured this beautiful image of the impact into Comet Tempel-1 three summers ago. Dust and gas streaming from the point of impact is lit up in the impact flash. Image: NASA.