Showing posts from July, 2010

NASA’s Messenger Spacecraft Discovers Surprises on Mercury

Source:  Kenneth Chang, New York Times Excerpt: Images suggest that Mercury was volcanically active well into its middle age, given that it formed 4.5 billion years ago with the rest of the solar system.

NASA Finds Super Hot Planet With Unique Comet-Like Tail

Source:   NASA News Astronomers using NASA's Hubble Space Telescope have confirmed the existence of a baked object that could be called a "cometary planet" ... gas giant ... HD 209458b, ... orbiting so close to its star that its heated atmosphere is escaping into space. Observations taken with Hubble's Cosmic Origins Spectrograph (COS) suggest powerful stellar winds are sweeping the cast-off atmospheric material behind the scorched planet and shaping it into a comet-like tail. …The planet, located 153 light years from Earth, weighs slightly less than Jupiter but orbits 100 times closer to its star than the Jovian giant ... zips around its star in a short 3.5 days. …Linsky and his team used COS to analyze the planet's atmosphere during transiting events.  

MESSENGER Spacecraft Reveals New Information About Mercury

Source:   NASA RELEASE: 10-170   Excerpt: WASHINGTON -- The first spacecraft designed by NASA to orbit Mercury is giving scientists a new perspective on the planet's atmosphere and evolution. ... MESSENGER conducted a third and final flyby of Mercury in September 2009 ... revealed the first observations of ion emissions in Mercury's exosphere, or thin atmosphere … and evidence of younger volcanic activity than previously recorded. ...During its first two flybys of Mercury, the spacecraft captured images confirming that the planet's early history was marked by pervasive volcanism. The spacecraft's third flyby revealed … cratered plains … younger than the basin they fill… the youngest volcanic deposits … yet found on Mercury,"  ... observations suggest the planet spanned a much greater duration volcanism than previously thought, perhaps extending well into the second half of solar system history."

How does Lutetia compare to the other asteroids and comets visited by spacecraft?

Source:  Emily Lakdawalla, The Planetary Society Excerpt: Almost a week after Rosetta flew past Lutetia, the asteroid is now a distant pinprick of light to the spacecraft, and the science team is getting down to the business of analyzing their data. To help them place things in context, I've prepared a new version of my "asteroids and comets to scale" image, laid out to be easy to drop into your slide presentation....

A Giant Planet Imaged in the Disk of the Young Star β Pictoris

Source:   Lagrange et al, Science AAAS Excerpt: The 10-million-year-old star β Pictoris, has long been suspected to host a planet. Through images obtained with the Very Large Telescope, an array of four telescopes located in Chile, Lagrange et al. (p. 57, published online 10 June) now confirm the presence of a young, giant planet, β Pictoris b, orbiting within the dusty disk that surrounds the star. β Pictoris b orbits closer to its star than Uranus and Neptune do to the Sun in our solar system. This orbital separation is consistent with the in situ formation of the planet via a core accretion mechanism. Thus, giant planets can form within a stellar dust disk in only a few million years.