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Where is Deimos?

September 25, 2012 Leave a comment

Mars Express image of the moons Phobos (foreground) and Deimos (background). Credit: ESA/DLR/FU Berlin (G. Neukum)

Despite more than a century of observations, the orbit of the Martian moon Deimos is still not known to a high degree of accuracy, but a new study using images taken by ESA’s Mars Express orbiter has provided the best orbital model to date.

135 years have passed since Asaph Hall discovered Phobos and Deimos, two small companions of the planet Mars. Since that time, the satellites have been imaged innumerable times from the Earth and from spacecraft, including recent measurements by the panoramic cameras on the Mars Exploration Rovers and instruments on the Mars Reconnaissance Orbiter.

Full Story: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50842

Slow-Moving Rocks Improve Oodds That Life Crashed To Earth From Space

September 25, 2012 1 comment

Microorganisms that crashed to Earth embedded in the fragments of distant planets might have been the sprouts of life on this one, according to new research presented at the European Planetary Sciences Congress (EPSC) on 25 September.

The researchers report that under certain conditions there is a high probability that life came to Earth — or spread from Earth to other planets — during the Solar System’s infancy when Earth and its planetary neighbours orbiting other stars would have been close enough to each other to exchange lots of solid material.

The findings provide the strongest support yet for lithopanspermia, the hypothesis that basic life forms are distributed throughout the Universe via meteorite-like planetary fragments cast forth by disruptions such as volcanic eruptions and collisions with objects such as asteroids.

Full Story: http://www.europlanet-eu.org/outreach/index.php?option=com_content&task=view&id=382&Itemid=41

Slow-Moving Rocks Better Odds That Life Crashed To Earth From Space

September 25, 2012 Leave a comment

Microorganisms that crashed to Earth embedded in the fragments of distant planets might have been the sprouts of life on this one, according to new research from Princeton University, the University of Arizona and the Centro de Astrobiología (CAB) in Spain.

The researchers report in the journal Astrobiology that under certain conditions there is a high probability that life came to Earth — or spread from Earth to other planets — during the solar system’s infancy when Earth and its planetary neighbors orbiting other stars would have been close enough to each other to exchange lots of solid material.

The findings provide the strongest support yet for “lithopanspermia,” the idea that basic life forms are distributed throughout the universe via meteorite-like planetary fragments cast forth by disruptions such as volcanic eruptions and collisions with other matter. Eventually, another planetary system’s gravity traps these roaming rocks, which can result in a mingling that transfers any living cargo.

Full Story: http://www.princeton.edu/main/news/archive/S34/82/42M30/

NASA’s Chandra Shows Milky Way Is Surrounded By Halo Of Hot Gas

September 25, 2012 Leave a comment

This artist’s illustration shows an enormous halo of hot gas (in blue) around the Milky Way galaxy. Image: NASA/CXC/M.Weiss; NASA/CXC/Ohio State/A.Gupta et al

Astronomers have used NASA’s Chandra X-ray Observatory to find evidence our Milky Way Galaxy is embedded in an enormous halo of hot gas that extends for hundreds of thousands of light years. The estimated mass of the halo is comparable to the mass of all the stars in the galaxy.

If the size and mass of this gas halo is confirmed, it also could be an explanation for what is known as the “missing baryon” problem for the galaxy.

Baryons are particles, such as protons and neutrons, that make up more than 99.9 percent of the mass of atoms found in the cosmos. Measurements of extremely distant gas halos and galaxies indicate the baryonic matter present when the universe was only a few billion years old represented about one-sixth the mass and density of the existing unobservable, or dark, matter. In the current epoch, about 10 billion years later, a census of the baryons present in stars and gas in our galaxy and nearby galaxies shows at least half the baryons are unaccounted for.

Full Story: http://www.nasa.gov/mission_pages/chandra/news/H-12-331.html
Also: http://chandra.harvard.edu/photo/2012/halo/