Astro Blog

Source:   NASA RELEASE: 12-153 Excerpt: NASA's Dawn spacecraft has provided researchers with the first orbital analysis of the giant asteroid Vesta, yielding new insights into its creation and relation to the terrestrial planets and Earth's moon. Vesta now has been revealed as a special fossil of the early solar system … Vesta more closely resembles a small planet or Earth's moon than another asteroid. …Scientists now see Vesta as a layered, planetary building block with an iron core - the only one known to survive the earliest days of the solar system. The asteroid's geologic complexity can be attributed to a process that separated the asteroid into a crust, mantle and iron core with a radius of approximately 68 miles (110 kilometers) about 4.56 billion years ago. The terrestrial planets and Earth's moon formed in a similar way. …Data also confirm a distinct group of meteorites found on Earth did, as theorized, originate from Vesta.  ...These objects account...

Source:   Eric M. Jones and Ken Glover, NASA Excerpt: …the actual recording of events which took place during the Apollo Program flights. The twelve astronauts who landed and explored the Earth's closest neighbor were the only human beings ever to observe firsthand the surface of a body in our universe other than the Earth. … their personal comments and interpretations made during their exploration of the Moon are rare national treasures.…. http://www.hq.nasa.gov/alsj/frame.html

Source:   NASA  RELEASE: 12-134   Excerpt: ...Findings from NASA's Dawn spacecraft reveal new details about the giant asteroid Vesta, including its varied surface composition, sharp temperature changes and clues to its internal structure. … Many of the materials seen by Dawn are composed of iron- and magnesium-rich minerals, which often are found in Earth's volcanic rocks. Images also reveal smooth pond-like deposits, which might have formed as fine dust created during impacts settled into low regions.  …Dawn obtained the highest-resolution surface temperature maps of any asteroid visited by a spacecraft. Data reveal temperatures can vary from as warm as -10 degrees Fahrenheit (-23 degrees Celsius) in the sunniest spots to as cold as -150 degrees Fahrenheit (-100 degrees Celsius) in the shadows…. http://www.nasa.gov/home/hqnews/2012/apr/12-134_Dawn_Vesta_Details.html

Source:  NASA RELEASE : 12-135   Excerpt: … Research by NASA and international scientists concludes giant asteroids, similar or larger than the one believed to have killed the dinosaurs, hit Earth billions of years ago with more frequency than previously thought. To cause the dinosaur extinction, the killer asteroid that impacted Earth 65 million years ago would have been almost 6 miles (10 kilometers) in diameter. By studying ancient rocks in Australia and using computer models, researchers estimate that approximately 70 asteroids the same size or larger impacted Earth 1.8 to 3.8 billion years ago. During the same period, approximately four similarly-sized objects hit the moon…. : http://www.nasa.gov/home/hqnews/2012/apr/HQ12-135_Asteroid_Imapcts_Earth_Rocks.html

Source:    Anil Ananthaswamy,  Slate/The New Scientist Excerpt: Interview with veteran astronomer, Geoffrey Marcy, who is turning his attention to the search for extraterrestrial intelligence. As the new chair of Search for Extra-Terrestrial Intelligence, Geoffrey Marcy has started looking for alien civilizations…. www.slate.com/articles/health_and_science/new_scientist/2012/04/geoff_marcy_on_seti_an_astronomer_joins_the_hunt_for_et_.html

Source:   Sindyan N. Bhanoo, The New York Times Excerpt: Astronomers have long theorized that the Moon was formed when an object the size of Mars slammed into Earth, sending a huge mass of rock into orbit around it. “According to the prevailing model prediction, approximately half of the Moon-forming material should come from the Mars-size impactor,” said Junjun Zhang, an isotope geochemist at the University of Chicago and the study’s first author. But samples of isotopic titanium from the Moon and from Earth now suggest that material from Earth is predominant on the Moon, researchers report in the journal Nature Geoscience. …She and her colleagues used lunar samples gathered by the Apollo missions in the 1960s and ’70s. They compared the isotopic titanium ratio in these samples to that of samples from Earth. The researchers also found that meteorites have a much wider range of isotopic titanium. “That also tells us that the impactor that hit the Earth was very unlikely...

Source:   European Southern Observatory (ESO)  Excerpt: A new result from ESO’s HARPS planet finder shows that rocky planets not much bigger than Earth are very common in the habitable zones around faint red stars. The international team estimates that there are tens of billions of such planets in the Milky Way galaxy alone, and probably about one hundred in the Sun’s immediate neighbourhood. … red dwarf stars…are faint and cool compared to the Sun, but very common and long-lived, and therefore account for 80% of all the stars in the Milky Way. "… about 40% of all red dwarf stars have a super-Earth orbiting in the habitable zone where liquid water can exist on the surface of the planet,” says Xavier Bonfils …. “Because red dwarfs are so common — there are about 160 billion of them in the Milky Way — this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone.” The HARPS team surveyed a carefully chosen sample of 102 red d...