Astro Blog

Source:  NASA RELEASE 13-011 Excerpt: …NASA-funded researchers analyzing a small meteorite that may be the first discovered from the Martian surface or crust have found it contains 10 times more water than other Martian meteorites from unknown origins. This new class of meteorite was found in 2011 in the Sahara Desert ...it weighs approximately 11 ounces (320 grams). ...a team of U.S. scientists determined the meteorite formed 2.1 billion years ago .... "The age of NWA 7034 is important because it is significantly older than most other Martian meteorites," said Mitch Schulte, program scientist for the Mars Exploration Program …Most Martian meteorites are divided into three rock types, …Shergotty, Nakhla, and Chassigny. These "SNC" meteorites currently number about 110. …Although NWA 7034 has similarities to the SNC meteorites, …"The texture of the NWA meteorite is not like any of the SNC meteorites," said co-author Andrew Steele… http://www.nasa.g...

Source:   NASA RELEASE 12-411  Excerpt: NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft… has provided compelling support for the long-held hypothesis the planet harbors abundant water ice … within its permanently shadowed polar craters. …"The new data indicate the water ice in Mercury's polar regions, if spread over an area the size of Washington, D.C., would be more than 2 miles thick," said David Lawrence, a MESSENGER participating scientist …. Given its proximity to the sun, Mercury would seem to be an unlikely place to find ice. However, the tilt of Mercury's rotational axis is less than 1 degree, and as a result, there are pockets at the planet's poles that never see sunlight. …MESSENGER's neutron spectrometer provides a measure of average hydrogen concentrations within Mercury's radar-bright regions. Water ice concentrations are derived from the hydrogen measurements…. http://www.nasa.gov/home/...

Source:  Alex  N. Halliday,  Science: Vol. 338 no. 6110 pp. 1040-1041 DOI: 10.1126/science.1229954 Excerpt: Any successful model of lunar origin has to explain the Moon’s angular momentum and its slightly lower density (than Earth). …The Moon formed relatively late given its size … more than 30 million years after the start of the solar system, whereas most objects this size are predicted to have formed in the first few hundred thousand years. The oldest rocks appear to have formed from a magma ocean, implying an intensely energetic fiery start…. The oxygen isotopic composition of the Moon is identical to that of Earth to within 5 parts per million, whereas that of nearly all asteroidal and planetary objects are different…. The Giant Impact Theory is the … widely accepted current explanation for the Moon’s late, molten start as a low-density object that now contributes most of the angular momentum in the Earth-Moon system. … an Earth when it was about 85 to 90% for...

Source:  Dennis Overbye, New York Times Excerpt:  The discovery last week of an Earth-like planet circling Alpha Centauri B "set off an epidemic of daydreaming among the astronomical and sci-fi set," including Sara Seager, an MIT astronomer, who repeated a call made last year by Berkeley astronomer Geoff Marcy that "we should drop everything and send a probe there.” "But if astronomers have learned anything over the last few years from devices like the Kepler satellite, it is that small planets come in packs. There is plenty of room in the system for more planets, habitable ones." Read the full article:http://www.nytimes.com/2012/10/23/science/space/discovery-rekindles-wish-for-a-journey-to-the-stars.html

Source:  NASA 12-343   Excerpt:  …Astronomers using NASA's Spitzer Space Telescope have announced the most precise measurement yet of …the rate at which our universe is stretching apart. …It … brings the uncertainty down to 3 percent, a giant leap in accuracy for cosmological measurements.   … "Just over a decade ago, using the words 'precision' and 'cosmology' in the same sentence was not possible, and the size and age of the universe was not known to better than a factor of two," said Freedman. "Now we are talking about accuracies of a few percent." … http://www.nasa.gov/home/hqnews/2012/oct/HQ_12-343_Spitzer_Cepheid.html

Source:  Jacob Aron, NewScientist Excerpt:  At … the IAU in Beijing, China, members unanimously voted to redefine the astronomical unit, or AU, which has long served as the fundamental unit of distance between objects in the solar system. … the official definition of the AU is now exactly 149,597,870,700 metres, and the unit should be written "au". Historically, calculating the astronomical unit was based on the average distance between Earth and the sun, or 149,597,870,691 metres. An amendment in 1976 complicated things by also tying the unit to the sun's mass. Although the recent decision doesn't alter the value by much, it simplifies things and should improve the accuracy of distance measurements over time.. www.newscientist.com/article/dn22276-sizing-up-a-new-measuring-ruler-for-the-solar-system.html

Source:  NASA,  Goddard Space Flight Center, ScienceDaily                Excerpt: … discovery of another moon orbiting the icy dwarf planet Pluto … estimated to be irregular in shape and 6 to 15 miles across … in a 58,000-mile-diameter circular orbit around Pluto…. The discovery increases the number of known moons orbiting Pluto to five. The Pluto team is intrigued that such a small planet can have such a complex collection of satellites. …"The discovery of so many small moons indirectly tells us that there must be lots of small particles lurking unseen in the Pluto system," said Harold Weaver of the Johns Hopkins University Applied Physics Laboratory…. www.sciencedaily.com/releases/2012/07/120711123038.htm