Stephen Ornes on February 28, 2008 4:36 PM
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According to the Meteoritical Society, more than 30,000 meteorities have been identified. (Meteorites are the interstellar rocks that make it through our atmosphere and land on Earth.) Most of them come from the rocky debris (like asteroids and comets) floating through space, but a few dozen are believed to have originated on Mars or the moon.
Or Mercury? (What, can anomalous meteorites only come from places the begin with the letter “M”?)
In a new paper submitted to the journal Meteoritics and Planetary Science, two Canadian astronomers crunch the numbers and find that we should expect Mercury-borne meteorites to strike the Earth at roughly half the rate of those from Mars. In other words, there might already be a few pieces of Mercury here on Earth.
Continue reading 'Mercurial Meteorites' >
Stephen Ornes on February 20, 2008 11:05 AM
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This isn’t going to shake up the big questions in cosmology, but it might change the way you think about the night sky. Those stars you see? They may not be where you think they are.
Gravitational lenses operate like funhouse mirrors in deep space. They can magnify, distort and bend the light from distant galaxies, and make them appear in different places than where you would expect. (No word yet on whether they can make galaxies look taller or thinner or shorter or heavier or wavier…) Gravitational lenses, as their name suggests, are usually giant galaxies so massive that they bend spacetime—and thus redirect light or anything else that happens to be traveling close by.
They can be helpful to astronomers: the magnification and redirection of light allows stargazers to see farther into deep space. And thus, farther back in time.
The Cosmological Evolution Survey (COSMOS), led by Nick Scoville at Caltech, recently completed a long, hard look at a patch of the sky roughly equal to the area of 9 full moons (1.6 square degrees). The survey used data from the major league of telescopes: the Hubble, Chandra, Spitzer, and the VLT all contributed images. The researchers found 67 new gravitational lenses.
Continue reading '67 new gravitational lenses; no word yet on scratch-resistant coating' >
