Dark Matter Near Earth Peaks Every March, New Study Suggests: Scientific American

Image: NASA/CXC/CfA/STScI/ESO

Billions of particles of invisible “dark matter” are probably flying through your body right now, passing through the spaces between your atoms without a trace. According to conventional thinking, these particles should be somewhat less abundant during the winter and should peak around June 1. But a new study suggests this calculation is way off; the real peak is actually at the beginning of March.

Dark matter is thought to constitute almost 27 percent of the universe’s total mass and energy, but its nature is a mystery. One of physicists’ best guesses is that theorized particles called WIMPs (weakly interacting massive particles) make up this matter, but WIMPs have so far eluded detection. Whatever dark matter is, it appears to clump into large clouds called haloes that engulf galaxies, including our own Milky Way. As the solar system makes its regular progression around the Milky Way, it flies through this halo, causing dark matter to bombard the sun and planets with a steady “wind,” just as flies will hit the windshield of a fast-moving car. Earth, however, is also rotating around the sun. Astrophysicists have assumed that when it is moving against the direction of the dark matter wind (which happens to be during summer), we should see an uptick in dark matter particles of a few percent, and a corresponding decrease when Earth is traveling with the tide during winter.

via Dark Matter Near Earth Peaks Every March, New Study Suggests: Scientific American.

Eyes on the Sky: Jan 6 thru Jan 12

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10 Years on Mars: NASA Rover Mission Celebrates 10th Martian Birthday | Space.com

Mars Rovers Celebrate 10 Years on Red Planet

NASA’s twin Mars rovers, Spirit and Opportunity, have now spent 10 years on the surface of Mars.  Credit: NASA/JPL

 

Ten years ago today, NASA dropped the first of two rovers onto the surface of Mars, kicking off a wildly successful mission that continues to beam home data about the Red Planet and its wetter, warmer past.

NASA’s Spirit rover touched down on the night of Jan. 3, 2004 (Jan. 4 GMT), followed three weeks later by its twin, Opportunity. The two robots were originally supposed to explore Mars for 90 days, searching their disparate landing sites for signs of past water activity on the Red Planet.

Both rovers found plenty of such evidence and just kept chugging along, far outlasting their warranties. Spirit got stuck in a sand trap in 2010 and was declared dead a year later, but Opportunity continues to operate today and shows no signs of slowing down.

via 10 Years on Mars: NASA Rover Mission Celebrates 10th Martian Birthday | Space.com.