Hayabusa 2 Lands On Asteroid, Rocks Fly! / Comma Crescent Punctuates Dusk

Hayabusa 2 touchdown on asteroid Ryugu Wow, wow, wow. What a great video. On February 21, Japan’s Haybusa 2 probe briefly touched down on the asteroid Ryugu, fired a bullet into the rocky rubble and collected a sample that will be returned to Earth in December 2020. You can see the collector horn at top…
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Sirius Is The Brightest Star In The Night Sky, Seriously

Sirius really shines this month. If you know where to look you can spot it just before sunset (more on that in a moment). Otherwise the star is plainly visible in a deep blue sky just a half-hour after sunset. Star brightness is determined by the magnitude scale, and Sirius sits at the top of…
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Mars ‘Mole’ Has Much To Chew On

My face still burns from this afternoon’s raw wind. For some of us it’s been a cold and long winter, but if you ever need perspective, check out the latest weather at Elysium Planitia on Mars. That’s where NASA’s InSight lander is parked, a few degrees north of the Martian equator in a wide, nearly…
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Ice Pillars Spear The Sky On Still, Snowy Nights

On a walk last night, I saw a huge shaft of light standing up in the northern sky over a hockey rink a couple miles from my house. A dog barked from that direction, and when I strained to listen, I could hear slap of hockey pucks in the still air. A light snow fell.…
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We Just Discovered The Moon Moves Through Earth’s Atmosphere

  Three-quarters of Earth’s atmosphere sits within the bottom 6.8 miles (11 km). At the space station’s altitude of 250 miles (400 km), there’s next-to-no air. But the faint breath of Earth continues into space as the geocorona or exosphere, the outermost layer of the atmosphere. Older estimates put its size at around 1.5 Earth…
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