SPACE NEWS FLASH: On Wednesday, April 19, the asteroid 2014 JO25 will pass by Earth, coming as close as about 1.1 million miles at 12:24 UTC (8:24 a.m. EDT / 5:24 a.m. PDT). Yes, this asteroid is fairly large—just under half a mile across—and is traveling very fast—about 21 miles a second— BUT even so it poses no danger to Earth as 1.1 million miles is still over four and a half times the distance to the Moon…and it’s simply not going to get any closer than that.
It’s. Just. Not.
It’s like something out of a Hollywood film or a science fiction novel: a dark star sneaks up on Earth from just outside the Solar System, discovered too late to do anything about it (and really, what could we do?) and plows through the cloud of comets that surrounds the Sun like a haze of icy gnats, sending them flying everywhere… including on collision courses with Earth. Mass hysteria ensues.
Except that this isn’t just a story concept – scientists think this is actually something that happened 70,000 years ago! Minus the mass hysteria, of course… our ancestors were just beginning to settle down in the fertile lands of the Middle East after wandering out of Africa and would have had no idea what was happening at the edges of the Solar System (besides maybe a bright star occasionally flaring up in the night sky.)
On Saturday, Feb. 14, 2015, the Rosetta spacecraft performed a bit of a barnstorming act, swooping low over the surface of comet 67P/C-G in the first dedicated close pass of its mission. It came within a scant 6 km (3.7 miles) of the comet’s surface at 12:41 GMT. The image above is a mosaic of four individual NavCam images acquired just shortly afterwards, when Rosetta was about 8.9 km from the comet.
Higher-resolution OSIRIS images should be downlinked from the spacecraft within the next few days.
The view above looks across much of the Imhotep region along the flat bottom of comet 67P’s larger lobe. (See a map of 67P’s named regions here.) At the top is the flat “plain” where the Cheops boulder cluster can be seen – the largest of which, Cheops itself, is 45 meters (148 feet) across.
After the close pass Rosetta headed out to a distance of about 253 km (157 miles) before beginning preparations to approach closer again. Over the course of Rosetta’s mission this year flybys will be the “new normal,” but none will be as close as the Feb. 14 pass.
Watch a video from ESA about the close pass below, and find more images from the flyby in my article on Universe Today here.
Just under two weeks from now, on Monday, Jan. 26, the 1/3-mile (0.5-km) -wide potentially hazardous asteroid 357439 (2004 BL86) will pass by Earth at 3.1 lunar distances, or 739,680 miles (1,190,400 km). While this may sound like a long way off, in the grand scheme of things it’s still a close pass… especially for an object as wide as the Burj Khalifa is high!
Don’t worry though – there’s no risk of an impact from 2004 BL86. It will go sailing by harmlessly at a relative 15.6 km/s velocity (that is, 34,900 mph) back out into the Solar System, just another rocky reminder that Earth is definitely not alone out here.
And, thankfully, astronomers will be watching.
On the afternoon of Friday, May 31, 2013, at 4:59 p.m. EDT, the nearly two-mile-wide asteroid 1998 QE2 will pass by our planet at a distance of about 5.86 million km (3.64 million miles)… about 15 times the distance between Earth and the Moon. And although it poses no threat of impacting Earth neither during this pass nor in the foreseeable future, on the eve of its close approach NASA revealed a surprising discovery about this cosmic visitor: it has a little moon of its very own!