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.
There are also no “ill effects” that a pass by an asteroid like JO25 would have on Earth or the Moon. It can’t gravitationally affect us, it won’t send debris our way, it’s not going to cause earthquakes or tsunamis or hurricanes or tornadoes or burn your toast. It’s just another close pass by a member of the Solar System, a reminder that we’re not alone out here.
What IS interesting about this pass though is that it’s the closest an object of this size will have gotten to Earth since September 29, 2004 when the 3.1-mile-wide asteroid Toutatis passed at about 961,000 miles. Considerably larger than JO25, Toutatis won’t get that close again for at least another 500 years, and its 2004 pass was the closest pass of anything that size over the last century.
You can see radar imagery of the gargantuan Toutatis below, captured by NASA’s Goldstone facility during a more distant pass in Dec. 2012.
The April 19 pass by 2014 JO25 will be the closest it also comes to Earth for at least the next 500 years, meaning nobody will have to worry about either it or Toutatis for a very long time. But astronomers will still use the close pass to acquire data on JO25, bouncing radar waves off it to get a better idea of its shape, rotation, and ultimately better plot its path around the Sun.
(After all, when it comes to mountain-sized space rocks moving faster than bullets it’s always better to have more information than less.)
UPDATE 4/18: Radar imaging of the approaching 2014 JO25 from NASA’s Goldstone facility has shown it to be a contact binary composed of two lobes joined together by a “neck,” not unlike the comet 67P/Churyumov-Gerasimenko (except 1/6th the size.) The larger lobe is estimated to be about 620 meters (0.38 mile) across. An animation made from radar images can be seen below, and you can read more about that here.