2017 VR12: Asteroid That Could Be Bigger Than Empire State Building Is About to Pass by Earth

An asteroid up to 1600ft in diameter is set to fly by Earth in the early hours of March 7. Named "2017 VR12", NASA has called the object "potentially hazardous."

But don't worry—the space rock shouldn't get closer than 900,000 miles from Earth. That's far enough to stay safe, and maybe even close enough to watch on a home telescope.

Larger than the Empire State Building?

It is difficult to work out an asteroid's size at great distance, but we can estimate. "The asteroid is a mere point of light in our telescopes: we cannot resolve its size that way," Paul Chodas, manager of the Center for Near Earth Object Studies (CNEOS) at NASA's Jet Propulsion Laboratory, told Newsweek.

Astronomers can guess the object's size from its brightness, but this can produce a wide range of results. A small but very luminous asteroid can look as bright as a larger but darker object.

3_2_Pyramid of Giza
The Great Pyramid of Giza in Egypt, also known as the Pyramid of Khufu or the Pyramid of Cheops, initially stood about 480 ft tall. After erosion and removal of its capstone, it now stands at approximately 450 ft tall. Djehouty/Wikimedia Commons

As of 5.00 a.m. ET March 2, estimates from NASA's Jet Propulsion Laboratory and the International Astronomical Union's Minor Planet Center put 2017 VR12 somewhere between 490 ft and 1600 ft in diameter. This means it could outstretch the Empire State Building's 1450 ft height.

Even at its smallest estimate, the asteroid outstretches the Great Pyramid of Giza in Egypt, which, historians think, was a measly 480 ft tall (or 280 Egyptian Royal cubits) when first built.

At its largest, 2017 VR12 is not that big for a near Earth object. The largest two, Chodas said, are about 18.5 miles across—that's almost the size of Aruba. "I would characterize 2017 VR12 as "mid-sized", he added.

3_2_Asteroid Ida
Asteroid Ida, discovered in 1884, is much larger than 2017 VR12. This picture was produced from frames taken by NASA's Galileo spacecraft in 1993. The asteroid which measures 19.5 miles across and has its own satellite. JPL/NASA

Rare opportunity for radar observation

Starting this weekend, astronomers will track the asteroid as it comes within the range of the Goldstone Solar System Radar in the Mojave desert and the Arecibo Observatory in Puerto Rico. This should lead to a better guess at its size, shape and surface. They might even snap an image of the object, Chodas said.

2017 VR12 represents a rare opportunity for astronomers—most near Earth objects are too distant to be within range of the radar, or too small to provide a detectable echo, Chodas explained.

Will I be able to see it?

Astronomers have a much better idea of the object's orbit than its size. Its close approach to Earth qualifies it as a "potentially hazardous asteroid" by NASA's standards. However, its orbit will keep it nearly four lunar distances from our planet.

Far enough to pass by safely, it's still a pretty close encounter with an asteroid of this size. It's so close, in fact, you may be able to watch it with a small home telescope.

3_2_Asteroid 1999 JD6 Radar images
Radar observatories can produce images of asteroids, like these showing the rotation of Asteroid 1999 JD6. GSSR/JPL-Caltech/NASA

It should make its closest approach to Earth at a speed of about 4 miles per second at 2.53 a.m. ET, give or take a minute.

"It will get as bright as about 12 magnitude, easily visible to northern hemisphere amateur astronomers with moderate-sized telescopes—perhaps even as small as six-inch telescopes," Chodas said.

Observers will still need a dark sky and a good ephemeris—a precise prediction of where exactly to point a telescope given the time and your location on Earth—he added.

If you don't have a telescope or you can't find a clear, dark sky, you can watch the asteroid pass by online. The Virtual Telescope Project will show a livestream of the asteroid's journey.