Two Asteroids, One The Size Of A House And Just Discovered, Do Close Flybys Of Earth On Asteroid Day

A recently discovered asteroid estimated to be the size of a house will do a fly-by of Earth on, appropriately enough, June 30, International Asteroid Day 2017. Designated 2017 MC1, the asteroid will join a smaller asteroid, 2017 MB3, which will also be traveling past the Earth on its namesake day. reported earlier this week that astronomers working with the Pan-STARRS 1 (Panoramic Survey Telescope and Rapid Response System 1, or PS1) telescope at the summit of shield volcano Haleakala on the island of Maui in Hawaii detected asteroid 2017 MC1 on June 20. Using astronomical cameras, telescopes, and a computing facility, Pan-STARRS is an astronomical survey that continually scans the skies in search of moving objects.

The movement of 2017 MC1 has been calculated, and the asteroid is scheduled to make its flyby of Earth at 21:25 UTC (Universal Time Coordinated, which is 5:25 p.m. Eastern Standard). The asteroid's calculated relative velocity is 11.6 kilometers per second (7.2 miles per second, or nearly 26,000 miles per hour).

The diameter of the newly discovered asteroid is estimated to be between 25 and 78 meters (82 feet and 256 feet), or about as big as a house. The latter measurement just 22 meters under the Potentially Hazardous Asteroids (PHAs) parameter of 100 meters. However, this is not to say that asteroids like 2017 MC1 are not dangerous themselves. For example, the Chelyabinsk Meteor that disintegrated in the skies over Russia in February 2013 was estimated to be only 20 meters (66 feet) in diameter. According to Space, that undetected rock detonated with the energy equivalent of 26 to 33 times as much energy as was expended at Hiroshima by a single atomic bomb. The shockwave generated at six miles above the planet damaged thousands of buildings in dozens of cities in the Chelyabinsk Oblast and sent over a thousand people to the hospital with injuries.

For those who worry about dangerous and catastrophic asteroid strikes like Chelyabinsk, it has been determined that 2017 MC1 poses no threat to Earth on its present trajectory. It will safely pass by the Earth at 2.5 lunar distances (LD), or 960,000 kilometers (nearly 600,000 miles).

asteroid nearing Earth with Sun shining
The newly discovered asteroid is about as big as a house, astronomers estimate. [Image by Elenarts/Shutterstock]

Asteroid 2017 MC1 will not be the only cosmic visitor doing a fly-by of Earth on Asteroid Day. Another recently discovered asteroid, 2017 MB3, will also make an appearance. Measuring at 16 to 49 meters (52.5 to 161 feet), this somewhat smaller space rock will pass by a little farther out, as well, at roughly five LD (1.92 million kilometers, or 1.19 million miles).

To date (June 29), astronomers have spotted 1,803 Potentially Hazardous Asteroids.

asteroid near miss
Roughly 70 to 80 percent of Potentially Hazardous Asteroids are still undetected, astronomers estimate. [Image by Vadim Sadovski/Shutterstock]

International Asteroid Day is an annual global event designed to raise awareness about asteroids and what can be done to protect the Earth from potentially harmful impacts.

[Featured Image by Rashevskyi Viacheslav/Shutterstock]