Two Celestial Visitor over Next Two Months

Two celestial visitors grace our skies over the next couple of months. The first one is a 2-mile-wide asteroid that, if it struck Earth, would cause significant damage. The second is a comet that, if it keeps getting brighter at the rate it is now, will become bright enough to cast shadows at night.

The first cosmic guest comes calling on April 29^th when asteroid 1998 OR2 passes by. The size of a small city, and therefore quite destructive should it ever strike Earth, it was discovered on July 24^th, 1998, by the now-defunct Near Earth Asteroid Tracking program, funded by NASA and operated jointly through several major U.S. observatories.

NASA classifies 1998 OR2 a “potentially hazardous asteroid.” To receive that designation, an asteroid must be at least 500 feet across and pass within 4,650,000 miles of Earth. While an asteroid at that distance poses absolutely no threat to Earth, its orbit could be altered by gravitational tugs from other planets or moons in our solar system so that, on a future orbit, it might pass much closer to Earth or even impact our planet.

The closest approach of 1998 OR2 occurs at 4:56 CDT in the morning of the 29^th. At that time, it will still be 3.9 million miles away, or 16 times the average distance between Earth and the Moon. Even with its relatively close proximity, it won’t be visible to the naked eye. But if you have a telescope and a clear, dark sky you can spot it. Go to https://earthsky.org/astronomy-essentials/asteroid-52768-1998-or2-april-2020-how-to-see#tips for tips and charts to locate it.

Asteroid 1998 OR2 Image credit Gianluca Masi and The Virtual Telescope Project

Comet C/2019 Y4 ATLAS may become a spectacular sight in our night sky in late May. It was discovered on December 28, 2019 by the Asteroid Terrestrial-impact Last Alert System (ATLAS, hence the name), another NASA-funded program, operated by the University of Hawaii. As astronomers tracked it after the discovery, the comet brightened at an unprecedented rate. While astronomers expect that rate of brightening to slow down, if it were it continue to brighten as it has been, it will rival a crescent Moon in our night sky.

One major hurdle exists before the comet can bloom into a bright, beautiful sight in our night sky. The comet will pass closer to the sun than Mercury. Bright comets passing close to the sun often break into pieces or even disintegrate altogether. But if it survives that close pass, it could become the brightest comet since Comet Hale-Bopp, which passed by in 1997.

ATLAS C2019Y4_200318_FB credit  Rolando Ligustri

These two should excite amateur astronomers and all those who wonder at the night sky.

Each month, I write an astronomy-related column piece for the Oklahoman newspaper. After it is published, I post that same column to my blog page.

This is reprinted by permission from the Oklahoman and www.newsok.com.