NASA estimates that the asteroid is between 1.1 miles and 2.5 miles (1.8 to 4.1 kilometers) wide. According to Asteroid Watch, 1998 OR2 will pass and that it will pass by at a safe distance that is more than 16 times the average distance between Earth and the moon. While NASA classifies asteroids that come within less than 4.6 million miles (7.5 million km) of Earth as “potentially hazardous,” there’s nothing to worry about with 1998 OR2.
“The orbit is well understood and it will pass harmlessly at 16 times the distance to our moon,” NASA wrote on Twitter. “No one should have any concern about it.”
The asteroid is currently too faint to see with most backyard telescopes, but it has been visible in larger telescopes for a while. The Virtual Telescope Project, a remote observatory founded by astrophysicist Gianluca Masi of the Bellatrix Astronomical Observatory in Italy, has been keeping an eye on the asteroid for about a month, periodically releasing new images of the space rock as it races through the cosmos at more than 19,000 mph (31,000 km/h).
Asteroid 1998 OR2 is currently only visible in professional telescopes, like the ones Masi uses at the Virtual Telescope Project. However, amateur astronomers will have a chance to see the asteroid for themselves when it becomes visible in smaller telescopes during its close approach.
According to EarthSky.org, asteroid 1998 OR2 is expected to reach a visual magnitude of 10 or 11 (magnitude is a measure of an object’s brightness). This means it will be visible in at least 6-inch or 8-inch telescopes, weather permitting.
If you aren’t able to watch the flyby, you can still see asteroid 1998 OR2 in a live webcast from the Virtual Telescope Project. Hosted by Masi, the free livestream will feature telescope views of the asteroid on April 28, starting at 2 p.m. EDT (1800 GMT).