Biggest Asteroid of the Year to Whiz Past Earth Tomorrow—and It Looks Like It's Wearing a 'Face Mask'

An enormous asteroid will sail safely past the Earth on Wednesday—and the space rock looks like it's wearing a face mask, scientists said.

According to data from NASA's Center for Near Earth Object Studies (CNEOS) the asteroid, known as 1998 OR2, is the largest to make a close approach to Earth in the next year, measuring somewhere between 1.1 and 2.5 miles in diameter.

On Wednesday April 29 at 5:56 a.m. ET, the asteroid will come within around 3.9 million miles of our planet—roughly 16 times the average distance between the Earth and Moon—while travelling at a speed of 19,461 miles per hour.

First spotted in 1998 by scientists with the NASA-run NEAT (Near-Earth Asteroid Tracking) program based at Hawaii's Haleakala Observatory, the trajectory of this object is well-known for the next couple of centuries at least and there is no chance that it could strike our planet, according to the space agency.

Nevertheless, professional and amateur astronomers alike have been tracking 1998 OR2 as it approaches the Earth. Among them is the team at the National Science Foundation's Arecibo Observatory in Puerto Rico—which is still conducting observations despite the pandemic—who noticed some intriguing features on the space rock in the radar images that they captured.

"The small-scale topographic features such as hills and ridges on one end of asteroid 1998 OR2 are fascinating scientifically," Anne Virkki, head of Planetary Radar at the observatory, said in a statement. "But since we are all thinking about COVID-19 these features make it look like 1998 OR2 remembered to wear a mask."

asteroid 1998 OR2
A radar image of the asteroid 1998 OR2. Arecibo Observatory

The asteroid is one of the brightest—and therefore the largest—that scientists know about. The Arecibo team says their data indicates that it measures 1.2 miles in diameter—which is within the range provided by the CNEOS data. They also say that the asteroid rotates once every 4.1 hours.

While the asteroid is not predicted to cross paths with Earth any time soon in its orbit around the Sun, the object is still classified as "potentially hazardous." This classification is given to any near-Earth objects (NEOs) that will come within 0.05 astronomical units (around 4.6 million miles) of Earth and are estimated to measure more than 460 feet in diameter based on their absolute magnitude.

NEO is a term that refers to any asteroid or comet orbiting the Sun that comes within 121 million miles of the star, and 30 million miles of Earth's orbit. Scientists don't know of any potentially hazardous NEOs that pose an immediate risk to Earth. However, observations of these objects allow astronomers to refine their future trajectories.

"The radar measurements allow us to know more precisely where the asteroid will be in the future, including its future close approaches to Earth," Flaviane Venditti, a research scientist at Arecibo, said in the statement. "In 2079, asteroid 1998 OR2 will pass Earth about 3.5 times closer than it will this year, so it is important to know its orbit precisely."

"Although this asteroid is not projected to impact Earth, it is important to understand the characteristics of these types of objects to improve impact-risk mitigation technologies," Virkki said.

In the event that astronomers discover an asteroid that is on track to strike the Earth, knowing characteristics such as size and rotation rate would be crucial for any planetary defense response. If an asteroid the size of 1998 OR2 did strike the Earth, the impact would cause widespread devastation and have "global effects," according to NASA.

1998 OR2 is so large and bright that amateur astronomers can view it through their telescopes, weather permitting of course. If you still want to watch the object pass by Earth but don't have the right equipment, or clouds block your view, the Virtual Telescope Project will be providing a live stream of the event starting at 2 p.m. ET.