Largest asteroid flyby of 2021, size of the Golden Gate Bridge, to make a “very close encounter” with Earth on March 21

An asteroid comparable in size to the Golden Gate Bridge will sweep past our planet this weekend – the largest and fastest asteroid to pass Earth this year.

But don’t worry, it won’t get too close.

The asteroid, officially known by NASA as 231937 (2001 FO32), is smaller than the last notable to approach Earth up close, but it will be three times closer, NASA said in a statement.

2001 FO32 is about 1,300 to 2,230 feet wide, according to observations from the NEOWISE mission team, putting it on the smaller end of the scale. It has an orbital period of 810 days.

It will be here to mark the first full day of spring.

2001 FO32 is rapidly approaching our planet, which will come within 1.25 million miles of Earth on Sunday, March 21 at 11:02 a.m. ET, just one day after the vernal equinox. That’s close enough for NASA to classify it as “potentially dangerousin its database of near-earth asteroids, a designation given when an asteroid comes within about 4.65 million miles from Earth and is greater than 150 feet in diameter.

The asteroid will buzz by at nearly 77,000 miles per hour, or 21 miles per second, peaking scientists’ interest as one of the fastest space rocks known to fly past Earth. It is “unusually fast” because of its steeply sloping and elongated orbit around the sun, which brings it closer to the sun than Mercury and twice as far from the sun as Mars.

“This is the closest predicted approximation in 2021 for any moderately large asteroid, where ‘moderately large’ means at least several hundred meters in size,” Paul Chodas, the director of the Center for Near-Earth Object Studies, told CBS News.

However, it does not pose a risk of impact and scientists know the path very accurately after studying it for about two decades.

“As 2001 FO32 makes its inner solar system journey, the asteroid picks up speed like a skateboarder rolling down a halfpipe, then slows down after being thrown back into deep space and back to the sun,” said NASA .

The upcoming encounter gives astronomers a unique opportunity to better understand the asteroid, including its size, reflectivity and composition. Some studies will use NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea in Hawaii.

“We’re trying to do geology with a telescope,” said Vishnu Reddy, associate professor at the Lunar and Planetary Laboratory at the University of Arizona in Tucson. “We’re going to use the IRTF to show the infrared spectrum its chemical composition. Once we know that, we can make comparisons to Earth’s meteorites to find out which minerals 2001 contains FO32.”

In addition, researchers can use radar observations from NASA’s Deep Space Network, which has ground stations in California, Spain and Australia, to study the asteroid’s orbit, dimensions, rotational speed, surface features, and potential satellites.

“Observations going back 20 years showed that about 15% of near-Earth asteroids similar in size to 2001’s FO32 have a small moon,” said Lance Benner, JPL chief scientist. “Little is currently known about this object, so the very close encounter provides an excellent opportunity to learn a lot about this asteroid.”

At its brightest, the space rock will still be “far too dim” to see with the naked eye, Chodas said. But space enthusiasts can see it with a telescope.

“A fascinating aspect of asteroids is that observers using backyard telescopes can see them as seemingly slow-moving ‘stars,'” said EarthSky. “It normally takes at least 5 to 10 minutes for users of a backyard telescope to detect the motion of a space rock in front of its star field. But asteroid 2001 FO32 will pass Earth so fast that, when it is closest, observers 8- inch or larger telescopes can detect its motion – its drift in front of the stars – in real time. “

Observers in lower northern latitudes and in the southern hemisphere will have the best chance of seeing it at its brightest, Chodas said. Star charts will help locate it.

Telescopes in New Mexico that are part of the Lincoln Near-Earth Asteroid Research program detected the asteroid in March 2001. The MIT Lincoln Laboratory program, funded by the United States Air Force and NASA, has been following it ever since.

After its visit on March 21, FO32 will continue its “solitary journey” – and will not return to Earth until 2052. In that year, it will be within 1.75 million miles of Earth, or about seven lunar distances.

The current greatest known threat is an asteroid called (410777) 2009 FD, which, according to NASA’s PDCO, has less than a 0.2% chance of hitting Earth in 2185.