2001 FO32, a near-Earth asteroid discovered two decades ago, will fly safely past Earth on March 21, 2021, at a distance of about 2 million (1.25 million miles), or about 5.25 times the distance from Earth to the Moon. After its brief visit, 2001 FO32 will continue its lonely voyage, not coming this close to Earth again until 2052, when it will pass by 2.8 million km (1.75 million miles).
An artist’s impression of an asteroid. Image credit: Mark A. Garlick, Space-art.co.uk / University of Warwick / University of Cambridge.
2001 FO32 was discovered on March 23, 2001 by the Lincoln Near-Earth Asteroid Research program at Lincoln Laboratory’s Experimental Test Site in Socorro, New Mexico.
The asteroid is between 440 and 680 m (1,300-2,230 feet) wide, and has an orbital period of 810 days.
During the March 21 approach, the object will pass by at about 124,000 kph (77,000 mph) — faster than the speed at which most asteroids encounter Earth.
The reason for this unusually speedy close approach is 2001 FO32’s highly inclined and elongated orbit around the Sun, an orbit that is tilted 39 degrees to Earth’s orbital plane. This orbit takes the asteroid closer to the Sun than Mercury and twice as far from the Sun as Mars.
“We know the orbital path of 2001 FO32 around the Sun very accurately, since it was discovered 20 years ago and has been tracked ever since,” said Dr. Paul Chodas, director of the Center for Near Earth Object Studies (CNEOS).
“There is no chance the asteroid will get any closer to Earth than 1.25 million miles.”
2001 FO32 will be the largest asteroid to pass this close to our planet in 2021.
This diagram depicts the elongated and inclined orbit of 2001 FO32 as it travels around the Sun (white ellipse). Image credit: NASA / JPL-Caltech.
The March 21 encounter will provide an opportunity for astronomers to get a more precise understanding of the asteroid’s size and albedo and a rough idea of its composition.
This will be achieved, in part, with the use of NASA’s Infrared Telescope Facility (IRTF), a 3.2-meter (10.5-foot) telescope atop Hawaii’s Mauna Kea.
“We’re trying to do geology with a telescope,” said Dr. Vishnu Reddy, a researcher in the Lunar and Planetary Laboratory at the University of Arizona.
“Observations dating back 20 years revealed that about 15% of near-Earth asteroids comparable in size to 2001 FO32 have a small moon,” said Dr. Lance Benner, principal scientist at NASA’s Jet Propulsion Laboratory.
“Currently little is known about this object, so the very close encounter provides an outstanding opportunity to learn a great deal about this asteroid.”
“The asteroid will be brightest while it moves through southern skies,” Dr. Chodas said.
“Amateur astronomers in the southern hemisphere and at low northern latitudes should be able to see this asteroid using moderate size telescopes with apertures of at least 8 inches in the nights leading up to closest approach, but they will probably need star charts to find it.”
This article is based on text provided by the National Aeronautics and Space Administration.