A massive asteroid first discovered 20 years ago will travel within 1.25 million miles of Earth on Sunday, before being hurled into deep space, NASA revealed.
Named 2001 FO32, at 2,230 feet in diameter, it is twice the size of the Eiffel Tower, making it the largest space rock to pass Earth to date this year.
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 swung back toward the sun, ” explained NASA from.
The space agency says it “poses no danger to Earth,” as it will be more than five times farther from our planet than the moon even at its closest point.
It will make its closest approach on March 21, but is only visible to astronomers using larger telescopes in the southern hemisphere and low latitudes in the north.
The asteroid, dubbed 2001 FO32, was first discovered 20 years ago and has a diameter of 2,230 feet, making it the largest space rock to have passed Earth so far this year.
The space rock “poses no danger to Earth” as it will be 1.25 million miles away, which is more than five times farther from Earth than the Moon.
Despite being more than a million miles away, NASA says it will give astronomers a ‘rare close-up’ of the rocky relic from the solar system’s beginnings.
“Amateur astronomers in the southern hemisphere and low northern latitudes should be able to see this asteroid using medium-sized telescopes with openings of at least 20 centimeters in the nights leading up to the closest approach,” Chodas said.
However, he added that it will not be easy to find because it is small and some distance away, saying they will ‘probably need star maps to find it’.
According to NASA guidelines for ‘Near Earth Object’, it will still be close enough to classify FO32 as a ‘potentially dangerous asteroid’ in 2001.
This is in part because its orbit crosses Earth’s orbit path – although not ‘in line’ or close to Earth for the foreseeable or even distant future, NASA said.
The space agency said in a statement that “there is no threat of a collision with our planet now or in the coming centuries.”
NASA said 2001 FO32 will pass at about 77,000 miles per hour faster than the speed at which most asteroids meet Earth.
The reason for the asteroid’s unusually fast approach is its steeply sloping and elongated (or eccentric) orbit around the sun.
This is an orbit tilted 39 degrees from the Earth’s orbital plane. This orbit brings the asteroid closer to the sun than Mercury and twice as far from the sun as Mars.
The space rock orbits the sun every 810 days (about 2 1/4 years).
“Little is currently known about this object, so the very close encounter provides an excellent opportunity to learn a lot about this asteroid,” said Lance Benner, chief scientist at NASA’s Jet Propulsion Laboratory.
NASA said astronomers hope to better understand the size of the asteroid and get a rough idea of its composition by studying light reflected off its surface.
The March 21 encounter provides astronomers with an opportunity to gain a more accurate understanding of the asteroid’s size and albedo – how bright or reflective its surface is – and to get a rough idea of its composition.
“When sunlight hits the surface of an asteroid, minerals in the rock absorb some wavelengths while reflecting others,” NASA said.
By studying the spectrum of light that bounces off the surface, astronomers can measure the chemical ‘fingerprints’ of the minerals on the asteroid’s surface.
This will be accomplished in part using NASA’s Infrared Telescope Facility, a 10.5-foot telescope atop Hawaii’s Mauna Kea.
It will observe the asteroid at close range in the days leading up to its approach using its workhorse infrared spectrograph, SpeX.
“We’re trying to do geology with a telescope,” said Vishnu Reddy, an associate professor at the Lunar and Planetary Laboratory at the University of Arizona in Tucson.
This diagram shows the elongated and inclined orbit of 2001 FO32 as it moves around the sun (white ellipse). Because of this orbit, as the asteroid approaches Earth, it will travel at an unusually high speed of 77,000 mph (124,000 km / h).
As 2001 FO32 makes its inner solar system journey, the asteroid “ picks up speed like a skateboarder rolling down a half-pipe, then slows down after being thrown back into deep space and swung back toward the sun, ” explains NASA from.
When sunlight hits the surface of an asteroid, minerals in the rock absorb some wavelengths of light while reflecting others. Scientists know which rocks reflect which wavelengths and can thus determine the composition of the asteroid from light.
“We’re going to use the IRTF to show the infrared spectrum its chemical composition,” explained Reddy. “Once we know that, we can make comparisons with Earth’s meteorites to find out which minerals 2001 contains FO32.”
For example, a low albedo, or darker asteroid, may contain a lot of carbon and thus could be the nucleus of a long-dead comet, according to NASA.
Other observatories will use radar to bounce signals off the rock, allowing them to determine its trajectory, dimensions and rotation, and look at surface features such as boulders and craters.
“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.”
This is an image from inside the dome of NASA’s Infrared Telescope Facility that will be used to measure the infrared spectrum of asteroid 2001 FO32
Amateur astronomers in some parts of the world should be able to make their own observations, especially those in the Southern Hemisphere.
“The asteroid will be brightest as it moves through the southern sky,” said Chodas, director of the Center for Near Earth Object Studies (CNEOS).
“Amateur astronomers in the southern hemisphere and low northern latitudes should be able to see this asteroid using medium-sized telescopes with openings of at least eight inches in the nights leading up to the closest approach,” he added.
Because of its distance and relatively small size compared to planets or stars, “they probably need star maps to find it.”
After its brief visit, FO32 will continue its journey in 2001, not getting that close to Earth until 2052, when it will pass at about seven lunar distances, or 1.75 million miles.
NASA said more than 95 percent of near-Earth asteroids the size of 2001 are FO32 or larger, and none of them have any chance of affecting our planet in the next century.