After its brief visit, FO32 will continue its solitary journey in 2001 and only come close to Earth again in 2052, when it will pass at approximately seven lunar distances, or 2.8 million kilometers.
Astronomical Geology
Asteroid 2001 FO32 was discovered in March 2001 by the Lincoln Near-Earth Asteroid Research (LINEAR) program in Socorro, New Mexico, and was estimated from optical measurements about 1 mile wide. In recent follow-up observations by NEOWISE, FO32 appears to be vague when observed in infrared wavelengths, indicating that the object is probably less than 1 kilometer in diameter. Analysis by the NEOWISE team shows that it is between 440 and 680 meters wide.
Even at the smaller end of the scale, 2001 FO32 will still be the largest asteroid to pass near our planet in 2021. The last major asteroid approach was the OR2 of 1998 on April 29, 2020. While 2001 FO32 is slightly smaller than 1998 OR2, it will be three times closer to Earth.
The March 21 meeting will give astronomers the opportunity to gain a more precise understanding of the size and albedo of the asteroid (ie, how bright, or reflective its surface is), and a rough idea of its composition.
This will be accomplished in part using NASA’s infrared telescope facility (IRTF), a 3.2 meter (10.5 ft) telescope on top of Hawaii’s Mauna Kea, which will detect the asteroid in the days ahead. approach using his work cell. infrared spectrograph, SpeX. “We’re trying to do geology with a telescope,” said Vishnu Reddy, an associate professor at the University of Arizona’s Lunar and Planetary Laboratory in Tucson.
When sunlight falls on the surface of an asteroid, minerals in the rock absorb some wavelengths while being reflected again. By studying the spectrum of light reflected from the surface, astronomers can measure the chemical “fingerprints” of the minerals on the surface of the asteroid. “We’re going to use the IRTF to show the infrared spectrum its chemical composition,” Reddy explained. “Once we know this, we can make comparisons with meteorites on Earth to determine which minerals 2001 FO32 contains.”
For example, if FO32 were identified as iron-rich, it would mean that it is denser and therefore more massive than a rocky asteroid of the same size; observations showing a surface with a low albedo (meaning it is dark) may indicate that the asteroid contains a lot of carbon, suggesting that it may be the core of a long-dead comet.
A closer look
In addition, radar observations can be made by the Deep Space Network (DSN) to get a detailed picture of the asteroid. The DSN is an operation of NASA’s Space Communications and Navigation Program (SCaN) and consists of three ground stations – one in California (Goldstone), one in Spain (Madrid) and one in Australia (Canberra). Their dish antennas can be used to reflect radio signals from 2001 FO32 so that other radio antennas can receive them. Such radar observations can provide extra insight into the orbit of the asteroid, a better estimate of its dimensions and rotational speed, and help to see the surface features (such as large rocks or craters). They can even reveal any small satellites that are in tow.
“Observations dating back 20 years have shown that about 15% of the asteroids near Earth, comparable to the size of 2001 FO32, have a small moon,” said Lance Benner, chief scientist at JPL. “Little is known about this object at present, so the very close encounter provides an excellent opportunity to learn a lot about this asteroid.”
More than 95% of the Asteroids near Earth of 2001 FO32 or greater have been discovered, detected and cataloged. None of the major asteroids in the catalog have a chance of affecting the Earth during the next century, and it is highly unlikely that any of the remaining undiscovered asteroids of this size could affect the Earth as well. Attempts are still being made to discover all asteroids that could pose an impact hazard. The more information about these objects can be gathered, the better mission designers can prepare to deduce them should the earth threaten in the future.
Meanwhile, amateur astronomers can gather their own information about 2001 FO32. “The asteroid will be the brightest as it moves through the southern sky,” JPL’s Chodas said. ‘Amateur astronomers in the southern hemisphere and low northern latitudes should be able to see this asteroid using moderate-sized telescopes with diaphragms of at least 8 centimeters in the nights that follow the closest approach, but they will probably have star charts needed to find it. ”
JPL presents CNEOS for NASA’s near-Earth observation program in NASA’s planetary defense coordination office. The University of Hawaii manages IRTF under contract with NASA. The SpeX instrument was built at the University of Hawaii.
More information about CNEOS, asteroids and near-Earth objects can be found at:
https://cneos.jpl.nasa.gov
For more information on NASA’s Planetary Defense Coordination Office, visit:
https://www.nasa.gov/planetarydefense
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