Two asteroids just brushed past Earth and NASA filmed the action

NASA’s Goldstone Planetary Radar System recently recorded two near-Earth asteroids, 2024 MK and 2011 UL21, passing close to our planet. Perhaps a little alarmingly, one of them was only detected 13 days before it passed safely by. Earthbut NASA scientists Jet Propulsion Laboratory (JPL) in Southern California assures that it is not a threat. The images they were able to collect are nevertheless extremely instructive.

“There was no risk that either near-Earth object would impact our planet, but the radar observations taken during these two close approaches will provide valuable practice for planetary defenseas well as information about their sizes, orbits, rotation, surface details, and clues to their composition and formation,” the team wrote in a press release.

The Goldstone Solar System Radar is located in the desert near Barstow, California. With its 230-foot-long (70-meter-long), fully steerable antenna (DSS-14)—the world’s only fully steerable radar for high-resolution ranging and imaging—it provides complete sky coverage and has been used to study objects of interest in the solar system over the past three decades.

During this period he managed to collect invaluable information about other planets, Mercury has Saturnand has supported numerous exploration missions, such as the Mars Exploration Rovers, the Cassini Saturn expedition, the Hayabusa asteroid explorers, SOHO the recovery of the solar observation probe, the Lunar Prospector, and the Venus-study Magellan’s effort.

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As seen this week, it has also been used to track and study near-Earth objects. asteroidshelping to prevent potential impact hazards and identify targets for future exploration missions. Radar is a powerful tool for studying the properties and orbits of asteroids: the ground station transmits radio waves to the asteroids, then receives reflected signals that scientists can use to glean relevant information. If an object’s “echo” is strong enough, radar imaging can achieve spatial resolution that can identify features as fine as 10 meters (32 yards).

Hello asteroids, goodbye asteroids

On June 27, the radar system tracked asteroid 2011 UL21 as it passed close to Earth at a distance of 6.6 million kilometers. As its name suggests, the asteroid is known for NASA scientists since 2011, after it was discovered during the Catalina Sky Survey in Tucson, Arizona.

About 1.6 kilometers (1 mile) across, the object was the first to come close enough to be photographed by Earth-based radar, allowing scientists to determine that it is roughly spherical in shape and is accompanied by its own “moon” that orbits about 3 kilometers (2 miles) from the asteroid.

“About two-thirds of asteroids this size are thought to be binary systems, and their discovery is particularly important because we can use measurements of their relative positions to estimate their mutual orbits, masses and densities, which provide key information about how they may have formed,” said Lance Benner, a principal scientist at JPL who helped lead the observations.

A pixelated, grainy rock spins in a black space.

(Image credit: NASA/JPL-Caltech)

Although NASA scientists say that due to its size, 2011 UL21 has been classified as potentially hazardous, calculations of the asteroid’s orbit indicate that it will not pose a real threat in the near future.

Then, just two days later, another asteroid appeared. The same team observed asteroid 2024 MK pass by our planet at a distance of just 295,000 kilometers, or just over three-quarters of the distance between our planet and Earth. the moon and Earth. Close approaches like this are relatively rare, the team says, but provide valuable information that would otherwise be difficult to obtain.

“This was an extraordinary opportunity to study the physical properties and obtain detailed images of a near-Earth asteroid,” Benner said.

2024 MK was first identified on June 16 by the Asteroid Earth Impact Alert System (ATLAS) at the Sutherland Observatory in South Africa. “Its orbit was altered by Earth’s gravity as it passed, reducing its orbital period by 3.3 years around it. the sun “approximately 24 days,” the team said in the statement.

a grainy image of the same space rocket shown from different angles in a grainy sea of black and white.

(Image credit: NASA/JPL-Caltech)

On June 29, scientists again transmitted radio waves to 2024 MK — but it timereceived the return signal with Goldstone’s 34-meter DSS-13 antenna rather than DSS-14. “This ‘bistatic’ radar observation produced a detailed image of the asteroid’s surface, revealing concavities, ridges, and boulders about 10 meters wide,” they wrote.

About 150 meters wide, this asteroid appears elongated and angular, with prominent flat and rounded areas. Although it is also classified as a potentially hazardous asteroid, calculations of its future motion show that it does not pose a threat to our planet in the near future.