Asteroid That Flew By Earth Has an Orbiting Moon, Caught on Space Radar. Interesting facts are surfacing about two asteroids that flew by Earth in recent days, thanks to the Deep Space Network’s Goldstone planetary radar. Surprisingly, one of the asteroids had a little moon orbiting it. Scientists say there was no risk of the asteroids impacting Earth.
Asteroid 2011 UL21, which passed by our planet on June 27 at a distance of 6.6 million kilometers or about 17 times the distance between the Moon and Earth, was discovered in 2011. It came close enough to be caught by the radar. This asteroid was classified as potentially hazardous because it was 1.5 kilometer wide. But calculations of its future orbits show that it won’t be a threat.
Lance Benner, principal scientist at NASA’s Jet Propulsion Laboratory, said two-thirds of asteroids of this size are binary systems. “Their discovery is particularly important because we can use measurements of their relative positions to guess their mutual orbits, masses, and densities,”. It provides significant information about how these asteroids may have formed.
The scientists also observed the second asteroid 2024 MK that flew by Earth from a distance of 295,000 kilometers on June 29. It was about 150 meters wide, elongated and angular, with prominent flat and rounded regions.
Goldstone Solar System Radar
NASA says the Goldstone Solar System Radar is located in the desert near Barstow, California in the US. It is 70 meter-long and has a steerable antenna (DSS-14). This is the only steerable radar in the world for high-resolution ranging and imaging.
The radar provides full-sky coverage. Scientists have used it to investigate asteroids, planets, stars, etc. within the solar system for the past three decades.
The Goldstone Solar System Radar has gathered information about other planets, such as Mercury and Saturn, and has supported exploratory missions with the likes of the Mars Exploration Rovers, Cassini’s Saturn expedition, and the Lunar Prospector, among others.