Scientists atcaptured detailed images of two asteroids as they zipped past Earth in late June.
Interestingly, this nearly mile-wide (1.5-kilometre-wide) space rock wasn't alone – radar observations revealed it has a small moon orbiting it.
Asteroid 2011 UL21 with moonlet (Image: NASA/JPL-Caltech)Using Radar to Reveal SecretsNASA's Jet Propulsion Laboratory used powerful radar technology to analyse 2011 UL21.
Even more surprising, the radar data confirmed the presence of a tiny moonlet circling the asteroid at a distance of about 1.9 miles (3 kilometres).
This resulted in a detailed image of the asteroid's surface, revealing depressions, ridges, and even boulders as large as 30 feet across.
(Image: NASA/JPL-Caltech)
NASA Our cosmic neighbourhood recently had some visitors. Scientists atcaptured detailed images of two asteroids as they zipped past Earth in late June. While neither posed a threat, these close encounters provided valuable data for future planetary defence efforts.
The first asteroid, 2011 UL21 , was discovered just 13 days before its closest approach on June 27. Interestingly, this nearly mile-wide (1.5-kilometre-wide) space rock wasn't alone – radar observations revealed it has a small moon orbiting it. While classified as "potentially hazardous," calculations show this asteroid won't hit Earth anytime soon.
Asteroid 2011 UL21 with moonlet (Image: NASA/JPL-Caltech)
Using Radar to Reveal Secrets
NASA's Jet Propulsion Laboratory used powerful radar technology to analyse 2011 UL21. They bounced radio waves off the asteroid, revealing it to be roughly spherical. Even more surprising, the radar data confirmed the presence of a tiny moonlet circling the asteroid at a distance of about 1.9 miles (3 kilometres).
A Closer Look at Another Space Rock
Two days later, on June 29, another asteroid, 2024 MK , made its closest approach, skimming by Earth at a distance of only 184,000 miles (295,000 kilometres) – closer than the Moon! This 500-foot-wide asteroid appears more elongated and rugged, with flat and rounded areas on its surface.
Scientists again used radar to get a closer look at 2024 MK. This time, they employed a special technique where they transmitted radio waves from one antenna and received the reflected signal with a different one. This resulted in a detailed image of the asteroid's surface, revealing depressions, ridges, and even boulders as large as 30 feet across.
Importance of Planetary Defence
While these recent flybys posed no danger, they highlight the importance of planetary defence. By studying asteroids with advanced radar technology, scientists can gather crucial information about their size, shape, composition, and orbit. This data helps us prepare for potential future encounters with near-Earth objects. So, while these space rocks might seem like distant visitors, NASA is keeping a watchful eye, ensuring our cosmic neighbourhood remains a safe place.
