NASA's Jet Propulsion Laboratory (JPL) in Southern California recently captured high-resolution images of two asteroids passing near Earth, providing crucial insights for planetary defense efforts. One of these asteroids, discovered just 13 days before its closest approach, revealed a smaller moon orbiting it, highlighting the complexity of these celestial bodies. The first asteroid, named 2011 UL21, was detected by the NASA-funded Catalina Sky Survey back in 2011. It passed Earth safely at a distance of 4.1 million miles (6.6 million kilometers), approximately 17 times farther than the Moon. Despite its classification as potentially hazardous, calculations confirm it poses no threat to Earth in the foreseeable future. Using the Goldstone Solar System Radar, scientists transmitted radio waves to 2011 UL21, revealing its spherical shape and the presence of a moonlet orbiting it from a distance of about 1.9 miles (3 kilometers). On June 29, NASA observed asteroid 2024 MK passing even closer, at a distance of 184,000 miles (295,000 kilometers), slightly more than three-quarters of the distance between the Earth and the Moon. This asteroid, measuring approximately 500 feet (150 meters) wide, exhibited an elongated and angular shape with distinct surface features like concavities, ridges, and large boulders up to 30 feet (10 meters) wide. Radar images captured by the Goldstone Solar System Radar provided detailed views of these surface characteristics. NASA emphasized that while these asteroids posed no danger to Earth, the radar observations during their close approaches are invaluable for refining planetary defense strategies. These observations yield crucial data on asteroid sizes, orbits, rotation, surface details, and clues to their composition and formation, enhancing our understanding of these cosmic objects. Radar observations like those conducted by the Goldstone Solar System Radar are essential for planetary defense efforts, offering scientists vital information to assess and potentially mitigate the risks posed by near-Earth objects (NEOs). These efforts underscore NASA's commitment to advancing our knowledge of asteroids and safeguarding Earth from potential impacts. Read More: Celebrating World Asteroid Day: How World Asteroid Day Benefits People Explore the Cosmos: NASA's New 3D Video of the Pillars of Creation NASA Extends Stay for Boeing Starliner Crew on ISS Amid Technical Delays NASA Astronaut Sunita Williams Stranded in Space with Limited Food Supply