All posts tagged: planetary defense

‘God of chaos’ asteroid Apophis will pass very close to Earth in 2029

‘God of chaos’ asteroid Apophis will pass very close to Earth in 2029

For a brief stretch on April 13, 2029, a giant space rock will slip closer to Earth than some of the satellites parked high above the planet. That object is Apophis, an asteroid once treated as a serious threat. Now it is viewed as one of the most unusual scientific opportunities in modern astronomy. Apophis is not headed for impact. That part is settled. But the asteroid’s close flyby is still extraordinary because of what Earth itself may do to it on the way past. The asteroid, officially known as 99942 Apophis, is expected to pass about 20,000 miles, or 32,000 kilometers, above Earth’s surface. At roughly 375 meters across on average, it is large enough to command attention and close enough to become visible to the naked eye in parts of Europe, Africa, and Asia, weather permitting. In fact, space agencies say it will be the closest approach of an asteroid this size that scientists have known about in advance. That makes the 2029 event more than a sky show. It turns Earth into …

NASA DART Mission data reshapes understanding of how near-Earth asteroids evolve over time

NASA DART Mission data reshapes understanding of how near-Earth asteroids evolve over time

Bright streaks on a small asteroid moon looked, at first, like a camera problem. They were faint, fan-shaped, and easy to miss in the final images NASA’s DART spacecraft took before it slammed into Dimorphos in 2022. However, after months of image cleanup and modeling, astronomers concluded the marks were real. They now say the streaks are the first direct visual evidence that one asteroid in a binary system can shed material that lands on its companion. The finding, published in The Planetary Science Journal, points to a surprisingly active relationship between the near-Earth asteroid Didymos and its moon, Dimorphos. Rather than acting like two isolated rocks in space, the pair appears to exchange debris in slow, gentle impacts. These impacts leave visible traces on the surface. “At first, we thought something was wrong with the camera, and then we thought it could’ve been something wrong with our image processing,” said lead author Jessica Sunshine, a professor with joint appointments in the Department of Astronomy and Department of Geological, Environmental, and Planetary Sciences at the …

Asteroid 2024 YR4 once feared to strike the Moon now appears harmless

Asteroid 2024 YR4 once feared to strike the Moon now appears harmless

Initially, much uncertainty surrounded the flight path of the space rock known as 2024 YR4, a small asteroid that has recently become an object of much scientific attention. 2024 YR4, measuring between 174 and 220 feet, was once thought likely to collide with Earth’s Moon in December 2032. Early estimates showed around a 4.3% chance of impact. However, through consideration of new observations made with the James Webb Space Telescope (JWST), scientists have since eliminated this potential collision. The JWST’s measurements show that the asteroid will safely fly by the Moon in December 2032, missing by approximately 13,200 miles (or about 21,200 km). Using two sets of data taken by the JWST’s Near-Infrared Camera (NIRCam) on February 18, 2026, and February 26, 2026, scientists from NASA’s Center for Near-Earth Object Studies at the Jet Propulsion Laboratory were able to refine the asteroid’s trajectory and eliminate the possibility of impact with either the Moon or Earth. The asteroid will pass by the Moon without impacting it on 22 December 2032. Animation of asteroid 2024 YR4’s potential …