Puzzling Near-Earth Asteroid Turns Out to Be Comet with Weak Tail
Follow-up telescope images showed a weak tail and led researchers to give the object a provisional comet designation, Nature Astronomy said.
- Astronomers reclassified a near-Earth object tracked for 28 years as an asteroid, revealing it is actually a comet in a study published July 10 in Nature Astronomy, earning the designation P/1998 SH2.
- During a close pass within 2 million miles of Earth on August 28, 2025, NASA's radar system failed to locate 1998 SH2 at its predicted position, with the object sitting 153 arcseconds from gravity-only predictions.
- Navigation engineer Davide Farnocchia's team measured nongravitational acceleration of about 1.4 hundred-billionths of a meter per second squared, consistent with gas jets escaping from the surface. At 380 meters across, 1998 SH2 is the smallest comet ever observed by radar.
- Astronomer Olivier Hainaut of the European Southern Observatory stated images from telescopes in Hawaii and Chile showed a weak but clear tail on September 17 and September 30, confirming 1998 SH2 is indeed a comet.
- Understanding these objects matters for planetary defense because comets and asteroids respond differently to deflection attempts like NASA's DART mission. As of late 2025, 285 of the 2,009 known near-Earth asteroids on comet-like orbits are classified as potentially hazardous.
12 Articles
12 Articles
A near-Earth asteroid tracked since 1998 turned up far from its predicted spot in the sky, and astronomers have now confirmed why — it is secretly a comet, nudged off its path by escaping gas, with a tail too faint for ordinary telescopes to see
The radar team at NASA’s Goldstone complex knew exactly where to point. Their target, a near-Earth object called 1998 SH2, had been discovered in 1998 and tracked until 2016, and in late August 2025 it was passing within 0.02 astronomical units of Earth, about 3 million kilometers. The 70-meter antenna swept the predicted position, and the echo never came back. The reason, published this month in Nature Astronomy, is that 1998 SH2 is not the ast…
After nearly 30 years, NASA realized this near-Earth asteroid is actually a comet. The discovery may help us defend the planet some day
A near-Earth object that astronomers believed was an asteroid for nearly three decades has been unmasked as a faint, active comet, revealing a case of cosmic mistaken identity that could help improve planetary defense.The object, known since its discovery in 1998 as 1998 SH2, appeared to be an ordinary asteroid. It follows a 4.5-year orbit around the sun and showed no obvious signs of cometary activity, such as the glowing coma or tail produced …
Puzzling Near-Earth Asteroid Turns Out to Be Comet with Weak Tail
The near-Earth object (875163) 1998 SH2, which is currently classified as an asteroid, has revealed a hidden identity: it’s actually a comet in disguise, according to a new study published in the journal Nature Astronomy. The post Puzzling Near-Earth Asteroid Turns Out to Be Comet with Weak Tail appeared first on Sci.News: Breaking Science News.
Coverage Details
Bias Distribution
- 67% of the sources are Center
Factuality
To view factuality data please Upgrade to Premium
