Particle.news
Download on the App Store
4 ARTICLES
·
6d ago

EarthSky Names 2025’s Top Stories, Led by Interstellar Comet 3I/ATLAS

The roundup spotlights discoveries that defined a year of skywatching.

This cosmic image of two nebulas shows a bright pink splotch in the middle and lots of points of light speckling the whole scene.
Composite of the first four images in this list.
Image
View larger. | The Hubble Space Telescope captured this image of interstellar object 3I/ATLAS on July 21, 2025. It was the sharpest image yet of the object, acquired when the object was 277 million miles (446 million km) from Earth. This object is now generally believed to be a comet by most astronomers. In this image, a comet-like, teardrop-shaped cocoon of dust can be seen coming off its solid, presumably icy nucleus. Image via NASA/ ESA/ D. Jewitt (UCLA); Image Processing: J. DePasquale (STScI).

Overview

  • Interstellar Comet 3I/ATLAS tops the list after a July discovery, with perihelion on October 29 and closest approach to Earth on December 19 at an estimated 130,000 miles per hour.
  • An expert tally estimates one to two Starlink satellites are reentering daily, highlighting the growing cadence of spacecraft coming down.
  • A meteorite that fell in July 2024 on Prince Edward Island was confirmed in January as the first known event captured with both impact audio and video.
  • Observations raised asteroid 2024 YR4’s chance of striking the moon to 4.3% for December 22, 2032, with NASA noting the moon’s orbit would not be altered if it occurred.
  • A newly identified quasi-moon, 2025 PN7, was found to share Earth’s orbit and is expected to remain in this configuration for roughly another 60 years.