Could “comet”3I/ATLAS be a piece of alien technology? A question that might sound straight out of a sci-fi movie is now being brought to the front of the space table by Abraham (Avi) Loeb the Baird Professor of Science and Institute director at Harvard University.
Interstellar comet 3I/ATLAS, first observed by the ATLAS survey in Chile on July 1, 2025, is the third confirmed object of its kind to enter the solar system. Analysis of its hyperbolic trajectory and inbound velocity of ~58 km/s confirms its extrasolar origin, while kinematic modeling suggests it formed in the Milky Way’s ancient thick disk, offering a rare opportunity to study early galactic comet chemistry.
A large asteroid designated 2008 DG5 will fly past Earth at a distance of 9.1 LD (0.023 AU; 3.4 million km / 2.1 million miles) at 23:57 UTC on June 5, 2025. This will be the closest approach of this asteroid between 1956 and 2125.
Newly-discovered Comet SWAN25F is rapidly brightening and may become visible to the naked eye by late April 2025. Its green coma and long tail are currently visible through telescopes.
Two studies published in Nature Communications explore and provide insights into efficient planetary defense strategies. These studies came out during the period when 2024 YR4 made headlines with its potential for impact in 2032. The results provide valuable insights into how to create better planetary defense procedures based on the behavior of asteroid Dimorphos ejecta produced by NASA’s Double Asteroid Redirection Test (DART) mission.
A rare lunar-origin asteroid, 2024 PT5, has been identified by astronomers, suggesting that high-energy impacts on the Moon may have ejected material into near-Earth space thousands of years ago.
Comet C/2024 G3 (Atlas), which made its closest approach to Earth on January 14, 2025, and reached perihelion a day later, is creating spectacular photographic opportunities as it brightens in the night sky. Astronomers and skywatchers in the Southern Hemisphere have reported a visible coma and an extended tail, making it one of the most striking comets of recent years.
Comet ATLAS (C/2024 G3) is rapidly approaching the Sun, with its perihelion expected at 10:15 UTC on January 13, 2025, promising a dazzling spectacle as it brightens to a potential magnitude of -5, twice as bright as Venus. The comet has entered the ESA/NASA LASCO C3 field of view at around 07:00 UTC today.
A large asteroid designated 2020 XR flew past Earth at a safe distance of 5.7 LD / 0.01477 AU (2.2 million km / 1.3 million miles) at 05:26 UTC on December 4, 2024 — exactly 4 years after its discovery. This is the closest approach of 2020 XR to planet Earth at least until December 2157.
A newly-discovered asteroid currently designated COWEPC5 is expected to impact Earth’s atmosphere over Siberia, Russia at around 16:15 UTC (08:15 PST) on December 3, 2024. This is the 11th predicted Earth impactor on record – and the 4th so far this year.
