COBS News archive
Interstellar comet 3I/ATLAS is spraying water across the solar system
For millions of years, a frozen wanderer drifted between the stars before slipping into our solar system as 3I/ATLAS—only the third known interstellar comet ever spotted. When scientists turned NASA’s Swift Observatory toward it, they caught the first-ever hint of water from such an object, detected through a faint ultraviolet glow of hydroxyl gas. Even more surprising, the comet was blasting out water at a rate of about 40 kilograms per second while still far from the Sun—much farther than where most comets “switch on.”
New ICQ Observation Method Keys for Sloan u′g′r′i′z′ CCD Photometry
Did an exploding comet wipe out the mammoths?
Scientists are uncovering new clues that a cosmic explosion may have rocked Earth at the end of the last ice age. At major Clovis-era sites, researchers found shocked quartz—evidence of intense heat and pressure consistent with a comet airburst rather than volcanism or human activity. The event could have sparked massive fires, blocked sunlight, and triggered a rapid return to ice-age conditions. These harsh changes may explain the sudden loss of megafauna and the disappearance of the Clovis culture.
NASA just caught a rare glimpse of an interstellar comet
An instrument aboard NASA’s Europa Clipper spacecraft captured rare ultraviolet observations of an interstellar comet while Earth-based telescopes were blinded by the Sun. The spacecraft’s unique position provided an unprecedented look at the comet’s dust and plasma tails from an unusual angle. Scientists detected hydrogen, oxygen, and signs of intense gas release, hinting at powerful activity after the comet’s closest approach to the Sun. The findings may reveal clues about how comets form around other stars.
The Non-Gravitational Acceleration of 3I/ATLAS
XMM-Newton sees comet 3I/ATLAS in X-ray light
The European Space Agency’s X-ray space observatory XMM-Newton observed interstellar comet 3I/ATLAS on 3 December for around 20 hours. During that time, the comet was about 282–285 million km from the spacecraft.
Comet 3I/ATLAS shows activity in Juice navigation camera teaser
During November 2025, ESA’s Jupiter Icy Moons Explorer (Juice) used five of its science instruments to observe 3I/ATLAS. The instruments collected information about how the comet is behaving and what it is made of.
ESA pinpoints 3I/ATLAS’s path with data from Mars
Since comet 3I/ATLAS, the third known interstellar object, was discovered on 1 July 2025, astronomers worldwide have worked to predict its trajectory. ESA has now improved the comet’s predicted location by a factor of 10, thanks to the innovative use of observation data from our ExoMars Trace Gas Orbiter (TGO) spacecraft orbiting Mars.
Comet 3I/ATLAS has sprouted an unusual tail
An interstellar visitor lights up the Red Planet’s sky
ESA’s Mars orbiters have observed comet 3I/ATLAS, only the third interstellar comet ever discovered. The faint, distant object revealed a glowing coma as it was heated by the Sun. Researchers are still studying the data to understand its makeup and origins. This rare event also foreshadows future missions like the Comet Interceptor, designed to chase such elusive visitors.
ESA’s Mars and Jupiter missions observe comet 3I/ATLAS
Comet 3I/ATLAS was first spotted on 1 July 2025 by an Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile.
Since then, Earth has been moving away from 3I/ATLAS as it approaches the Sun. The comet is now on the other side of the Sun, making it impossible to observe from Earth.
ESA is making the most of its interplanetary missions to observe the comet from much better vantage points.
Where do 3I/ATLAS and other interstellar visitors come from?
Bright Comet suprise
Interstellar Comet imaged during Lunar eclipse
On Sept 7th, darkness fell across the Kalahari Desert as Earth's shadow enveloped the full Moon. It was a total lunar eclipse--and the perfect time to photograph an interstellar comet. "We took advantage of the total lunar eclipse to take a deep image of Comet 3I/ATLAS under the dark skies of Namibia," says amateur astronomers Michael Jäger and Gerald Rhemann. Here is what they saw.
NASA’s Webb Space Telescope Reveals Secrets of Interstellar Comet 3I/ATLAS
Our solar system has a new interstellar visitor: Meet 3I/ATLAS
Is 3I/ATLAS really a Comet?
The most intriguing mystery in astronomy today is the nature of interstellar object 3I/ATLAS. Most astronomers believe it is a comet. However, iconoclast Avi Loeb of Harvard University makes the case that it might be something else--like alien tech.
Hubble just snapped the clearest-ever picture of a rare interstellar comet
This interstellar comet may be a frozen relic from before the Sun
A newly discovered comet, 3I/ATLAS, may be the most ancient visitor ever detected, potentially older than our solar system itself. Unlike previous interstellar objects, this ice-rich comet seems to originate from the thick disk of the Milky Way, a region filled with ancient stars. First spotted in July 2025, it’s already showing signs of activity and could help scientists understand more about galactic chemistry and the origins of planetary systems.
Tycho Tracker: A comperhensive all‐in‐one tool for Comet photometry
In the latest issue of The Comet's Tail, the British Astronomical Association (BAA) highlights "Tycho Tracker: A Comprehensive All-in-One Tool for Comet Photometry," an article detailing a significant advancement in comet observation technology. Tycho Tracker emerges as a powerful software solution, streamlining the process of comet photometry for both amateur and professional astronomers.
More in recent issue of The Comet's Tale: https://britastro.org/wp-content/uploads/2015/11/tail43.pdf