The interstellar 3I/ATLAS comet, spotted in July, is significantly larger than initial estimates. The object, which is now shedding dust and gas, is traveling toward Earth from outside our solar system.
Updated Estimates of 3I/ATLAS Comet Size
New measurements indicate the comet’s nucleus is more massive than previously estimated. Its span is at least 3.1 miles across, with a weight of more than 33 billion tons.
The object is shedding huge amounts of carbon dioxide and dust as it gets closer to the Sun. This “outgassing” has caused a “non-gravitational acceleration” in its movement, suggesting a heavier mass than early models assumed.
Third Interstellar Visitor Follows Oumuamua
The 3I/ATLAS comet is the third interstellar visitor ever detected, following Oumuamua in 2017 and 2I/Borisov in 2019. It is significantly larger than its predecessors.
Oumuamua was about a quarter-mile long, and 2I/Borisov was approximately 0.6 miles across. According to astrophysicist Avi Loeb, the new object is much more massive. “[This makes 3I/ATLAS three to five orders of magnitude more massive than the previous two interstellar objects we’ve observed,]” Loeb stated.
Loeb’s Alien Artifact Theory for the 3I/ATLAS Comet
Avi Loeb has claimed the comet could be an artifact of alien technology rather than a purely natural body. This echoes his previous controversial claims about the interstellar visitor Oumuamua.
Loeb cautions against making early judgments based on the object’s surface composition. “[We should not decide about the nature of 3I/ATLAS based on the chemical composition of its skin,]” he said, adding, “[For the same reason, we should not judge a book by its cover.]“
Proposed NASA HiRISE Camera Observation
The comet will pass within 1.67 million miles of Mars’ orbit next week. It will also pass close to the orbits of Jupiter and Venus.
Loeb has urged NASA to use the HiRISE camera on its Mars Reconnaissance Orbiter to observe the object. He suggests a single bright pixel could help scientists fine-tune estimates of its true dimensions.
