Astronomers have discovered that an interstellar comet, designated 3I/ATLAS, is significantly larger than previously estimated. Harvard astrophysicist Avi Loeb reported on Thursday that the comet likely weighs over 33 billion tons. This assessment was made after analyzing the object's trajectory and comparing its mass loss rate and outflow speed using data from the Webb Space Telescope, collected on August 6.

Loeb indicated that the nucleus of the comet is likely more than 3.1 miles in diameter, making it larger than two other known interstellar objects. He noted that the comet is primarily composed of carbon dioxide, as evidenced by the detection of carbon dioxide gas in its coma, which is the comet's extended gaseous atmosphere, along with water ice in its nucleus.

3I/ATLAS was first identified in July through data from the Asteroid Terrestrial-impact Last Alert System (ATLAS), an asteroid impact warning system based in Rio Hurtado, Chile, and funded by NASA. The comet is traveling through the solar system after originating from interstellar space, approaching from the direction of the constellation Sagittarius.

Astronomers have confirmed that the comet poses no threat to Earth. However, its unusual trajectory will bring it close to several planets, including Jupiter, Mars, and Venus. Loeb mentioned that 3I/ATLAS is expected to come within approximately 1.67 million miles of Mars' orbit on October 3.

This event marks only the third time in history that an interstellar object has been recorded entering the inner solar system. The first was the cigar-shaped object known as "Oumuamua," detected in 2017, followed by the comet "21/Borisov" in 2019, which is believed to have originated from another star system.

After September, 3I/ATLAS will pass too close to the sun to be visible. However, it is anticipated to reappear on the other side of the sun in early December. Loeb's findings were published in a paper on Wednesday, which has not yet undergone peer review.