Interstellar Comet 3I/ATLAS Nears Earth on Dec. 19, Offering Rare Insights Into Cosmic Visitors

The interstellar comet 3I/ATLAS will pass by Earth on Friday, Dec. 19, providing astronomers a rare opportunity to study one of the smallest and most alien visitors to our own solar system. Detected on July 1 by NASA-funded ATLAS telescopes in Chile, the comet is just the third to make a confirmed visit from interstellar space following 1I/‘Oumuamua in 2017 and 2I/Borisov, which was discovered last year. Its path indicates that it came from interstellar space and will eventually travel back out into interstellar space, passing safely by our sun no closer than about 1.8 astronomical units (AU), or 168 million miles (270 million kilometres), not much farther away than the orbit of Mars.

Comet 3I/ATLAS Flyby Offers Rare Opportunity to Study Cosmic Dust and Gases

According to a European Space Agency report, 3I/ATLAS poses no threat to Earth or other planets, but its passing gives scientists an opportunity to observe the dust and gases emitted by one of these objects' icy nuclei when it warms in the sun. Scientists mention that studying those materials will offer important clues about how comets and planetary material develop around other stars, broadening our understanding of cosmic chemistry.

In recent times, observatories such as Hubble or JUICE have been checking the comet in order to get images of its faint tail and measure what it is made of, to help plan observations.
Watch Comet 3I/ATLAS Close Approach Live: Virtual Telescope Stream Offers Global Access and Scientific Insights

3I/ATLAS can be observed online by amateur astronomers at 11 p.m. EST on Dec. 18 using Gianluca Masi's Virtual Telescope livestream, where it will have a brief flyby of Earth.

Astronomers state that watching 3I/ATLAS is something of a unique show from space so far away, it offers special interstellar data that will help improve trajectory models and to understand the materials molding planets beyond our solar system.