New Interstellar Comet 3I/ATLAS Speeds Through Solar System

A newly confirmed interstellar comet is making a rare passage through our solar system — and skywatchers can catch it live online tonight. The object, now called 3I/ATLAS, is just the third interstellar visitor ever detected after the well-known ‘Oumuamua (2017) and 2I/Borisov (2019). The comet was so fresh when first detected on July 1 by the ATLAS telescope in Chile that it hadn't even been given a name yet; the Minor Planet Center has it listed as “3I,” the “I” standing for interstellar. Tonight's webcast will kick off at 6 p.m. EDT (2200 GMT) from the Virtual Telescope Project's virtual observing facilities in Italy.

Interstellar Comet 3I/ATLAS Speeds Toward Sun at 68 km/s, Offers Rare Study Opportunity

As per a report by Space.com, 3I/ATLAS was detected as a faint object displaying subtle cometary features, including a marginal coma and a short tail. Currently located 4.5 astronomical units (AU) from the sun — about 670 million kilometers (416 million miles) — the comet is faint at magnitude 18.8, making it invisible to amateur telescopes. The interstellar object is traveling at an astonishing pace of 68 kilometers per second (152,000 mph) relative to the sun, but NASA officials say it poses no danger to Earth.

It was imaged by the Virtual Telescope Project on July 2, showing the comet as a point of light within the trailing background stars — a sure indication that it is indeed moving through space. 3I/ATLAS should brighten a little as it approaches the sun, particularly when it gets closest, or its perihelion, on Oct. 30, when it swings within 1.4 astronomical units of the sun or Mars' orbit.

The close pass by this interstellar visitor is a rare chance for astronomers to study the materials and dynamics outside our solar system. 3I/ATLAS, which is racing along at a frenetic pace on an elliptical orbit, may also support research into how these objects change as they sit in different stellar environments.

After disappearing behind the sun in late fall, 3I/ATLAS is projected to return to observational reach in early December. Researchers anticipate further analysis then, expanding our understanding of these rare visitors that traverse the galaxy — and occasionally, pass through our celestial neighborhood.