Interstellar comet 3I/ATLAS makes closest pass of Earth. Where’s it heading next?
Comet 3I/ATLAS passed Earth last night as astronomers around the world continue to collect data on the interstellar visitor.
The comet made its closest approach around 1 a.m. ET on Friday, December 19, finding itself approximately 168 million miles (270 million kilometers) from our planet.
Comet 3I/ATLAS is up to a few kilometers wide and did not come close enough to be visible to the naked eye. However, sky observers observed it using telescopes.
And last night was far from our last chance to see the comet. It will remain observable in the pre-dawn sky with a small telescope until spring, according to NASA. If you don’t have a telescope, then the best way to see comet 3I/ATLAS is online.
THE Virtual Telescope Project in Italy, is hosting a live broadcast of the comet passing by Earth on Friday at 11 p.m. EST. The live broadcast, scheduled for last night but postponed due to rain, will feature real-time images of the comet as it zooms toward Jupiter.
Comet 3I/ATLAS is worth a look because it is a rare example of an interstellar object originating from outside our solar system. This is only the third interstellar visitor ever detected and could be the the oldest comet ever seen.
The origins of the comet have been the subject of much speculation, including repeated suggestions that it could be a alien spaceship. However, almost all astronomers are convinced that 3I/ATLAS is a comet of another star system.
Researchers discovered Comet 3I/ATLAS in July, when they spotted an unknown object traveling at about 140,000 mph in Jupiter’s orbit. After passing the sun, reach the closest point to our star (perihelion) at the end of October, the comet is leaving our solar system.
After receiving daily requests for literally months, I’m happy to share 3i/Atlas with you. The “Alien” comet, captured entirely with my own equipment. What do I think about it? I will share my observations in the answers. pic.twitter.com/XfPDhosoJNDecember 17, 2025
What’s next for Comet 3I/ATLAS?
Comet 3I/ATLAS will then pass Jupiter, where it is expected to make its closest approach on March 15, 2026, according to NASA. The comet will come much closer to Jupiter than Earth, being approximately 54 million kilometers from the gas giant. Spaceship parked at Jupiter, like Junomay be able to observe the comet as it approaches.
The interstellar intruder will then cross Saturn’s orbit in July 2026; The orbit of Uranus in April 2027; and Neptune’s orbit in March 2028. However, it will not come close to any of these planets. You can track Comet 3I/ATLAS yourself using NASA tools. Eyes on the solar system simulation of the comet’s trajectory.
Researchers will keep an eye on Comet 3I/ATLAS as long as it remains in our cosmic neighborhood. After all, there is still a lot they don’t know about its properties. For example, the size of the comet is uncertain. Hubble Space Telescope Observations suggest it is between 1,440 feet (440 meters) and 3.5 miles (5.6 km) wide.
Researchers also don’t know which star system made comet 3I/ATLAS, and they may never know. The comet traveled a very long way and could have traveled through space for billions of years before visiting our solar system.
