A Mysterious New Visitor Has Entered Our Solar System—Here's What Astronomers Know So Far

For only the third time in recorded history, an interstellar object has crossed into our solar system, creating quite the buzz in the space community. 

A comet named 3I/ATLAS was discovered by a NASA-funded survey telescope in Rio Hurtado, Chile, on July 1, 2025. This telescope is one of four worldwide in the Asteroid Terrestrial-impact Last Alert System (ATLAS), which probes the sky for moving objects that could threaten our planet. So, what makes this cosmic object stand out from other discoveries in the past? Here’s what you need to know about this fantastic find.

Don't Miss

July's Full Buck Moon Will Share the Sky With Mars and Saturn—Here's How to See the Celestial Phenomenon

The Earth Is Spinning Faster—Here’s Why July and August Will Have Record-Short Days

Identifying and Naming the Comet

According to the National Aeronautics and Space Administration (NASA), 3I/ATLAS is considered a comet versus an asteroid because astronomers can see that it has an icy nucleus and coma, a cloud of gas and dust surrounding a comet as it approaches the sun. The comet's size and physical properties are currently being investigated by astronomers nationwide.

Comets are typically named after who discovers them, in this case the ATLAS survey term. The first part of its name—3I—helps identify the comet. In this case, the "I" represents it being interstellar (meaning not originating in our solar system) and the "3" for it being the third of its kind discovered.

Determining 3I/ATLAS's Origin

Astronomers were able to make some important observations about 3I/ATLAS since its discovery. The comet is making excellent time on its travels, clocking a speed of nearly 137,000 miles per hour when it was discovered. After carefully studying the comet’s movement, both past and present, astronomers were able to determine the comet does not follow a closed orbital path around the sun, allowing them to conclude that the object is interstellar. Per NASA, 3I/ATLAS formed in another star system and was somehow ejected into interstellar space. The comet drifted for millions or billions of years until entering our solar system.

Possibility of Collision

Thankfully, there isn't a chance of the comet colliding with Earth. According to NASA, although it might be on a path to enter the inner part of our solar system, it won’t be close enough to pose any danger to our planet. At its closest point, 3I/ATLAS will be roughly 150 million miles away from Earth. According to Space.com, even the sun and Mars will be far enough away from any sort of impact.

Seeing the Comet Is Difficult

Seeing 3I/ATLAS will be difficult. Per Space.com, the comet is currently hanging out where the Milky Way curves by the Sagittarius constellation. Because of its location and magnitude in the sky, it’s roughly 2.5 million times dimmer than the Northern Star. This makes it tough to spot without the help of a powerful telescope and camera.

However, NASA reports that astronomers are currently studying the comet through ground-based telescopes, and should be able to collect more information through September (including pictures). The comet will be tough to capture as it nears the sun, but observations will resume again when it emerges on the other side, likely in early December.