Comet 3I/ATLAS is just the third object that we know of that has been observed to pass through our solar system from interstellar space; hence, it is a rare and scientifically significant finding.Simply put, the comet didn’t form with the rest of the solar system, but it is an icy one that came from a different star system and has probably spent millions, if not billions, of years going wherever in the vast space before finally arriving at our place.3I ATLAS was discovered in July 2025, and it sparked immense worldwide interest regarding its speed, trajectory, and the composition of the object, providing an entirely new perspective on the birth and evolution of other solar systems.Experts have made it clear that the freezing visitor is not dangerous to the Earth; however, its short stay is a priceless moment to take samples of the region beyond our solar system and, subsequently, get a step closer to the extent of the Milky Way.
What is comet 3I/ATLAS
Comet 3I/ATLAS is an interstellar comet, which means it is not from our solar system. It is only the third one to be found in the entire universe. After Oumuamua in 2017 and 2I Borisov in 2019, it was the next. To begin with, astronomers gave it a cometary nature as the object consists of an icy nucleus and has a visible coma, which is the emission of a gas and dust cloud produced as the object gets heated near the Sun.Its ornaments, colours, and activities are all very similar to what scientists predict for comets, although they were made in a different stellar system.
3I/ATLAS: Discovery and naming
1 July 2025 saw the discovery of a comet by the ATLAS survey telescope, a project funded by NASA in Rio Hurtado, Chile. The finding was communicated to the Minor Planet Center, the agency that keeps a record of new objects found in space.The name 3I ATLAS is a way of showing how important the object is. The digit three denotes the third interstellar object ever to be found, the letter ‘I’ means ‘interstellar’, and ATLAS is the name of the telescope system that made the discovery. ATLAS is one of the instruments in NASA’s planetary defense network whose goal is to keep a watch on the skies for objects that can cause harm to Earth.
size and physical characteristics of 3I/ATLAS
Astronomers are still uncertain about the precise size of 3I ATLAS. But the Hubble Space Telescope observations on 20 August 2025 estimate the diameter of its nucleus to be somewhere between 1,400 feet and 3.5 miles, or approximately 440 meters to 5.6 kilometers.When the comet nears the Sun, the ice on its surface melts, and gas and dust are ejected. This makes a bright coma around the nucleus, which is the visible part of the comet, and hence, it is not an asteroid.
3I/ATLAS speed and trajectory
Extreme speed is one of the main points that 3I ATLAS is a foreign object from another star system. The very first time the comet was spotted, it was going 221,000 kilometers per hour (137,000 miles per hour). Its speed was increased by gravity as it got closer to the Sun, and so at perihelion, the comet was moving at about 246,000 kilometers per hour (153,000 miles per hour).Comet is on a hyperbolic orbit, meaning that it is moving too fast to be held by the Sun’s gravity. It is a temporary guest in the solar system, and after that, it will be back to interstellar space, the way it came, with the same speed.
Where did 3I ATLAS come from?
Scientists consider 3I ATLAS as a product of a different star system, and as a result of gravitational interactions, it was thrown out into interstellar space. It has been roaming the space that lies between stars for a very long time.The comet came to our solar system from a very remote area of space, specifically the constellation Sagittarius, close to the central region of the Milky Way. It was quite far when it was spotted; it was already within the orbit of Jupiter.
Why 3I ATLAS is important
Comet 3I/ATLAS is like a once-in-a-lifetime opportunity to see the makeup of a cosmic body that originally formed around a different star. The stuff it is made of and how it behaves may be quite different from the comets that we know inside the solar system, so figuring out those differences will be a wonderful way to understand the formation of planetary systems in other parts of the galaxy.It is going to be a one-way trip to interstellar space, and it will be gone forever later this week, but the information gathered during its flyby will be immensely helpful to scientists in comprehending the variety of objects that lie beyond our Sun and in broadening our knowledge of the universe.
