3.07.2025
CAPE CANAVERAL, Fla.— Astronomers are monitoring an object headed our way that may have wandered over from another star system.
Scientists have discovered what might be only the third known interstellar object to pass through our solar system, the European Space Agency said Wednesday.
The harmless object is currently near Jupiter hundreds of millions of miles (kilometers) away and moving toward Mars, but it should get no closer to the sun than that, according to scientists.
It’s too soon to know whether the object, designated for now as A11pl3Z, is a rocky asteroid or a icy comet, or how big and what shape it is. More observations are needed to confirm its origins. NASA said it is monitoring the situation.
Astrophysicist Josep Trigo-Rodriguez of the Institute of Space Sciences near Barcelona, Spain, believes it is an interstellar object based on its odd path and extreme speed cutting through the solar system. He estimates its size at roughly 25 miles (40 kilometers) across.
The first confirmed interstellar visitor was in 2017. It was dubbed Oumuamua, Hawaiian for scout, in honor of the observatory in Hawaii that discovered it. Classified at first as an asteroid, the elongated Oumuamua has since showed signs of being a comet.
NASA Discovers Interstellar Comet Moving Through Solar System
On July 1, the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey telescope in Rio Hurtado, Chile, first reported observations of a comet that originated from interstellar space. Arriving from the direction of the constellation Sagittarius, the interstellar comet has been officially named 3I/ATLAS. It is currently located about 420 million miles (670 million kilometers) away.
Since that first report, observations from before the discovery have been gathered from the archives of three different ATLAS telescopes around the world and the Zwicky Transient Facility at the Palomar Observatory in San Diego County, California. These “pre-discovery” observations extend back to June 14. Numerous telescopes have reported additional observations since the object was first reported.
The comet poses no threat to Earth and will remain at a distance of at least 1.6 astronomical units (about 150 million miles or 240 million km). It is currently about 4.5 au (about 416 million miles or 670 million km) from the Sun. 3I/ATLAS will reach its closest approach to the Sun around Oct. 30, at a distance of 1.4 au (about 130 million miles or 210 million km) — just inside the orbit of Mars.
The interstellar comet’s size and physical properties are being investigated by astronomers around the world. 3I/ATLAS should remain visible to ground-based telescopes through September, after which it will pass too close to the Sun to observe. It is expected to reappear on the other side of the Sun by early December, allowing for renewed observations.
Quelle: NASA