Interstellar Comet 3i / Atlas will be observed by the Mars and Jupiter probes as it passes in front of the sun this month
The European Space Agency uses space vessels designed for the missions of Mars and Jupiter to follow the interstellar comet 3i / Atlas while it continues its trip through our solar system.
Spotted for the first time in July 2025 by an atlas telescope (asteroid of the last terrestrial impact alert system) in Chile, 3i / Atlas has become the third interstellar object known to go through our solar system. Astronomers have identified its extrasolar origin because of its unusual trajectory, which does not follow an orbit closed around the sun and a speed of around 130,000 MPH (219,000 km / h). Astronomers noted that 3i / Atlas would remain visible for ground telescopes until September 2025, before its path transported it too close to the sun – And finally behind the point of view of the earth.
This brief window complicates efforts to study the size, composition and surface activity of the comet, clues that could shed light on what these interstellar objects are made and if they resemble comets born in ours solar system. However, scientists take the opportunity to look at the comet in real time beyond the earth using a fleet of planetary missions of ESA and NASA in orbit around the inner solar system. From their point of view on the side oriented side of the sun of the comet’s trajectory, these spaceships will be able to continue to observe 3i / Atlas even after it slips out of the earth.
“Between October 1 and 7, our orbiters Mars Express and Exomars Trace Gas Orbiter will observe the comet when she goes near Mars, with the nearest distance between the spacecraft and the comet being 30 million kilometers on October 3,” wrote in a spacecraft statement. The mission of Psyche de la Nasa, currently on the way to the asteroid psyche 16 located in the Main asteroid belt Between Mars and Jupiter, will also see an overview.
Between November 2 and 25, Jupiter Icy Moons Explorer d’ESA (Juice) will turn her instruments around 3i / Atlas. Juice’s observations will start just after 3i / Atlas reaches the perihelion – its approach closest to the sun. This moment is crucial because the heat of the sun leads the comet in its most active phase, spraying and flowing its ice in space.
“Juice will be the best position for the important period around the Périhelion 3i / Atlas, when the observations of the earth will be the most difficult,” said T. Marshall Eubanks, chief scientist at Space Initiatives Inc in A previous interview with Space.com. “Various orbit spaceships Mars recognition orbiter (Mro), Tianwen-1, and Hope, all have both the point of view and good equipment to provide good data on 3i / Atlas. [However,] Of all these elements, I think that juice data close to the periHelion are probably the most critical. “”
The ESA notes that the observation of the comet during this period will produce the most precious data, revealing its true chemical makeup and its activity at the maximum intensity. Indeed, it will be close enough to the sun that the solar radiation will heat the ice in the heart of the comet, spray it and make it burst from the surface of the comet. The core of the comet will be surrounded by a luminous halo of gas and dust, with a long tail flowing behind. This window will allow astronomers to measure the complete composition of the comet through the released gases and dust, offering a 3i / atlas chemical footprint.
For an interstellar visitor like 3i / Atlas, this is particularly exciting because it will allow scientists to compare their composition with the comets formed in our own solar system. If chemistry corresponds, it suggests that planetary systems through the galaxy can share common construction blocks; If not, it could reveal exotic ingredients from another star system.
Be that as it may, the observation of 3i / Atlas in this active phase will give some of the clearest ideas on the mystery of interstellar comets.
