The European Space Agency's (ESA) two satellites and several NASA spacecraft at and near Mars zoomed in on the comet as it passed the red planet just 29 million kilometres away last month.
NASA revealed close-up pictures of 3I/ATLAS, the interstellar comet that’s currently racing through our solar system.
The comet will eventually hightail it back into interstellar space, never to return.
A comet is a cosmic snowball of frozen gases, rock, and dust that orbits the Sun, according to NASA. However, 3I/ATLAS’s speed and trajectory show that it’s not gravitationally bound to the Sun - meaning it must have originated in another star system and wandered into ours by chance.
Researchers, therefore, have a rare opportunity to study the material from beyond our cosmic neighbourhood while it’s traversing our solar system.
“This object is a comet. It looks and behaves like a comet, and all evidence points to it being a comet,” Amit Kshatriya, NASA’s associate administrator, said in a video revealing the new images.
“But this one came from outside the solar system, which makes it fascinating, exciting, and scientifically very important. This is only the third interstellar object like this that humanity has ever found”.
The European Space Agency's (ESA) two satellites and several NASA spacecraft at and near Mars zoomed in on the comet as it passed the red planet just 29 million kilometres away last month.
Scientists at ESA also used the Juice spacecraft, bound for Jupiter, to train its cameras and scientific instruments on the comet, particularly after it made its closest pass to the sun.
However, scientists won't get any of these observations back until February because Juice's main antenna is serving as a heat shield while it's near the sun, limiting the flow of data.
A cruising visitor in our solar system
Astromers have previously confirmed 3I/ATLAS is racing through space at more than 61 kilometres per second, and its speed is increasing as it approaches the Sun.
The comet is visible from Earth in the predawn sky by using binoculars or a telescope and will come closest to the Earth at just 269 million kilometres in mid-December.
While the size and shape of the comet are still unclear, NASA says the size of the comet could be anywhere from 440 meters to 5.6 kilometres in diameter.
“We will get better on that one,” said Thomas Statler, a lead scientist for solar system small bodies in the planetary science division at NASA.
“The shape of the nucleus is also difficult to pin down because generally we're not resolving it in our observations. It's obscured by the dust, and especially it's obscured the reflected sunlight off of the dust in the inner part of the coma,” Statler added.
The space agency has previously said the comet was “no threat to life here on Earth,” in a post on X.
NASA scientists said it is likely that 3I/ATLAS came from a solar system older than our own solar system.
“The 3I/ATLAS is not just... a window into another solar system, it's a window into the deep past and so deep in the past that it predates even the formation of our earth and our sun,” Statler said.
3I/ATLAS was first captured by the ATLAS survey telescope in Chile in July, sparking speculations about whether 3I/ATLAS could be more than a comet.
Last month, the space agency confirmed that 3I/ATLAS is the third interstellar object ever observed in our corner of the cosmos from another star - after ʻOumuamua in 2017 and 2I/Borisov in 2019.
