Earth’s famous Hubble Telescope has just revealed the first images of a mysterious interstellar object racing through our solar system.
Spotted on Monday, Hubble has helped astronomers confirm that the massive, high-speed visitor is a comet from a distant part of the Milky Way galaxy.
First spotted in late June, the comet named 3I/ATLAS has been on an 800-million-year journey to reach this solar system.
The new images from Hubble captured what appears to be an icy tail that’s ejecting rocky material from its 12-mile-long core.
Those observations were reinforced by a new study published Tuesday morning which revealed 3I/ATLAS has water ice present in its coma, the luminous cloud of gas and dust surrounding a comet’s nucleus.
That revelation about 3I/ATLAS also confirmed that life-giving water exists far beyond our solar system, carried by comets throughout the cosmos, and potentially spreading the building blocks of life to other worlds.
The giant comet has become the third interstellar object recorded by astronomers entering the solar system, joining Oumuamua in 2017 and the comet Borisov in 2019.
It will make its closest pass to Earth on December 17 as it speeds through the solar system at 41 miles per second (roughly 150,000 miles per hour).
3I/ATLAS was detected by astronomers in late June and will clear our solar system in 2026
The new study published on the pre-print server arXiv, also revealed that the comet’s coma is made up of 30 percent water ice and 70 percent of a dust similar to a type of meteorite (Tagish Lake) that contains organic materials.
While the study didn’t detect organic molecules directly, the reddish dust in 3I/ATLAS resembles D-type asteroids, which are known to sometimes carry simple organic compounds like amino acids or hydrocarbons.
These are the kinds of molecules that could, under the right conditions, contribute to the chemistry needed for life on a distant planet.
Since 3I/ATLAS is an interstellar object – meaning it has traveled between star systems – it could theoretically visit other planetary systems.
If it collided with a planet or released its material into a planet’s atmosphere, it might deposit water and possibly organic molecules on those worlds.
This process, called panspermia, is the idea that life’s building blocks (or even simple life forms) could be transferred between worlds by objects like comets or asteroids.
Here on Earth, a 2022 study published in Nature Communications found the five building blocks for DNA and RNA in several carbon-rich meteorites discovered around the world.
Scientists have said this and similar discoveries support the theory that the origins of life on Earth were delivered by meteorites and other cosmic bodies like 3I/ATLAS billions of years ago.
Scientists believe the comet is up to 12 miles long, making it significantly bigger than the last 2 interstellar objects discovered
3I/ATLAS is expected to make its closest pass by Earth on December 17. Scientists believe the object will come within 223 million miles of the planet
The comet is by far the biggest known interstellar visitor to pass through the solar system.
At 12 miles long, it dwarfs Oumuamua, which was only about 300 to 1,300 feet long, and Borisov’s core, which was about half a mile in diameter.
Scientists don’t believe 3I/ATLAS poses any threat to Earth. That’s good news because the object would fall into the category of a ‘planet killer’ – likely causing an extinction-level event if it struck the Earth.
On its current trajectory, it’ll come within 2.4 astronomical units of the planet (223 million miles) in mid-December.
An astronomical unit (AU) is equal to the distance between Earth and the sun, 93 million miles. Technically, the comet has already entered the solar system, and was less than four AU away from Earth after its discovery in early July.
In October, the object from outside the solar system is expected to make its closest pass to a planet, coming within 0.4 AU (37 million miles) of Mars.
In 2017, an interstellar object named Oumuamua passed through the solar system. Harvard physicist Avi Loeb famously argued it may have been of alien origin
To reach these findings, scientists took optical spectra (light measurements in the visible range) to see the colors in the comet’s dust.
Astronomers then used the NASA Infrared Telescope Facility to measure near-infrared light, which helped detect materials like water ice.
The presence of water ice also hints that 3I/ATLAS formed in a cold, distant part of its original solar system, providing a clue about its origins and showing similarities to comets in our solar system.
Harvard physicist Avi Loeb and student researcher Shokhruz Kakharov previously traced the path of the interstellar object to a thicker part of the Milky Way galaxy’s disk, where older stars are found.
They have estimated that 3I/ATLAS is older than our sun, which is 4.6 billion years old.
