New analysis investigates the likelihood that totally different spacecraft might go to Comet 3I/ATLAS, giving scientists a singular on-location view of the interstellar customer, and even providing the prospect to gather materials that might be a lot older than the our bodies of our photo voltaic system.
Found on July 1 by the ATLAS (Asteroid Terrestrial-impact Final Alert System), 3I/ATLAS is simply the third-ever object discovered drifting by our photo voltaic system that’s believed to have originated from round one other star. It due to this fact provides scientists a singular alternative to review materials from one other planetary system. Nonetheless, latest examination of this interstellar intruder’s trajectory and its velocity of round 130,000 mph (219,000 km/h) has revealed that it might truly originate from a area of our galaxy a lot older than the photo voltaic system and its quick environment.
The truth that 3I/ATLAS appears to originate from the Milky Manner’s “thick disk” of stars implies that it might be 7 billion years outdated and even older, making it at the least round 2.5 billion years older than our solar, the planets of the photo voltaic system, and its horde of asteroids and comets. Thus, it represents the chance to study material that formed much earlier than that of the solar system during a period of the universe called “cosmic noon,” an exciting prospect for scientists. But there is a problem.
Like the comets of the solar system do, 3I/ATLAS is shedding material as it approaches the sun, where solar radiation heats the ice at its core and converts it directly to gas, which erupts from the comet’s surface. This process gives comets their distinctive tails and haloes (or “comas”) and gives scientists a chance to assess what chemicals lie at the core of the comet.
A comet loses the most material when it comes closest to the sun, a passage known as its perihelion. The authors of this new research point out that when 3I/ATLAS makes its perihelion passage, it will be at the other side of the sun in relation to Earth.
That means that the telescopes that have been integral to the study of 3I/ATLAS will miss what will be potentially the most revealing period of its passage through the solar system. Earth-based telescopes like the four ATLAS telescopes located in Hawaii, Chile, and South Africa, and Earth-orbiting telescopes like the James Webb Space Telescope (JWST) and the Hubble Space Telescope have all studied the comet so far, but they will be out of view during its perihelion.
“A telescope on Earth will be at a huge disadvantage, as 3I/ATLAS will unfortunately reach its closest point to the sun behind the sun, if viewed from the Earth. It means that we would need to look through or past the sun to observe 3I/ATLAS,” research author and University of Luxembourg researcher Andreas M. Hein told Space.com. “This is a big issue, as the sun is a very bright object and 3I/ATLAS is very faint. We would not be able to see 3I/ATLAS from Earth.”
Thus, Hein and his colleagues, including lead author T. Marshall Eubanks, Chief Scientist at Space Initiatives Inc., set about assessing which spacecraft could avoid this issue and get an up close and personal view of 3I/ATLAS, or even pass through its cometary tail and collect some material.
“The Earth and its satellites, including our space telescopes, are, purely by chance, poorly situated to observe 3I/ATLAS when it is closest to the sun, as it will also happen to be on the far side of the sun as seen from Earth,” Eubanks said. “The period at and just after perihelion is when a comet (including 3I/ATLAS) is heated the most, and thus throws off the most material, has the biggest tail, and has the highest chance of fragmenting, or even disappearing.
“Spacecraft offer a chance of observing this period.”
What spacecraft could catch a glimpse (or a chunk) of 3I/ATLAS?
“Thanks to its Venus gravity assist on Aug. 31, JUICE will be in the best position for the important period around the 3I/ATLAS perihelion, when observations from Earth will be the hardest,” Eubanks explained. “Various spacecraft orbiting Mars, including the Mars Reconnaissance Orbiter (MRO), Tianwen-1, and Hope, all have both the vantage point and good equipment to provide good data on 3I/ATLAS.
“Of all of these, I think that the JUICE data near perihelion is likely to be the most critical.”
The researcher added that at its closest approach, Psyche will be around 28 million miles (45 million km) from 3I/ATLAS, while JUICE will come to around 43 million miles (68 million km) from the comet. At their closest, the spacecraft orbiting Mars will be around 18 million miles (29 million km) from the comet.
All of these spacecraft will be much closer to 3I/ATLAS than the comet will ever come to Earth. The interstellar comet’s closest approach to our planet is estimated to be 168 million miles (269 million km) on Dec. 19, 2025.
Eubanks added that 3I/ATLAS will also pass through the fields of view of the ESA’s Solar and Heliospheric Observatory (SOHO), NASA’s PUNCH solar monitoring spacecraft, and the Parker Solar Probe as the comet passes near the sun. That means these spacecraft will provide scientists the opportunity to monitor the day-by-day behavior of 3I/ATLAS, albeit at larger distances and lower resolutions.
Other spacecraft may not get a good look at 3I/ATLAS, but could still play an important role in investigating the interstellar visitor.
“The Europa Clipper, Hera, and the Lucy spacecraft will all be exterior to 3I/ATLAS, with the sun being behind the interstellar object from their vantage point, which will mostly or entirely prevent them from imaging 3I/ATLAS,” Eubanks said. “However, 3I/ATLAS will also provide the possibility that they will fly through the cometary tail of this body, providing a different means of studying it.”
The likelihood of a spacecraft passing through the cometary tail of 3I/ATLAS will depend on how it develops.
“It depends on the direction of the tail. The Europa Clipper and Hera spacecraft are moving at a farther distance than 3I/ATLAS and may pass through its tail or observe it at a closer distance,” Hein said. “Ideally, we would be able to do mass spectroscopy to find out about the composition of 3I/ATLAS. The results would tell us if 3I/ATLAS indeed has its origin in the thick disk.
“It’s like an aeon-old fridge, which will open during the next months to release some of its contents.”
A rare oppotunity to study the universe
Eubanks and Hein explained to Space.com just why scientists shouldn’t miss this opportunity to study 3I/ATLAS and to potentially snatch some material from its tail.
“Stars in the galactic thick disk have formed billions of years earlier than those in the thin disk, which includes our sun,” Hein explained. “If 3I/ATLAS has been ejected from a thick disk star system, it means that we could gain insights into it without flying there – something which we will not be able to do for the foreseeable future. Hence, observing 3I/ATLAS is a literal example of: If the prophet cannot go to the mountain, let the mountain come to the prophet.”
Eubanks added that as far as scientists know, almost everything in the solar system was formed around 4.6 billion years ago, or afterwards, barring some small “pre-solar” grains in some meteorites that are older than the solar system.
“The oldest of these, the pre-solar grains found in the Murchison meteorite, are ‘only’ 5 to 7 billion years old. 3I/ATLAS should be considerably older than that,” Eubanks continued. “The cosmic noon, the period in which it seems to have formed, a time of high star formation, can be observed with other galaxies, but at a distance of 6 billion light-years. Now, we can study it in our own solar system, many trillions of times closer.”
As for just how rare an opportunity this is, even this team of scientists isn’t sure. That’s because we currently can’t say exactly how many interstellar invaders from beyond the solar system are zipping through our cosmic backyard.
“Imagine being in a dark room. There might be all kinds of objects buzzing around, but you cannot see them in the dark, and hence, it is impossible to know how many there are. Telescopes are a bit like searchlights in a dark room that allow us to see some of those objects,” Hein said. “Of course, this is just an analogy as real telescopes collect light instead of shining light on objects. Their resolution is limited, and a lot of them can only observe narrow spots. Hence, we still only get a sketchy picture of what is going on. This is basically the situation until recently.
“Some believe that those objects are fairly common, but I am skeptical. If similar objects had buzzed through the solar system, we would have observed them much earlier than in 2017 when we observed ʻOumuamua or 2019 when we observed 2I/Borisov.”
“However, I believe that these objects are rarer than commonly assumed and particularly thick disk objects, as the number of thick disk stars is only a fraction of thin disk stars,” Hein continued. “Hence, it might be decades or even longer until we may have another opportunity to observe a potential thick disk object.”
Whether 3I/ATLAS is unique in the solar system or not, the team is clear that this is the first time we’ve been presented with a clear opportunity to study an object from cosmic dawn in our own backyard.
“This is certainly the first time we have been offered such an opportunity,” Eubanks said. “This could be literally a once-in-a-lifetime opportunity.”
Excitingly, 3I/ATLAS may leave behind fragments that allow it to be studied after it has departed the solar system to continue its voyage through the Milky Way.
“Due to the size of 3I/ATLAS, it may actually have satellites up to a distance intersecting with the orbits of Mars and Earth. Hence, we might be able to observe dust particles in the form of a meteor shower entering the atmospheres of Mars and Earth or even larger pieces of 3I flying past those planets,” Hein concluded. “The coming months will be very exciting as more and more data from 3I/ATLAS will be collected. We hope that some of its mysteries will be solved!”
The team’s research is available on the paper repository site arXiv.
