New interstellar comet 3I/ATLAS is hurtling through the solar system

[LazyHippo]

A rare interstellar visitor from beyond our solar system is racing toward the sun.

 

Astronomers have identified this cosmic interloper as '3I/ATLAS', making it only the third confirmed object from outside the solar system after 'Oumuamua' (2017) and comet '2I/Borisov' (2019). The interstellar comet, originally designated C/2025 N1 (ATLAS), was observed on July 1 by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in Rio Hurtado, Chile. It has since been designated 3I/ATLAS by the Minor Planet Center (MPC), with "3I" marking it as the third known interstellar object.

 

"There are tentative reports of cometary activity," The MPC report states. "With a marginal coma and a short 3" tail".

 

Currently, 3I/ATLAS is about 4.5 astronomical units (AU) — or 670 million kilometers (416 million miles) — from the sun according to NASA, and around magnitude 18.8, far too faint for backyard telescopes.
 

 

Trajectory of interstellar comet 3I/ATLAS as it passes through the solar system. (Image credit: NASA/JPL-Caltech)
 

 

But it's expected to brighten slightly as it approaches perihelion (closest point to the sun) on Oct. 30, when it will pass just 1.4 AU (130 million miles or 210 million km) from the sun inside the orbit of Mars.

The object is speeding through the solar system at 68 kilometers per second (152,000 mph) relative to the sun, and it poses no threat to Earth, according to NASA.

 

After dipping behind the sun in late fall, 3I/ATLAS is expected to reappear in early December, giving astronomers another chance to study this rare visitor from beyond our cosmic neighborhood.
 

 

3I/ATLAS imaged on July 2 by Gianluca Masi of the Virtual Telescope Project. (Image credit: Gianluca Masi, The Virtual Telescope Project)
 

 

 

@RedBaird said on 01/06/2025

Quote

I swear, @LazyHippo, that you are someday going to announce the End of the World here! 

 

Not yet bud but close call ? 

[LazyHippo]

The recently discovered interstellar visitor 3I/ATLAS may be one of the oldest comets ever seen by humanity.

 

New research has shown this potentially "water ice-rich" visitor could be even more extraordinary than initially believed. 3I/ATLAS could be around 3 billion years older than our 4.5 billion-year-old solar system and thus any comet ever before observed.

 

University of Oxford astronomer Matthew Hopkins is part of a team of scientists that think 3I/ATLAS, discovered on July 1, 2025 by the ATLAS survey telescope, is around 7 billion years old.

 

"All non-interstellar comets, such as Halley's comet, formed at the same time as our solar system, so they are up to 4.5 billion years old," Hopkins said in a statement. "But interstellar visitors have the potential to be far older, and of those known about so far, our statistical method suggests that 3I/ATLAS is very likely to be the oldest comet we have ever seen."

 

The key to the advanced age of 3I/ATLAS is the fact that it comes from a completely different region of the Milky Way than previous interstellar visitors.

 

Based upon the steep trajectory that 3I/ATLAS appears to be taking through our galaxy, Hopkins and colleagues theorize that it originated in the Milky Way's "thick disk" of stars.

[LazyHippo]

So there has been a lot of expectation and things around 3I/ATLAS that makes up more questions than answers.

 

Right now its close to Mars, recently the Exo Mars TGO (Trace Gas Orbiter) took position of the supposed "comet" entering the asteroid ring.

 

Also found this images in social media but I think its not much than fake evidence? brought here to make opinions.

 

 

 

Now its located at the Virgo constelation, almost 400 millions of kilometers from Earth.

 

Next its going to go very close to the Sun to observe and will reappear on the other side of the Sun by early December, 2025.

 

 

[LazyHippo]

Comet 3I/ATLAS heads for the outer solar system

 

On Friday (Dec. 19), the interstellar invader, comet 3I/ATLAS, made its closest approach to Earth, coming to within 168 million miles (270 million kilometers) of our planet at 1 a.m. EST (0600 GMT).

 

 

Comet 3I/ATLAS making its closer approach to Earth on December 19th, 2025. (Image credit: NASA)

 

 

First spotted by NASA's Asteroid Terrestrial-impact Last Alert System (ATLAS) on July 1, 2025, with its trajectory indicating its origin lies elsewhere in the Milky Way.

 

In fact, its path through space suggests that this interstellar comet comes from a region of our galaxy that is much older than the 4.6 billion-year-old solar system.
 

The water-rich comet seems to originate from the Milky Way's "thick disk" of stars, rather than the thin stellar disk of which the sun is a member. The thick disk formed earlier than the thin disk, meaning 3I/ATLAS could be up to 7 billion years old.

As 3I/ATLAS  began to make its closest approach to the sun, or its perihelion, on Oct. 29, the comet brightened more than scientists had expected.

 

Comets tend to brighten as they approach our star due to solar radiation heating their icy cores and causing solid ice to transform straight into vapor, which erupts from the comet, growing its halo or "coma" and its characteristic glowing tail.

 

Quite why 3I/ATLAS brightened more than expected as observed by STEREO-A and STEREO-B, the twin spacecraft that make up Solar Terrestrial Relations Observatory (STEREO), the sun observing Solar and Heliospheric Observatory (SOHO), and the weather satellite GOES-19, is still unknown.

 

 

Image credit: (© NASA, ESA, STScI, D. Jewitt (UCLA). Image Processing: J. DePasquale (STScI))

[LazyHippo]

NASA space telescope sees interstellar visitor comet 3I/ATLAS flare up while exiting the solar system

 

New infrared observations reveal the rare interstellar visitor comet 3I/ATLAS dramatically brightening during its farewell tour of the solar system.

 

NASA's SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) space telescope captured views in December 2025 of the comet releasing a surge of gas, dust and complex molecules two months after the object's closest approach to the sun — a surprising outburst that's giving scientists their clearest chemical look yet at material formed around another star, according to a statement from NASA.

 

The SPHEREx images were taken as the comet was already heading back out of the inner solar system. Instead of fading quietly into the dark, 3I/ATLAS flared with activity, developing a glowing coma rich in water vapor, carbon dioxide and organic compounds. Observations also show a pear-shaped dust tail, created by rocky material being ejected as the comet's activity increases.

 

"Comet 3I/ATLAS was full-on erupting into space in December 2025, after its close flyby of the sun, causing it to significantly brighten," Carey Lisse, lead author of the study, said in the statement. "Even water ice was quickly sublimating into gas in interplanetary space."
 

NASA's SPHEREx captured these infrared observations during a December 2025 campaign, revealing dust, water, organic molecules and carbon dioxide in comet 3I/ATLAS's coma. (Image credit: NASA/JPL-Caltech)

[LazyHippo]

Comet 3I/Atlas update

 

Using the Atacama Large Millimeter/submillimeter Array (ALMA), scientists have discovered that the interstellar invader comet 3I/ATLAS formed in a much colder region of the Milky Way than our solar system.

The discovery came about when scientists made the first-ever measurement of so-called semi-heavy water (or deuterated water) for an object that originated beyond the solar system. Deuterated water refers to water in which one hydrogen atom is replaced with deuterium, a heavy hydrogen isotope that has an atomic nucleus composed of one proton and one neutron. ALMA's measurements of deuterated water revealed that 3I/ATLAS contains around 30 times as much semi-heavy water as is found in comets that originate in the solar system.

 

The findings indicate that 3I/ATLAS, just the third interstellar object discovered passing through the solar system, formed in a much more frigid region of space compared to our planetary backyard.
 

"Our new observations show that the conditions that led to the formation of our solar system are much different from how planetary systems evolved in different parts of our galaxy," team leader Luis E. Salazar Manzano at the University of Michigan said in a statement.

Manzano and colleagues studied 3I/ATLAS as it reached its closest point to the sun, a feat made possible by the ability of ALMA's 66 radio antennas to point toward the sun, something optical telescopes can't do because of the glare of sunlight.

This elevated ratio points to 3I/ATLAS having formed in an exceptionally cold and chemically distinct environment somewhere else in the Milky Way.

 

"The chemical processes that lead to the enhancement of deuterated water are really sensitive to temperature and usually require environments colder than about 30 Kelvin, or about minus 406 degrees Fahrenheit (207 degrees Celsius)," Manzano said.