Interstellar Comet 3I/ATLAS unleashes bright green glow in stunning new images

Comet 3I/ATLAS shines emerald green in latest astronomical observations. (Image Credit: Michael Jäger/Gerald Rhemann)

The "interstellar visitor" is turning into bright green as it approaches the halfway point on its journey through the solar system. New photos of comet 3I/ATLAS were taken during last week's total lunar eclipse.

The 3I/ATLAS is the third known object from outside our solar system, with a hyperbolic trajectory indicating it's not gravitationally bound to the Sun. This was first spotted in early July. This comet was likely ejected from a distant star system within the Milky Way and is probably much older than the solar system.

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

The interstellar comet 3I/ATLAS will have a close encounter with Mars next month, flying within 30 million kilometers of the Red Planet on October 3. Afterwards it will reach its closest point to the Sun on October 29.

A surprising emerald hue were seen in recent photos taken by astrophotographers Michael Jäger and Gerald Rhemann during a total lunar eclipse, also known as a "blood moon" eclipse, on September 7. The darker skies allowed them to capture images of the comet with a greenish tint, which scientists believe could be due to the comet's increasing proximity to the Sun.

There are alternative theories about the green glow's cause. One theory suggests that dicarbon molecules in the comet's coma emit light in the green spectrum when activated by solar radiation. Harvard astronomer Avi Loeb proposes another theory, linking the color shift to increased cyanide production as the comet approaches the Sun. Additionally, the green hue could result from previously unknown chemical reactions or interactions between the comet's composition and solar radiation.

Hubble photographs 3I/ATLAS, showcasing its icy nucleus and dust plume. (Image Credit: NASA/ESA/David Jewitt)

Comet 3I/ATLAS will soon disappear from our view as it passes behind the Sun. But the astronomers are eager for its reappearance in a few months. It will approach its closest point to Earth in December. As the researchers continue to examine Comet 3I/ATLAS, they might find new information regarding the enigmatic chemistry of comets and the beginnings of our solar system.