3I/ATLAS

3I/ATLAS is a roughly 7-mile-wide (11 kilometres) comet that was first spotted in early July and is zooming toward us from beyond the asteroid belt between Jupiter and Mars. Scientists quickly realized that the superfast object did not originate within our cosmic neighbourhood. Instead, it was likely ejected from a distant star within the Milky Way and is now passing by us as it flies through the galaxy. It is unclear exactly where the comet originated, but initial findings hint that it is likely much older than the solar system.

On Aug. 27, astronomers at the Gemini South telescope in the Chilean Andes captured a detailed new photo of 3I/ATLAS, revealing the first clear look at the comet’s tail. This plume of ice and dust is blown away from the comet by the solar wind, the stream of charged particles emanating from the sun. The tail is only starting to appear now, as the comet’s frozen shell, or nucleus, soaks up more solar radiation, causing it to expel more particles from its icy surface. The tail will continue to grow as the comet gets closer to the sun in the coming months, and will eventually become several times wider than the comet itself.

3I/ATLAS will reach perihelion, its closest point to the sun, on Oct. 29. But it will be on the opposite side of our home star as Earth, meaning we will lose sight of it during this time and may miss out on seeing its tail at its peak size. The comet will reach its minimum distance to Earth in December, when it will come within 170 million miles (275 million km) of our planet — around 700 times farther than Earth is from the moon — before beginning its long journey back out of the solar system.

Astronomers are racing to study the object as much as possible over the next year or so, to learn more about where it came from and how different star systems form and evolve. Recent observations from the James Webb Space Telescope hint that 3I/ATLAS has unusually high levels of water and carbon dioxide compared with other known comets. Additional photos of the comet, including a detailed shot from the Hubble Space Telescope and a colourful image from the Gemini North telescope in Hawaii, have also shed light on its composition.

Credits: Live science: Https://Www.Livescience.Com/Space/Comets/New-Photos-Of-Interstellar-Comet-3i-Atlas-Reveal-Its-Tail-Growing-Before-Our-Eyes