Interstellar Comet 3I/ATLAS Surprises Astronomers with Nickel Gas Discovery
Astronomers have detected nickel vapor surrounding the interstellar comet 3I/ATLAS, even though it’s far from the Sun and too cold for metals to evaporate. The finding offers new clues about the chemistry of objects from beyond our solar system.
![Hubble Space Telescope image of the interstellar comet 3I/ATLAS, captured as it passed through our solar system. The image reveals the comet’s bright coma and a developing tail of gas and dust. (Image credit: NASA/ESA/David Jewitt [UCLA]; Image Processing: Joseph DePasquale [STScI])](https://assets.science.nasa.gov/dynamicimage/assets/science/missions/hubble/releases/2025/08/STScI-01K1X6XDR76ZD4FYJ9VTWN1ERB.tif?w=1546&h=1140&fit=crop&crop=faces%2Cfocalpoint)
Hubble Space Telescope image of the interstellar comet 3I/ATLAS, captured as it passed through our solar system. The image reveals the comet’s bright coma and a developing tail of gas and dust. (Image credit: NASA/ESA/David Jewitt [UCLA]; Image Processing: Joseph DePasquale [STScI])
Astronomers were astonished to find nickel gas around the interstellar comet 3I/ATLAS, detected while it was nearly four times farther from the Sun than Earth. The discovery was made using the European Southern Observatory’s Very Large Telescope in Chile, with its X-shooter and UVES spectrographs.
This nickel vapor appeared without the usual presence of iron, a puzzling result since metals rarely vaporize at such cold distances. Scientists think the nickel may come from fragile, sunlight-sensitive molecules that break apart easily.
3I/ATLAS, confirmed on July 1, 2025, is only the third known interstellar visitor to our solar system. The comet will reach its closest point to the Sun on October 29, 2025.
Quick Facts:
• 3I/ATLAS is the third confirmed interstellar object to enter our solar system.
• Nickel vapor was detected using the VLT’s advanced spectrographs while the comet was far from the Sun.
• The absence of iron suggests the nickel may come from special molecules that sunlight breaks apart.