Something strange is happening on Mars! NASA's Perseverance rover snapped a photo of a peculiar stripe on the Martian surface, and the internet is buzzing with theories. Is it an alien spaceship? A Martian moon? The truth might be a bit more down-to-earth, but it's still fascinating.
What Did Perseverance See?
The image, taken on October 4, 2025, shows a long, thin streak. Some people immediately jumped to the conclusion that it was the interstellar object 3I/ATLAS, also observed by the ESA's ExoMars Trace Gas Orbiter (TGO) and Mars Express spacecraft, streaking across the sky. 3I/ATLAS is an icy wanderer that's been making headlines as it journeys through our solar system. The European Space Agency's probes even took images of the comet as it passed by Mars earlier this year.
However, experts suggest a more likely explanation. Harvard professor Avi Loeb suggests the streak is related to the rover's camera and the angular resolution of the image. The apparent length of the stripe far exceeds any known measurement of 3I/ATLAS.
ESA's ExoMars and Mars Express Observe Comet 3I/ATLAS
Between 1 and 7 October, ESA’s ExoMars Trace Gas Orbiter (TGO) and Mars Express spacecraft turned their eyes towards interstellar comet 3I/ATLAS, as it passed close to Mars.
The two Mars orbiters had the closest view of the comet of all ESA spacecraft. During its closest approach to the Red Planet on 3 October, the interstellar interloper was 30 million km away from them.
Each spacecraft used its dedicated camera to watch the comet pass. Both cameras are designed to photograph the bright surface of Mars just a few hundred to a few thousand km below. Scientists were unsure what to expect from observations of a relatively dim target so far away.
ExoMars TGO captured a series of images with its Colour and Stereo Surface Imaging System (CaSSIS). Comet 3I/ATLAS is the slightly fuzzy white dot moving downwards near the centre of the image. This dot is the centre of the comet, comprising its icy-rocky nucleus and its surrounding coma.
So, What's the Real Story?
While the mystery stripe might not be an alien encounter, it highlights the incredible work being done by space agencies like NASA and ESA. They're constantly exploring and observing, pushing the boundaries of our knowledge about the universe. Even if it's just a quirk of the camera, it sparks our imagination and reminds us of the wonders that lie beyond our planet.