- A previously overlooked photo from the Curiosity rover shows an odd “jellyfish” on Mars. Is it a real anomaly or an imaging artifact?
- The “jellyfish” is a small, dark shape that looks like it is sitting on top of a distant rocky hill.
- There are various possible explanations, but some kind of imaging artifact is the most likely.
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The ‘jellyfish’ on Mars
The rovers on Mars sometimes see things that look really odd. Typically, it’s weird rocks or other surface features. But sometimes it’s in the sky. Those usually turn out to be pixel artifacts or other glitches in the cameras. And there’s a new case that’s going viral on social media. The image is from the Curiosity rover, in Gale crater, and is actually from August 20, 2023 (sol 3924 for the rover).
But it was largely overlooked until Kari Sivertzen posted it on X on August 12, 2026. The image shows what looks like a “jellyfish” shape in the distance. The “tentacles” look like they are touching the top of a rocky hill. What is it really?
Object or imaging artifact?
It looks intriguing, so what is this mysterious “jellyfish”? Notably, images that Curiosity took less than two minutes earlier, looking in the same direction, didn’t show the odd shape.
The original image is a raw, grayscale image, so not the highest resolution. And the shape only covers about 15 pixels, so quite tiny. The image is from Curiosity’s right navigation camera. The same camera then took another image about 78 minutes later and the shape was gone.
Theories about the ‘jellyfish’ on Mars
Since the shape is absent in subsequent images, that shows it is not a permanent feature of the landscape. With that in mind, there are a few theories, as also mentioned by Amit Surti on Medium.
The possibilities include a cosmic ray artifact, an electronic or transmission artifact and what astronomers would call a transient physical phenomenon.
Cosmic ray artifact?
Firstly: could the “jellyfish” be a cosmic ray artifact? Both the Curiosity and Perseverance rovers have seen many of these before. As Surti described on Medium:
Curiosity’s cameras operate in a high-radiation environment. High-energy particles known as cosmic rays constantly bombard CCD detectors in space. When a cosmic ray strikes the silicon grid during a calibration step called a bias frame, it deposits a localized charge. The camera’s processing pipeline later subtracts the bias measurement from the actual exposure. That subtraction converts the bright charge from the particle strike into a dark residual imprint.
The physical movement of charge along the detector’s pixel columns, a process called charge diffusion, combined with the specific readout direction, could produce thin downward-pointing extensions from that dark core. That would explain the jellyfish shape. And because the interaction is momentary rather than persistent damage, the artifact would appear in only one exposure.
A similar shape was also seen in a navigational camera image in 2022, sol 3613. It’s a compelling explanation, but we’d need complete engineering logs to confirm it or not.
Astrophysicist explains mysterious Mars “jellyfish”. Video via Astraveo/ YouTube.
Electronic or transmission artifact?
The shape could also be due to an electronic or transmission glitch. From Medium:
A pixel value can change at multiple points between the camera sensor and the final image file on Earth. Within the readout electronics, inside the flight computer’s storage, during onboard compression, throughout the downlink transmission or during ground processing.
Specific failure modes that produce localized dark regions include: temporary pedestal drift in the electronics, single-event upsets in the image buffer from radiation, temperature spikes from nearby rover hardware triggering dark-current surges, packet loss during transmission generating empty dark blocks and minor mismatches in flat-field calibration files leaving regional residuals.
This could produce a similar dark shape that appears in one image, but not the previous one or the next one.
Transient physical phenomena
Finally, what about something physical, but impermanent? It could be a dust particle or even a dust devil. But to confirm this, data from wind sensors or the left navigation camera would be needed … and both are missing in this case.
The lack of corroborating data shows how difficult it can be to observe an “anomaly” on Mars and try to figure out what it is when there is only one low-resolution image available and not much other data. And most likely, we will see more oddities like this in the future.
Interestingly, some UAP – Unidentified Anomalous Phenomena – have been described as jellyfish-like over the years. Such as this one from over a U.S. joint operations base in Iraq in 2018. Or this one – the floating brain – from over the Atlantic on January 1, 2020.
Bottom line: A previously overlooked photo from the Curiosity rover shows an odd “jellyfish” on Mars. Is it a real anomaly or an imaging artifact?
Via:
Medium
YouTube
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