Perseverance's latest selfie is impressive, but its search for life within ancient rocks is even more fascinating.

      It’s not just Instagram users and vacationers taking selfies — even robots are joining in. The latest image from NASA's Perseverance rover showcases a remarkable selfie taken while the rover was collecting a fresh sample of martian rock.

      Captured on May 10, this selfie was intended to commemorate the rover’s 1,500th day on Mars. Since a Martian day, or "sol," is slightly longer than an Earth day, at about 24 hours and 39 minutes, NASA tracks its Mars missions in sols. Beyond being an entertaining image for both scientists and the public, it allows the engineering team on Earth to assess the rover's condition as it has been exploring since its February 2021 landing.

      The rover can be seen covered in red dust, as the Martian surface is coated with regolith, a dusty material that contributes to the planet's iconic red appearance. Dust poses significant challenges for Mars missions, as it can infiltrate every nook and cranny during intense dust storms and can hinder electronics and solar panels. Fortunately for Perseverance, while it may appear a bit dirty on the outside, all its essential functions are still operating effectively.

      “After 1,500 sols, we might look a bit dusty, but our beauty runs deeper than surface appearance,” said Art Thompson, the Perseverance project manager at NASA’s Jet Propulsion Laboratory. “Our multi-mission radioisotope thermoelectric generator is providing all the power we require. All our systems and subsystems are in good shape and functioning properly, and our outstanding instruments continue to yield data that will contribute to scientific discoveries for years to come.”

      However, even with all instruments functioning correctly, getting the rover to take a selfie isn’t a quick endeavor. The image was captured with Perseverance’s WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera located at the end of its robotic arm. While the rover was capturing the selfie, it also unexpectedly captured a wind feature known as a dust devil in the background.

      “To achieve that selfie look, each WATSON image must have its own specific field of view,” explained Megan Wu, a Perseverance imaging scientist from Malin Space Science Systems. “This required 62 precise movements of the robotic arm. The entire process takes about an hour, but it's worth it. Having the dust devil in the background makes it a classic shot.”

      With the celebrations ongoing, the rover is set to explore a new Martian area known as “Krokodillen,” named after a Norwegian mountain ridge. This region is particularly intriguing as it is believed to contain some of the oldest rocks on Mars, which could provide insights into the formation of the solar system.

      On Earth, there is a tectonic system where portions of the crust are gradually pulled towards the mantle at fault lines. Consequently, Earth's rocks are continuously recycled in a cycle of melting and solidifying, which results in very few rocks that are extremely old remaining on the surface.

      Conversely, Mars tells a different tale. Lacking plate tectonics, very old rocks can remain on its surface for billions of years. Some of these rocks may be up to 4 billion years old or even older, making them critical for scientists to learn about how the rocky planets formed in our solar system approximately 4.5 billion years ago.

      To study these ancient rocks, Perseverance needs to locate them first. It is believed that very old rocks exist along the edge of the massive Jezero Crater where the rover landed. The Jezero Crater spans nearly 30 miles and was likely formed by a significant meteorite impact billions of years ago. That collision ejected large quantities of material, including substantial rock fragments that remain today.

      Thus, by examining the rim of the crater, Perseverance can search for these ancient rock pieces and utilize its instruments to analyze them. This can also help address a critical question scientists aim to answer: how long was there water on Mars? They know that Mars, although dry and barren today, once had abundant liquid water on its surface. It might have even resembled Earth at one time — and water is essential for life formation.

      The uncertainty lies in how long water existed on Mars and if it was present long enough to allow potential life to develop. Therefore, determining when Mars lost its water is vital to understanding the planet and its capability to support life.

      To assist with this inquiry, Perseverance will be on the lookout for clay minerals that form in water's presence, potentially even existing prior to the impact that created the crater. These minerals could contain potential biosignatures, like organic compounds.

      “If we discover a potential biosignature here, it would likely date from a much earlier period in Mars' evolution than what we identified last year,” said NASA scientist Ken Farley. “The Krokodillen rocks were formed before the Jezero Crater's creation, during Mars’ earliest geological period, the No