Since the 1976 Viking missions, when NASA first successfully placed uncrewed landers on Mars, scientists who study life in the universe, known as astrobiologists, have been gathering evidence to determine whether microorganisms ever lived on the red planet. It has been a challenging determination to make. Until a Mars sample return mission occurs, all necessary analyses must take place on Mars, using instruments designed as much to withstand the stresses of space travel as to collect data, which limits how thoroughly scientists can study Martian rocks. As a result, the search for evidence of microbial life on Mars is inherently incremental. 

Recently, scientists added another piece of exciting, yet inconclusive, evidence to their search. In the summer of 2024, the Mars 2020 Perseverance Rover science team was searching for signs of ancient microbial life in a 3,700-million-year-old lake bed on Mars, known as Jezero Crater. In the process, they detected complex, carbon-containing organic molecules in mudstones within a river channel that once brought water to the now-dry lake bed. 

This is not the first time complex organic molecules have been detected in Martian mudstones. However, there are 2 reasons that astrobiologists are particularly interested in this new discovery. First, these organic molecules are widely dispersed across all 4 river channel mudstones they analyzed. Second, some of the organic molecules they found are associated with minerals that are known to support microbial life on Earth. 

Widely dispersed organic molecules associated with minerals that can support microbial life are exactly what astrobiologists would expect to see if microorganisms once lived in Jezero Crater. However, organic molecules can also form through geological processes, like when gases and minerals react at high temperatures and pressures at deep-sea vents on Earth. Therefore, astrobiologists must carefully assess organic molecules to determine their origin. 

In July of 2026, more than 60 Perseverance science team members took a first step towards determining whether ancient microorganisms could have made the organic molecules found in Jezero Crater. They compared the organic molecule detections in Martian mudstones to similar detections of organic molecules in samples of known origin, including fossilized Earth life, meteorites, and minerals. 

NASA scientists detected the organic molecules in Jezero Crater with a rover instrument called Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC). SHERLOC uses a 248.6 nanometer (nm) wavelength laser to excite molecules in unknown materials. When molecules are excited, they absorb and scatter the laser light, causing characteristic shifts in the wavelength of the scattered light. 

Instruments like this, known as Raman spectrometers, detect the shifted light and display the detections as lines called spectra, which scientists use to identify the unknown molecules. The Raman spectra from the 4 mudstones in Jezero crater showed shifts of about 1600 nm, which is characteristic of complex carbon molecules. These shifts appear as bands in the spectra that are often called G-bands.

Raman spectrometers are common laboratory instruments, but most use lasers with wavelengths of 485 nm or higher, so the spectra they produce can be slightly different from SHERLOC spectra even when the laser excites the same kind of molecule. To get around this issue, the scientists compared the Mars spectra with spectra of complex carbon molecules from fossilized Earth microorganisms, coal, graphite, meteorites, and synthetic samples collected by Raman instruments using the same wavelength laser that SHERLOC uses. They found that the spectra collected on Mars overlap with at least one example from every sample type except graphite. 

These results don’t rule out the possibility that organic molecules in Jezero Crater were produced by ancient microbial life, but they can’t tell us exactly how they formed either. That determination will have to wait until the samples are brought to Earth so they can be studied with laboratory instruments.

The Perseverance team has made a small but critical contribution towards determining whether microbial life ever inhabited our closest planetary neighbor, Mars. Their efforts exemplify how the science of astrobiology and the search for possible extraterrestrial life slowly and carefully move forward. If we keep at it, humans may one day have a definitive answer to one of our most consequential questions: Are we alone?

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More than 140 million miles away from Earth, a rare event recently occurred in the twilight skies above Mars, and it was all captured on camera by NASA’s Perseverance rover.

Imagery of a celestial alignment, featuring Earth as it briefly vanished behind the Martian moon Phobos, was revealed in composite photos captured by Perseverance’s Mastcam-Z instrument in early July as the intrepid rover embarked on its 1,907th Martian day, or sol, on the Red Planet.

The rover’s Mastcam-Z camera system, developed by Arizona State University in collaboration with Malin Space Science Systems, was built for capturing high-resolution panoramic zoom imagery of the Martian landscape. Although its main objectives involve its investigations of Jezero Crater and ancient geological features preserved there for eons, which may even include evidence of past microbial life, cases like the recent celestial alignment showcase how the rover’s cameras can also provide unique insights into astronomical events.

A Robot on Mars Captures an Occultation

Captured against fading twilight, our Earthly home appears as little more than a tiny, bright speck of light as it slowly passes behind the irregularly shaped Martian moon, in what astronomers refer to as an occultation.

NASA applied processing to the rare images, which helped to filter out some of the background light, revealing the brief celestial pairing in greater detail. The resulting imagery offers a glimpse of a dark backdrop that now better highlights the motion of Earth and Phobos in their treks through the Martian sky.

A Sunset Unlike Any Other

The image was obtained roughly 40 minutes after the Martian sunset, as the natural orbital path Phobos follows causes it to appear to drift upward in the new sequence of images, while Earth moves diagonally downward, then slips out of view behind the oddly shaped Martian companion.

In an annotated version released by NASA, timestamps spanning just 40 seconds illustrate the progression of the event in single frames, offering a look at a sunset unlike any ever seen on Earth.

That isn’t to say that the same effect can’t be seen from our planet, but in reverse: a lunar occultation where Mars passes behind the Moon can also be observed here, under the right conditions.

Occultations are frequently used by astronomers to help study the positions and motions of various celestial bodies in this way. However, seeing one from the surface of another planet is a rare treat, offering a view of Earth as a distant point of light.

In the past, Perseverance has also captured images of a lunar eclipse from its position on the Martian surface, as Phobos was seen passing in front of the Sun. Past imagery collected by NASA’s robotic explorer has also documented appearances of the Martian moon Deimos in the Red Planet’s early morning skies.

Colors of Change on a Red Planet

Although Mars’ characteristic rusty hues are ever-present, the recent imagery also offers a glimpse of other subtle colors seen in the Martian environment, particularly at twilight. With subtle bluish grays that gradually transition to redder tones, the new images offer a more nuanced and colorful look at the Red Planet.

Perseverance has now spent more than five years exploring Mars, and its ongoing discoveries have added a wealth of new information to the growing body of knowledge scientists have collected about our nearby planetary neighbor.

As for the recent imagery the rover captured, such a unique view requires careful timing, along with a bit of good fortune, according to Mark Lemmon, a Mastcam-Z co-investigator at the Space Science Institute in Boulder, Colorado.

“Phobos crosses the Martian sky three times a day, and Earth is visible for months at a stretch,” Lemmon said in a statement, adding that “catching one directly behind the other takes planning and a little luck.”

Additional details provided by NASA about the new imagery can be found here and here.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.

A tiny green dot appearing in an image taken by NASA’s Mars Reconnaissance Orbiter (MRO) captures a historic tale of Red Planet exploration by one of its first Earthling visitors.

That visitor—a robotic rover named Perseverance—has been conducting investigations on Mars since February 18, 2021, and the new aerial images reveal its current location in an area that mission specialists have dubbed “Arbot.”

While Perseverance’s latest appearance reveals little more than a greenish spec on the planet’s rust-colored surface, also visible in the new images are the long path its formidable tires have left in the Martian soil as the robotic explorer has trekked west of its initial landing site.

The new images, captured on June 13, 2026, were taken just one day before Perseverance broke the previous distance record held by a robotic explorer on Mars: NASA’s Opportunity rover.

However, Perseverance completed this phase of its journey in record time compared to its predecessor, which took more than 11 years to traverse a similar distance. Perseverance, by contrast, covered the same distance in less than half that time, with just five years and four months of travel now behind it.

The images were made possible by the MROs’ High-Resolution Imaging Science Experiment (HiRISE) camera, which also captured surface features in the Arbot area that include ridges and windswept areas along Mars’ rugged exterior.

Built and operated by the University of Arizona, HiRISE captures images with resolutions as fine as about 25 centimeters (10 inches) per pixel, allowing researchers to distinguish features roughly the size of a kitchen table from orbit. The camera has returned hundreds of thousands of detailed images since the MRO arrived at Mars two decades ago, contributing to a growing data set that has transformed scientists’ understanding of the Red Planet.

Documenting everything from active dust avalanches and shifting dunes to fresh impact craters, the unprecedented resolution its imagery provides has made HiRISE one of the most powerful planetary imaging instruments ever deployed.

Last year, the MRO’s HiRISE camera also successfully captured images of the interstellar comet 3I/ATLAS as it made its way past Mars during its trip through our Solar System. Although the HiRISE images weren’t the clearest images of the interstellar visitor obtained during its visit, they did help demonstrate just how formidable NASA’s MRO and its suite of instruments are.

Additional details about Perseverance and its mission can be found at NASA’s official web page, and information about the MRO can be found here.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.