Scientists Say "Kidney Bean" Fossils on Mars Hint at Past Life Support

• While they look like kidney beans, the structures in Mars' northern hemisphere are actually sand dunes blanketed with carbon dioxide ice.
• The severity of winter temperatures on Mars relies on the planet’s axial tilt. When the northern hemisphere of Mars tilts closer to the Sun, it experiences milder conditions; conversely, when it tilts away, it becomes colder.
• When the temperature increases sufficiently, the CO2 ice transforms into vapor and ascends into the atmosphere. Times when this greenhouse gas led to a denser atmosphere provided the potential for liquid water on Mars, possibly supporting life.

Structures resembling oversized kidney beans (or blobs of chocolate syrup, based on your perspective) could potentially indicate certain conditions. Mars was habitable in the distant past.

Recently imaged by the HiRISE The High-Resolution Imaging Science Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance Orbiter (MRO) reveals these formations resembling kidney beans; they are essentially sand dunes immobilized by carbon dioxide ice. Sand dunes on Mars behave like those on Earth They move as wind-blown sands shift back and forth, gradually inching along the ground. During the Martian winter in the northern hemisphere, frost settling on them immobilizes their movement until it melts away with warmer temperatures.

Through imaging of the dunes, researchers can determine the amount of carbon dioxide frost that accumulates on them during the Martian winter. As temperatures rise in spring, this frost sublimates, changing directly from a solid to a gas state and disappearing into the atmosphere.

The quantity of frost relies upon the tilt of Mars around its axis. How much does it slants toward or away from the sun impacts temperatures in both its northern and southern hemispheres at specific times of the year. Currently, Mars has a tilt that is only marginally greater than Earth's. Our planet’s tilt Is believed to stay relatively unchanged due to the Moon's gravitational influence.

Nevertheless, Mars' moons, Phobos and Deimos, do not possess sufficient mass to generate substantial gravitational forces capable of stabilizing the planet’s axial tilt. According to scientific simulations, Mars’ axis can vary considerably over time—ranging from nearly zero degrees up to an extreme tilt exceeding 80 degrees. Although these models become less precise when projected too far back, conducting such simulations across vast timescales spanning hundreds of millions, or even billions of years, still aids in approximating the degree of tilting during specific epochs. A minimal tilt keeps the poles chilly, whereas a significant tilt causes either the northern or southern pole to more directly confront the Sun.

How then can tilt ascertain? potential habitability The hemisphere that tilts closest to the Sun undergoes extended summer periods where both carbon dioxide and ice sublime and remain within the atmosphere. Both CO2 and water vapor act as greenhouse gases. When Mars experiences higher temperatures, its atmosphere expands, retaining more heat and increasing surface pressure. This allows water on the surface to maintain a liquid state rather than freezing. Should Mars have hosted any sort of life forms at any point, they would most probably have thrived during those warmer epochs.

Billions of years ago, Mars might have resembled Earth. At one point, it possessed a dense atmosphere similar to ours, enabling liquid water to flow across its surface. In contrast to Earth, due to its smaller size, Mars has a less substantial iron core, preventing it from producing a sufficiently powerful magnetic field needed to retain such an atmosphere. As a result, the Sun-stripped red planet has become an excessively harsh environment for sustaining life (at least as far as we know). life as we understand it ).

By continuing to monitor the alterations in Martian ice formations, like frost-covered dunes that appear surprisingly appetizing, perhaps scientists will uncover evidence of past habitability on the planet.