Scientists used to consider Mars a geologically dead planet. It's smaller than Earth and loses internal heat faster.
In the past, there was a lot of activity in its depths, and there are many traces of huge volcano eruptions on its surface.
The largest volcano in the Solar System, Olympus, can be seen from Earth even with an amateur telescope. But volcano eruptions on Mars stopped a long time ago.
The planet's interior cooled and solidified, the internal cooling weakened its magnetic field, the solar wind blew away the atmosphere, and the remaining water froze.
But recently, Mars has become more active. Everything changed when astronomers studied thousands of images of the Martian equatorial region.
The images were taken between 2006 and 2020 by the NASA Mars Reconnaissance Orbiter.
The HiRISE camera took the images at an altitude of 300 kilometers above the Martian surface. The images allow us to distinguish individual objects with a size of up to 1 meter.
The study revealed a large number of landslides and debris flows on the slopes of the Martian volcanoes. Scientists have discovered more than 4,500 traces of rocks that have left characteristic patterns in the shape of a Christmas tree, which usually happens after strong earthquakes.
The longest trace is more than 2.4 kilometers [1.5 miles] long and in total, these traces are around 900 kilometers [560 miles] long.
About a third of the traces weren’t present on images before 2006, indicating that they formed later.
It’s clear that only very powerful underground tremors are capable of moving these huge boulders.
However, until recently, such tremors weren’t found on Mars.
What helped scientists find out that Mars woke up? How did the recent samples taken from one crater almost come to life?
And why will one of the most harmful gasses on Earth be so crucial for Martian colonists?