Is Mars Still Geologically Active?

Or is it dead? If the interior of the planet has cooled off, there probably haven’t been any volcanic eruptions for 100’s of millions of years. If this is true, no hot springs, no geysers, no warmth…and likely, no life.
From what is known now (from our satellites and landers), is it a good bet that the planet is dead? Or do we have to go there to find out (manned expeditions).

Mars is likely still volcanically active, but at a very low level compared with Earth. Currently there is no evidence of any volcanoes that are active at the present time, but we have a couple of lines of evidence that volcanoes were active in the geologically recent past and therefore it’s likely that some may erupt again in the geologically near future (i.e. within a few million years).

First, we have meteorites that are actually volcanic rocks from Mars. These were ejected from Mars during impact cratering, and wandered the inner solar system until they happened to fall onto the Earth. There are several different classes of martian meteorite, and one class, the shergottites, have a grouping within them that have a measured crystallization age (the age in which it froze out after being a lava) of about 175 million years old. That may sound pretty old, but not much has happened on Mars for over 3 billion years. 175 million years ago on Mars, for all intents and purposes, is basically the present-day. Also, it is exceedingly unlikely that the impact crater that launched those shergottites into space just happened to form on the very youngest lava flow on Mars, so there are likely even younger lavas on the surface.

The best way to estimate the age of surface features on Mars is to count up the number of craters that have accumulated on them. The longer a piece of land sits on the surface of Mars (or any body in the solar system, for that matter), the more impact craters accumulate. Using estimates of the impact rate, we can estimate how old a surface is by counting up the craters. There are lava flows on Mars that are estimated to be only a couple of million years old. The caldera of Olympus Mons, for instance, has lava ponds that are estimated to be about 2.4 million years old, which, geologically speaking, is yesterday. And if there were lavas yesterday, there’s a good chance that there will be lavas tomorrow.

Mars has a lot of water ice in its subsurface which could melt during volcanic activity. Whether or not there is any life there on the planet in the present day, or in the distant past, is still an open question.

Mars is presently geologically active in the broader sense. There are active avalanches, dust devils, and sand dunes that creep across the surface. There are impact craters that have formed during the time that we’ve been surveying the surface. There aregullies and even evidence for relatively recent precipitation (maybe a thundersnow storm induced by a big impact).

Geothermal (areothermal?) isn’t the only source of heat for Mars. Even just from solar heating, like we rely on here on Earth, it still occasionally gets above the melting point of water, at some times and places. And it’s not impossible for life to survive in sub-freezing temperatures, anyway.