What are glaciers?

Glaciers are massive rivers of ice that move downhill under the force of gravity. Most people on this planet would be able to identify a glacier if they saw one, but fewer would be able to recognise landforms that have either been made as a result of the glacier’s erosional power or that have been deposited by them. Form Drumlins, Cirquees, Arrets, and Roche Moutonnée.

Figure 1 – Image showing the Morteratsch Glacier in Switzerland

However, something that might have alluded to you, as it did to me for many years, is the formation of these landforms on other planets. For many years now, we have been scouring the skies looking for other planets that may harbour life, but so far we have been unsuccessful. However, recent findings from Bennu show a significant amount of water on the asteroid. Furthermore, when looking at distant planets like Mars, we can see evidence of ancient river channels and steep valleys, all suggesting that water once flowed on the planet’s surface. Therefore, would it be stupid to suggest that glaciers may have once carved their way through the Martian landscape many millions of years ago?

The answer to this is a resounding no, as thanks to the great work of institutions like NASA, we have not only countless images of the red planet but also satellites and rovers on and around the planet. These have not only contributed to the discoveries that have been made but are also allowing for further research into the matter.

How do they form?

To understand what they are, we first need to understand how they form, and to do this, we will look at examples on Earth. The main feature we will be looking at is the basic glacier valley, otherwise known as a U-shaped valley. These valleys were most probably river valleys that were then glaciated during the last glacial maximum around 18,000 years ago. A river would carve a steep V-shape into the rock. Then, when the glaciers advance down through the valley, they change the shape of the landscape by eroding the slide of the valley, which would steepen the walls. This often creates a landscape that has a large valley with a small river, creating the illusion that the river has eroded the whole valley.

Even though some of them are 10’s, if not hundreds of thousands of years old, we can still see them on our planet’s surface, even with our highly volatile climate. Therefore, the argument that these features would still be visible on the Martian surface is very likely, especially considering the only erosional force on Mars is wind.

Mars

The famous red planet, a place where some of the world’s richest and most powerful men have set their eyes, is the fourth planet from the Sun in our solar system and the second-smallest behind Mercury. The planet’s surface is scarred with tales of its past in a world roughly 1,000 times drier than Earth’s (B. Hubbard, 2014). From Valles Marineris, which is the largest canyon in the solar system, to the great Olympus Mons, which is the highest mountain in the solar system, it is around two and a half times the height of Everest. (NASA, 2024)

More than 1,300 glacial landforms are found in the mid-latitudes of the Martian surface; these include deposits of dust that mimic the flow of ice down a mountainside. (B. Hubbard, 2014)

Figure 2 – Eskers on the surface of Mars. Source: NASA/JPL-Caltech/Arizona State University

Figure 2 shows eskers, which are formed when subglacial streams backfill themselves and fill with sediments and rocks. When the glacier melts, these long ridges are left behind. Lots of these ridges have been found on the Martian surface, but to get a definitive answer, a sample of them would be required to see what they are made from. (Arizona State University, 2024)

The polar regions of Mars are covered in a permanent cap of ice. The ice caps are predominantly water ice, with the diameter of the northern ice cap measuring 1100 km compared to 400km on the southern ice cap. The southern ice cap is much thicker than the northern ice cap, meaning both ice caps have a similar volume. (AntarcticGlaciers, 2020)

Future

In the near future, when humans set foot on their first planet, it will be of paramount importance to make sure the astronauts have a safe, reliable source of water, so information on past ice flow at least proves water was present on the Martian surface. In 2018, it was revealed that the European Space Agency Mars Express spacecraft had used its onboard sensors to detect a possible subsurface lake beneath the polar ice cap.

Mars has about 5 million cubic kilometres of ice near or at the planet’s surface, which could be a major lifeline for humans employing practices used in Antarctica, where you go a long way away from camp and place a heater down the whole way to melt the ice, pumping it out once it has melted. (Davis, 2022)

Hopefully, answers to the questions posed by scientists will be answered once humans make it to the planet and are able to take samples of some of the planet’s features.

Bibliography

AntarcticGlaciers, 2020. Introduction to Glaciers on Mars. [Online]
Available at: https://www.antarcticglaciers.org/glacial-geology/glaciers-on-other-planets/glaciers-mars/
[Accessed 16 February 2024].

Arizona State University, 2024. Glacial Evidence. [Online]
Available at: https://marsed.asu.edu/mep/ice/ice-ages/glacial-evidence
[Accessed 13 March 2024].

B. Hubbard, C. S. a. S. B., 2014. Glacier-like forms on Mars. The Cryosphere, Issue 8, pp. 2047-2061.

Davis, J., 2022. Your guide to water on Mars, s.l.: The Planetary Society.

NASA, 2024. Valles Marineris: The Grand Canyon of Mars. [Online]
Available at: https://science.nasa.gov/resource/valles-marineris-the-grand-canyon-of-mars/
[Accessed 16 February 2024].