So to add some #scicomm to all your timelines, I’m going to talk about volcanoes on Mars! I’ll discuss general volcanism, how it is similar to volcanoes here on Earth, and specifics on the inactive (but possibly active!) volcanoes on the red planet! 🌋 (1/16) 
So, what are volcanoes? Volcanic activity occurs when the internal heat of a planet causes rock to become molten. The molten rock, or magma, consists of silicates, other minerals, and dissolved gas such as water vapor and CO2. (2/16)
The magma then ascends through the planet’s crust due to it being less dense compared to the surrounding rock. Once it has reached a similar density, it either forms a magma chamber or erupts onto the planet’s surface, becoming lava. (3/16)
Magma can erupt either quietly or explosively depending on how much gas is dissolved within it. As magma ascends, the decreased pressure leads to gas bubbles forming, and more gas will lead to a disruptive eruption. The creation of bubbles... (4/16)
...also leads to the creation of glassy shards that can erupt as tephra, or otherwise known as volcanic ash. This volcanic ash can also contribute to climate change, specifically global warming due to the spewing of CO2, a greenhouse gas. (5/16)
The most common type of volcanism on both Earth and Mars is basaltic. Basalts are igneous rocks that are rich in magnesium and iron and look black. Iron-rich basalts lead to more fluid flow, like syrup. High-silica magma is instead stiffer. (6/16)
Volcanic activity on Mars is slightly different from Earth mainly due to its weaker gravity and thinner atmosphere. Lower gravity leads to much deeper and larger magma chambers, and when you add the thin atmosphere, it takes more time... (7/16)
...for the lava to cool, which leads to the flow going much farther than it would on Earth, and also volcanic ash traveling and expanding further. Another difference between volcanism on Mars and Earth is the huge size difference... (8/16)
...that is caused by the details I mentioned earlier. On Mars, the largest volcanoes hail from the Tharsis and Elysium regions. They consist of many shield volcanoes, which are volcanoes that are much wider than they are high. (9/16)
One of the most famous volcanoes from this region is the shield volcano Olympus Mons, which is actually the largest volcano in the entire solar system! It is about twice as high as Mount Everest, and is comparable to the second largest... (10/16)
...shield volcano here on Earth, Big Island of Hawaii. Geologists also believe that Mars volcanoes grow so large because of the lack of tectonic plates on Mars. The lack of movement allows a hot spot to grow in a singular location. (11/16)
The Tharsis region, which consists of built upon layers of lava and volcanic ash contains some of the youngest lava flows, but the bulge itself is supposedly very old. It may have even altered Mars’ rotational axis and affected climate. (12/16)
Volcanic eruptions on Mars has affected a lot of its landform, and something that scientists are researching right now is whether these volcanoes are truly inactive, or whether they’re just in a quiet period. The slopes of Tharsis... (13/16)
...volcanoes show only little amounts of impact craters, which can hint at the fact that the lava flows are relatively young. Geologists have estimated the lava flows to be just millions of years old. This is research that is still ongoing! (14/16)
There is still a lot to learn about volcanoes on Mars, and missions like the Curiosity Rover and InSight lander helps provide more information! Maybe even future astronauts on Mars (like myself 😎) can also contribute to this research! (15/16)
Well, I hoped you guys liked this short and slightly informative thread on Mars volcanism, and as always please let me know if there is anything I need to correct. Next time I’ll talk about what terraforming Mars would take! (16/16)
