Mars



Mars is the 2nd smallest planet in the solar system and is the 4th farthest from the Sun. It is also the 2nd closest from Earth. It has a red surface and a thin atmosphere. It also has a low density than the other terrestrial planets, making it the least dense terrestrial planet. It is around 6000 km in diameter, just a bit larger than the largest moon in the solar system, Ganymede.

Exploration
NASA has sent many rovers to mars to explore the surface of it. There are the viking 1 and 2 rovers, the small 1997 sojourner, 2004 opportunity and spirit, 2011 curiosity and 2020 perseverance. Also more rovers not by JPL phoenix in 2008 and insight in 2018. The USSR/Russia has also sent a few missions to mars.

History and Alien Life
Mars is belived to have a magnetic field when it was just formed. After it has cooled down enough, liquid water appears on its surface, and probably life too (along with earth and venus).

As mars is small and its core is not very hot compared to the other rocky planets (earth and venus), the core cools down faster, and the core cooling down and eventually solidifying causes the magnetic field to deactivate. No magnetic field means that nearly all liquid water and atmosphere is stripped away by solar winds.

Today, mars contains certain rocks and surface features that gives evidence that water has once existed there. Ice is also present on mars today.

Volcanos, Valleys, Craters, and Dust Devils
Mars is known for having the tallest volcano in the solar system, Olympus Mons, with a height of more than 22 kilometers, almost 3 times the size of Mount Everest

Mars has loads of valleys and craters that are caused by surface changing events or an impact from an asteroid.

Mars has "dust devils", which are simply really small dust storms. Despite being named after dust, dust devils clears dust and has been very useful for the solar-powered NASA rovers.