v0.2 - 25-04-2020
Not all lander missions target earth. Landings on Mars and Venus have been performed quite a few times. Landing on a different planet, however, has challenges of its own. Where Mars has a very lean atmosphere, Venus has an extremely thick atmosphere. Some landings occur on bodies where there is no atmosphere such as the moon, or sometimes even without the presence of a significant gravitational field.
Mars is one of the most explored planets in our solar system. Ever since the start of the space race, it has been a target for planetary exploration missions including several landers and rovers. Landing on Mars is notoriously difficult as the atmosphere is quite lean, thus atmospheric deceleration is low.
The second rock from the sun has been a target for mainly Russian landers. The planet is characterised by its extremely high atmospheric pressure making landings both easier and harder. The surface of the planet is known for its immense temperature and pressure making survival hard as well.
Earth's moon has low gravity and no atmosphere. This makes parachute landings infeasible. However, the story of moon missions is quite interesting as the engineers had no idea what to expect after landing. As Earth is not the only planet with a moon, missions to other moons, such as Huygens, are also discussed.
The outer planets are called gas giants. They are Jupiter, Saturn, Uranus and Neptune respectively. So far only one mission dove into the thick atmosphere of these gas giants.
Asteroids or comets are bodies in space that are small, sometimes not more than a few meters in diameter. This means that these bodies have very low gravity and thus landing on them becomes much more challenging.