Getting into space is one thing, but humans have long desired to find alternative places to live.
Before we can live on another planet, we have to find out whether it is habitable.
We can find out a lot of this information from space, but some things cannot be seen from space, such as finding life or analysing the soil for minerals.
So we need to land a probe or laboratory on the planet surface.
A lander is a remote controlled robot that lands on a planet's or moon's surface and take photographs and measurements.
A rover is a lander that can move around.
They perform experiments such as
Photograph from the surface of Venus taken by the short-lived Venera 13 lander sent by the Soviet Union in 1981. Landers to Venus do not generally survive longer than 2 hours because of the 457 C (855 F) temperatures.
They varied from the tiny Sojourner (on Mars) to the gigantic Curiosity (also on Mars)!