A space probe is a spaceship that travels through space collecting space science information and sending them back to scientists on Earth to analyse like pictures, mass, density and chemical composition of the planets and objects in space. They are normally unmanned. The first probe into space was Sputnik 1.

The probes that went to moon are Luna 9, Luna 3, Luna 16 and Lunokhod 1. Mariner 10, the first probe to Mercury. Probes to Venus are Venera 4 and Venera 7. The probes that are sent to Mars are Mariner 9, Mars 3, Sojourner, Spirit and Opportunity. Pioneer 10, the first probe to Jupiter. The first probe to Saturn is Pioneer 11.

Voyager 1 was launched in September, 1977. It is still operational and had trekked past Jupiter and Saturn. It is the longest lasting mission for NASA and is the farthest man made object from Earth. It was 12 billion miles from the Sun as of September 12, 2013. (Credit:en.wikipedia.org/wiki/Space_probe)