yes cassinni
no
I don't know of any planet with exactly 21 known moons. The best answer is probably "Uranus" with 27 moons (natural satellites).
As of now, no robots or satellites have explored Eris directly. Eris, a dwarf planet located in the Kuiper Belt, has only been observed from afar using telescopes. The most detailed observations of Eris were made by the Hubble Space Telescope and other ground-based observatories, but there are currently no missions planned to visit or study Eris up close.
Betelgeuse is a star, not a planet, so it does not have any satellites. Satellites, also known as moons, typically orbit planets, not stars.
Saturn is a planet with thousands of rings. There are three other planets in the solar system with rings, which are Jupiter, Neptune, and Uranus.
Yes
yes
does saturn have satellites or robots
everything sucks
no
I don't know of any planet with exactly 21 known moons. The best answer is probably "Uranus" with 27 moons (natural satellites).
No they mostly looked at Mars.
no there hasnt been any robots or anything
no
it has neither. also there are no man made orbiting spacecrafts.
Yes, there are satellites in orbit that record information about our planet.
True. Uranus has 27 known moons, which is more than any other planet in our solar system.