Opportunity and Spirit,
No one has sent 15 rovers to Mars
THEY WERE SENT TO MARS SO THAT WE CAN DISCOVER MANY NEW THINGS ON MARS!!!
We have sent rovers to Mars but there have been no manned missions.
Yes, we have sent many probes and some rovers to Mars.
7 rovers have been sent to mars. The first one landed in 1971
There are no plants on Mars. We know this because of the rovers we have sent and the satellites we have taking pictures of the planet.
4 - Pathfinder, Spirit, Opportunity, Curiosity
Probes, satellites, and rovers have been sent to the planet Mars. These devices have been able to gather data, pictures, and materials from the planet.
"Spirit" and "Opportunity". Those two were sent in January, year of 2004. Before that a small one called "Sojourner". And now "Curiosity", of course. So that's 4 altogether. That's not counting those that failed.
None. Saturn does not have a solid surface. There is nothing to land a rover on. The only planet to which rovers have been sent is Mars.
2:12:15:40 sols:hours:minutes:seconds
We have looked at at the surface of Mars and seen the rocks and have even sent rovers there to take samples of those rocks.