The first planet on the other side of Earth further from the sun is Mars.
Mars is sometimes called the red planet, and you can see why!
(from: wikipedia - mars)
Mars is the second smallest planet in our solar system,
the temperatures are as cold as −225°F and hot as 95°F.
but it's possible that astronauts could survive in space suits on the planet's surface.
Scientists have been very curious about Mars, since it's so close.
There are two robotic machines on Mars right now:
NASA's Opportunity rover, which landed on January 25, 2004
(from: wikipedia - opportunity rover)
NASA's Curiosity rover, which landed on August 6, 2012
(from: wikipedia - curiosity rover)