Hi Students,

Ladies, I'll take this one also. We've been to Mars since Mars is the most "Earth-like" planet in our solar system. There is an atmosphere, it does contain oxygen, but at low levels, and carbon dioxide, a lot. There's evidence of strong, past volcanic activity on the planet as well. There are also numerous valleys, and large channels that suggest water flowed on Mars in the distant past, how long ago, not sure. The hunt for "life" as we know it, is following what's called the "water" trail! While we've found water, and Ice on Mars, we've not found positive proof of life there today or in the past, thus it will require more than likely visits by future Astronauts to determine this.

Regarding Venus, its simply too "HOT" An average surface temperature of more than 850 Deg F. It to is a highly "volcanic" world, with literally thousands of volcanoes on its surface, its the kind of place you would not want to go on summer break!

See this link on Mars exploration;

http://marsrovers.jpl.nasa.gov/home/index.html

It gives you all the data, photographs, etc on the Mars Exploration Rover Missions... Visit their homepage... The next scheduled Robotic Rover going to Mars is scheduled for next Year, named Curosity!