Get a printable version of this page. Mars Odyssey may be on its way to the red planet, but it recently sent back a photo of Earth and the Moon it took while speeding away from us. Pioneer 10, the most distant man-made object from Earth, is still operating after 29 years in space. Scientists recently detected its faint signal. Distance Gardening When humans one day travel to Mars, they'll need to bring along plants to grow as a food source.
Some researchers believe it's time to find out.