Transit of Earth from Mars

Transit of Earth from Mars means that Mars can see Earth from where it is in space. This is possible because the orbits of Mars and Earth are very close together. When Earth is directly between Mars and the Sun, we call this a "transit," because from Mars' perspective, Earth appears to be crossing in front of the Sun. Transits happen very rarely because the two planets have to be in just the right positions for Mars to be able to see Earth crossing in front of the Sun.