Hi Jeremy,

Wow! I didn't know that solar eclipses had been observed on Mars. I will have to remember this for the class I am teaching on the solar system. Most scientists tend to be very focused on one particular area of research, so I'm not sure if any of the other Solar Week scientists will know any more about the solar eclipses observed on Mars than I do.

Below is a link to an article that talks about the eclipses observed on Mars.

http://www.space.com/news...onshadow_991102.html

According to the article, solar eclipses on Mars are thousands of times more frequent than on Earth. Mars has two small, irregularly shaped moons named Phobos and Deimos. One of Mars' two small moons casts its shadow on the surface of Mars a few times each day. A partial or total solar eclipse can be seen from Earth only once or twice a year, and then it is only visible to observers located on a very narrow region of the Earth's surface.

Although solar eclipses occur more often on Mars than they do on Earth, an observer on Mars would never see a total solar eclipse. Because of its distance from Mars, the Sun appears to be only about two-thirds of the size it looks from Earth, but Mars' moons Phobos and Deimos are still not large enough to block out the entire Sun. We can see total solar eclipses on Earth because it just happens that the angular size of the Moon is almost the same as the angular size of the Sun as viewed from Earth. This means that if the alignment of the Earth, Sun, and Moon are in the proper alignment, Earth's Moon is big enough to block out the entire Sun as viewed from Earth.

Although most of the popular science articles I found about the Mars rover observations call these events "eclipses," scientists generally use the term "transit" for an "eclipse" in which the intervening body covers only a small fraction of the more-distant body. For example, transits of the sun by Mercury and transits of Jupiter by Jupiter's moons are common observations from Earth.