Mars

	Diameter		4,222 miles (6,794 km)
	Average Distance from Sun		141,600,000 miles (227,900,000 km)
	Planet Composition		rock and metal
	Atmosphere		thin carbon dioxide
	Average Temperature		-85°F (-65°C)
	Number of Moons		2
	Orbital Period		687 days
	Period of Rotation		24 hours 37 minutes

The red color of Mars is caused by iron oxide, or rust, in the soil. In the picture above, a cloudy haze makes the atmosphere a slight blue color, and the frozen water and carbon dioxide at the polar icecaps appears white.

Mars has a gigantic canyon five miles deep and almost 2,000 miles long. That could stretch across most of the United States!

Mars has the largest volcano in the solar system. Olympus Mons is 15 miles high and nearly as big as the state of Texas.

Weather on Mars

Mars is more like Earth than any other planet in the solar system. It is about half Earth's size, and its rotation and axis tilt are nearly identical. However, it is much colder, and its thin atmosphere has almost no oxygen for us to breathe. There is no liquid water on the surface, but there is ice frozen underground and in the polar ice caps.

If there is any life on Mars today, it is probably just simple bacteria buried in the soil.

Mars probably had a thicker atmosphere in the past, allowing liquid water to form rivers and lakes on its surface. Perhaps it had complex life forms long ago that died out when the environment changed.

Mars has two tiny moons that are probably captured asteroids: Phobos and Deimos.

Links

quest.arc.nasa.gov/mars/background/ The Mars Team Online provides facts about Mars and lots of links to information about Mars probes, missions, and research projects.

Activity Idea: teachspacescience.stsci.edu/graphics/pdf/10000273.pdf the Destination: Mars activity packet encourages students to learn about scientific exploration on Mars. It includes lessons on navigation and trajectory, soils, making and mapping volcanoes, and understanding geological sequence of events while mapping craters and river channels. This guide is available free for download in PDF format.

Activity Idea: www.thursdaysclassroom.com/index_02dec99.html has information about looking for extraterrestrial life, especially on Mars. It includes stories about an imaginary Mars Vacation, Martian Math, a bar graph exercise, and activities about planning for human exploration and colonization of the Red Planet.

Mars: Planet 4

Links