Phobos

Satellite Mean distance from planet (miles) Maximum diameter (miles)

Phobos 5,830 17

Table of moons

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The Earth Scientist, Volume XXVI, Issue 1, Spring 2010

This very special issue of The Earth Scientist (our biggest ever!) is sponsored by the Cooperative Institute for Climate and Ocean Research at the Woods Hole Oceanographic Institution and is focused on the world’s oceans....more

Lower Atmosphere

The atmosphere of Mars is much thinner than that of Earth, with a surface pressure averaging 1/100th that at the surface of the Earth. Surface temperatures range from -113oC at the winter pole to 0oC...more

Planet Structure

The uniquely red global surface of Mars is marked by many interesting features - some like those on the Earth and others strangely different. The reddish color is caused by rust (iron oxide) in the soil....more

Martian Global Dust Storms

This image shows a local dust storm near the edge of the south polar cap. Viewing of this image at high resolution is recommended. This fascinating image shows dust swirling over a large area. Martian...more

An Overview of the Mars '98 mission

The Mars '98 mission was supposed to study the climate, weather, and surface at the Martian south pole. Mars '98 was to build upon the discoveries of the Mars Pathfinder and Mars Global Surveyor missions...more

An Overview of the Mars Global Surveyor Mission

The mission of Mars Global Surveyor (MGS for short) is to map the surface of Mars from space, a mission somewhat like to the Magellan mission to Venus. The mission is also investigating the topmost portion...more

Mars Observer

The Mars Observer set out to observe the atmosphere , magnetic field, and surface of Mars. It carried with it 8 instruments. However, the Mars Observer (called MO for short) failed on August 21, 1993,...more

The Lamb

The small, round rock shown here was named The Lamb. It was found as part of Mars Pathfinder's investigation of the surface of Mars. This rock is special because of the soils found around the rock. They...more

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