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The fourth planet from the Sun. Mars orbits the Sun at an average distance of 1.52 times Earth’s distance. The planet is about 10 percent as massive as Earth, and a bit more than half as big. It is made of solid, rocky material, and has a thin atmosphere of carbon dioxide. Iron oxide, or rust, on the surface of Mars gives it its characteristic red color. The planet has bright polar ice caps made of frozen water and carbon dioxide. Mars also has two small moons, Phobos and Deimos.


Mars' Moons February 19, 2016


Mars February 10, 2016

Radio Programs

Moon and Mars Digging deep valleys on Mars February 10, 2019

Mars and Uranus Red and green in the evening sky February 9, 2019

InSight at Mars Looking deep into Mars November 24, 2018

Challenging Arrival Tricky arrivals at Mars November 23, 2018

Moon and Mars Bright “beanie caps” for Mars November 15, 2018

Friendlier Mars A friendlier planet Mars October 28, 2018

Moon and Mars A dark season on Mars October 17, 2018

More Moon and Mars Keeping the planet Mars active August 23, 2018

Moon and Mars Hovering above the surface of Mars August 22, 2018

Moon and Mars Ambitious plans for the planet Mars July 27, 2018

Martian Grub Growing vegetables on Mars July 25, 2018

Mars and Company Bright sights in the night sky July 24, 2018

Mars at Opposition The Red Planet shines bright July 23, 2018

Moon and Mars Sniffing for life on Mars June 29, 2018

More Moon and Mars Digging deep into the Martian surface June 3, 2018

Phoenix Mars Digging up ice on Mars May 24, 2018

Tharsis Ridge Scaling the Martian heights May 23, 2018

Martian Autumn A new season for the Red Planet May 22, 2018

Moon and Mars “Hot spots” on the surface of Mars May 5, 2018

InSight New insights into the Red Planet May 4, 2018

Moon and Mars Dusty skies for the Red Planet April 7, 2018

Mars and Saturn Sibling worlds in the morning sky April 1, 2018

Moon, Mars, and Saturn Drying out Martian streams March 9, 2018

Moon and Mars Living on a new world March 8, 2018

Red Rivalry Colorful rivals in the dawn sky February 8, 2018

Moon and Mars More water on two nearby worlds December 12, 2017

Moon and Mars Making moons over and over again November 14, 2017

Moon and Mars A long period of quiet on Mars October 16, 2017

Mars Returns Stepping toward the Red Planet September 15, 2017

Looking for Canals II Sensational reports from Mars August 4, 2017

Looking for Canals Looking for Martian canals August 3, 2017

Mars Pathfinder Blazing a path on the Red Planet July 4, 2017

Martian Spring Springing into a new season May 5, 2017

Moon and Mars Looking for “gassy” microbes on Mars March 30, 2017

Moon and Planets Climbing through Martian history February 28, 2017

More Moon and Planets Digging up Martian ice January 31, 2017

Moon and Planets Too hot, too cold, and just right January 30, 2017

Moon and Mars Drying out some Martian gullies November 5, 2016

More ExoMars A dress rehearsal for a Mars rover October 17, 2016

ExoMars Lining up an approach to Mars October 16, 2016

Moon and Mars Making ice on a warming planet October 7, 2016

More Moon and Planets Variety in the evening sky October 6, 2016

H.G. Wells Creating an alien invasion September 21, 2016

Mars and Antares Rivals line up in the evening sky August 23, 2016

Martian Tsunami Churning up the Martian ocean August 3, 2016

Moon and Mars Boiling up an avalanche July 13, 2016

Moon and Mars Heating up the Red Planet June 16, 2016

Mars Opposition V Seeing things on the Red Planet — after this. May 22, 2016

Mars Opposition IV Lining up the Red Planet May 21, 2016

Mars Opposition III Living on Mars — sort of May 20, 2016

Mars Opposition II Stripping away the Martian atmosphere May 19, 2016

Mars Opposition A planet makes its own skin crawl May 18, 2016

Moon and Planets A beautiful morning quartet April 24, 201