Mars is the fourth planet from the Sun and the second closest planet to Earth. Although Venus is called Earth's sister planet, Mars is more similar to our home planet in many ways. A Martian day, at twenty-four and a half hours, is almost equal to an Earth day. At 687 Earth days, a year on Mars is almost twice as long as an Earth year. Mars is about half the size of our globe, however because of Earth's oceans, the total amount of land surface area is about the same.
Mars experiences seasons but unlike Earth, Martian seasons are due to the elliptical shape of its orbit and not the tilt of its axis. A summer day on Mars can be as warm as 80 degrees Fahrenheit, but a cold winter night near one of the poles can be as frigid as -200 degrees Fahrenheit.
Mars experiences much activity. Dust storms can toss the red Martian dirt into the air and obscure the surface for weeks at a time. Its thin atmosphere is made almost entirely of carbon dioxide, including the ice that forms at the poles during winter. Mars also has shown evidence of a watery past. The channels cut into the rock and dirt on the planet were carved by flowing water, suggesting that Mars was once a very different world from the one we see today.
One of the most amazing features on Mars is the dust devils that can form and twirl across the landscape. These tightly spinning sandstorms would certainly cause problems for human inhabitants. The Mars rover Spirit has even captured a dust devil in action. You can view the whirling winds at NASA's web site.
Some of the surface features on little Mars greatly outrank Earth's most impressive landforms. For example, Mars's Olympus Mons is the largest volcano in the entire solar system. Valles Marineris, sometimes called the Grand Canyon of Mars, is in fact much larger than Earth's Grand Canyon. Valles Marineris is up to seven times deeper than Arizona's Grand Canyon and would stretch from the West to East coast if placed in the United States.
Mars has two small moons that were once asteroids from the nearby asteroid belt that made passes close enough to the Red Planet to be sucked in to its gravitational field. Phobos, meaning "fear," is the bigger of the two moons and closer to the planet. Deimos, meaning "panic," is the smaller satellite and farther out.
Despite excitement over the reported "canals" on Mars or the meteorite ALH 84001 from Mars that once was thought to harbor a fossil of Martian life, Mars is currently considered a dead world. Numerous missions to the planet, including Viking, Pathfinder, Mars Global Surveyor, and Mars Climate Orbiter have found no evidence of life. This is not to say that life does not or has never existed on the planet. But for now, we have no evidence that is does. Although there is no current spaceship in the works for Mars or a date and price tag set, Mars is the next solar system object that humans are determined to explore. Maybe when we reach Mars we will be able to explore the nooks and crannies more thoroughly in our search for life. Or maybe it will be Earthlings who create and sustain a new life on Mars.
For more on the solar system, follow the links below.
Sun Mercury Venus Earth Jupiter Saturn Uranus Neptune
Kelly Whitt - I have been a professional writer for more than a decade, covering many topics from science-based articles to do-it-yourself home ...
