Planet Mars Facts - Mars Pictures

Planet Mars

Sunset on Mars

Spectacular image of a Martian sunset taken by NASA's rover Spirit

Martian crater

NASA's rover Opportunity explores the edges of a Martian crater

Planet Mars Facts

Mars is the fourth planet from the sun, its diameter is only around 4,200 miles (6800 km) which is half the size of Earth.
It travels around the sun every 687 days and rotates on its own axis every 24 hours 40 minutes.
The average distance from Mars to the sun is around 142 million miles (228 million km), one and half times further away from the sun than our planet.
The distance between Mars and Earth varies, from as little as 34 million miles (55 million km) to as much as 249 million miles (401 million km).
There are vast amounts of ice under the Martian surface, most of it near the South Pole.
Evidence shows that water used to flow on the surface of Mars.
Mars has seasons just like Earth.
Gravity on Mars is around two fifths of that on Earth.
Clouds made from frozen CO2 form in the Martian sky. Haze and fog are also common.
Dust storms on Mars can last for months and cover the entire planet.

Surface, Atmosphere & Temperature

Surface

Mars has similar surface features that exist on Earth such as plains, valleys and polar ice. The main difference is that craters occur all over the planet. There are also mountains larger than Mount Everest.

Atmosphere

The thin atmosphere of Mars is only around 1% the density of our own atmosphere. It consists mainly of carbon dioxide 95.3%, the rest is made up of 2.7% nitrogen, 1.6% argon, 0.13% oxygen, carbon monoxide and water vapor make up 0.10%.

Temperature

Surface temperatures on Mars vary from as low as -125C (-195F) near the poles to as high as 20C (68F) at midday near the equator.

Moons, Name and Life

Mars thin atmosphere

Moons & Origin of Name

Mars has two very small moons, Phobos which has a diameter of 17 km (28 km) and Deimos which has a diameter of 9 miles (15 km).
It is probable that they were once asteroids that were caught by the gravity of the planet.
Mars is named after the Roman God of War.

Life on Mars

Mars may once have harbored life and may still do today. Most likely life could exist in warm pockets beneath the ground, methane has been detected in the Martian atmosphere which could have been produced biologically. In the summer months the amount of methane increases dramatically giving further credence to this theory.

Colonizing Mars

When considering planets in the solar system that mankind can colonize there really only is one candidate. The two rocky planets close to the sun, Venus and Mercury, are baking hot infernos and the gas giants such as Jupiter and Saturn have no solid surface. So that leaves us with Mars, even though it is extremely inhospitable to humans in most respects it is by far the most Earth like when compared to the other planets of our solar system.

The red planet has many qualities that make it attractive to prospective colonizers such as its closeness to Earth, the familiarity of a 24 hour day or the fact that Mars has seasons just like on Earth. Undoubtedly though the most important quality is the abundance of water on Mars. Underneath its surface lies a thick layer of water ice, apart from its obvious uses such as drinking, cooking and hygiene, water can also be used for energy, such as rocket fuel by separating the hydrogen and oxygen.

Bases could be built on Mars in the form of interconnecting reinforced domes which allow for the largest space with the least amount of materials. Colonies would eventually become completely self sufficient, growing their own food, perhaps hydroponically, without the need for soil. Mars could also be used as a base for mining the incredible mineral wealth of the asteroid belt, the iron taken from there could be used to build more structures on the surface without the need of supplies from Earth, which could see colonies rapidly grow.

Of course there are many hazards on Mars, the thin atmosphere gives little protection from the suns rays so radiation levels are very high. Temperatures even in the warmest areas of Mars can dip below -60C (-80F) and there are frequent massive dust storms, you don’t want to be going for a walk on Mars unless you are very well protected. Another factor that needs to be taken into account is that gravity on Mars is only around two fifths of what we experience on Earth, this may not be enough to stop our bones and muscles from deteriorating, daily exercise may have to be part of a colonizers routine.

Even with all the dangers Mars poses there would be no shortage of volunteers to become 21st century pioneers. Many will not be able to resist the lure of visiting an alien planet, witnessing a red sky or visiting the breathtaking canyons and volcanoes that exist on Mars.

Images and Video

The Red Planet

Cloud movement over Mars

Mars North Pole

The surface of Mars (Pathfinder Lander)

Future and Past Missions to Mars

20.

ExoMars

Launch: 2018
Agency: ESA (Europe)

The ExoMars rover will be designed to search for life on Mars.

19.

Maven

Launch: 2013
Agency: NASA

The Mars Atmosphere and Volatile Evolution Mission will address key questions about Mars climate and habitability.

18.

Mars Science Laboratory (MSL)

Launch: 2011
Agency: NASA

MSL will be the next generation of Mars rovers, it will employ a rocket and cable assisted descent mechanism in order to reach a landing site in more rugged terrain.

17.

Yinghuo-1

Launch: 9th November 2011
Agency: CNSA (China)

China's first planetary mission will perform studies of Mars from an elliptical, equatorial orbit.

Update: Yinghuo-1 was on board the same rocket as Phobus-Grunt (see below for details).

16.

Phobos-Soil (Phobos-Grunt)

Launch: 9th November 2011
Agency: RFSA (Russia)

Designed to land and collect samples from the Martian moon Phobos and storing them within a capsule, the craft will then pass by Earth releasing the capsule which will be picked up for study.

Update: The Soyuz rocket carrying Phobus-Grunt launched successfully but unfortunately while in Earth orbit the engines which would have set it on course to Mars failed to fire.

15.

Phoenix

Launch: August 2007
Arrival: May 2008
Agency: NASA

Landed near Mars north pole to study the water ice found there.

14.

Mars Reconnaissance Orbiter

Launch: August 2005
Arrival: March 2006
Agency: NASA

MRO is searching for evidence of past water on Mars and also looking for future landing sites. It will also act as a communications relay for future missions.

13.

Mars Exploration Rover Opportunity

Launch: July 2003
Arrival: January 2004
Agency: NASA

Opportunity is still roving across the Martian landscape finding abundant evidence for the action of liquid water. It has survived many times longer than planned.

12.

Mars Exploration Rover Spirit

Launch: June 2003
Arrival: January 2004
Agency: NASA

Spirit had to rove several kilometers before it found evidence of past water. It is now exploring ancient Mars rocks preserved in mountains. It has survived many times longer than planned.

11.

Mars Express

Launch: June 2003
Arrival: December 2003
Agency: ESA (Europe)

As it entered orbit Mars Express immediately began returning stunning 3D color images. It also detected surprising levels of methane and evidence for recent volcanic activity. Unfortunately the lander it carried, Beagle 2, apparently crashed into the Mars surface.

10.

Mars Odyssey

Launch: April 2001
Arrival: October 2001
Agency: NASA

Mars Odyssey is capturing images of the Martian surface and has detected massive deposits of water under the near polar regions. It also serves as a communications relay for the exploration rovers.

Mars Pathfinder & Sojourner

Launch: December 1996
Arrival: July 1997
Agency: NASA

Successfully landed on the Mars surface, the six wheel rover Sojourner also successfully rolled of the ramp onto land returning images and weather data. The mission scheduled to last 30 days lasted almost 3 months.

Mars Global Surveyor

Launch: November 1996
Arrival: September 1997
Agency: NASA

Initially had problems on its arrival due to an issue with one of its solar panels. It wasn't until a year and a half later that it started returning a wealth of data and high resolution images. Contact was lost in November 2006.

Viking 2

Launch: September 1975
Arrival: August 1976
Agency: NASA

The Viking 2 lander successfully touched down on the planet taking extensive atmospheric readings and conducting experiments on soil samples. The lander functioned for 4 years observing several winters which covered it in an extremely thin layer of frost. The orbiter was shut down in July 1978. Between them the two landers had taken 1,400 images of the Martian surface and the orbiters 50,000 images creating a global map which is still used today.

Viking 1

Launch: August 1975
Arrival: June 1976
Agency: NASA

Entered Mars orbit and immediately began searching for a safe landing site for the lander. The lander successfully touched down on the Mars surface taking extensive weather readings and conducting experiments on soil samples collected with a scoop. The orbiter was powered down in August 1980. The lander survived until November 1982.

Mars 4,5,6 and 7

Launch: July - August 1973
Arrival: February - March 1974
Agency: Soviet Union

Mars 4,5,6 and 7 were rushed forward by the Soviets in an attempt to get a craft on the Martian surface before the United States. As a result they were mostly unsuccessful. Even so they did still manage to send back some data before they're quick demise including taking images and gathering data on the atmosphere. Notably Mars 6 did manage to launch a lander into the Martian atmosphere which broadcast data for almost 4 minutes before abruptly cutting off.

Mars 2 and 3

Launch: May 1971
Arrival: November - December 1971
Agency: Soviet Union

Mars 2 and 3 had the misfortune to arrive at Mars during one of the worst dust storms ever recorded there. Even so one of their landers managed to touch down briefly on the planet's surface before being apparently blown over after only 20 seconds. The orbiters were somewhat more successful returning images, recording temperatures and studying the Martian atmosphere.

Mariner 9

Launch: May 1971
Arrival: November 1971
Agency: NASA

The first spacecraft to go into orbit around another planet. It had to wait a month and a half to begin its mission as a dust storm had covered the entire planet. Afterwards though it sent back a whole raft of data including over 7,000 images of Mars, the atmospheric and surface composition, density and pressure of its atmosphere, also details about the planet's gravity and topography. On top of that it also sent back the first close up images of the two moons of Mars, Phobos and Deimos.

Mariner 6 and 7

Launch: February - March 1969
Arrival: July - August 1969
Agency: NASA

Mariner 6 and 7 successfully flew by Mars collecting data on the mass, radius, the shape of Mars and the composition of its southern ice cap. Between them they took 200 images.

Mariner 4

Launch: November 1964
Arrival: July 1965
Agency: NASA

The first spacecraft to fly past Mars taking close up images of the planet. It also confirmed the existence of a thin atmosphere consisting mainly of carbon dioxide.

Mars Statistics

Comparison with Earth

Diameter: 4,212 miles (6,779 km)
Average Distance from Sun: 142 million miles (228 million km)
Orbital Period: 687 days
Rotation Period: 24.62 hours

Maximum Surface Temperatures: 20C (68F)
Minimum Surface Temperatures: -125C (-195F)

Gravity: 3.693 m/s² (38% Earth's Gravity)
Density: 3.94 g/cm³ (71.4% Earth's Density)
Mass: 6.4185 x 10²³ kg (10.7% Earth's Mass)
Volume: 1.6314 x 10¹¹ km³ (15% Earth's Volume)

Atmosphere: 95.32% carbon dioxide, 2.7% nitrogen, 1.6% argon, 0.13% oxygen, 0.08% carbon monoxide.

Diameter: 7,926 miles (12,756 km)
Average Distance from Sun: 93 million miles (150 million km)
Orbital Period: 365.24 days
Rotation Period: 23.934 hours

Maximum Surface Temperatures: 58C (136F)
Minimum Surface Temperatures: -88C (-126F)

Gravity: 9.766 m/s²
Density: 5.515 g/cm³
Mass: 5.9737 x 10²⁴ kg
Volume: 1.0832 x 10¹² km³

Atmosphere: 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide.