Does Mars Have Life?
The Mysteries of the Red Planet

Does Mars Have Life?
The Mysteries of the Red Planet

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars.

It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance.

Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts, and polar ice caps of Earth.

The rotational period and seasonal cycles of Mars are likewise similar to those of Earth.

Mars is the site of Olympus Mons, the highest known mountain within the Solar System, and of Valles Marineris, the largest canyon.

The smooth Borealis basin in the northern hemisphere covers 40% of the planet and may be a giant impact feature. Until the first flyby of Mars occurred in 1965, by Mariner 4, many speculated about the presence of liquid water on the planet's surface.

This was based on observed periodic variations in light and dark patches, particularly in the polar latitudes, which appeared to be seas and continents; long, dark striations were interpreted by some as irrigation channels for liquid water.

These straight line features were later explained as optical illusions, yet of all the planets in the Solar System other than Earth, Mars is the most likely to harbor liquid water, and thus to harbor life.

Geological evidence gathered by unmanned missions suggest that Mars once had large-scale water coverage on its surface, while small geyser-like water flows may have occurred during the past decade.

In 2005, radar data revealed the presence of large quantities of water ice at the poles, and at mid-latitudes.

The Phoenix lander directly sampled water ice in shallow Martian soil on July 31st, 2008. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Martian Trojan asteroid.

Mars is currently host to three functional orbiting spacecraft: Mars Odyssey, Mars Express, and the Mars Reconnaissance Orbiter.

On the surface are the two Mars Exploration Rovers (Spirit and Opportunity) and several inert landers and rovers, both successful and unsuccessful.

The Phoenix lander completed its mission on the surface in 2008. Observations by NASA's now-defunct Mars Global Surveyor show evidence that parts of the southern polar ice cap have been receding.

Mars can easily be seen from Earth with the naked eye. Its apparent magnitude reaches −3.0 a brightness surpassed only by Venus, the Moon, and the Sun.

Just about every two years, the planet Mars makes its closest approach to Earth... around 36 million miles.

That's when we pack our robotic emissaries off to the Red Planet, timing their launches to spend the least effort to get there. Some fly around it... snapping pictures.

Others land ... to sample its surface...a few to crawl around its canyons and craters.

These probes may pave the way for human explorers and, perhaps permanent settlers who'll dig deeper still in search of answers to our most pressing question:

Did Mars develop far enough -- and stay that way long enough -- for life to arise? And, if so, does anything live now within Mars' dusty plains beneath its ice caps or maybe somewhere underground?

Mars does not give up its secrets easily ... it's almost as if the little planet is embarrassed. Over a century ago, a few observers thought they saw clues that Mars is alive. 

Mars Exploration Rover

NASA's Mars Exploration Rover Mission (MER) is an ongoing robotic space mission involving two rovers, Spirit and Opportunity, exploring the planet Mars.

It began in 2003 with the sending of the two rovers—MER-A Spirit and MER-B Opportunity—to explore the Martian surface and geology.

The mission's scientific objective was to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars.

The mission is part of NASA's Mars Exploration Program, which includes three previous successful landers: the two Viking program landers in 1976 and Mars Pathfinder probe in 1997.

The total cost of building, launching, landing and operating the rovers on the surface for the initial 90-Martian-day (sol) primary mission was US$820 million. Since the rovers have continued to function beyond their initial 90 sol primary mission, they have each received five mission extensions.

The fifth mission extension was granted in October 2007, and runs to the end of 2009. The total cost of the first four mission extensions was $104 million, and the fifth mission extension is expected to cost at least $20 million.

In July 2007, during the fourth mission extension, Martian dust storms blocked sunlight to the rovers and threatened the ability of the craft to gather energy through their solar panels, causing engineers to fear that one or both of them might be permanently disabled.

However, the dust storms lifted, allowing them to resume operations.

On May 1, 2009, during its fifth mission extension, Spirit became stuck in soft soil on Mars. After nearly nine months of attempts to get the rover back on track, including using test rovers on Earth, NASA announced on January 26, 2010 that Spirit was being retasked as a stationary science platform.

This mode will enable Spirit to assist scientists in ways that a mobile platform could not, such as detecting "wobbles" in the planet's rotation that would indicate a liquid core.

JPL lost contact with Spirit after last hearing from the rover on March 22, 2010 and continued attempts to regain communications until May 25, 2011 bringing the elapsed mission time to 6 years 2 months 19 days or over 25 times the original planned mission duration.

In recognition of the vast amount of scientific information amassed by both rovers, two asteroids have been named in their honor: 37452 Spirit and 39382 Opportunity. The mission is managed for NASA by the Jet Propulsion Laboratory, which designed, built, and is operating the rovers.

Mars - The Red Planet

This series takes a fascinating new look at a very old universe. Fifty years after man first ventured into outer space, we examine the greatest secrets of the heavens. Each episode outlines how humans have explored the universe, and scrutinizes the discoveries they have made.

We look at hi-tech space telescopes which record the violent birth of stars, robotic rovers which glimpse the red surface of Mars, and sophisticated NASA probes which delve into the mysterious make-up of comets.

As the earth churns ominously with the effects of global warming, this is a revealing and prescient journey into the heavens. From the planets to the stars and out to the edge of the unknown, history and science collide in this epic exploration of the Universe and its mysteries.

In Mars: The Red Planet, we investigate the nature and composition of the planet in our solar system that shares the most similarities with Earth. Despite otherworldly features - such as the largest volcano in the Solar System - the red planet had much in common with our own one. Rumors of life on Mars may be substantiated as NASA orbiters and rovers discover new evidence of frozen water just beneath the rusty soil.

Did alien life exist there? As Earth reels with the effects of global warming, Mars becomes the most likely candidate for eventual human habitation. Cutting-edge computer graphics are used to show what life would be like on Mars, and to imagine what kind of life forms might evolve in alien atmospheres.

In 1877, the Italian astronomer Giovanni Schiaparelli noted markings... which he saw as a latticework of lines. He called them "canali" in Italian... meaning nothing more than "shallow channels" in English.

American astronomer, Percival Lowell, found the lure of these features irresistible. He saw Schiaparelli's channels as artificial canals.

He speculated that they carried melting snow from the poles to the dry interior.

After all, on Earth, the Suez Canal had recently opened to ship traffic. The Panama Canal was beginning to be dug. The Martian canals, Lowell said, were built by a sophisticated society confronting an environmental catastrophe on the grandest of scales.

Those Martians, he thought, must face urgent choice: move water across vast arid regions, or perish on an increasingly dry planet. As the 19th Century gave way to the 20th, Lowell took his case to the public, in a series of three best-selling books.

And the public responded with... questions. Who were these Martians, who had the means to remake an entire planet? Some offered schemes for making contact. Giant mirrors would flash greetings... Light beams... Mental telepathy. Many astronomers grew deeply skeptical... but Lowell's vision of a harsh, yet Earth-like planet endured in the public's imagination..

That vision was dealt harsh blow in 1964. The Mariner Four spacecraft ventured in for a closer look... And what it saw looked like the Moon. Three more Mariners followed.

They found huge dormant volcanoes... the deepest and longest canyon in the solar system...but not a trace of life, present or past.

In the mid-1970's, two lander-orbiter robot teams, named Viking, took up residence at Mars.

Maybe the Martians were just hiding, so the Vikings tested the soil for signs of life. But all the evidence from Viking told us... Mars is not only barren... but in fact hostile to life.

It's no wonder. Martian air temperatures range from --20 degrees Fahrenheit to down below --200.

It's also very, very dry. The Sahara Desert on Earth is a rainforest, by comparison. If all of the water vapor in Mars' thin atmosphere fell as snow, it would make a layer of frost not thicker than your fingernail.

On Earth, impact craters erode over time from wind and water... and even volcanic activity. On Mars, they can linger for billions of years.

But so can the imprint of riverbeds, lake bottoms and ocean shorelines... And the Viking orbiters saw a lot of them. It's not hard to believe that a great deal of water once flowed here.

But where did all the water go? To find out, scientists needed to do real field-geology on Mars. They needed rovers... travelling robots with tools and instruments.

This artist's concept animation depicts key events of NASA's Mars Science Laboratory mission, which will launch in late 2011 and land a rover, Curiosity, on Mars in August 2012.

The Mars Science Laboratory (MSL), known as Curiosity, is a NASA rover scheduled to be launched in November 2011 and would perform the first-ever precision landing on Mars.

It is a rover that will assess whether Mars ever was, or is still today, an environment able to support microbial life.

In other words, its mission is to determine the planet's habitability.

It will also analyze samples scooped up from the soil and drilled powders from rocks. The MSL rover will be over five times as heavy as and carry over ten times the weight of scientific instruments as the Spirit or Opportunity rovers.

The United States, Canada, Germany, France, Russia and Spain will provide the instruments on board. The MSL rover will be launched by an Atlas V 541 rocket and will be expected to operate for at least 1 Martian year (668 Martian sols/686 Earth days) as it explores with greater range than any previous Mars rover.

Mars Science Laboratory is part of NASA's Mars Exploration Program, a long-term effort of robotic exploration of Mars, and is a project managed by NASA's Jet Propulsion Laboratory. The total cost of the MSL project is about $2.3 billion USD.

Mars: The Red Planet

The red planet Mars has two moons (Phobos and Deimos) and some of the most interesting features in the Solar System, including the towering volcano Olympus Mons.

Of all the planets in the Solar System, the seasons of Mars are the most Earth-like, due to the similar tilts of the two planets' rotational axes.

However, the lengths of the Martian seasons are about twice those of Earth's, as Mars’ greater distance from the Sun leads to the Martian year being about two Earth years long.

Martian surface temperatures vary from lows of about -87 °C during the polar winters to highs of up to -5 °C in summers. The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure, and the low thermal inertia of Martian soil. The planet is also 1.52 times as far from the sun as Earth, resulting in just 43% of the amount of sunlight.