Mars - Dead or Alive?
Has Life Ever Existed on Mars?
|Life on Mars?
Has Life Ever Existed on Mars?
|Scientists have long speculated about the possibility of life on Mars owing to the planet's proximity and similarity to Earth.
Although fictional Martians have been a recurring feature of popular
entertainment, it remains an open question whether life currently exists
on Mars, or has existed there in the past.
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.
It is believed that Mars at one point flourished with life. If life exists on Mars today than it is believed it would most likely be bacteria.
The key for finding life is generally to locate water, but scientists are starting to discover that this is not always the case.
During the next two decades, NASA will conduct several missions to address whether life ever existed on Mars.
The search begins with determining whether the Martian environment was ever suitable for life.
Evidence suggests that the planet was once significantly more habitable than it is today, but whether living organisms ever existed there remains unknown.
Tests conducted by the Phoenix Mars lander have shown that the soil has a very alkaline pH and it contains magnesium, sodium, potassium and chloride.
The soil nutrients may be able to support life but life would still have to be shielded from the intense ultraviolet light.