Orbiter probes question: Is there life on Mars?
The Mars Mariner missions of the late 1960’s revealed the truth about the red planet and shattered dreams of life on Mars.
What they found, however, was that Mars’ surface is heavily cratered, lined with extinct volcanoes, colder than Antarctica and drier than the Sahara Desert. There is very little atmosphere, no vegetation and no Martians.
But now, in the year 2002, the Odyssey Orbiter may have found something new.
According to the Odyssey Orbiter Web site found at www.nasa.gov, the orbiter was launched into space in April 2001. It will orbit Mars for more than one Martian year, which is equivalent to 687 Earth days.
According to the Web site, detecting water is the primary mission of the Mars Odyssey. The Odyssey landed on Mars on Feb. 6, 2002. It began mapping Mars at the end of that month.
“The experiments are specifically looking for hydrogen and other minerals and elements of what Mars is made up of,” John Raitt, head of the physics department at Utah State University, said.
The orbiter uses incoming cosmic rays, or high-energy particles, to detect some of the minerals that lie up to three feet under the surface of Mars, he said. The incoming rays collide with atoms in the soil, and neutrons are released. The atoms become interactive in the process and gamma rays are emitted.
The orbiter detects the neutrons and the gamma rays, Raitt said. The rate at which the gamma rays react determines which minerals are in the soil.
The orbiter has found various spots underneath Mars’ surface where hydrogen is active and could be in the form of water.
According to the Web site the first hints of water near Mars’ surface came in 2000 from the Mars Orbiter Camera (MOC) on board NASA’s Mars Global Surveyor spacecraft.
“There is evidence of what they think is water at the poles of Mars,” Raitt said.
The surface water of Mars is likely to be evaporated, he said, and the signs of water underneath the surface are unlike the water underneath the Earth’s surface. Water found under the Earth’s surface is groundwater, and some of it is even flowing like a river. Most likely the water found under Mars’ surface is not flowing, it is likely to be frozen and in the form of ice.
According to the Web site and to Raitt, if water is found there is a possibility there was life or still may be life on Mars.
Life on Mars, however, would be different from life on Earth in many ways, Raitt said. The Earth’s magnetic field acts as a shield against charged particles the sun lets out. The Earth’s atmosphere also acts as a protector against smaller meteorites, which get burned up in the atmosphere before they can reach the Earth’s surface.
The Mars Orbiter is trying to discover what kind of magnetic field is on Mars and what kind of energy is allowed into Mars’ surface, according to the Web site. In addition, the atmosphere on Mars is not strong enough to burn up smaller meteorites, and if a human wanted to live on Mars, extra precautions would have to be made, Raitt said.
“The first step is to determine water and evidence of primitive life,” he said. “Then they must reconstruct what happened in the past so that life may exist now.”
Another aspect of studying possible life on Mars is if there actually was life on Mars, why it disappeared, Raitt said.
“And if Mars went into a decline is it possible the Earth will?” he asked.
The Odyssey Orbiter will continue to find the substances that make up Mars, and NASA will continue to study the possibilities Mars promotes.