Share it! Science : Water on Mars?!

With NASA's big announcement about evidence of water on Mars and this past weekend's Supermoon Eclipse, I just can't stop thinking about space! So what is the big deal about water on Mars? Haven't we been talking about evidence of water and ice on the red planet for the past few years?

This announcement is slightly different, but immensely more important. Evidence of ice, or water existing on Mars in the past has been common, but this time around the evidence is pointing to water intermittently flowing on the planet in present day.

In order to determine if there is life as we know it on other planets NASA scientists have followed evidence of water as their guide. Living things need water, so it stands to reason if you find water, you could also find life.

Mariner 9, launched in 1971, was the first to identify evidence of water on Mars when it transmitted images of riverbeds, canyons, erosion and fog back to Earth. Mariner 9 was the first artificial satellite of Mars, and photomapped 100% of the martian surface from 1971-1972.

Scamander Vallis from Mariner 9. By Jim Secosky, NASA image. [Public domain], via Wikimedia Commons

The Viking program further revolutionized our thinking about water on the red planet. The Viking spacecraft were the first to land safely on the surface of Mars. Both Viking 1 and Viking 2 reached the planet in 1976. The two pairs of lander and orbiter systems collected scientific data and photographed the surface in addition to completing biological experiments aimed to determine whether their was life on Mars. In the process the Viking landers discovered many geological features that further indicated the presence of water historically on the planet, such as deep valleys and valley networks in addition to erosion on the bedrock.

Image from Viking program. By Jim Secosky, modified NASA image [Public domain], via Wikimedia Commons

Investigation and evidence building toward the discovery of water on Mars continued throughout the next few decades with the Mars Global Surveyor (data on mineral composition), Mars Pathfinder (temperature readings and evidence of clouds and maybe fog), Mars Odyssey (evidence of vast regions of ice under the surface of Mars), Phoenix Mars Lander (confirmed evidence of water ice), Mars Rovers- Spirit and Opportunity, and finally the Mars Reconnaissance Orbiter (evidence of hot springs, heavy precipitation, and hydrated salts causing dark streaking).

Frost at landing site. By Roel Van der Hoorn [Public domain], via Wikimedia Commons

Mars Odyssey Image by Jim Secosky, modified NASA image.

The announcement of present day water on Mars comes from data from the Mars Reconnaissance Orbiter. Spectrometer readings showed hydrated salts that coincide with streaking noticed on the surface. The concentration of salts would lower the freezing point of briny water so that it could flow as a liquid. This is the same principle in place on icy roads in the winter, salt lowers the freezing point of the water so that the road is not coated with a layer of ice. The dark streaking on the surface showed how the salty water flowed downhill during warmer temperatures, and the streaks lightened during cooler temperatures indicating that the flow has slowed or stopped. The liquid is most likely just under the surface and wicking to the surface causing the streaking patterns. This evidence led to NASA's big announcement about water on Mars.

This announcement is just another step towards NASA's Journey to Mars, a mission to send humans to Mars in the 2030's, a goal outlined in the NASA Authorization Act of 2010 and in the U.S. National Space Policy, also in 2010.

Mars Streaks. By Jim Secosky modified NASA image [Public domain], via Wikimedia Commons

There are so many ways to use this historic announcement to raise interest in space education. NASA has a wealth of information and teaching resources that you will in the resources section below. You can also keep up with all things NASA at home or in the classroom with NASA TV, a live stream on YouTube.

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