In 2004, NASA's Opportunity rover finds evidence that there were once large quantities of water on Mars. Scientists theorize that salt crystals may have formed from the water and later dissolved.
New Evidence of Water Once on Mars: Salt Crystal Traces Examined
TOM BROKAW, anchor:
NBC News IN DEPTH tonight: Was there once life on Mars? It has been one of the most vexing mysteries of the universe. Today NASA presented compelling new evidence from its Mars rover that the Red Planet was once a very wet planet. What does that all mean? Here's NBC's Robert Hager.
ROBERT HAGER reporting:
It's a first finding from the rover that there were conditions on Mars at one time that could have supported life. What sort of conditions? The project's lead scientist, Cornell's Steve Squyres...
Mr. STEVE SQUYRES: We have concluded that the rocks here were once soaked in liquid water.
HAGER: Water, one of the key building blocks of life. What's the evidence? It's from examination of this eight-inch-high outcropping nicknamed "El Capitan." Close up, the rover found myriads of half-inch-long holes shaped like crystals, a sign, they said, that salt crystals formed out of water and later dissolved, leaving the holes.
Even more convincing, when the rover bored inside the rock, it found enormous quantities of sulfur or salt compounds. Lockheed Martin's Benton Clark...
Mr. BENTON CLARK: The only way you can form such large concentrations of salt on Earth normally is to dissolve it in water and have the water evaporate.
HAGER: Exciting, Brown University geologist and planetary expert James Head told us.
Mr. JAMES HEAD: What that means is that it creates an environment that was conducive to the formation and evolution of life.
HAGER: ‘Habitable’ was how NASA described it.
Mr. SQUYRES: By `habitable,' I mean it's an environment that would be capable of supporting life as we know it on this planet.
HAGER: But it by no means proves yet that there was ever life.
Scientists can't even tell when and for how long the water was there nor whether it was a lake or just ground water running through the rocks.
But scientists say these rocks are ideal for preserving fossils, so if a future unmanned shot could bring some back to Earth, inside we might find answers to the age-old question, whether there's life beyond our planet.
Robert Hager, NBC News, Washington.
Mars might have been a wilder water world than we thought. Scientists scanning the terrain have discovered signs of two massive tsunamis in the northern hemisphere — events that might have been caused by massive, crater-carving impacts.
Planet Mars, Life, Liquid Water, Evidence, El Capitan, Rocks, Geology, Outcropping, Salt Crystals, Rovers, Spirit, Opportunity, Data, Research, Sulfur, Salt Compounds, Theory, Climate, Habitat, Groundwater, Lakebed, Biology, Environment, Red Planet, Discovery, Exploration, NASA, Dr. Steven Squyres, In Depth