The Truth About Water on Mars: 5 New Findings

• Mars
• Phoenix Mission
• NASA
• research
• ice

When scientists found perchorate on Mars last year, there was a heated discussion in the scientific community. Rocket scientists worried about contamination because perchlorate is a constituent of rocket fuel. Others worried that finding the chemical would mean that Martian soil was less hospitable to life because it's a water contaminant here on Earth. The latest study from Hecht shows that both concerns were overblown. The fuel used for landing doesn't contain perchlorate, which makes contamination unlikely, and while perchlorate can have harmful health effects on humans, bacteria have no trouble feasting on the chemical.

Perchlorate's relationship with water, Hecht says, bears both good news and bad news. The good news is that perchlorate salts are highly soluble—they easily dissolve in water, and when they do they lower its freezing point by anywhere from 35 to 70 degrees Celsius, depending on their chemical composition. That would widen the temperature range that liquid water could exist on the surface.

However, because perchlorates dissolve so easily into water, you'd expect to see grains or streaks of them left over when the water evaporates, Hecht says. These streaks are not evident on Mars. Instead, perchlorates appear to be more randomly distributed through soil. That argues against recent wetness on Mars, Hecht says, but doesn't preclude the possibility that "thin films" of water could still be on the surface.

CLICK FOR MORE The Truth About Water On Mars
Lesson 1: Layers of Ice	Lesson 2: Calcium Carbonate	Lesson 3: Martian Clouds	Lesson 4: Perchlorate Controversy	Lesson 5: Life on Mars

Comment Title
Your Name
Email Address
Website	make public
Comment
Please enter the characters shown below:
	Make sure your comment is relevant to the topic discussed. Comments not relevant to the topic will be deleted. Neither you nor Popular Mechanics has the ability to make your e-mail address public. However, we ask that you submit your e-mail address to us just in case we need to contact you. Thank you for your understanding--The Editors.