NASA: Liquid water once on Mars

[dlavery]

Originally Posted by KenWittlief

I think these guys need a reality check

isnt Mars twice as far from the sun as the earth is?

I could belive ice on Mars

but liquid water? wouldnt any body of water there freeze solid?

isnt the average temp at the equator something like -70°F

?!

A few facts for your reality check....

On average, the Sun-Mars distance is approximately 185% of the Sun-Earth distance (281x10^6Km, vs. 149x10^6Km). The solar illumination level (tau) at the surface of Mars is typically higher than at the equivalent latitude on Earth, due to the lower atomospheric column depth and reduced amounts of suspended materials. Localized solar-induced heating effects at the surface can be significant.

Saturated salt brines can remain liquid well below zero degrees farenheit.

In January, the noon-time temperature on the surface of Mars at the Spirit rover landing site was approximately 35 degrees (F) WARMER than it was in Boston, MA.

At equatorial latitudes, the summer surface temperature can get up to around 50 degrees F.

Subsurface temperatures increase above surface temperatures. That, combined with the pressures induced by the overburden, create conditions conducive for the formation of subsurface aquifers. One of the leading theories concerning the distribution of water in the Martian environment results in significant amounts of water (approximately twice the amount contained in Lake Superior) being held in active aquifers extending from the Mars polar caps (which are known to contain water ice in addition to CO2 ice) to mid-latitudes.

The Thermal Emissivity Spectrometer aboard the Mars Odyssey mission has mapped hydrogen spectra in the shallow subsurface in areas covering over half of the planet (extending from the poles to the mid-equatorial regions). For the volumes detected, subsurface aquifers are the most probable explanation for the detected signals (note: even more precise observations are expected when the MARSIS sub-surface radar is deployed from the ESA Mars Express spacecraft on April 20, 2004).

Mars today is very different than it was aeons ago. The announcement concerning the current discoveries has to do with the ancient water history of Mars, and what it was once like - not what it is like now. You might want to read up on it here and even more here to make sure that you understand this discovery before you post again.

-dave

[sanddrag]

Very nice explanation Dave. The scary part is I understood every word you said.