Water Found on Mars

[masmdu]

http://www.esa.int/SPECIALS/Mars_Express/SEMYKEX5WRD_0.html

snip>

Thanks to ESA’s Mars Express, we now know that Mars has vast fields of perennial water ice, stretching out from the south pole of the Red Planet.

[Adams Wulff]

1. pardon me, but...

Couldn't we see the ice fields from here, with a cheap telescope, some 50 million dollars ago?
just curious

[Ready4Change]

There were questions

Some thought the caps may have been frozen carbon dioxide. Or, if it was water ice, was it perhaps a thin frosty layer, or was it a thick cap which would indicate large quantities of water and perhaps an ability to support life.

[aquart]

2. We saw something. No way to know what it was.

Only Velikovsky insisted there had been water on Mars, and nobody who is anybody believed him.

[Nihil]

3. Oh

Just another lucky guess then?
Like the temperature of Venus too?
Okay

> We saw something. No way to know what it was.

Guess all of those spectroscopy devices only work from orbit?

No way to tell what substances are in any of the planetary atmospheres
unless we send an orbiter?

(Sorry Aquart, not getting at you personally, just the idea that this
is somehow news.)

[mobuto]

4. For good and sufficient reason

Velikovsky was a loon.

[Zero Gravitas]

8. Velikovsky

"The internal heat developed by the earth and the scorching gases of the comet were in themselves sufficient to make the vermin of the earth propagate at a very feverish rate. Some of the plagues like the plague of the frogs...or of the locusts, must be ascribed to such causes (192). "

Velikovsky had no idea what he was talking about, if he mentioned that there was once water on Mars it was pure coincidence that he turns out to be correct.

[Rabbit of Caerbannog]

5. Dumb question, but...

why don't they just land a rover on one of the ice caps? Thy got two crawing around in dry craters - seems like going to where the water is would be a better use of time and $$$

[salvorhardin]

6. Polar landings

Polar landings are a lot harder, especially using NASA's "faster, better, cheaper" approach to space exploration in recent years. Powered descent requires (relatively) large rockets, which requires lots of fuel to be transported along with the lander to Mars, which requires more fuel to reach orbital velocity and so on. This all adds up to lots of money. So instead NASA essentially just lobs landers at Mars and uses the friction of the Martian atmosphere to slow them down enough to where parachutes can take over. Then, just before the lander slams into the Martian soil, the parachutes are cut and the lander bounces on airbags until it comes to a rest.

Of course, for this to work the atmosphere has to be thick enough to slow down the lander to a reasonable enough speed and for the parachutes to actually work. Mars atmosphere is particularly thin, but at the equatorial regions it's just thick enough that this seemingly insane way of doing things works -- and if it doesn't, well, the idea is that you were able to send two or more spacecraft for the price of one expensive powered lander. That's why when picking landing sites for the two latest rovers, only equatorial regions were considered.

NASA did attempt to set down a lander at the southern Martian pole back in 1999 but that mission was unsuccessful. The Mars Polar Lander failure, along with the incredibly stupid metric conversion error that caused the loss of the Mars Climate Orbiter are the primary reasons that caused former NASA administrator Dan Goldin to redirect NASA to the "faster, better, cheaper" approach. Well, that and chronic underfunding of NASA while pouring billions into asinine and corrupt defense programs such as "missile defense" and the Bradley Fighting Vehicle. (odd tidbit: Bill O'Reilly -- yes, that Bill O'Reilly -- won a National Headliner Award for a series of exposes on the Bradley Fighting Vehicle. Guess he did real journalism once upon a time.)

Here's some more information on the MPL and MCO if you're interested...
http://www.space.com/missionlaunches/mars_polar_lander_031222.html">Whatever Happened To The Mars Polar Lander?
http://www.cnn.com/TECH/space/9909/30/mars.metric.02">Metric Mishap Causes Loss of NASA Orbiter

[salvorhardin]

7. Forgot. to mention

The other reason Gusevv Crater and Meridiani Planum were chosen as landing sites for Spirit and Opportunity is they can tell us a great deal about how wet Mars once was and whether or not the water flowed in rivers as it does here on Earth. This is important science as it can tell us about how planetary climates change over large periods of time which in turn can tell us a lot about where Earth may be heading.