Hellish Vision of Mars Unveiled

mvladivostok writes "Yahoo has an interesting little article in which it is suggested that Mars may not have once been a warm, wet and hospitable planet that somehow lost its atmosphere; instead, it is suggested that the dead planet was occasionally bombarded by melting meteorites that carved out its distinctive craters and valleys. An interesting read."

Comments

Still

[Thaelon]

It's got water, that would make future colonization that much easier/more feasible.

What? Not Doom 3?

[dzym]

At first I thought this article was about Doom 3.

A bit contrived, perhaps?

[Montreal Geek]

This is certainly not my field (more like a hobby) but it it just me or is this scenario a bit contrived?

While it's certainly possible that Mars would have been bombarded this way, it doesn't appear likely for two reasons:

For one, there is no evidence of any other planetary body which would have gotten a significant infusion of water this way and it seems unlikely that Mars would have been the only target.

But the most important detail seems to be to just be a question of quantity. Regardless of maturity, in order for deep riverbeds such as appear on Mars to form you need a lot of water flowing for a fairly long time (years, not days). To get that water from impacts would mean that a LOT of such impacts need to have taken place over a (cosmologically) short period; which makes the first point above all the more noticable.

Even if Mars did get significant amounts of water this way (or had enough of it melted out by side effects) the water wouldn't have been around long enough to make geological constructs unless there was an atmosphere allowing it to remain liquid long enough to flow around for years.

I'm surprised someone at NASA would publish national-enquirer quality science like that. More likely, Yahoo misread the paper to extract the nice sounding bits.

-- MG

Re:A bit contrived, perhaps?

[franimal]

Nope! One theory goes that this is the same way that Earth got its water. (Orginal water was boiled away in early hot days when there was no atmosphere). The only problem with such theories is the isotope ratios of the water found in comets versus Earth. Search around a bit, you'll find more. One Two Three

Re:A bit contrived, perhaps?

[ianscot]

For one, there is no evidence of any other planetary body which would have gotten a significant infusion of water this way and it seems unlikely that Mars would have been the only target.

Discover ran a story about someone who thinks Earth is still being bombarded by smaller bodies like this -- it was a couple of years ago I think. He's regarded as a flake, but he's at least on the edges of the real scientific community.

Regardless of maturity, in order for deep riverbeds such as appear on Mars to form you need a lot of water flowing for a fairly long time (years, not days).

Ever hear of the Lake Missoula ice-age floods? Water from a penned-in glacial lake burst through ice dams several times, ripping up the northwestern US in colossal floods. The entire surface of eastern Washington state was formed through quite sudden flooding:

"In about two days the water of Glacial Lake Missoula emptied through the breached dam. The amount of escaping water was equal to ten times the discharge of all the Earth's rivers today." Water several hundred feet deep flooded the region and ripped up hundreds of feet of soil and rock, carrying it inside the torrent of water westward toward the sea. The flood cut channels and carved islands, leaving behind the scarred landscape now called the Channeled Scabland.

Imagine ripples like in a streambed, only on the scale of hillsides. It doesn't necessarily take years.

Not that I'm buying this idea, but it's not as outrageous as all that.

3.85 billion years ago ...

[franimal]

The same thing was happening on Earth. Earth gets smacked, life gets crushed, picks itself up, and tries again. Thankfully, life has yet to crush itself.

Re:speculating

[splateagle]

"CONCLUSIVE" proof of anything is impossible. One day I expect we'll have gathered enough information to be able to settle comfortably on one martian theory over the others, but the whole point about science is that you don't get to *know* the answers, you just have to keep asking the questions.

In that light this is an interesting article: personally I still think the atmospheric therories carry more wieght, but this is an interesting new way of asking the Mars question all the same.

Real advances are often the product of what someone in an earlier post refered to as "National Enquirer Science", which might more neutrally be called "thinking outside the box"

Misinterpreted article

[Anonymous Coward]

This article is not quite clear in its interpretation of the research- the main source of the water would be ice on the planet, not on the meteorites.

For a better article head to the bbc website http://news.bbc.co.uk/1/hi/sci/tech/2546923.stm

The gist is that large impacts by asteroids or other bodies would heat water in subsurface ice, leading to massive flash flooding. They are speculating that very large impacts would have planet wide effects for short periods of time. This isn't that contrived, as there is evidence around small martian craters that suggest that ice has been melted leading to mud flows around the crater rim.

However, this doesn't explain why the northern hemisphere of mars looks like a dessicated ocean floor, which suggests a relatively long period of warm conditions.

Re:NASA and Disney, you mean

[ianscot]

My father worked at a mapmaking company. They had some charts of Mars that NASA printed through the USGS.

Down in the corner there was a standard disclaimer to the effect that if you found any inaccuracies in the map during use, NASA and the USGS weren't responsible.

Use?

Re:Atmosphere

[Planetes]

"Mars has a denser atmosphere than Earth. While spaceborne objects would be a nice explanation for these formations- if a bit uncreative- it forgets the element of the atmosphere, which is the only reason Earth doesn't get pounded into rubble every meteor shower."

Interesting. There's only one problem. You're incorrect. Mars' surface density is pretty close to the Earth's at 35000 meters. Roughly 0.015 kg/m3. Earth's at the surface (sea level) is approximately 1.2 kg/m3.

The martian figure is from Nasa (http://www.grc.nasa.gov/WWW/K-12/airplane/eqstat. html)

and the Earth figure is from any standard atmosphere chart available on the web. I don't have my texts with me so I just grabbed the one off USA Today's site. (http://www.usatoday.com/weather/wstdatmo.htm)

Even if it were, Mars' atmosphere is much thinner and has a much lower pressure than Earth's. Meteors entering Mars' atmosphere stand a much better chance at reaching the surface than they would on Earth. Combined with the ambient atmospheric temperature of the planet's atmosphere, even the density wouldn't prevent this.

The equation of state for an ideal gas shows this relationship. (http://www.grc.nasa.gov/WWW/K-12/airplane/eqstat. html)

"Admittedly, it's possible that the atmosphere was carried in a solid-frozen format on said bombardial objects, but that's even more of a stretch."

I have one word: "Comets" They are believed to be responsible for a large amount of the atmospheres of Venus, Earth, and Mars.

Anyway, just my $.02.. :-)

Daniel
Aerospace Engineering major
University of Central Florida - Orlando