Best Images Ever of Mercury's Scorched Surface
J Thoendell stashed this in Space
NASA's MESSENGER spacecraft is set to plunge to its doom on April 30, ending nearly four years of exploration of Mercury. Before it goes, the mission is sending back the best images of the planet ever taken.
In the shots, released on 16 March, the bottoms of craters reveal ice materializing in pits and swirls, still frozen despite being so close to the Sun. Elsewhere on Mercury, short, staircase-like ridges appear, miniature versions of the huge ‘scarps’ that the planet is famous for. And tiny hollows mark places where parts of the surface have been scoured away through some kind of powerful space weathering.
MESSENGER, which has been orbiting Mercury since 2011, has nearly run out of propellant to guide it. The spacecraft is currently about 15 kilometres above the planet's surface, the closest that it has ever been.
“We’re able to see at close range portions of the planet we haven’t seen in such detail before,” says Sean Solomon, a geophysicist at the Lamont-Doherty Earth Observatory in Palisades, New York, and principal investigator for the mission.
It looks even hotter and drier than I thought. The ice is a surprise.
"powerful space weathering" - I need more information!
Yeah, that's a surprisingly unsearchable phrase on Google.
Space weathering is kind of the equivalent of erosion on Earth.Except it's not water and air here, but sun radiations and the "solar wind" that "erodes".
The solar wind is a plasma made of energetic charged particles that washes the whole solar system even causing planet's atmospheres to evaporate if they are not protect by a magnetic field like we have on Earth. That's what happened to Mars' atmosphere because its magnetic field didn't last long enough.
Thank you, Oce!
I will never take earth's magnetic field for granted again.
Gravity is sweet, too.
And water. I like the earth's water.
I'm fond of our gases.
And our oxygen! Don't forget the oxygen.
Relevant enough, an answer I wrote in a topic on imgur forum about terraforming cirteria.
<< Also I focus on "life as we know it", can't make assertions on an hypothetical life based on slilicon and CH4 cycle (like on Titan).
- First of all, you need a sustainable atmosphere.
- For the atmosphere to be sustainable you need a magnetic shield to protect it from the solar wind: plasma sent by the sun that washes everything unprotected, that's what happened to Mars' atmosphere.
- To have this magnetic field, you need the planet core to be active and so young or big enough so it didn't cool down already.
- An atmosphere with the correct gaz mix, temperature and pressure: we need O2 and CO2 for plants and animals, O3 to protect against solar UV, H2O CO2 and CH4 for the greenhouse effect, and all kinds of dusts for cloud formation.
- A safe distance from the star, enough energy but not too much.
- A water cycle: rivers, oceans, clouds, rain etc.
- Extremely stable orbital parameters otherwise they could fuck up seasons really fast and destroy the atmosphere and all living forms in couple of millenniums. Earthlings should be very thankful to have a huge moon to stabilize them, otherwise ice ages would have been much much worse.
All these reasons make Earth extremely special and priceless.
They also show how the basic notion of "Circumstellar habitable zone" is archaic, there's much more requirements than only being in the correct distance from the star. >>
Geez, there are so many things that make Earth rare!
Do the things that make Earth rare also make it fragile?
Yes because any of those things is disruptable.
2. 3. 5. and 7. are safe from the human stupidity for now.
But 1, 4 and 6 are endangered by pollution: global warming, deforestation, water pollution etc..
I'd like to state right here that this earthling (two thumbs) is very grateful for our huge moon.
Me too. And for the phrase "safe from human stupidity for now". :)
Oh, so this was never a plausible movie plot!
Of course not. Arnold Schwarzenegger movies put the fiction in science fiction!
> a turbinium reactor that will create a breathable atmosphere for Mars when activated
It would only work if they also create a magnetic shield. : )
Heh heh. How hard is it to create a magnetic shield?
I think we don't even fully understand how it happens inside the Earth core dynamo.
And the size of this "dynamo" is far beyond the human technology for now.
We still have much to learn, especially in our lifetimes!