Came across some cool pictures from Mars today. These are from or of four recent craft sent to Mars:

Mars Reconnaissance Orbiter
Orbits Mars, armed with high definition cameras and sensors. Left Earth August 12, 2005, entered Martian orbit March 10, 2006.

Spirit rover
Six-wheeled, 400 pound, solar-powered surface vehicle, left Earth June 10, 2003, landed on Mars January 4, 2004. Spirit has been stuck in soft soil since May of this year; NASA has been working on getting it free, but even with carefully coordinated wiggling drive maneuvers, it's currently only making about 1% of its normal speed (and its normal speed is only 10mm per second), poor thing.

Opportunity rover
Sister craft of Spirit, left Earth July 7, 2003, landed on Mars January 25, 2004. Currently on a 12 km journey to the 22 km-wide Endeavor crater; it will take about 2 years to get there at its normal drive speed.

Phoenix
Landing craft; left Earth August 4, 2007, landed on Mars May 25th, 2008. Took detailed soil samples, etc. Is now out of power; sent its last message on November 2, 2008, as the Martian winter approached.

Various tests and scans have found a lot of water ice on Mars: the planet's northern ice cap is about a third the size of the ice sheet covering Greenland, and polar areas have maybe a foot of ice under the dusty surface. They're also finding ice (snow, frost) collecting in crater rims closer to the equator.

And the pictures I thought were particularly nifty:


MRO pictures:


(image by NASA (source))

The MRO catches an avalanche taking place on the Martian surface. The scale is about 500 feet from top to bottom of the image.



(image by NASA (source))

MRO image of the "face" on the surface of Mars. The "face" is a Martian surface feature close to 300 meters long.



(image by NASA (source))

MRO spots tracks left on the Martian surface by the Opportunity rover.



(image by NASA (source))

MRO photo of the Phoenix lander descending to the surface, suspended from its landing parachute. Here Phoenix is about 12 km above the 10 km "Heimdall" crater. This is the first photo of a spacecraft landing taken by a separate spacecraft.


Opportunity pictures:


(image by NASA (source))

Opportunity landed about 25 km off-target; NASA had thought the area in which it landed was flat and featureless, so imagine their surprise when it landed inside this 22 meter crater, dubbed Eagle crater--from the golf term, since they called the accidental landing right in the crater a "hole in one." Here's the MRO's overhead view of the landing site:


(image by NASA (source))



(image by NASA (source))

That's "Heat Shield Rock," so-called because Opportunity found it resting near where its discarded heat shield had landed. This basketball-sized object turned out to be an iron and nickel meteorite: the first meteorite found on another planet; Opportunity has found at least one other meteorite on the Martian surface so far, and it's worth pointing out that several meteorites had previously been found on the Moon.



(image by NASA (source))

Opportunity drove a quarter of the way around the 730-meter Victoria crater, and then went down into it a little way to take readings. Here's a nice top-down view of Victoria by the MRO:


(image by NASA (source))

and an MRO capture of Opportunity in the crater:


(image by NASA (source))


Spirit picture:


(image by NASA (source))

And here's poor Spirit trying to wiggle free of the soft soil it's been stuck in most of the year. This maneuver only got it a few millimeters. If Opportunity scored a hole-in-one, I guess Spirit's hit a sand trap. NASA's Free Spirit web site follows their efforts to get the mired rover back to solid ground.

Amazing stuff. I just (last week?) saw a special about the Opportunity and Spirit on one of those Discovery channels I get ( we get like 5 of them.). Dude, these things are like 5 years old! They have survived sand storms, dirty solar charging panels, sticky wheels etc...wow.

Anyhow, Im strangely thrilled by the fact that these 2 pieces of technology have survived and acted out a somewhat human-like drama of survival and exploration. Poor Spirit - being stuck for too much longer will doom it I believe.

Well, I guess they could power it down if they couldn't get it out, and then future Marstronauts can dig it out and put it in some sort of shrine or something when they get there in 2030 or whatever.

Or they could use it to carry sandwiches.

There are multiple Discovery channels??

lol!

So, I'm pretty sure they said on the show I saw that they don't have a way to "turn off" the Spirit....although now that some time has gone by, Im not 100% sure about that.

And wow, yeah I got lots of Discovery channels - here they are, in no particular order: Discovery Channel (regular and HD), Discovery Kids, Science Channel (its a discovery channel according to the guide), Discovery Health (ick not for me! to many surgerys shown!) Investigation Discovery.

that +100 other channels. And I still have a hard time finding something I want to look at. Go figure.

Yeah it's funny how hospital dramas are always the rage; whenever I happen to catch one they seem to have at least two open-chest surgeries per episode, and it's like, ew.

Oh, they sometimes show real surgeries on discovery health, and sadly, I usually catch the knee surgery (barf)


And....
Can't show nudity, but we can show Open chest surgery!?! All seems a bit strange

: )

Yeah America's funny that way. Maybe that's WHY those shows are so popular... It's like, we can't show the outsides of people, but we can show the insides, so we might as well watch that!

Phobos!


image by NASA (source)

The Mars Reconnaissance Orbiter has got some pretty sweet images of Mars' larger moon, Phobos; there are also pictures of the smaller Deimos but it's kind of bland looking. :P

Phobos is a tiny moon with an irregular shape, averaging 22 km across. It's got some awesome craters, the largest of which is Stickney, 9 km across:


image by NASA (source)

Phobos and Deimos got their names from a passage in the Illiad, where Ares (aka Mars, god of war) summons Dread (Deimos) and Fear (Phobos).

What's it scared of? Well, in a mere 11 million years, it's going to be destroyed by Mars! Either smashing into it, or, which is more likely, being torn into pieces, which will form a short-lived asteroid belt before they hit Mars. It's going to crash because it has the closest orbit of any moon in the solar system--just 9377 km--which means that it has to move very quickly (2.138 km/s) just to keep its position; but moving that fast means it orbits far faster than Mars rotates--it completes about three orbits per Earth day, and on a Martian day, actually moves across the sky twice, *backwards* from what we typically think of as a moon orbit (and compared to Deimos) because it's going so fast. Here's the shadow of Phobos on the surface of Mars:


image by NASA (source)

and Phobos going across the Sun as seen from the Martian surface:


image by NASA (source)

So anyway, because it's moving faster than Mars rotates, and the gravitational pull of the moon makes Mars bulge slightly--just like our own Moon does the Earth--that bulge, behind the speedy Phobos, acts as a slightly offset, backward pull that slows the moon down, a process called tidal deceleration. Slowing down in an orbit is bad, because instead of falling outward along your orbital path, you fall more downward, toward the thing you're orbiting: in this case, Mars. Phobos' speed loss translates into a loss of about 20m of orbital distance per century. In 11 million years it gets too close! A 22 km rock (or series of smaller rocks) hitting Mars should be pretty spectacular.

Dark spots around areas of spider-like traces on the surface, above CO2 ice deposits (Mars' south polar ice cap is 85% CO2 ice, 15% water ice; even so, if it melted, it would cover the whole planet in about 11 m of water!--and water ice may exist in significant quantities as much as 1 km deep around the planet's surface), suggest that sunlight shines through surface ice, sublimates CO2 ice below the surface, and it belches forth in Martian geysers; these theoretical geysers have not yet been directly observed.

MRO photo of "spiders" with spots:


image by NASA (source)

Dark sand cascading down defrosting dunes makes these strange-looking streaks:


image by NASA (source)