Also, in the second video, the engines blacken the earth ( the mars?) not only just beneath the lander, but also in a certain radius outside of the diameter of the lander on all sides, not to mention the sideways travel, and tilt of the craft just as it lands, effectively painting the ground with the torch of the engine exhaust as it passes over, right where the samples are going to be taken from. Seems to me that this would alter or destroy any water evidence in at least the first few centimeters of soil, which is what the video shows that cute little backhoe scraping up for testing.

They shoulda put some wheels on that thing.

From the Phoenix website:

"The RA will be 2.35 meters (just under 8 ft) long with an elbow joint in the middle, allowing the arm to trench about 0.5m (1.6ft) below the martian surface, deep enough to where scientists believe the water-ice soil interface lies. "

I'm sure they tested the lander in Pasadena numerous times, or they wouldn't be attempting this, though releasing a video of that would be simpler and more convincing than the animation. What I doubt is whether that tiny little scoop is going to find anything terribly significant in the top centimeter of soil. We need to get some serious drills up there. Maybe they should call this the JSS lander, for "just scratching the surface".

If this thing lands on its feet Ill eat my hat.

As for life, or signs thereof…..I would have gone for a drill, not a scoop. Again….sort of seems 'wrong'

Nothing like making things really complex….millions of miles away.

If this thing lands OK AND finds signs of life….Ill eat my underwear as well.

Hope Im wrong.

Still, let's see. I hope I'm wrong.

Most researchers believe that any significant amounts of water ice will be buried several centimeters (but possibly up to 1 meter) under the dusty and rocky surface of the northern plains of Mars.

The surface layer probably contains a small quantity of ice that is acting as a "cement" holding some of the dust and gravel together. The retrorockets may kick up some dust during descent, but as you see in the animation, they actually shut down while the lander is a meter or so above the surface and then the lander just drops.

Water ice isn't stable on the surface of Mars during the summer. If water ice is exposed it won't melt, it will sublimate (go from the solid phase to the gaseous phase). This will be a challenge if the lander is lucky enough to scoop up some subsurface ice with the robotic arm because the sample will be exposed to the atmosphere for several minutes as the arm moves to dump the sample into one of the onboard chemistry instruments for analysis.

The fact that the rocket blast never gets to close to the surface combined with the fact that any appreciable water ice is likely to be buried means that researchers don't expect the landing operation to cause much loss of ice. Even if there was some ice loss, it would probably only be directly under the spacecraft. The robotic arm will be digging in areas next to the spacecraft, not under it, so it should be okay.

Cheers

Idk. Maybe Im missing something here.