by henk21cm » Wed May 28, 2008 12:36 pm
BMAONE23 wrote:I wondered about that myself, especially since the area around the lander appears to be darkened from the thrusters.
If any disturbance has occured, it will be superficial. Soil -especially dry soil- is known to have a poor heat conductivity, so if the soil is heated up, just a few centimeters deep it will be virtually undisturbed. So if Phoenix is ably to digg a few cm deep, distubance by exhaust gasses is a minor problem. Additionally, hot gasses have a tendency to rise, even in the thin Martian atmosphere, not in the least cooling will have occured by induced turbulence and entrainment, when Martian atmosphere is mixed with burned 'fuel' gasses.
The only scenario which may have caused seroius damage is, when the lander is already sound and fixed at the surface, while the engines are still working. It may be an urban myth, when Apollo11 landed on the moon, it was told that the engines were shut down a few meters above the Lunar surface, in order to prevent too much dust.
"Forward, forward, picking up dust, forward. Engines stopped, Tranquility base, the Eagle has landed" or words of similar meaning and rearrangement.
[quote="BMAONE23"]I wondered about that myself, especially since the area around the lander appears to be darkened from the thrusters.[/quote]
If any disturbance has occured, it will be superficial. Soil -especially dry soil- is known to have a poor heat conductivity, so if the soil is heated up, just a few centimeters deep it will be virtually undisturbed. So if Phoenix is ably to digg a few cm deep, distubance by exhaust gasses is a minor problem. Additionally, hot gasses have a tendency to rise, even in the thin Martian atmosphere, not in the least cooling will have occured by induced turbulence and entrainment, when Martian atmosphere is mixed with burned 'fuel' gasses.
The only scenario which may have caused seroius damage is, when the lander is already sound and fixed at the surface, while the engines are still working. It may be an urban myth, when Apollo11 landed on the moon, it was told that the engines were shut down a few meters above the Lunar surface, in order to prevent too much dust. [i]"Forward, forward, picking up dust, forward. Engines stopped, Tranquility base, the Eagle has landed"[/i] or words of similar meaning and rearrangement.