Mars Express acquires sharpest images of martian moon Phobos.

[Notebook]

http://www.esa.int/esaSC/SEM5H48N9JF_index_0.html

30 July 2008
Mars Express closed in on the intriguing martian moon Phobos at 6:49 CEST on 23 July, flying past at 3 km/s, only 93 km from the moon. The ESA spacecraft’s fly-bys of the moon have returned its most detailed full-disc images ever, also in 3-D, using the High Resolution Stereo Camera on board.


N.

 

[C3PO]

Cooooool!!!
It's got stripes!

 

[astrosammy]

with a nominal resolution of 90 cm/pixel

Let's make new textures and meshes of Phobos for Orbiter!

 

[adamb193]

Woo-hoo 3-d luckliy I had some 3-d glasses laying around

 

[astrosammy]

I have some 3d glasses with the wrong colors . Have to build one.

 

[Missioncmdr]

Really impressive pictures!

 

[TSPenguin]

I can't wait for the processed data to come out!

 

[mrspacely]

anyone know what those long ridges are? im thinking theyre left over from the event that destroyed mars' earth-like climate and magnetic field?

 

[Linguofreak]

anyone know what those long ridges are? im thinking theyre left over from the event that destroyed mars' earth-like climate and magnetic field?

Both dissapeared because Mars was too small to maintain them. It wasn't an event, it was a process.

 

[tblaxland]

anyone know what those long ridges are? im thinking theyre left over from the event that destroyed mars' earth-like climate and magnetic field?

My understanding is that they were most likely formed by Phobos collecting ejecta from impacts on Mars. The reasoning behind this is that they are centred on Phobos' leading hemisphere.

Both dissapeared because Mars was too small to maintain them. It wasn't an event, it was a process.

That process being:

Mars cools as the heat of its formation is radiated away -> There is no longer sufficient heat to maintain the dynamo that powers the magnetic field -> The solar wind is no longer held at bay by a magnetosphere and atmospheric particles are stripped away by collisions with solar wind particles.

 

[Linguofreak]

My understanding is that they were most likely formed by Phobos collecting ejecta from impacts on Mars. The reasoning behind this is that they are centred on Phobos' leading hemisphere.


That process being:

Mars cools as the heat of its formation is radiated away -> There is no longer sufficient heat to maintain the dynamo that powers the magnetic field -> The solar wind is no longer held at bay by a magnetosphere and atmospheric particles are stripped away by collisions with solar wind particles.

Actually the solar wind is only a small part of the atmospheric loss process, although it is a factor. The main thing is thermal loss. Basically, your atmosphere has a half life (amount of time taken for half the atmosphere to leave the planet) based on the local escape velocity and the temperature. At a given temperature, your particle velocities form a Bell curve, and the particles that end up at velocities beyond escape velocity leave the planet. The higher the temperature, or the lower the escape velocity, the more of the bell curve goes beyond the escape velocity line, and thus the more particles you lose, and thus the shorter the half life of the atmosphere. Mars has an escape velocity of only about 5 km/s, which means it can't hold an Earthlike atmosphere at Earthlike temperatures for very long. Also a factor is that without internal heat, Mars' former vulcanism has died down, which means the atmosphere doesn't get replenished (at least not as much as before, there are indications of volcanic activity in the last few million years) through outgassing.

 

[Kyle]

Phobos Textures L 11 anyone?

 

[teago]

I guess the ESA must finally be reading Trevor Johns' tutorials.

 

[TJohns]

I guess the ESA must finally be reading Trevor Johns' tutorials.

Like that one...

Trev