Phobos - Revision history

Michel Lamontagne: /* Mining Phobos */

2024-04-18T12:35:33Z

Mining Phobos

RichardWSmith: fixed a typo.

2022-07-23T15:53:53Z

fixed a typo.

RichardWSmith: /* Mining Phobos */

2022-07-03T05:50:41Z

Mining Phobos

RichardWSmith: Estimate that Phobos will hit Mars in about 50 million years.

2022-07-03T05:48:45Z

Estimate that Phobos will hit Mars in about 50 million years.

Michel Lamontagne at 12:56, 16 May 2019

2019-05-16T12:56:16Z

Jburk at 15:52, 10 July 2018

2018-07-10T15:52:33Z

Farred: correction

2009-09-29T02:26:57Z

correction

Farred: minor addition

2009-09-29T01:48:50Z

minor addition

Laertes: mining phobos

2009-01-12T22:37:31Z

mining phobos

Jarogers2001: 4 revision(s)

2009-01-02T08:22:03Z

4 revision(s)

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 ==Mining Phobos==
-If Phobos does indeed contain volatiles, it could be mined for use by settlements on [[Mars]], [[Luna]], or [[Earth]] orbit. Sale of Phobos resources could be an important part of [[interplanetary commerce]].  Since it is already at Mars' orbital velocity, it would take much less delta vee, to move these resources to the Asteroids, Luna, or Earth orbit than from Mars itself.
+If Phobos does indeed contain volatiles, it could be mined for use by settlements on [[Mars]], [[Luna]], or [[Earth]] orbit. Sale of Phobos resources could be an important part of [[interplanetary commerce]].  Since it is already at Mars' orbital velocity, it would take much less deltaV to move these resources to the Asteroids, Luna, or Earth orbit than from Mars itself.
 ==Phobos Photos==

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 It is likely that Phobos will break up into a [[planetary ring]] once its orbit reaches the [[Roche Limit]] at about 7000km.
-If Mars had Earth's gravity, its atmosphere would be more tightly compressed, and held closer to the planet.  However, Mars' gravity is 48% of Earths, so Mars' atmosphere is 'puffier', extending further into space.  As Phobos' orbit decays, atmospheric friction (currently almost zero) will slowly increase.
+If Mars had Earth's gravity, its atmosphere would be more tightly compressed, and held closer to the planet.  However, Mars' gravity is 38% of Earths, so Mars' atmosphere is 'puffier', extending further into space.  As Phobos' orbit decays, atmospheric friction (currently almost zero) will slowly increase.
 ==Mining Phobos==

@@ Line 19: / Line 19: @@
 ==Mining Phobos==
-If Phobos does indeed contain volatiles, it could be mined for use by settlements on [[Mars]], [[Luna]], or [[Earth]] orbit. Sale of Phobos resources could be an important part of [[interplanetary commerce]].
+If Phobos does indeed contain volatiles, it could be mined for use by settlements on [[Mars]], [[Luna]], or [[Earth]] orbit. Sale of Phobos resources could be an important part of [[interplanetary commerce]].  Since it is already at Mars' orbital velocity, it would take much less delta vee, to move these resources to the Asteroids, Luna, or Earth orbit than from Mars itself.
 ==Phobos Photos==

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 ==Danger for Future Mars Colonists==
-The [[orbit]] of Phobos is not constant. [[Tidal forces]] consume a certain amount of energy and lead to an annual loss in height of about 18 mm. Eventually, in some million years, the moon might drop onto the surface, destroying any colony. But there are [[Bringing down Phobos|concepts]] to mitigate the threat.
+The [[orbit]] of Phobos is not constant. [[Tidal forces]] consume a certain amount of energy and lead to an annual loss in height of about 18 mm. Eventually, in about 50 million years, the moon is expected to break up.  The debris will be slowed by the thin air, and larger fragments might drop onto the surface, destroying equatorial colonies.  (Note that this is ~250 times longer than humans have been a species, so we will be doing VERY well, if we are on Mars in 50 million years.)  But there are [[Bringing down Phobos|concepts]] to mitigate the threat.
-It is also possible that Phobos will break up into a [[planetary ring]] once its orbit reaches the [[Roche Limit]] at about 7000km.
+It is likely that Phobos will break up into a [[planetary ring]] once its orbit reaches the [[Roche Limit]] at about 7000km.
 ==Mining Phobos==

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 Phobos is highly nonspherical, with dimensions of 27 × 21.6 × 18.8 km. Because of its shape alone, the [[gravity]] on its surface varies by about 210%; the tidal forces raised by Mars more than double this variation (to about 450%) because they compensate for a little more than half of Phobos' gravity at its sub- and anti-Mars poles.
 Phobos' orbit has an [[eccentricity]] of 0.0151 with an [[apoareion]] of 9518.8km.<ref>[http://en.wikipedia.org/wiki/Phobos_%28moon%29 Wikipedia entry for Phobos.]</ref>
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 ==Phobos Photos==
-*There is good imagery at http://mars.jpl.nasa.gov/mro/gallery/press/20080409a.html .  As the commentary states, there are obvious crater chains on Phobos.  It is suggested that these roughly straight line chains may have been caused when debris from an impact on Mars later hit Phobos.  Researchers maintain such a hypothesis in a scholarly paper.<ref> http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2195.pdf </ref> They refer to raised rims on craters in the crater chains as supporting evidence, but the photographic evidence of such raised rims is less than compelling.
-*Here is a suggestion from outside [[NASA]].  Phobos may be composed to a considerable extent of volatile solids.  Stress concentration along a line caused some flow of material along a line causing that material to be preferentially exposed to the vacuum of space.  In the course of a billion and more years enough material along that line sublimed away to cause the collapse of overlying material, leaving craters on the surface.  This linear irregularity caused neighboring linear stress concentrations resulting in further subsidence and other linear crater chains.  A lack of raised rims around craters forming the grooves would be consistent with craters formed by subsidence.
+*There is good imagery at http://mars.jpl.nasa.gov/mro/gallery/press/20080409a.html .  As the commentary states, there are obvious crater chains on Phobos.  It is suggested that these roughly straight line chains may have been caused when debris from an impact on Mars later hit Phobos.  Researchers maintain such a hypothesis in a scholarly paper.<ref>http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2195.pdf </ref> They refer to raised rims on craters in the crater chains as supporting evidence, but the photographic evidence of such raised rims is less than compelling.
 ==References==
-<references/>
+<references />
 [[category:Moons_(Natural_Satellites)]]

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 Phobos is highly nonspherical, with dimensions of 27 × 21.6 × 18.8 km. Because of its shape alone, the [[gravity]] on its surface varies by about 210%; the tidal forces raised by Mars more than double this variation (to about 450%) because they compensate for a little more than half of Phobos' gravity at its sub- and anti-Mars poles.
-Deimos' orbit has an [[eccentricity]] of 0.0151 with an [[apoareion]] of 9518.8km.<ref>[http://en.wikipedia.org/wiki/Phobos_%28moon%29 Wikipedia entry for Phobos.]</ref>
+Phobos' orbit has an [[eccentricity]] of 0.0151 with an [[apoareion]] of 9518.8km.<ref>[http://en.wikipedia.org/wiki/Phobos_%28moon%29 Wikipedia entry for Phobos.]</ref>
 The Soviet spacecraft [[Phobos 2]] reported a faint but steady release of dust particles from Phobos, but the spacecraft failed before it could determine the nature of the material.<ref>[http://www.iki.rssi.ru/IPL/phobos.html The USSR's Phobos mission.]</ref> [[Phobos Photos|Recent images]] from [[Mars Global Surveyor]] indicate that Phobos is covered with a layer of fine-grained [[regolith]] at least 100 metres thick; it is believed to have been created by impacts from other bodies, but it is not known how the material stuck to an object with almost no gravity.

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