"If you can't come up with a reasonable alternative explanation for the data, you have to accept the presented explanation."
Actually, one is always free to reject all presented hypotheses, and await formulation of new ones to test. Sometimes, it's best to say "I don't know".
Note I don't believe Atheism is legitimate - because you can't prove the absence of something.
Yours is a common but twisted definition of atheism. The definition of an atheist is *not* someone who can prove there is no god. An atheist simply does not believe in a god or gods. And yes, for many people it's functionally equivalent to agnosticism, because nobody can prove the non-existence of anything.
Just to reiterate a point that a few others have made: the presence of water ice at the surface of Mars has been understood since at least the 1970's for high latitudes. This goes for parts of the polar caps (also made up of CO2 ice), and the seasonal frosts that are known to coat the very study area visited by the Phoenix lander.
Here's a snippet from an abstract of an article from 1982 (Journal of Geophysical Research, 87:367-370): "A new reflectance spectrum of the Martian north polar cap is analyzed, and it shows water ice absorption features. This evidence confirms the result of the Viking IRTM and MAWD experiments, which indicate that the north residual polar cap of Mars is composed of water ice during the season observed." The Viking 2 lander directly saw seasonal frost in the late 70's, as the Phoenix lander will in the coming months: http://www.jpl.nasa.gov/jplhistory/captions/vikinglander-t.php
The Phoenix results are new in that ice has been directly confirmed for shallow regolith ("soil") materials at the Phoenix site (as opposed to spectroscopically identified from orbit or from the Earth). This is a nice and important result, but is not a huge surprise (the site is known to be seasonally coated with water-ice frosts, and its sediments are distributed in a polygonal pattern that is analogous to what we see at high latitudes on Earth where freeze-thaw action dominates).
Phoenix is a great mission, but let's also give due credit to earlier workers.
The word "wet" implies the presence of a meaningful amount of liquid water. In this regard, the soil at the site is very unlikely to be wet (and note that the linked articles don't actually say that it is). The temperature and pressure conditions at the site only allow for solid and gas phases for H2O. Solid ice slowly converts to gas through sublimation when the ice is exposed by the scoop.
Materials can clump for a variety of reasons. For example, lunar soil can cling to itself and to things like spacesuits even though absolutely no water is present at all. All sorts of factors can influence the cohesion of planetary soils, including the physical shapes of soil grains, the electrostatic properties of the grains, binding by spatter through micrometeorite bombardment (unlikely on Mars due to atmospheric protection) and, in the case of the Mars soils, even small amounts of ice have the potential to bind grains.
As others have noted, plenty of astronauts have views that don't seem consistent with their backgrounds. For example, Jim Irwin's (Apollo 15, 8th human on the Moon) post-NASA life was focused in large part on trying to find Noah's Ark.
The fact is: 1) smart people aren't immune to having views inconsistent with basic logic or common sense; and 2) many astronauts are not trained as scientists.
Do the actual scientific articles have quantitative scales that express mineral abundances? Otherwise, what's the point of figures such as those given in the press release? Can't we do better than "green means clay is present"? Clays form very readily from common minerals (like feldspars) and are likely to be present to some degree everywhere on Mars (as with oxides and other secondary minerals). How much is "a lot"?
Slashdot Mirror
"If you can't come up with a reasonable alternative explanation for the data, you have to accept the presented explanation."
Actually, one is always free to reject all presented hypotheses, and await formulation of new ones to test. Sometimes, it's best to say "I don't know".
Note I don't believe Atheism is legitimate - because you can't prove the absence of something.
Yours is a common but twisted definition of atheism. The definition of an atheist is *not* someone who can prove there is no god. An atheist simply does not believe in a god or gods. And yes, for many people it's functionally equivalent to agnosticism, because nobody can prove the non-existence of anything.
Surveyor 3 recorded a fuzzy image of an eclipse from the lunar surface in 1967.
http://science.nasa.gov/headlines/y2009/25feb_kaguyaeclipse.htm
Just to reiterate a point that a few others have made: the presence of water ice at the surface of Mars has been understood since at least the 1970's for high latitudes. This goes for parts of the polar caps (also made up of CO2 ice), and the seasonal frosts that are known to coat the very study area visited by the Phoenix lander.
Here's a snippet from an abstract of an article from 1982 (Journal of Geophysical Research, 87:367-370): "A new reflectance spectrum of the Martian north polar cap is analyzed, and it shows water ice absorption features. This evidence confirms the result of the Viking IRTM and MAWD experiments, which indicate that the north residual polar cap of Mars is composed of water ice during the season observed." The Viking 2 lander directly saw seasonal frost in the late 70's, as the Phoenix lander will in the coming months: http://www.jpl.nasa.gov/jplhistory/captions/vikinglander-t.php
The Phoenix results are new in that ice has been directly confirmed for shallow regolith ("soil") materials at the Phoenix site (as opposed to spectroscopically identified from orbit or from the Earth). This is a nice and important result, but is not a huge surprise (the site is known to be seasonally coated with water-ice frosts, and its sediments are distributed in a polygonal pattern that is analogous to what we see at high latitudes on Earth where freeze-thaw action dominates).
Phoenix is a great mission, but let's also give due credit to earlier workers.
The word "wet" implies the presence of a meaningful amount of liquid water. In this regard, the soil at the site is very unlikely to be wet (and note that the linked articles don't actually say that it is). The temperature and pressure conditions at the site only allow for solid and gas phases for H2O. Solid ice slowly converts to gas through sublimation when the ice is exposed by the scoop. Materials can clump for a variety of reasons. For example, lunar soil can cling to itself and to things like spacesuits even though absolutely no water is present at all. All sorts of factors can influence the cohesion of planetary soils, including the physical shapes of soil grains, the electrostatic properties of the grains, binding by spatter through micrometeorite bombardment (unlikely on Mars due to atmospheric protection) and, in the case of the Mars soils, even small amounts of ice have the potential to bind grains.
As others have noted, plenty of astronauts have views that don't seem consistent with their backgrounds. For example, Jim Irwin's (Apollo 15, 8th human on the Moon) post-NASA life was focused in large part on trying to find Noah's Ark. The fact is: 1) smart people aren't immune to having views inconsistent with basic logic or common sense; and 2) many astronauts are not trained as scientists.
Do the actual scientific articles have quantitative scales that express mineral abundances? Otherwise, what's the point of figures such as those given in the press release? Can't we do better than "green means clay is present"? Clays form very readily from common minerals (like feldspars) and are likely to be present to some degree everywhere on Mars (as with oxides and other secondary minerals). How much is "a lot"?