How do we know anything about the climate on Mars, even if it has one. We've never even been there. They say there is water on Mars. Ok maybe there's a liquid, but we don't have a sample to analyze so how can we say its even water. NASA really cracks me up with some of the shit they come up with.Jim
Originally Posted by Mr MojoRisin
.. on the other hand ...
"We" have years of experience at sample taking.
On a more serious note:
"Gamma-ray spectroscopy (GRS) is a well-established technique [e.g., Evans et al., 1993; Boynton et al., 1993] for determining the elemental compositions of planetary bodies. Such measurements can be performed from orbit or on the surface. Previous missions have all used the ambient cosmic-ray flux to produce neutron-induced reactions on elements in the planetary surface which, in turn, produces the characteristic gamma-rays that are used to determine the elemental concentrations. The last spacecraft GRS was built for Mars Observer [Boynton et al., 1992] and was designed to operate from orbit and provide information on the global surface elemental concentrations and their variations over large spatial regions. Extending these measurements to a surface lander is important, because they can provide a direct analysis without having to compensate for atmospheric effects or contributions. Thus, surface measurements can verify and extend the interpretation of orbital measurements and provide a better estimate of the variance that can be assigned to orbital measurements. A surface GRS can also identify specific lithologies and, thus, enable one to evaluate local heterogeneities and perform detailed mapping, perhaps from a rover-based system. In addition, a surface GRS can provide information about diurnal and seasonal variations of constituents, like those that might be produced in a region with permafrost. Typical GRS systems are capable of detecting essentially all major rock-forming elements, as well as volatile components like H, C, O, and S (See Table 8 for a comparison of APX and GRS analyses of a model comet.). It should also be noted that a GRS measurement can be integrated with a penetrator, where such an approach is desired for determining the true intrinsic planetary body composition by analyzing material beneath any disturbed surface, whether it be distillation product on a comet [Evans et al., 1986], a weathering patina on an asteroid, or an evaporitic crust on a terrestrial planet.
The use of neutron-induced gamma-ray production for evaluating elemental content has also been applied to subsurface measurements on the Earth [Schweitzer, 1993; Herron et al., 1993]. While some measurements make use of natural gamma-ray production from K, U, and Th, the most significant multi-element analyses are performed with a pulsed neutron generator (PNG). The use of such a generator for surface planetary measurements is practical, as it is a reasonably compact, rugged device with a power requirement that is well within typical power budgets. Current systems use about 20 W during operation (which would typically be no more than 50% of the time during continuous spectroscopic measurements). Systems have been envisioned whose power requirements during operation would be reduced to 1 to 2 W, though with lower neutron output. The main advantage of such a device is that it produces an ambient neutron flux which is approximately 5 orders of magnitude more intense than that produced by the ambient cosmic-ray flux, a factor that only increases if the planetary body has an atmosphere. This means that if a cosmic-ray flux based measurement would take a month to achieve the desired statistical level, the same GRS detector with a PNG could perform the measurements to the same statistical level in about half a minute. This makes it practical to sample many locations or to monitor temporal variations, such as daily or seasonal variations in volatile components in, for example, a martian permafrost layer. A further advantage of a PNG is that timing of spectral acquisition relative to the neutron production permits a separation of gamma-rays produced by different types of reactions, all of which are combined when the ambient cosmic-ray flux is used as a source. This timing capability significantly increases the signal-to-noise content of the detected spectra, improving the sensitivity for detecting elemental concentrations for the same neutron flux and gamma-ray detector system."
http://www.lpi.usra.edu/publications/psiw/psiw3.html
The technology has improved ... thank God of the hydrocarbon industry.
And when NASA hasn't been teaching Muslim children the value of space exploration .... as the current duffus in the White House ordered his appointee to implement as a goal of NASA ... imaging and "spectroanalysis" have explored Mars ... and other planets.