how can the different gases in the atmosphere of mars be tested?

Question

I need the list of the equipment which is used by astronauts and space scientists to test which gases are present in the atmosphere of mars.

Answer 1

Spectrometer.

When an element is burned and the light is looked at through a prism it gives of unique bands of colors. If you burn a collection of gasses then shine the light through a prism and let a camera record the color bands created then you can tell what elements are in that sample. If you know that there is carbon and oxygen then it is a safe guess to say that there is carbon dioxide.

This is how we know the matter inside of stars and hot gases in our universe; we study the burning light through a prism and map out the elements there. Then based on our knowledge of chemistry we know that certain chemical compounds will be created when chemicals are there in certain amounts. For example since we have carbon and oxygen we could also have pure oxygen, but if there is more carbon then we probably won't. If there is more oxygen and some of it is exposed to solar radiation then we know that not only will pure oxygen be present but probably ozone as well. That's because of the chemical compounds. Carbon dioxide = CO2, pure oxygen = O2, ozone = O3 and carbon monoxide = CO. If we know the temperature then we can tell what elements are solid and what are gases.

This is why one of the most important scientific instruments we use in astronomy is as spectrometer.

According to Wikipedia: http://en.wikipedia.org/wiki/Spectrometer
“A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization state. The independent variable is usually the wavelength of the light, normally expressed as some fraction of a meter, but sometimes expressed as some unit directly proportional to the photon energy, such as wavenumber or electron volts, which has a reciprocal relationship to wavelength. A spectrometer is used in spectroscopy for producing spectral lines and measuring their wavelengths and intensities. Spectrometer is a term that is applied to instruments that operate over a very wide range of wavelengths, from gamma rays and X-rays into the far infrared.

In general, any particular instrument will operate over a small portion of this total range because of the different techniques used to measure different portions of the spectrum. Below optical frequencies (that is, at microwave, radio, and audio frequencies), the spectrum analyzer is a closely related electronic device.“

Answer 2

Further to what Eri and Dan S have said it is often possible to tell what molecules are present (as opposed to just the elements), particularly with infrared spectroscopy which can see the energy absorbed by molecular vibrations. Very similar instruments are used on remote sensing satellites in Earth orbit to measure the concentrations of various molecules in the Earth's atmosphere.

The Viking landers of the 1970s also had a mass spectrometer on board which sampled the Martian atmosphere directly and recorded the abundances of different molecules.

Answer 3

The Viking lander has a gas chromatograph - mass spectrometer on board which analysed the Martian atmosphere directly.

http://marsprogram.jpl.nasa.gov/missions/past/viking.html

Answer 4

It's called spectroscopy.