Chemistry Rockets to Mars

NASA is developing the most powerful rocket in history, the Space Launch System (abbreviated to SLS) to launch the spacecraft known as Orion. Orion is expected to carry humans beyond the Moon and on to Mars in the 2030s.
It is well known that engineers, physicists, mathematicians and computer programmers play a quintessential part in the design, development, launch, trajectory and landing of rockets and spacecraft, but what about chemists?
Chemistry also plays an important role in getting rockets off the ground.
Without an understanding of chemistry there would be no fuel, no thrust, no take-off!

Read more in the December 2017 issue of AUS-e-NEWS.

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Martian Elements

NASA's Mars Science Laboratory rover, Curiosity, is due to be launched between November 25^th and December 18^th 2011 and should land on Mars in August 2012. Curiosity will carry a next generation, onboard "chemical element reader" to measure the chemical ingredients in Martian rocks and soil.

The Alpha Particle X-Ray Spectrometer (APXS) instrument uses alpha particles and X-rays to bombard a target, causing the target to give off its own characteristic alpha particles and X-ray radiation. This radiation is than read by an X-ray detector which reveals which elements are present in the sample, and how much of the element is present.
Scientists will use information from APXS to figure out the present and past environmental conditions that are preserved in the rocks and soils.

Currently, scientists believe that the most abundant elements on Mars are silicon and oxygen, then iron, magnesium, aluminium, calcium, and potassium, which are the elements that make up igneous rocks, the minerals that crystallize from magma. The characteristic red colour of Mars is due to the presence of iron oxides. Titanium, chromium, manganese, sulfur, phosphorus, sodium and chlorine are also present in much smaller amounts.
Hydrogen is present in water. In 2008, NASA announced that the Phoenix lander had confirmed the presence of water in the form of ice on the Martian polar ice caps.
Carbon occurs as carbon dioxide in the atmosphere, and as dry ice at the Martian poles, while some carbon is stored as carbonates. Phoenix Mars lander in 2007 found alkaline soil containing calcium carbonate, and in 2010, Mars Exploration Rover Spirit identified deposits of magnesium-iron carbonate.
About 95% of the Martian atmosphere is carbon dioxide. Nitrogen gas makes up 2.7% of the Martian atmosphere, then smaller amounts of argon, oxygen, carbon monoxide, water vapor, and nitric oxide. Tracer amounts of neon, krypton, formaldehyde, xenon, ozone and methane have also been detected.

Reference
NASA/Jet Propulsion Laboratory (2011, February 20). Advanced NASA instrument gets close-up on Mars rocks. ScienceDaily. Retrieved February 22, 2011, from http://www.sciencedaily.com­ /releases/2011/02/110220204711.htm

Further Reading
Elements and Compounds
Metals and Non-metals
Periodic Table
Radioactivity

Study Questions:

1. Draw up a table with two headings; element name and chemical symbol. Enter the name and symbol of each element named in the article above into the table.
   
2. Draw up a table with two headings, elements in Martian rocks, and, elements in Martian atmosphere. Enter each element mentioned in the article above into the table in the appropriate column.
3. Draw up a table with three headings, metals, non-metals and semi-metals (metalloids). Enter each of the elements named in the article above into the table in the correct column.
4. Use a Periodic Table to find the atomic number of each element named in the article above.
5. Name three compounds mentioned in the article above and write the chemical formula for each one.
6. Name each of the Group VIII (Noble Gases) mentioned in the article and give the chemical symbol for each one.
7. Name the organic (carbon) compounds mentioned in the article and give the molecular formula for each one.
8. What is an alpha particle?
   

Life on Mars?

Was there life on Mars?
Scientists continue to look for organic compounds such as proteins in Martian soil, but to date none have been found, even though organic molecules are found in many other places in the Solar System.

Astrobiologists are beginning to wonder if the iron oxides that make up the soil on Mars, giving the planet its distinctive red colour, are photocatalysts which use energy from ultraviolet light to oxidize carbon-containing molecules trapped in soil particles converting them to carbon dioxide and gases such as methane. This suggests that the absence of proteins or other organic molecules on Mars does not necessarily mean it has never supported life forms.

Reference:
Ilya A. Shkrob, Sergey D. Chemerisov, Timothy W. Marin. Photocatalytic Decomposition of Carboxylated Molecules on Light-Exposed Martian Regolith and Its Relation to Methane Production on Mars. Astrobiology, 2010; 10 (4): 425 DOI:
10.1089/ast.2009.0433

Study Questions:

1. Define an organic compound.
2. What elements are proteins made up of?
3. Proteins are produced when what smaller compounds react?
4. What is the name given to the bond between these smaller compounds making up a protein?
5. Why do you think Astrobiologists look for proteins in order to determine if life existed on Mars in the past?

Further Reading:

1. http://www.ausetute.com.au/proteins.html
2. http://www.ausetute.com.au/aminoacid.html