Sending Astronauts To Mars
When sending a spacecraft to space and other planets, sterilization is key to the process. If one does not sterilize the spacecraft, years of research could be defunct, due to the spacecraft containing organisms found on Earth. Also, sterilization is key to our own safety on Earth.
To sterilize a spacecraft before going into space, NASA puts the spacecraft in the oven and heats it at 220 degrees past the boiling point to decontaminate it of organisms. The problem is, there are still extremophiles that can withstand the temperatures, including different forms of bacteria that eat radiation. Different types of bacteria can survive within extreme heat and extreme cold, and they can also survive without water. Bacteria from Earth stayed on the moon despite temperature swings and lack of water, for 31 months. This means that bacteria can easily live through different conditions (http://www.panspermia.org/bacteria.htm).
Some decontamination protocols, such as the use of strong hydrogen peroxide vapors, are in the early stages of development. Gamma radiation, ultraviolent radiation and heat are all used to help aid in the sterilization process, however, forward contamination (contamination coming from Earth) is still extremely possible, despite our efforts. Earth bacteria and organisms could cause quite the problem to possible organisms on Mars. Similar circumstance to the European's landing in North America could occur from a spacecraft landing on a different planet. When European's came to the New World, they released several diseases that were completely unheard of in the New World. Smallpox, Typhus, Cholera, and Measles all came from European explorers who moved to America. The spread of disease grew and infected harshly. Also, the way of life of the organisms who lived in the New world was greatly altered.
When spaceships return with Martian soil, they try and bring back samples that haven't touched the Martian atmosphere. To protect backward contamination (contamination coming from other planets to earth), containers are being designed to do protect from contamination. Also, diagnostic tests are an option being studied, thusly to reveal contamination before it reaches the Earth.
Complete sterilization should be perfected before we attempt to have manned exploration on mars in the next decade. Though the benefits of the exploration would be fruitful to humanity (information gathered from the planet, possible discovery of new organisms, possible place for human colonization, etc.) it could also be very destructive. If a bacteria or organism from Mars that was completely damaging to humanity (possible viruses and infectious bacteria) was spread, it could be devastating to the human population. The advantages are great, however human protection is most important, and this should be covered before we reap the advantages we could obtain.
I think when subduing land, humanity should also respect the land in which it controls. I think it would be selfish to contaminate the natural state of land with human problems, and once again, it could tarnish our own control over the Earth. Much like the European contamination of the New World, Mars contamination or Earth contamination is extremely possible. Safety measures should be performed to protect Mars or any other planet we decide to visit. If we were to destroy the land with our presence, then we would be controlling it correctly, we would be destroying it.