There are many challenges and many benefits of growing food on Mars. For a long-term mission, it isn't cost effective to haul food to Mars if we can grow it there. And with the reports of Martian salt water this week, we can start a biological life support system by filtering the salt out of the water that is already there.
I became a promising classical violinist by the age of 10. Two years later I joined the orchestra, and then I became leader of the orchestra. Glamorous, neat, classy, we toured everywhere playing classical music in opera houses. I loved it, but with every concert my "little dream" of becoming an astronaut was fading away without me even realizing.
I find myself living at a very particular point in the almost 4 billion years of the evolution of life on this planet. I feel extraordinarily lucky to be alive right now, when for the very first time, we are able to investigate terrestrial life on scales smaller than the size of atoms, as well as look to the skies for evidence of extra-terrestrial life many hundreds of light years beyond Earth.