Why and how did you decide to send Opportunity to the Meridiani Planum?
Dear Melissa, NASA has a long term goal of trying to find the origin of life. This is not simple, and there are many different places to look. The reason Earth is not so good is that the oldest rocks on Earth, that may have contained traces of the very first life, has been remelted because the continents of Earth floats on the surface and are subducted here and there. The oldest rocks we know of on Earth are 3.8 billion years old – and the Solar System and the Earth formed 4.6 billion years ago. But, for example on Mars, we know that there are very old rocks still to be found (a 4.5 billion years old Martian meteorite has fallen on Antarctica) so to find good places to look, first we try to find places where water may once have been abundant. And this is the reason Meridiani Planum was chosen as landing site for Opportunity and Gusev Crater for Spirit. On Meridiani instruments flown on Mars Global Surveyor and Mars Odyssey had found a mineral hematite that it was thought may have forme
