Congratulations to the Phoenix team! It is exciting to read about the apparent discovery of ice on Mars. This has vast implications of course, with one being the possibility that life once existed there.
I firmly believe that there is life elsewhere in the Universe. I believe that we will discover other Earth-like planets in addition to discovering life in remote, hostile areas like Mars.
Now, the question on whether or not Earth has been visited by aliens is different topic. Although an intriguing idea, I am skeptical that we have been visited by other intelligent beings. I myself have seen odd things, including in space, but they have all turned out to be explainable events.
What do you think? Are we alone in this Universe? Will someone invent the warp drive soon and allow us to explore farther with probes and astronauts?