Nasa announced today out of mars. check this out. evidence of flowing water on the red planet. and where there's water, of course, there could potentially be life. the news could have an important impact on the space agency's quest to send a manned mission to mars by the 2030s. joining me now, astronaut and associate administrator for nasa at john gruns feld. john, this has to be a really exciting day for scientists like you. i learned a new word today, rsl. can you explain that? >> sure. every day is exciting for nasa science, but today's an especially exciting one, because we've been observi...