Welcome to “This Week in Outer Space,” where you’ll find a roundup of the best space coverage from Yahoo News and our partners. This week, we’ve got the space equivalent of the census, a pitch for who should be on the first mission to Mars, and a mystery about solar wind potentially solved. But first, everyone’s favorite topic: aliens. Whistleblower claims the intelligence community is holding back information on UFOs There’s been a lot of talk about UFOs lately: mysterious balloons popping up in February, congressional testimony from the Pentagon’s UFO chief in April, and last week NASA held a…