NASA followed one of the classic rules for Internet videos during its first space-to-Earth Google Hangout on Friday: If you want to bring in the viewers, don't forget the cats.
Astronaut Tom Marshburn's demonstration of how an astronaut in the International Space Station's zero-gravity environment can imitate a falling kitty was one of the highlights of the hourlong video chat, which addressed more than 30 questions sent in via YouTube, Twitter, Facebook, Google+ and real-time hookups with kids across the country.
One of the questions, phrased in the form of a video, came from the host of the "Smarter Every Day" webcast series, a rocket engineer known as Destin. (He keeps mum about his last name to protect his kids, who appear in the webcasts.) Destin ran his own mini-video showing how a falling cat rights itself in the air to land on its feet, and asked if the astronauts could match that feat in zero-G.
"We don't have any cats onboard," said space station commander Kevin Ford, "but we have a medical doctor who maybe can try to demonstrate the next best thing to a cat."
Marshburn, who's a physician as well as an astronaut, then proceeded to float in front of the camera and twist his body to change position — not quite as adroitly as the cats, but not bad for a human.
"I hope you believe that what you saw happened with the cat isn't a mystery, and that it can happen in space, too," Ford concluded. You can watch the demonstration around the 33-minute mark in the Hangout video.
Other astronauts participating in the chat included Canada's Chris Hadfield aboard the station, and NASA's Ron Garan and Nicole Stott on the ground. They took questions passed along from social media by NASA moderator John Yembrick; from live-video hookups with classrooms at University High School in Orlando, Fla., and Mescalero Apache School in New Mexico; and from a youngster named Fred whose video link was facilitated by the Make-a-Wish Foundation.
Here are a few more nuggets from the video:
- Hadfield said that this week's communications outage on the space station was "not that big a deal," and that the crew members were well-trained to operate the station even when they were out of contact with ground controllers. "It wasn't any sort of panic or anything, it was just us dealing with a problem on the ground, and our crew dealing with the problem on board," he said.
- Getting into the right sleep cycle is a big challenge on the space station, where there are 16 sunsets and sunrises every day. Garan said that when it gets close to bedtime, some astronauts avoid looking out the window at Earth's bright side. Stott said NASA is experimenting with a scheme that makes the lighting inside the space station more bluish for the "morning" of the astronauts' workday, and more orangish during the "evening."
- The station's crew members showed off the medical kits they kept on board for health problems, but if there's a life-threatening emergency on board, astronauts would get into one of the Russian Soyuz capsules attached to the station and fly the stricken crew member back to Earth. "Our Soyuz is our ambulance," Marshburn said.
- When the astronauts were asked which scientist from the past they wish they could bring to the space station, Marshburn instantly said Isaac Newton, who drew up physics' three laws of motion in the 17th century. "We see what he could only imagine," Marshburn said.
- Taking pictures from space is a challenging task that requires advance training, due to the sharp contrast between the blackness of outer space and the brilliance of the planet below, Hadfield said. But there's one big plus: Because of the zero-G environment, it's a lot easier to handle huge telephoto lenses. "Every photographer in the world would love to have that much glass in front of their eyes ... and not have to balance it," Hadfield said.
- When the astronauts were asked about their growing social-media stardom, Hadfield said, "I don't think anybody tries to push the edge of human experience more than we do." Being able to see the whole world below is "too good an experience not to share," and avenues such as Twitter, Facebook and Google+ help facilitate that, he said. He noted that a lot of the astronauts' popularity had to do with their unique perspective. "We know just how lucky we are to be here," Hadfield said.
For more outer-space video goodness, tune in the Weekly Space Hangout at 3 p.m. ET Friday. Yours truly will be on the screen along with other scribes to review the week's space news, including the meteor blast that hit Russia a week ago.
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.