Dive summary: 

• At 11:00 am on Feb 22, NASA is hosting an hour-long question-and-answer session on Google+ with three astronauts at the International Space Station.
• Google has preselected video questions that the astronauts will answer; some will be from #askAstro hashtag on YouTube submitted before Feb 12. 
• The public will be able to ask written questions in real-time by using the hashtag #askAstro on Google+ and Twitter or by submitting to the Facebook thread during the event. 

From the article: 

"NASA has broadcast live onboard many of its space vehicles, with astronauts giving tours of spacecraft and answering questions, but this will be the first time NASA conducts such an event using multiple forms of social media to solicit questions.

The event will be viewable through NASA's Google+ page or through its YouTube channel."