NASA defines a black hole as `` a place in space where gravity pulls so much that even light can not get out , '' where `` the gravity is so strong because matter has been squeezed into a tiny space . '' NASA has some fun with Black Friday on its Twitter account . The agency is offering a free trip to the International Space Station for anyone who tweets about #BlackFriday2015 or mentions @NASA.
NASA has some fun with Black Friday on its Twitter account . The agency is offering a free trip to the International Space Station for anyone who tweets about #BlackFriday2015 or mentions @NASA.