While the shoppers across the US remained hooked to Black Friday shopping mania, NASA surprised everyone by launching its own event named Black Hole Friday.

NASA's move to grab the attention of the Americans came just a day after Thanksgiving by releasing several unknown facts about black holes.

The black holes are actually stellar objects which are tiny in size but are capable of generating incredible amounts of gravity. Black holes are generally formed by stars collapsing in on themselves. The gravitational force of these black holes is so strong that they do not even allow the light to escape.

NASA researchers spent the day tweeting facts about black holes, including some Black Friday-themed jokes.

The world's premier space agency also tweeted a black hole-themed game. NASA sent out over a dozen tweets and retweets on black holes. The "2-for-1 deal" was a hit, garnering over 1,000 retweets.

NASA defines a black hole as "a place in space where gravity pulls so much that even light cannot get out," where "the gravity is so strong because matter has been squeezed into a tiny space."

The California-based space agency also posted some fun and less-known facts about black holes.