"If I had any remaining doubt that turning 50 was seismic, this a.m.'s Hollywood earthquake made the point! #TheBigOne," Lowe tweeted.
Lowe also received some birthday love from the other side of the country. The American Association of Retired Persons sketched Lowe's face onto sidewalk-chalk membership cards in four different locations around New York.
Soho sidewalk! What does it say when one's birthday becomes "street art" on the other side of the country? pic.twitter.com/oiPx6vQdcT— Rob Lowe (@RobLowe) March 16, 2014
Swim Week Miami Beach 2014 [PHOTOS]