Reuters Elon Musk mistook the moon for Mars in a tweet - and the internet is calling him out. The SpaceX CEO tweeted a picture of the moon with the caption "Occupy Mars" and other Twitter users were quick to correct him. Musk's tweet came within hours of him saying that he is accelerating the development of Starship, a rocket that is designed to go to Mars. Visit Business Insider's homepage for more stories . The internet is mocking Elon Musk after he mixed up the moon and Mars. Musk tweeted out a photograph on Sunday with the caption "Occupy Mars" but Twitter users were quick to point out that the image was not of the red planet, but of the moon during the July 2018 lunar eclipse - a phenomenon known as the blood moon. Tweet Embed: //twitter.com/mims/statuses/1142904294196178944?ref_src=twsrc%5Etfw pic.twitter.com/yUUSNdWMEw "That's the moon," said Twitter user Viv , to which Musk responded with two laughing face emojis . He later said "moon too," adding : "Moon 1st, as it's only 3 days away & u don't need interplanetary......