SpaceX CEO Elon Musk tweeted that he "Will be announcing something really special at today's talk" and you can watch the live stream on YouTube. Musk is speaking at the 68th International Astronautical Congress 2017 in Adelaide, Australia, where he's going to explain more about his plans to make humanity multi-planetary by colonizing Mars. He recently highlighted an old SpaceX simulation of how its rockets in an Instagram post, and has been posting glamour shots of spacesuits all over social media. The talk kicks off local time Friday at 2:30 PM, or 12:30 AM ET / 9:30 PM PT.

Update: Musk just posted this image to Instagram, showing a "Moon Base Alpha" concept, then followed it up with an image of "Mars City." Notably, it's appearing a day after Russia and US space agencies announced plans to team up on an effort, and of course, earlier this year SpaceX said it would send two people on a trip around the moon in late 2018. Surely we'll find out more about more about this plan in just a few hours.