Join us for a tweet-along of the Apollo 11 Moon landing episode, Mare Tranquillitatis, of the HBO mini-series From the Earth to the Moon at 9 pm on July 20. You can join in by:

• Attending the free screening of the episode at the National Air and Space Museum; get free tickets
• Watching the episode on your own at the same time, via DVD, BluRay, HBO Go, HBO Now, HBO On Demand, or elsewhere; just press play at exactly 9 pm ET!

Tweet along with the episode using #EarthToMoon and follow along with the hashtag. We'll be sharing thoughts on the episode and other historical context.