On Monday, the fantastic and beloved actor Martin Landau passed away. While he is surely remembered for his award-winning performances in Ed Wood and Crimes and Misdemeanors, science fiction fans remember him best for playing Commander Koenig on the cult TV show Space: 1999. And after news of Landau’s death spread, those fans took to Twitter to share some Moonbase Alpha love.

For those who weren’t around in the 1970s, or didn’t have an awesome Space: 1999 storybook given to them by their older cousins, the plot of the show centered on Earth’s moon getting blown out of orbit, permanently. This means everyone living on Moonbase Alpha was sent careening through space on the Moon, which became a kind of moving spaceship and space station simultaneously. Landau was the heroic leader of Moonbase Alpha, Commander Koenig, a guy who played things a little cooler than say, William Shatner as Captain Kirk.

Space: 1999 also was the forerunner for other space-station centric shows like Babylon 5 or Star Trek: Deep Space Nine. It also had the best — and funkiest — sci-fi TV show theme song, possibly ever.

Fans on Twitter shared these memories, as well as some great facts about the show and Landau in specific.

A lot of fans pointed out that Landau left a starring role on Mission: Impossible to do Space: 1999. You can’t imagine Tom Cruise doing the same thing now.

The ‘70s sci-fi aesthetic of Space: 1999 was way more 2001: A Space Odyssey and Star Trek: The Motion Picture than it was Star Wars. Which was part of its charm.

Where’s our Moonbase Alpha already?

It takes a real good actor to pull of some of the premises of these episodes.

The cast of Space: 1999: your parents look awesome in space.

Influential science fiction news magazine Starlog put Space: 1999 on the cover of its second issue ever. Inverse profiled the rise of Starlog earlier this year.

Look at this handsome space commander!

Space: 1999 is currently available in its entirety to stream on Hulu.

Watch the opening sequence from the 1st season (complete with that funky, funky sci-fi beat) right here: