Is Elon Musk about to make good on his mecha proposal? A cryptic tweet published Thursday has led to speculation that the SpaceX CEO is about to make an announcement related to planet-scouting robots. The tweet, which reads “Tomorrow Brings a Lemur” alongside a picture of a lemur, has also led to speculation that Musk could announce something related to his Tesla electric car firm.

Moments after its publication, followers on Reddit and Twitter noted a possible link between Musk’s tweet and NASA’s Jet Propulsion Laboratory. The group has been working on a series of LEMUR robots. Musk also posted a mysterious tweet earlier this week about creating a mecha, fueling speculation that the entrepreneur is making a coded statement about robotics.

The LEMUR bots could give Musk a helping hand. At the IEEE International Conference on Robotics and Automation in 2012, NASA demonstrated the LEMUR IIB, which it dubbed “the world’s first rock climbing robot.” The machine used 750 hand-made claws to traverse the sort of surfaces you’d find on asteroids and planets. It’s the sort of skill that could be ideal for scoping out a landscape, say as part of an unmanned mission to Mars in 2022.

Musk posted the below image in the early hours of Thursday morning:

Musk later retweeted this video shared in the replies:

Steven Sinofsky, who was previously president of Microsoft’s Windows division, also got in on the action:

It’s not the only theory out there about Musk’s statement. A Reddit user called “TeslaModelII” said on the Tesla subreddit that there could be a link with the tweet and the Apollo Lunar Module from the 1969 moon landing, also known as the LEM. The user suggested the extra letters could stand for “ultra-reusable” or “robot.”

Another user called “Xaxxon” pointed out that lemurs have good night vision, suggesting that Musk’s follow up tweet claiming that “you’ll see” could be related to improving night vision. This led to speculation that the post could be related to improvements to Tesla’s semi-autonomous Autopilot driving system, which recently received an update to version nine and is expected to receive an upgrade to point-to-point autonomous driving for drivers that have paid for the software upgrades pack.

Whatever the tweet may concern, hopefully tomorrow brings further details alongside a lemur.