This afternoon, Jeff Bezos’ spaceflight venture Blue Origin is set to make a big announcement about... something. The company hasn’t provided any details yet, but speculation is high that the announcement will be related to Blue Origin’s plans to explore the Moon.

The only clue we have about this event is a cryptic tweet that Blue Origin sent out on April 26th. The tweet shows a picture of a ship surrounded by ice, with the caption “5.9.19.” Sharp-eyed space fans were quick to point out that the ship in the picture was explorer Ernest Shackleton’s Endurance. Shackleton famously led expeditions to the Antarctic in the early 1900s, and because of his exploits, a site on the south pole of the Moon was named the Shackleton crater.

That’s why many think today’s Blue Origin announcement will have lunar leanings. The Shackleton crater has often been considered an attractive landing site for future lunar exploration. NASA and others are eager to visit the south pole of the Moon, as many scientists believe the area might be awash in water ice. If there’s enough ice present, it could be mined and turned into drinking water, rocket fuel, and more that could help sustain a human presence on the surface of the Moon. The image of the Endurance surrounded by ice may be a nod to that.

The Shackleton crater is also enticing because there are some areas near the site that receive constant sunlight. That’s unusual, as most other areas of the Moon experience a two-week lunar daytime followed by a two-week lunar nighttime. This makes exploring the Moon difficult since many spacecraft rely on solar power as their main energy source, and it can be hard to maintain power through two weeks of cold and darkness.

Cryptic pictures aside, this would be a good time for a Moon-related announcement, given the fact that the US is very focused on getting back to the lunar surface soon. In December 2017, President Trump signed his first Space Policy Directive that called on NASA to put humans back on the Moon. In March 2019, Vice President Mike Pence challenged the space agency to fulfill this goal by 2024, four years earlier than NASA had originally planned.

That means NASA is going to need a lot of hardware fast to pull off this task — most notably, lunar landers that can carry people to the Moon. Today’s announcement may revolve around the vehicles that Blue Origin plans to make to explore the Moon, which could serve as a pitch to NASA about what the company is capable of achieving.

However, if today’s announcement is about the next step in lunar exploration, the picture that Blue Origin shared is somewhat foreboding. Shackleton’s vessel Endurance did not have a successful mission to Antarctica. In 1915, the ship got stuck in sea ice in the Weddell Sea, and it was eventually crushed. The crew of the vessel survived for months camped out on the ice before escaping to an island using three lifeboats. It took several rescue attempts to eventually save the crew.

Let’s hope that the picture is meant to represent Shackleton and perhaps the lunar ice that Blue Origin may be aiming for on the Moon. We should get more details at 4PM ET today. There’s no word yet on whether there will be a live stream, but we will update this post if we get one.