We all have an idea of what an iceberg looks like, and usually we imagine a chunky mountainous formation or an irregular slab with a seal lounging on top.

And then there's the iceberg photographed last week by NASA's Operation IceBridge team. It's so rectangular that it looks totally wild.

Enlarge Image NASA Operation IceBridge

Operation IceBridge is on a mission to measure and monitor polar ice and document changes over time. The team caught sight of the unusual iceberg during a flyover and posted it to Twitter last week.

From yesterday's #IceBridge flight: A tabular iceberg can be seen on the right, floating among sea ice just off of the Larsen C ice shelf. The iceberg's sharp angles and flat surface indicate that it probably recently calved from the ice shelf. pic.twitter.com/XhgTrf642Z — NASA ICE (@NASA_ICE) October 17, 2018

Operation IceBridge refers to the formation as a tabular iceberg and says it was found floating in the sea ice just off the Larsen C ice shelf in the Antarctic. "The iceberg's sharp angles and flat surface indicate that it probably recently calved from the ice shelf," the team writes.

Twitter users jumped on the odd-looking image, dropping references to everything from aliens to tofu to the monolith from Stanley Kubrick's 2001: A Space Odyssey.

Some also accused the image of being fake, but it's a perfectly natural phenomenon.

NASA ice scientist Kelly Brunt told Live Science that tabular icebergs are shaped like sheet cakes and split off from the edges of ice shelves. She said the visible portion is just a small part of the mass and the rest is underwater.

The tabular iceberg is a standout due to its extremely geometric shape, but it's not the only one that looks like it could fit into a Mondrian painting. Operation IceBridge posted a look at a fairly triangular iceberg late last week.

From yesterday's #IceBridge flight:Triangular iceberg surrounded by many different types of sea ice, off the Larsen ice shelf in the Weddell Sea. In the open water, grease ice is forming. pic.twitter.com/L4WB36bV5H — NASA ICE (@NASA_ICE) October 19, 2018

The Larsen C ice shelf is also the source of the infamous iceberg A-68, a monster that calved in 2017. The tabular iceberg photographed recently is much, much smaller than that beast.

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