Although it is clearly too late to be considered spring cleaning, the gigantic whale model at New York’s American Museum of Natural History is getting its annual cleaning.

Based off a dead female whale discovered off the coast of South America in 1925, the fiberglass whale is 21,000 pounds and 94-feet long as reported by Reuters. The whale is suspended from the ceiling of the museum and meant to appear as if he is swimming through the air. Each year cleaners spend two to three days cleaning the whale, using a tool similar to a vacuum cleaner in order to reach all parts of the whale and reveal its true blue color underneath.

Museum marine biologist Melanie Stiassny said to New York Daily News that, “People don’t realize how dusty she gets. I don’t even realize it until she gets clean.”

Interestingly, when the fiberglass whale was first suspended in the museum in 1969, it was actually a shade of gray because no one had ever seen a blue whale that was alive before. Its color was only changed to a more realistic blue in 2003.