Largest animal on Earth seen off the coast of Massachusetts in rare double sighting

One of nature's most awe-inspiring creatures, the rare and giant blue whale, was seen off the coast of Massachusetts in a rare back-to-back sighting.

Cape Ann Whale Watch, a touring group based in Gloucester, Massachusetts, took to Facebook on Monday to share footage of one of two blue whale sightings that day.

"We got to see this 'largest animal on our planet' on both of our trips today," the group wrote alongside footage of the blue whale spouting water and breaching to the surface.

Blue whales are indeed the largest animals on Earth, according to the National Oceanic and Atmospheric Administration (NOAA), which reports in the North Atlantic and North Pacific, blue whales can grow up to about 90 feet and are over 100,000 pounds.

The agency notes that blue whales are found in all oceans except the Arctic, generally migrating based on the season between feeding in the summer and breeding in the winter.

Cape Ann Whale Watch noted that blue whale sightings are incredibly rare in the region, believing there hasn't been a known occurrence in two decades.

"This whale is not common to our waters at all," the group wrote, adding, "I believe the last time we heard of a blue whale sighting in our waters was over 20 years ago."

The reaction to seeing the blue whale was very emotional, according to the group, "Our naturalist shed tears and could barely speak," they wrote, adding, "Interns too had tears and were in total awe."

Blue whales are listed as endangered under the Endangered Species Act and protected under the Marine Mammal Protection Act, according to NOAA, which they note has led to population increases worldwide.

Commercial whaling was a major threat to the species throughout the 1900s before these protections were instated. According to NOAA, the primary threats blue whale populations currently face are vessel strikes and getting entangled in fishing gear.

During the back-to-back whale watching trips Monday, Cape Ann Whale Watch reported seeing several wildlife species in addition to the blue whale, including a small pod of harbor porpoise, humpback whales, fin whales, lots of huge basking sharks and a pod of common dolphins.

"My main goal on the boat is to get people curious about nature," Christina McMahon Foley, senior naturalist with Cape Ann Whale Watch, told ABC News. "And this was like a little gift from mother nature," she said of the blue whale sighting.