The Internet Is Losing It After Neil deGrasse Tyson Explains Gender Of Santa’s Reindeer Rudolph

Neil deGrasse Tyson found himself at the center of another internet debate after a Christmas-themed science post reignited long-running arguments about fiction and whether anyone really wants biology lessons on Christmas Eve.

The astrophysicist’s comment, which featured an old observation about reindeer antlers, quickly spread across X and prompted thousands of reactions ranging from sarcastic jokes to outright annoyance.

Neil deGrasse Tyson’s holiday post sparked annoyance among X users

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The controversy began when Tyson shared a post explaining that both male and female reindeer grow antlers, but males typically lose them by late autumn.

Based on that biological detail, he concluded that Santa’s reindeer, including Rudolph, would therefore be female.

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“In case you didn’t know… Both male & female Reindeer grow antlers, but males lose them in late Autumn,” Tyson wrote. “All Santa’s reindeer are therefore female, which means Rudolph is persistently misgendered.”

The post rapidly went viral with 3.1 million views and thousands of replies, many of whom were not appreciative of the astronomer’s comments.

Social media responded Neil deGrasse Tyson’s holiday post with sarcasm and irritation

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The replies quickly turned blunt and comedic. One user wrote, “You’re never gonna believe this, but Reindeer can’t fly around the world either.”

Another added, “Rudolph also has a red nose and can fly, because he’s a fictional character. Anything goes in fiction. Quit taking everything so seriously.”

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Others leaned into sharper humor. “Why are you over there thinking about reindeer genitals on Christmas Eve?” one comment read, while another simply declared, “You must be fun at parties.”

The tone of the backlash suggested that many readers were less offended by the science itself and more exasperated by what they saw as an unnecessarily petty post during the year’s biggest holiday.

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For some, the post also represented a broader frustration with some people’s tendency to nitpick beloved traditions.

This was far from the first time Neil deGrasse Tyson made the same observation about Santa’s most famous reindeer

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Longtime followers were quick to point out that Tyson had made the exact same argument years earlier. On December 25, 2015, he posted: “Male & female Reindeer grow antlers, but males lose them in winter. All Santa’s reindeer, Rudolph too, are therefore female.”

That earlier post triggered a similar wave of reactions, with some commenters stating that Tyson was trying to “ruin Christmas.”

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Tyson’s interest in Rudolph’s biology and physics has also extended beyond antlers. In December 2011, he shared another analysis, writing: “According to the song, Rudolph’s nose is shiny, which means it reflects rather than emits light. Useless for navigating fog.”

On the same day, he followed up with a correction: “Red light cuts thru fog better than white. So if Rudolph’s nose did glow, he’d indeed prevent Santa from flying into mountains.”

Rudolph’s origin story predates the science debates by decades

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Rudolph the Red-Nosed Reindeer did not originate from ancient folklore or traditional Christmas mythology. The character was actually created in 1939 by copywriter Robert L. May for a Montgomery Ward holiday promotion.

May wrote the story to give away as a free booklet to customers, and it featured Rudolph as an underdog whose glowing red nose set him apart. The story also framed Rudolph as a target of ridicule before ultimately saving Christmas.

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The character’s popularity exploded a decade later when May’s brother-in-law, Johnny Marks, adapted the story into the song Rudolph the Red-Nosed Reindeer.

Recorded by Gene Autry in 1949, the song became one of the best-selling Christmas singles of all time and permanently cemented Rudolph in holiday culture.