Every few years when the same story about the zodiac signs changing emerges, the TL is flooded with protesting cries of, ‘But I’m such a Libra. This can’t be true!’ And every few years, NASA is forced to confirm that, no, it did not change the signs.

Earlier this week, it once again ‘emerged’ that there’s a ‘13th sign’ called Ophiuchus (pronounced oh-few-cuss), which means all the zodiac dates are wrong. For example, if you were born between May 20 and June 20, you would previously be considered a Gemini, but with the addition of the ‘new sign’, you would now be a Taurus (no way, right?).

In an explainer on Dazed earlier this week, we told you that this theory had consistently been debunked by astrologists, who explain that Ophiuchus has always existed and is “a constellation located northwest of the centre of the Milky Way, somewhere near Scorpio and Sagittarius”. Ophiuchus was deliberately left out by the Babylonians 3,000 years ago, and was therefore never factored into the zodiac signs. 

The key takeaway here is that constellations are not signs, so while Ophiuchus does exist, it has no impact on the zodiac.

Anyway, now NASA has published a blog about it to clear up any misunderstandings. It reads: “Here at NASA, we study astronomy, not astrology. We didn’t change any zodiac signs, we just did the math.”

The agency goes on to explain that over three millennia ago, the Babylonians divided the zodiac (made up of constellations of stars which lie close to an imaginary line that is drawn from Earth through the sun and out into space) into 12 equal parts. As Earth orbited the sun, the sun seemed to pass through each of these 12 parts. Because the Babylonians already had a 12-month calendar based on the phases of the moon, they picked 12 constellations, allocating one to each month.

“But even according to the Babylonians’ own ancient stories,” NASA continues, “there were 13 constellations in the zodiac. So they picked one, Ophiuchus, to leave out. Even then, some of the chosen 12 didn’t fit neatly into their assigned slice of the pie and crossed over into the next one.”

NASA confirms that in the 3,000 years since the zodiac was created, “the sky has shifted because Earth’s axis (North Pole) doesn’t point in quite the same direction”. However, because the zodiac was never accurate in the first place, this shift doesn’t actually impact the signs we know and love.

“The constellations are different sizes and shapes, so the sun spends different lengths of time lined up with each one,” concludes NASA. “The line from Earth through the sun points to Virgo for 45 days, but it points to Scorpius for only seven days. To make a tidy match with their 12-month calendar, the Babylonians ignored the fact that the sun actually moves through 13 constellations, not 12. Then they assigned each of those 12 constellations equal amounts of time.”

Basically, the zodiac has always been wrong, but don’t worry, you’re still technically a Libra.