Has your horoscope changed? NASA ‘does the math’ and reveals 13th Zodiac sign

NASA is setting the record straight after a recent surge of social media posts claiming the agency has ‘changed’ everyone’s astrological Zodiac signs.

In a Tumblr post, the agency explains what’s really going on – and also reminds everyone that Astrology is not Astronomy!

Here’s NASA’s explanation:

The Babylonians lived over 3,000 years ago. They divided the zodiac into 12 equal parts – like cutting a pizza into 12 equal slices. They picked 12 constellations in the zodiac, one for each of the 12 “slices.” So, as Earth orbits the sun, the sun would appear to pass through each of the 12 parts of the zodiac. Since the Babylonians already had a 12-month calendar (based on the phases of the moon), each month got a slice of the zodiac all to itself.

But even according to the Babylonians’ own ancient stories, 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.

When the Babylonians first invented the 12 signs of zodiac, a birthday between about July 23 and August 22 meant being born under the constellation Leo. Now, 3,000 years later, the sky has shifted because Earth’s axis (North Pole) doesn’t point in quite the same direction.

The constellations are different sizes and shapes, so the sun spends different lengths of time lined up with each one. The line from Earth through the sun points to Virgo for 45 days, but it points to Scorpius for only 7 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.

So, we didn’t change any zodiac signs…we just did the math.

False stories claiming that Ophiuchus is going to mess up everyone’s astrological signs have been popping up since 2002, according to Snopes, and NASA itself posted about it in 2011.

So next time you see a panicked post like this, take it with a huge grain of salt.