Nasa post sparks panic that everyone's starsigns have changed – but the truth is more complicated

Numerous new articles have suggested that Nasa has all of a sudden changed everyone's starsigns.

The news has led people to panic that they have lost some important part of their identity – that their sign might have been wrong all along, and that not only their horoscopes but their entire character may have been a lie.

But Nasa has done no such thing, and it has neither the power to alter starsigns, nor any particular interest in doing so.

The stories do however make reference to an interesting – though not at all new – fact about how the constellations change, and the implications that they could have for people who believe in astrology and horoscopes.

The new stories appeared all across the media in recent days, and made reference to the fact that the arrangement of the stars above our heads have changed over the course of the thousands of years since the Babylonians first happened upon them, 3,000 years ago.

They noted, correctly, that Nasa has in the past spoken about the phenomenon of "axial precession", or the fact that the Earth wobbles as it rotates, a little like a spinning top. That effect means that the stars appear from Earth to be in a different place from where they were 3,000 years ago, and so the constellations that make up the starsigns have moved, too.

They were also correct that Nasa had also told the story of how the Babylonians had looked to fit the 13 constellations into the easily divisible 12 months of the year, and so removed one – known as Ophiuchus – from their charts. Some of the articles claimed that Nasa "created" Ophiuchus, but it was and is a constellation that was in the sky when the current system of the zodiac was made, and all Nasa did was point that out.

But both of those things happened thousands of years ago, and are well established facts. So the modern-day use of the starsigns were formed in full knowledge of that information.

Since astrology is a system used by humans to discuss their lives, it does not necessarily need to line up with the stars as they actually are. As such, people can stick with their existing starsign, or opt to use their supposedly newly calculated one – the only thing that really matters is that the astrologers who then use those starsigns are using the same system.

If everyone switched to the more contemporary system – of 13 starsigns and different dates – then it could feasibly be said that people have been given a new starsign. But that does not appear to be happening, and as long as it does then people can stick with their existing understanding of themselves and their horoscopes.

Perhaps the most important thing to note is that Nasa has not changed the star signs, or done any of the other things that the stories related to it claim. Many have suggested that the space agency has had a sudden change of heart, made some sort of breakthrough, or decided to confess that it had secretly known that star signs were wrong all along.

But it is not in Nasa's power to change the starsigns, even if it wanted to. And it almost certainly doesn't want to: the space agency has been disparaging of astrology, even in the same post that appears to have led to the current furore.

"It's not science," the post reads, as it discusses how astrology is different from astronomy. "No one has shown that astrology can be used to predict the future or describe what people are like based only on their birth date. Still, like reading fantasy stories, many people enjoy reading their 'astrological forecast' or 'horoscope' in the newspaper every day."

That post has been on Nasa's website for years, and was part of a page intended to educate children on the difference between astronomy and astrology, and how the starsigns originally came about.