Rumours of a freak ‘double-moon’ phenomenon due to occur tomorrow are being dismissed as ludicrous by astronomers.

Fevered internet speculation suggests Mars will loom as large in the sky as the moon itself – creating a rare effect where both appear to sit side by side.

According to online accounts, the event only happens on occasions when Mars is closest to Earth.

So frantic has the speculation been on social media, that reports of the much anticipated - but wholly false - occurrence have been shared thousands of times on Twitter and Facebook.

The South East Kent Astronomical Society says the rumours are based on a misunderstanding which happened over 10 years ago.

Honorary president Paul Andrew said: “The moon is around a quarter of a million miles away, while Mars is 140 million miles off.

“So they will never appear the same size to the naked eye. It’s ludicrous.

“A scientist once explained that if you looked at Mars through a telescope of times 75 magnification, it would appear the same size as the moon to the naked eye.

“This was famously misinterpreted at the time.”

Mr Andrew also explains that Mars is at its closest point to Earth every two years – last year, and next year.