The BBC's Gravity-Defying April Fool's Prank

On April 1st, 1976, renowned astronomer Patrick Moore made a startling announcement on BBC Radio 2. At precisely 9:47 AM, he declared, a once-in-a-lifetime astronomical event would occur: Pluto would pass directly behind Jupiter, and their combined gravitational pull would temporarily reduce Earth's gravity. If listeners jumped in the air at that exact moment, Moore explained with scientific authority, they would experience a strange floating sensation.

The phones started ringing almost immediately.

Hundreds of listeners called the BBC to report their experiences. One woman claimed she and her eleven friends had risen from their chairs and hovered around the room. Another caller said he and his entire dinner party had floated. The reports kept coming, each more elaborate than the last, as Britons across the country swore they'd felt the effects of what Moore had dubbed the "Jovian-Plutonian Gravitational Effect."

Of course, it was completely made up.

Why People Believed It

Patrick Moore wasn't just some random prankster—he was one of Britain's most trusted voices in astronomy. He'd been presenting The Sky at Night on BBC television since 1957, making him a household name in science broadcasting. When Moore spoke about the cosmos, people listened. His credibility gave the hoax instant legitimacy.

The prank also had just enough pseudo-science to sound plausible to non-experts. Planetary alignments are real phenomena, and Jupiter is indeed massive—318 times Earth's mass. The idea that such a giant planet might have some gravitational influence on Earth isn't completely absurd to someone without a physics background.

The Reality Check

Here's why the "Jovian-Plutonian Gravitational Effect" could never happen:

• Distance matters exponentially. Jupiter was about 390 million miles from Earth at the time. Gravitational force decreases with the square of distance—at that range, Jupiter's pull on Earth is essentially zero.
• Pluto is tiny and impossibly far. Pluto has less than 1% of Earth's mass and was roughly 3 billion miles away. It might as well not exist gravitationally speaking.
• The Moon's gravity is millions of times stronger. If planetary alignment could affect Earth's gravity, we'd feel the Moon's influence constantly—and we don't, beyond ocean tides.

The Legacy

The 1976 hoax became one of the most famous April Fool's pranks in broadcasting history. It demonstrated the power of trusted authority figures and the public's willingness to believe in the extraordinary, especially when it comes from a credible source.

Moore himself never regretted the prank. In later interviews, he chuckled about the creative stories people invented to match their expectations. The human mind is remarkably good at feeling what it expects to feel.

The BBC has continued the tradition of April Fool's pranks over the decades, but few have matched the elegant simplicity and widespread success of Moore's gravity gag. It remains a masterclass in how to blend just enough real science with complete nonsense to create something truly believable—at least for one morning in April.