Check out this article over at Universe Today outlining the long tradition of astronomical April Fool’s pranks from the past. Here are just a few of those shared:
In 1974, John Gribbin published The Jupiter Effect, claiming that a Grand Alignment of the planets would spell doomsday for the Earth on March 10th, 1982. On April 1st 1976, Astronomer Sir Patrick Moore made an announcement along a similar vein to BBC listeners. A rare conjunction of the planets Pluto (which was still classified as a planet at the time) & Jupiter would weaken the gravitational field of the Earth at precisely 9:47AM. This would cause the law of gravity to become temporarily suspended, and cause things to fly about. Big hint: Pluto was nowhere near the gas giant at the time. Not that it would matter or have any consequence for the Earth! Although the hoax was quickly revealed, that didn’t stop several listeners from calling in and reporting observed results from the fake Jovian-Plutonian Gravitational effect!