A conjunction?

1. Betelgeuse ready to explode in supernova – are we in danger?
In October 2019, Betelgeuse – the red giant star marking Orion's right shoulder – was dimming. Usually the 10th brightest star in the sky, by February it was 23rd. Betelgeuse is a variable star, but this was extreme. Of the possible explanations, social media seized on the most dramatic: the star was about to explode as a supernova. Astronomers have been saying that it could explode soon. Was Earth in peril?

Note: When an astronomer says “soon”, it's not usually a normal sort of soon. For Betelgeuse, it actually means around 100,000 years or more. In any case, Betelgeuse is 600 light years away, close enough to provide a spectacular sight, but at that distance, not a danger to Earth.

Hubble Space Telescope observations show that the dimming probably resulted from the ejection of an enormous amount of hot material which created a dust cloud around the star, blocking its light.

2. The Mayan calendar end-of-the-world revisited
Remember 2012 when social media were full of the Mayan calendar predicting the end of the world on December 21? It was resurrected in 2020 with a change of date.

People who actually had studied Mayan civilization had pointed out that the Mayan calendar did not predict the end of the world. Their calendar no more shows the end of time than does December 31st on your calendar. Others wondered why, even if the Mayans had been in the prediction business, should we assume it was accurate?

The basis of the 2020 nonsense was a tweet explaining how the conversion from the Mayan calendar was incorrect and the date was actually June 21, 2020. No, the conversion was fine, but the “prediction” was silly, and the original poster of the tweet said it was a joke. That didn't, of course, stop its circulation, but we're still here.

3. Alien temple with view + black dome structure
Some people obsessively study NASA photographs, looking for signs of alien civilization. Despite the absence of alien structures, these folk still keep "finding" them.

Seeing patterns in random things is called pareidolia. I suppose it happens to most of us from time to time, but only a few people announce it to the world as being real.

The best known of the imaginary Martian sights is the Face on Mars, a low resolution image from the Viking orbiter in the 1970s. There are people who still maintain that it's an ancient artifact, even though years later Mars Global Surveyor's high resolution image clearly shows that it's a rock formation.

Someone who had a great 2020 is a self-styled UFO expert, who finds alien structures everywhere. For example, he explained to the British Express newspaper that he'd found an “ancient alien temple” in Mars rover photos. "There are lines going vertical and horizontal [which] should be impossible. Lines should only go in one direction as the rock is forming.” He also said that the "structure" was designed to have a view.

I saw rocks and shadows. What did you see?

4. Mars as big as the full moon
In August 2020 a Facebook meme said:

Aug 27th you will see two moons in the sky, but only one will be the moon. The other will be Mars. It won't happen again until 2287. No one alive today has ever witnessed this happening.

In most years from 2003 onwards, this has appeared in some form.

The Moon wasn't full on August 27, but Mars was getting nearer to us for a close approach in October. However the closest it ever gets is about 55 million km (34 million miles). That's some 230 times the distance of the Moon.

The two moons? "No one alive today has ever witnessed this happening." That's true and it will continue to be true.

5. Look up, cheer up for a smiley face in the sky
On May 16, we were in for a treat when “a rare conjunction between Jupiter, Venus, and the crescent Moon” would make a smiley face in the sky. A conjunction occurs when two or more heavenly bodies appear close together in the sky. The header image of this article shows what we were supposed to see.

The story went all around the internet. On that day Venus would be very bright in the west around sunset. But Jupiter, far from being nearby, wouldn't even rise over the eastern horizon until a few hours after Venus had set. And the Moon? It was nowhere near Jupiter or Venus, rising before dawn and setting in early afternoon. It was a crescent moon, but not the smile in the header – it would have looked like this.