Planet? Moon? What’s the difference!?

This will be the last “supermoon” post, I hope. There’s just something about it which seems to make journalists become especially stupid. Perhaps the Victorian doctors who said the moon caused “lunacy” were onto something.

Anyway, here’s what has pride of place on the Mail‘s science page today:

You know, lunar planet! That… moony planet?

Okay, Daily Mail Reporter, find your nearest 8 year old relative and ask them what the difference is between a “planet” and a “moon“. The answer may (not) surprise you!

The photos in the article are very nice looking, but the reason the moon looks so giant in them isn’t because of the “supermoon”. The trick is to take the photos of the moon when it’s very low on the horizon, grazing very distant buildings. Using a powerful zoom lens, you zoom in on the distant buildings, so they look normal sized and the moon looks gigantic. This isn’t something unique to supermoons, it can be done any day.

Like I said in last week’s post, the “supermoon” would never be as dramatic as the papers claimed – it was only 6% larger than usual, and this happens twice a month. Without a decent telescope and a camera, you probably wouldn’t notice the “supermoon” at all.

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The Supermoon did NOT cause the earthquake

Normally, scientists are meant to be circumspect and reserved about cause and effect. We’re supposed to deal in probabilities, statistics and uncertainties. However, on this occasion, I have absolutely no qualms in saying this: The Daily Mail is wrong. The “Supermoon” had nothing to do with the terrible earthquake off the coast of Japan today.

Ben Goldacre and Phil Plait have already produced some admirable rebuttals to the Mail‘s exploitative scaremongering; these are my thoughts, but I recommend reading the linked posts.

The powerful tsunami that today slammed into Japan’s eastern coast comes just two days after warnings that the movement of the moon could trigger unpredictable events on Earth.

Except none of these “warnings” come from scientists. The only people who took the “Supermoon” seriously were internet conspiracy theorists and the tabloids. And…

Astrologers predicted that on March 19 – a week tomorrow – the so-called ‘supermoon’ will be closer to Earth than at any time since 1992, just 221,567 miles away, and that its gravitational pull will bring chaos to Earth.

An astrologer is the not same thing as an astronomer. A warning from an astronomer should (generally) be taken seriously. A warning from an astrologer isn’t worth the paper it’s printed on.

Others on the Internet have predicted it will cause further catastrophes such as volcanic eruptions and earthquakes.

“Others on the Internet”? Of course, everything that was ever written on the internet MUST be true.*

* Fully aware of the hypocrisy, thank you very much.

However the ‘supermoon’ date is still eight days away. But those that adhere to this particular belief could claim that this was still close enough for there to be some kind of effect.

Ok, as everyone knows, the moon orbits once a month. Once every two weeks, it comes close to the Earth – this is the “perigee” of its orbit – and in between these perigees we have the furthest points: the “apogee”. This means that eight days before the perigee, it will be as far away as possible from the Earth; the exact opposite of a “supermoon”. Its gravity would be weaker, not stronger.

The energy needed to produce an earthquake builds slowly through stress and strain in the rocks where tectonic plates meet, over years or decades. A tiny change in the position of the moon – a change which, remember, happens twice a month – will have virtually no effect compared the constant force of billions of tons of rock pressing against each other.

Two days ago, in an interview with ABC radio discussing the potential impact of the March 19 supermoon, astrologer Richard Nolle, who first coined the term in 1979, said he was convinced that lunar perigees cause natural disasters on Earth.

‘Supermoons have a historical association with strong storms, very high tides, extreme tides and also earthquakes,’ he said.

The only one of those that is true is that “Supermoons” can cause high tides (and even then, it only changes the tidal range by a couple of percent). There is no association between “Supermoons” and storms or major earthquakes. And again, an astrologer is NOT an astronomer.

Natural disasters are unfortunately common. Earthquakes, storms and floods happen with depressing regularity – look hard enough and you can find disasters happening around any supermoon. What’s important is to the look at the disasters that weren’t linked to a supermoon. No scientific study has shown an increase in quakes or storms around supermoons.

What do the actual scientists say?

Dr David Harland, space historian and author, said: ‘It’s possible that the moon may be a kilometre or two closer to Earth than normal at a perigee, but it’s an utterly insignificant event.’

Professor George Helffrich, a seismologist at the University of Bristol was equally dismissive.

‘Complete nonsense. The moon has no significant effect on earthquake triggering.

‘If the moon triggers “big” earthquakes, it would trigger the many of millions of times more “small” earthquakes that happen daily. There is no time dependence of those; hence no moon effect.’

[…]

John S Whalley, geoscience programme manager at the University of Portsmouth, agreed there was no correlation.

‘There is no established correlation between variations in the orbit of the moon and either the number or magnitude of earthquakes.

‘It is all too easy, with hindsight, to link major earthquakes to variations in all sort of parameters.

‘The real test is to look at the vast numbers of earthquakes of all magnitudes that occur on a daily basis worldwide.

‘Any correlation with the lunar orbit would have to be established on the basis of this population of earthquakes, not on individual high magnitude events. In need hardly add that no such correlation has been established.’

I would end this post with another glib link to the SMBC comic, but frankly I don’t feel like this the right time for daft jokes. Nor is it the appropriate time for a newspaper with a readership of millions to be giving a platform to charlatans and conspiracy theorists, who seize on a terrible tragedy just to get a little bit of publicity for their pseudoscientific claims.

Supermoon!

You've met with a terrible fate, haven't you?

The question: Could ‘supermoon’ next week disrupt Earth’s weather?

The web was yesterday awash with apocalyptic warnings that the movement of the moon will trigger tidal waves, volcanic eruptions and even earthquakes next week.

The conspiracy theorists claim that on March 19, the moon will be closer to Earth than at any time since 1992 – just 221,567 miles away – and that its gravitational pull will bring chaos to Earth.

The answer:

But astronomers have dismissed the claims as pure nonsense.

Take us away, Saturday Morning Breakfast Cereal.

Edit:

The Sun and Metro have both managed to be much worse than the Mail. The Sun has the headline “‘Disaster’ as Moon closes in” while Metro has “‘Supermoon’ may cause weather chaos for coastal Britain“. Bear in mind that the Moon comes almost this close twice a month – the only thing that makes this time “super” is that it happens to coincide with a full moon, and even then, that happens every 2 or 3 years. This will cause slightly higher tides, yes, but according to the NOAA, these happen 3 or 4 times per year (since they can be triggered by new moons and nearly-full moons too) and the change in the tide is only around 2%.

The Telegraph‘s coverage is better – there’s far less doom – though as much as I hate to be a party pooper, it’s going to be less dramatic than they make out. On average. the moon’s “angular diameter” – the amount of the sky it fills up – is 0.259 degrees. In other words, the moon would appear the same size as a five pence coin held 1.99 metres (6 feet 6 inches) away from your face. During the supermoon, its angular diameter is 0.274 degrees- the same as a five pence coin held 1.88 metres (6 feet 2 inches) away. That’s roughly a 6% increase in size – and this increase happens twice every month.

If you could compare the two side by side, you would see the difference – if you’ve got a small telescope or a decent pair of binoculars, then a supermoon should be a great opportunity to have a look up there – but otherwise, you probably couldn’t tell (the moon illusion causes the size of the moon to appear to vary by way more than 6% anyway). At any rate, the Telegraph‘s illustration is… a little exaggerated.