Not such a Super Moon after all
I AM in two minds about the hype surrounding this week’s Pink Super Moon (Mail). It’s a good thing to have a distraction from the gloom and doom, and to encourage people to look upwards to appreciate the spectacle of the night sky. Even in light-polluted cities, you can see the Moon, if nothing else. It would be an even better thing if our decision makers understood the consequences of light pollution not only to astronomers, but for human health and the wellbeing of our wildlife. However, claiming the Super Moon would appear 14 per cent bigger and a third brighter than usual was overselling it. Because of its egg-shaped orbit around the Earth, the Moon appears larger or smaller in the sky as it gets nearer or further away over the course of each orbit of 27½ days. The shape of the orbit varies so that the distance of closest approach when the Moon appears largest and brightest in the sky also varies over a period of around 200 days. The closest approach also has to coincide with a Full Moon, which makes it a Super Moon. This week’s Super Moon appeared just 6 per cent larger in the sky than average, barely 0.1 per cent larger than the last Full Moon in March and only 0.6 per cent larger than the next one in May. I doubt anyone could tell the difference in size or brightness just by looking at it. Every Full Moon is a spectacle, as are many other things to be seen in the night sky, if you manage expectations. But by over-egging the pudding with announcements of Super Moons; great meteor showers, which may amount to one every few minutes if you’re lucky; and spectacular comets, which usually don’t make the grade, there is a risk of the public seeing astronomy as bunkum. Yes, there was a genuine spectacular comet in 1976 and great meteor shower in 1833, but even then you had to be in the right place at the right time!
KEN WOOD, Newport, South Wales.