Saturday, December 9, 2023

Giants of the sky


Juno image of Jupiter (courtesy of NASA)


Amateur astronomer Brian Watkiss peers into the Village night sky.

August, this year, will be taken over by the two giant planets of our Solar System – at least the evening skies will be. As soon as the sky starts to darken, which will be quite late for most of the month as the Sun doesn’t set until nearly nine o‘clock, the first object to become visible will be Jupiter, low in the south.

This is a colossal planet. If your average aeroplane could fly around the world non-stop, it would take about two days. To fly around Jupiter would take nearly three weeks.

Not that it could, because Jupiter is mostly hydrogen gas – although the visible surface is made up of clouds of ammonia which, due to the planet’s high spin rate, swirl into huge storms with wind speeds of nearly four hundred miles per hour, as revealed in wonderful close-up by the probe Juno recently.

The Moon flies close by on the 9th, though, and it has the bright star Antares just below.

Further east (or left because remember you are looking south) is Saturn, almost as bright because it is nearly as big as Jupiter but, bizarrely, only has about a quarter of its mass.

Its surface appears quite serene by comparison and it has those beautiful rings, a must-see for anyone with even a small telescope. This planet has also been photographed in exquisite detail by the Cassini probe. The Moon trundles by on the 11th and 12th.

This is around the time of one of the best meteor showers of the year. It is caused by the Earth passing through the trail debris left behind by the comet Swift-Tuttle and although they peak on the 13th, they can be seen a few days before and after this.

They are called the Perseids because the point which they all seem to come from is in the constellation of Perseus. This doesn’t mean that the this is best place to spot them. You can, in fact, spot them anywhere in the sky; just find the biggest patch of sky that you can and keep looking because the moment you stop, there will be a big bright one that everyone will be talking about.

While you are out, take a moment to look to the north and admire the glow from the lights of Birmingham. Just above it you should see the Plough, and this time of year it’s the right way up and looking a bit like an old-fashioned horse-drawn plough.

This month should see the launch of a new space craft capable of carrying people. It’s the Boeing Starliner and this will be an unmanned test mission to the ISS. It may be visible in Alvechurch so check for sighting times – and anyway, this is a great time of year for spotting the Space Station.

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