A Christmas star is born
Aligned planets dazzle in night sky – so is this what the Wise Men followed?
SO far this year, the stars haven’t aligned favourably for most of us on planet Earth.
But last night there was a bright spot on the horizon to lift stargazers’ spirits. And it was shining more brilliantly than it has in nearly 800 years – where there were clear skies, at least.
Jupiter and Saturn, the two largest planets in the solar system, appeared close together, creating a spectacular sight in the south-western skies after sunset. They were last this close in the 17th century – but were more easily visible from Earth back in 1226.
The especially vibrant planetary conjunction, which sees them lie so near one another that you may not be able to distinguish between them is popularly known as the ‘Christmas Star’.
Some have suggested it may have been the bright light that came to be known as the Star of Bethlehem.
Robert Massey, deputy executive director of the Royal Astronomical Society, said yesterday: ‘They were just 0.1 degrees apart, or about one fifth of the diameter of the full Moon.
‘Conjunctions that are this close are very unusual, and Jupiter and Saturn were last seen in such close proximity in 1623. On that occasion, the two planets were close to the Sun in the sky, so would have been hard to pick out.
‘The last time the planets were both this close and so easy to see was in 1226, long before the invention of the telescope. No one alive has seen the so-called Great Conjunction quite so close as those lucky enough to get a clear view last night.’
Alignments between Jupiter and Saturn occur once every 20 years. Last night’s was rare because of how close the planets appeared to one another. Dr Massey said as they move around the Sun, the planets often ‘appear’ near to each other in the sky.
He added: ‘Jupiter and Saturn will still be almost 800million kilometres ( 497million miles) apart, despite appearing to be almost next to each other from the Earth’s perspective.’
However many in Britain were left disappointed as rain and clouds blocked the view. Both planets are bright – in the case of Jupiter, brighter than stars – so would have been obvious in a clear sky, Dr Massey said.
But he had good news for those who missed the winter solstice spectacle due to bad weather – as the planets should still appear unusually close for the next few days.
The Irish Astronomical Association said the planets would be this close again in 2080 but would be ‘extremely difficult’ to see. The next time they will be as clear is 2414.
‘Brightest display in 800 years’