An astronomical delight will take place in deep space above Gloucestershire on Monday – but will we be able to see it?
To us on earth, it will look as if the two planets Jupiter and Saturn have become one shortly after sunset in the Great Conjunction 2020.
Of course, they will remain millions of miles apart, but from our vantage point on Earth, the two gas giants will make a‘ Christmas star of Bethlehem’
Such a sight hasn’t been visible since the middle ages, but will the weather be kind to us on December 21 to enable us to see the event?
Unfortunately, the Met Office forecast for Monday shows cloudy conditions at the best time to see the two planets – sunset.
The sun is due to set at around 4pm in Gloucestershire, and the forecast suggests cloudy conditions in the county.
Of course, the forecast can change and stargazers can hope for a break in the clouds.
And the BBC forecast has a bit more hope as it says it could be ‘partly cloudy’ around sunset.
The last time the conjunction of the two planets happened was in 1623, but the proximity of the gas giants to the sun mean it was not visible.
You have to go back to 1226 for the last Great Conjunction of the two planets.
It will be visible from anywhere in the world, but the best views will be closer to the equator.
British astronaut Tim Peake has told his 1.5million twitter followers to look out for the phenomenon.
He tweeted last week: “If you are in UK, look SW from 4.30pm GMT. They will have sunk beneath the horizon by 6.20pm GMT.”
NASA has also made much of the forthcoming event, saying: “What makes this year’s spectacle so rare, then?
“It’s been nearly 400 years since the planets passed this close to each other in the sky, and nearly 800 years since the alignment of Saturn and Jupiter occurred at night, as it will for 2020, allowing nearly everyone around the world to witness this ‘great conjunction’.
“The closest alignment will appear just a tenth of a degree apart and last for a few days. On the 21st, they will appear so close that a pinkie finger at arm’s length will easily cover both planets in the sky.
“The planets will be easy to see with the unaided eye by looking toward the southwest just after sunset.”
NASA’s top tips to see the Great Conjunction
• Find a spot with an unobstructed view of the sky, such as a field or park. Jupiter and Saturn are bright, so they can be seen even from most cities.
• An hour after sunset, look to the southwestern sky. Jupiter will look like a bright star and be easily visible. Saturn will be slightly fainter and will appear slightly above and to the left of Jupiter until December 21, when Jupiter will overtake it and they will reverse positions in the sky.
• The planets can be seen with the unaided eye, but if you have binoculars or a small telescope, you may be able to see Jupiter’s four large moons orbiting the giant planet.