Saturn and Jupiter will come the closest they have done in hundreds of years on Monday, creating what astronomers predict will be the marvellous spectacle of an apparently single bright star, creating the illusion of a “Christmas star.”
Jupiter and Saturn align every 20 years or so, the last time Jupiter and Saturn were this close together was in 1623 however it has been nearly 800 years since the alignment occurred at night, as it will this year.
The next time the two planets will be this close to each other again will be March 2080.
“You can imagine the solar system to be a racetrack, with each of the planets as a runner in their own lane and the Earth toward the center of the stadium,” says Henry Throop, an astronomer in the Planetary Science Division at NASA.
“We’ll be able to see Jupiter on the inside lane, approaching Saturn all month and finally overtaking it on December 21.”
What is the Christmas star?
The two biggest planets in the solar system, Jupiter and Saturn will dance in a planetary conjunction, lining up perfectly to create the illusion of a “Christmas star.” The planets will be just 0.1 degrees apart, and appear together as the brightest object in the sky.
How can I see the Christmas Star?
The advice to keen stargazers is to look to the south west as soon as possible after sunset, with the best time between 4.30pm and 6pm,
Jupiter will look like a bright star and will be easy to spot, while Saturn will be slightly fainter and will appear just above and to the left of Jupiter. Jupiter will overtake Saturn, then the planets will reverse positions in the sky
You won’t need a telescope or binoculars to see the conjunction, but if you have them weather permitting, it may make it possible to see the four large moons that orbit Jupiter.
What will the weather be like?
The Met Office has forecast rain early on Monday, and said the visibiliy between 3-6pm is Very Good for the Swindon area.
MONDAY
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| Weather symbol |  |
|
|
 |
|
 |
|
|
| Chance of precipitation | 80% | 90% | 90% | 60% | 50% | 20% | 10% | 10% |
| Temperature (°C) |
7°
|
8°
|
10°
|
11°
|
11°
|
10°
|
8°
|
7°
|
