UAE skies: first 'Christmas Star' in 800 years to shine bright in rare celestial event on Monday

Planets Saturn and Jupiter will come together to form ‘The Great Conjunction’, visible in UAE for more than two hours

An image beamed back from the UAE's Hope Probe showing Saturn and Jupiter growing ever closer last month. Courtesy: Hope Probe / MBR Space Centre

A rare celestial event will be visible to the naked eye in the UAE and around the world on Monday – the appearance of a Christmas Star.

The phenomenon is caused by the near alignment of planets Saturn and Jupiter and has not appeared in the night skies for nearly 800 years. The next such event will be in 2080.

Sky gazers in the UAE will have two hours on December 21 to spot the Christmas Star, said Dubai Astronomy Group. It will appear from sunset (5.40pm) until 7.49pm.

In the nativity story, the Christmas Star, also known as the Star of Bethlehem, led three wise men to the infant Jesus.

US space agency Nasa described the visibility of the planetary conjunction as "merely a coincidence" based on the planets' orbits and tilt of the Earth.

“Conjunctions like this could happen on any day of the year, depending on where the planets are in their orbits,” said Henry Throop, astronomer in the Planetary Science Division at Nasa headquarters in Washington.

“The date of the conjunction is determined by the positions of Jupiter, Saturn, and the Earth in their paths around the Sun, while the date of the solstice is determined by the tilt of Earth’s axis.

“The solstice is the longest night of the year, so this rare coincidence will give people a great chance to go outside and see the solar system.”

Saturn and Jupiter came this close 400 years ago, but it is the first time they will align in the night time.

The closest alignment will appear just a 10th of a degree apart and will last a few days.

“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 towards the centre of the stadium,” Mr Throop said.

“From our vantage point, we’ll be able to be to see Jupiter on the inside lane, approaching Saturn all month and finally overtaking it on December 21.”

Dubai Astronomy Group will hold a paid event – Dh30 a person – for the observation of the celestial event using telescopes at Thuraya Astronomy Centre in Mushrif Park. The event starts after sunset.

It will be visible to the naked eye if observed away from light pollution.

But with the use of telescopes, Jupiter’s four large moons – Io, Europa, Ganymede and Callisto – may also be visible.

A live stream by the University of Exeter and Exeter Science Centre will be available online.

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