Jupiter Saturn conjunction: see tonight’s ‘Christmas star’

Prepare for 21 December 2020, when the “winter solstice nice conjunction” of Jupiter and Saturn brings them closest within the night time sky since 1623


21 December 2020

Alan Dyer/VWpics/Science Photograph Library

Tonight, stargazers the world over will probably be handled to an occasion that solely occurs as soon as each 19.6 years, on common. On 21 December, the winter solstice, Jupiter and Saturn will seem in the identical place within the night time sky in an occasion referred to as an awesome conjunction.

These two so-called fuel giants of our photo voltaic system, that are often vibrant sufficient to see with the bare eye even from the light-polluted coronary heart of a metropolis, will align, as seen from Earth, to seem like one extraordinarily vibrant planet. This 12 months, the pair will probably be simply 0.1 levels aside within the sky, making it the closest such occasion since 1623. For reference, the diameter of the complete moon within the sky spans round 0.5 levels as we see it from Earth. The subsequent time these planets will probably be seen this shut collectively within the night time sky would be the 12 months 2080.

Jupiter and Saturn are essentially the most distant of the planets that may be seen simply with the bare eye. Uranus is just seen this fashion in notably darkish skies, and also you all the time want binoculars or a telescope to see Neptune.


As a result of Jupiter and Saturn are the furthest from the solar of all of the naked-eye planets, they orbit the slowest. It takes virtually 30 years for Saturn to do a lap of the solar, whereas Jupiter takes about 12. That is why conjunctions between the 2 are the rarest of these between all of the simply seen planets.

The place to search for the good conjunction

Whereas the occasion itself takes place on 21 December, the planets will probably be shut within the sky within the days main as much as it and afterwards. To see the conjunction, look south-west as quickly because the solar units and discover the brightest factor you possibly can see. As a result of the timing coincides with the winter solstice, the shortest day of the 12 months within the northern hemisphere, sundown will probably be early. Jupiter and Saturn will probably be low within the sky and can set rapidly, so ensure you have a very good view of the western horizon to catch them.

In case you have a pair of binoculars handy, the 2 will probably be seen as separate planets. Saturn will probably be above and to the left of Jupiter within the northern hemisphere and under and to the best within the southern hemisphere.

But when your binoculars are highly effective sufficient, a minimal magnification of seven, you would possibly even catch a view of Jupiter’s 4 Galilean moons. Within the northern hemisphere, two of those, Callisto and Ganymede, will probably be on the left of Jupiter. On Jupiter’s proper, a lot nearer to the planet, you would see Io and Europa. Within the southern hemisphere, the moons will line up in the wrong way to this.

For stargazers with a telescope, if you happen to can spot the planets earlier than they dip too low on the horizon, the view will definitely be value it and it isn’t one thing you’ll be fortunate sufficient to see usually: Saturn, its rings and a few of its moons together with Jupiter, its Nice Purple Spot and Galilean moons, all seen directly.

What you want

A transparent sky

BInoculars (optionally available)

A telescope (optionally available)

Stargazing at residence seems each 4 weeks

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