Kiwi stargazers are in for an early Christmas treat as the two largest planets in the solar system, Jupiter and Saturn,
appear at their closest since Galileo was alive 400 years ago.
Known as a Great Conjunction, the two planets will be visibly at their closest to each other on 21st December, but also
strikingly close between 19th and 23rd December.
Astronomers at Auckland’s Stardome Observatory & Planetarium, are encouraging Kiwis young and old to look to the west from half an hour after sunset on these nights to
see the rare astronomical event.
“The Great Conjunction refers to a time when the two largest planets in the solar system pass close to each other in the
sky as viewed from Earth,” says John Rowe, astronomy educator at Stardome Observatory & Planetarium.
“This is extremely exciting because it is the closest the two planets have appeared since 1623. And given the next time
Jupiter and Saturn will be this close is 2080 - 60 years from now – this really is a rare once in a lifetime experience
for most people.”
This Great Conjunction is being referred to by many as the Star of Bethlehem because of the two points of light coming
together at Christmas. It represents the Three Wise Men following the star west to Bethlehem.
Mr Rowe says the spectacle will be easily visible with the naked eye and will appear especially striking to spectators
with clear views of the western horizon away from bright city lights.
“If you look low on the western horizon just to the right of where the sun sets, about half an hour or so after sunset,
then you should get a great view – weather permitting of course.
“The planets will appear to sink quite quickly so are only going be visible for about an hour and a half each of the
four evenings. Perfect timing for the kids to see before bedtime too,” he says.
The celestial phenomenon occurs because the planets are in line as viewed from Earth.
“While it looks like the planets are touching, they are in fact not even close to each other. Jupiter orbits the sun at
a distance about five times greater than Earth, and Saturn about ten times the Earth-Sun distance.
“Nonetheless, the view from here on Earth looks like a spectacular near-miss of the two largest planets in our solar
system. It is going to be quite incredible to see.”