SATURN AND JUPITER WILL APPEAR AS ONE BRIGHT OBJECT AFTER SUNSET

‘Grand conjunction’ of the planets will be first one visible since 1226

The richly luminous planets Saturn and Jupiter will be so close in the sky tonight they’ll appear to meld together with a starkness that has not been widely seen on Earth since the 12th century.

The paths the planets follow around the sun will bring them into rough alignment shortly after the sun sets in the southwest, creating what astronomers call a “grand conjunction.”

It can also be called an optical illusion; the planets will be about 450 million miles away from each other at the time. But as seen from Earth, they will be only 0.1 degrees apart in the sky, close enough to look as though they’re fusing into a single object.

“The planets will be a bright

whitish-yellow to the naked eye, but you’ll really be able to discern color if you use binoculars,” said Lisa Will, an astronomy professor at San Diego City College.

“If you look at Saturn through binoculars you might also be able to see the moons of Jupiter. This should be spectacular.”

The phenomenon will play out over several hours on the first night of winter, beginning about 5:30 p.m. The conjunction will happen low in the sky, making San Diego County beaches a good vantage point, on a night when light winds are expected to keep the marine layer offshore during early evening.

Jupiter travels about 29,236 mph as it orbits the sun — roughly 7,500 mph faster than Saturn. But the planets align roughly every 20 years. It last happened in May 2000. But most people were not well positioned to see it. That’s because the grand conjunction doesn’t always occur at the same spot. There are variations in the orbital tracks of the two planets, making close alignments rare.

Astronomers say the last time lots of people around the world were in places to observe the kind of phenomenon expected tonight was March 1226, when Earth had a population of about 400 million. Today, the figure is almost 7.6 billion.

This is a must-see astronomy event.

“This is the ‘greatest’ great conjunction between Jupiter and Saturn for the next 60 years, with the two planets not appearing this close in the sky until 2080,” NASA says in an online primer.