Jupiter to appear brightest when it makes its closest pass by Earth on Sep 20th

WASHINGTON - On Monday, September 20th, Jupiter will appear brightest to skygazers, as it will come closest to the Earth at just 368 million miles away.

Although throughout September, on any clear night it will appear bigger than it used to be.

“Jupiter is always bright, but if you think it looks a little brighter than usual this month, you’re right. Jupiter is making its closest pass by Earth for the year. And this year’s pass is a little closer than any other between 1963 and 2022,” said says Robert Naeye, editor in chief of Sky ‘n’ Telescope magazine.

Jupiter is nearest to Earth on the night of Monday, September 20th: 368 million miles away. But it remains nearly this close and bright throughout the second half of September.

At the closest point of its previous swing-by, in August 2009, Jupiter was 2 percent farther than this time.

That translated into 8 percent dimmer, all things considered. At its next pass, in October 2011, it will be a little less than 1 percent more distant than now.

In addition, Jupiter is an additional 4 percent brighter than usual because one of its brown cloud belts has gone missing.

For nearly a year the giant planet’s South Equatorial Belt, usually plain to see in a small telescope, has been hidden under a layer of bright white ammonia clouds.

Coincidentally, Jupiter is also passing almost in front of the planet Uranus just now. Uranus is 5 times farther away and almost 3,000 times dimmer, so it’s invisible to the unaided eye and contributes no light to speak of.

But binoculars or a telescope will show Uranus less than 1 degree from Jupiter now through September 24th.

On the other end of the brightness scale, the full Moon joins this celestial scene around the same time too — shining above Jupiter on the evening of September 22nd and left of it on the 23rd.

More coincidences are also happening here-Jupiter and Uranus find themselves close to the point on the sky known as the vernal equinox, where the Sun crosses the celestial equator on the first day of spring.

And, all of this takes place around the date when fall begins in the Northern Hemisphere: on September 22nd.

Astronomers are wondering if all these coincidences mean something.

“Nothing at all. People forget that lots of things are going on in the sky all the time. Any particular arrangement might not happen again for centuries, but like the saying goes, there’s always something. Enjoy the show,” said Alan MacRobert, a senior editor at Sky ‘n’ Telescope. (ANI)