Jupiter will be closer on September 20 than it has been since 1963 – closer than it will be again until 2020. That’s happening because Jupiter’s orbit – like Earth’s orbit – isn’t perfectly round. Jupiter’s closest point to the sun in its 12-year orbit will come about six months from now, in March, 2011.

So we will be passing between Jupiter and the sun (Jupiter’s opposition) on September 21, 2010. And Jupiter will be closest to the sun in March, 2011. That is why Jupiter comes closest to us – at a distance of 368 million miles – around the time of this opposition. The exact date of Jupiter at its closest is September 20, 2010 – the day before opposition. The giant planet will be closer that day than it has been since 1963, and it won’t come so close to Earth again until the year 2022.

So look for Jupiter in the night sky, and expect it to be big and bright!

If you have ordinary binoculars lying around the house, be sure to turn them in Jupiter’s direction. Jupiter is always a fun object to see through binoculars, and that will be especially true this year since the planet is closest. Through binoculars, you can see one, two or more of the planet’s four largest moons, known as the Galilean satellites. They will appear as tiny ’stars’ strung out in a line bisecting the planet. (Image: Nabarun Sadhya)

A telescope would reveal even more detail within Jupiter’s cloudtops. Dedicated observers, who track this detail over years and decades, know that the planet has recently lost its South Equatorial Belt. At the same time, the Great Red Spot has intensified in color.

By the way, the planet Uranus – shining barely within the limit of visibility to the unaided eye, and best seen in a dark sky – will be less than a degree from Jupiter on the night of opposition, September 21. When the moon is not nearby, shedding its glare on the scene, look through binoculars for Uranus near Jupiter. Both planets will be visible in the same field of view.