Big Breakout on Jupiter

After thinning to practically nothing last year, Jupiter's North Equatorial Belt has erupted with a broad dark band full of bright and dark spots that can be observed with backyard telescopes.

The King of Planets has been putting on quite a show lately. Last week two observers spotted a bright fireball in Jupiter's midsection, the sixth such impact to be witnessed since the late 1970s. But even before that fleeting flash, the planet had been roiling with a vigorous outbreak of activity in its North Equatorial Belt.

The NEB is one of two iconic dark bands that bound the planet's brighter Equatorial Zone, an Oreo-cookie arrangement that's visible even in the smallest of backyard telescopes. You might recall that the South Equatorial Belt disappeared in mid-2010, apparently masked by bright, high-altitude clouds. It returned to view by year's end.

These images, taken six months apart, reveal big changes on Jupiter. In that interval the planet's North Equatorial Belt (NEB) greatly expanded and its North Temperate Belt (NTB) experienced a resurgence. South is up, to match the inverted view seen through many astronomical telescopes. Click on the image for a larger version.
Christopher Go
Now the NEB is taking its turn in the spotlight. Last year the dark band started narrowing, its northern edge gradually whittling away. This in itself wasn't unusual — the same thing has occurred every few years for decades, most recently in 2009. According to John Rogers, who heads the Jupiter Section of the British Astronomical Association, these thinnings often precede a rapid expansion.

But this time the diminution was much more pronounced, until nothing was left but a thin ribbon. Then, just before the planet disappeared into mid-May's conjunction with the Sun, Pennsylvania observer Wayne Jaeschke noted an outbreak of spots in the northern belt's location. By the time Jupiter returned to view in June, a full-blown revival was under way — for the first time since 1926, according to Rogers. And the actiuon wasn't limited to the NEB, as the adjacent North Tropical Belt also seethed with activity.

"Sectors of the belts and the intervening North Tropical Zone, which were still light in June, have now filled in with intense turbulence and reddish (ochre) color," Rogers reports. Visually you'll see one vast brown-and-ochre belt from the NEB's southern edge to the NTB, and a reddish hue is more evident. (Notably, the Great Red Spot remains quite pale.) The NEB's large-scale eruptions have run their course, he says, and familiar types of smaller markings have started to reappear: dark "barges", white ovals, and bright rifts in the belt.

Rogers offers more details about the belt's big breakout in the November issue of Sky & Telescope.

Right now Jupiter rises in the east by 11 p.m., but it won't be well up in the sky (when telescopic views will be better) until after midnight. You might prefer to simply get up before dawn, when you'll find the big planet nearly overhead and tangled in the horns in Taurus. Jupiter reaches opposition on December 3rd, by which time complete order should be restored among its colorful belts and zones.

6 thoughts on “Big Breakout on Jupiter

  1. Gail Kohler

    I recently acquired a 5 1/2 inch telescope, by Meade. I have been fascinated all my life with the stars. But even now I know very little. Can anyone recommend a web site where I can find times and directions of stars etc.? I would really appreciate the help. Or if there is not such a site maybe someone reading this wouldn’t mind me emailing them and asking questions? Thank you so much for any help that you can provide! -Gail-

  2. Michal

    Gail,

    There are many easy to use resources that can help you watch for interesting sights. I like either of the following for beginners as they are easy to use and understand, and you can print them out:

    Evening Sky Map – free pdf download
    http://www.skymaps.com/downloads.html
    a bit awkward to locate on web page, but look down the page for the pdf download for the month AND hemisphere (northern for U.S.)

    Abrams Sky Calendar – requires subscription
    http://www.pa.msu.edu/abrams/SkyCalendar/Index.html

    The next step up would be planetarium apps for an iPod Touch, iPhone or similar device, or your desktop computer. Too many to list here.

  3. Paul Cox

    I’m running two live free shows tonight, showing live images of Jupiter and the occultation of Europa. We’ll also see the darkened North Equatorial Belt (as written about here). We watched some large "barges" just below the belt last night.

    The shows are free to the public on the Slooh.com homepage (it’s part of Slooh’s "Month of Live Astronomy").

    Monday, Sept 17th: 6:15 PM PDT ¦ 9:15 PM EDT ¦ 01:15UTC

    International times here: http://goo.gl/BcW2N

  4. Navneeth

    Gail, while I’m sure the plenty of online astronomy resources will no doubt be of immense help to you, at different stages of your hobby, it is completely different to an expert guiding you around the sky. Have you checked whether there are any clubs around where you live?

    Check for listings here: http://www.astronomyclubs.com/ (of course, it goes without saying that the list is not exhaustive)

    Not only will you learn about the sky, but also how to use your telescope. And if lucky, maybe view a distant galaxy or a storm cell on Jupiter through a monster 18" or something. :)

  5. Chris McKitterick

    Gail, if you have a smartphone or similar portable device, you can download tons of apps to help you find your way around the sky. The most popular is probably Google Sky, which uses the GPS in your device to identify where you are, so you can hold up the screen and see what’s up there. Other, more-complete apps cost very little. I’ve noticed that telescope-accessory companies are now making mounts for such devices for pointing telescopes!

  6. Anthony Barreiro

    Gail, welcome and best wishes as you learn to observe the cosmos through a small telescope. Here are some resources I’ve found helpful. The best book for beginners is _The Monthly Sky Guide_, text by Ian Ridpath, illustrated by Will Tirion. My favorite mobile application for a smart phone or tablet is SkySafari 3 Plus by Southern Stars. Whether or not you’re using a mobile app, a printed sky atlas is essential. The two best small atlases are _Sky & Telescope’s Pocket Sky Atlas_ by Roger W. Sinnott and _The Cambridge Star Atlas, 4th Edition_ by Wil Tirion. Like Navneeth, I would encourage you to connect with your local astronomy club. nightsky.jpl.nasa.gov has a searchable database to help you find a club in your area and to learn about events that are open to the public. Amateur astronomers love to share our equipment, knowledge, and love of the sky with new folks! And of course, you should subscribe to _Sky and Telescope_!

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