Posted on by David Dickinson

Watch: An Amazing, Mesmerizing Full Rotation of Jupiter

Jupiter as imaged by Michael Phillips on July 25th, 2009... note the impact scar discovered by Anthony Wesley to the lower left.
Jupiter as imaged by Michael Phillips on July 25th, 2009.

Jupiter is a happening place in the solar system. While bashful Mars only puts on a good show once every two year opposition period, and inner worlds such as Mercury and Venus yield no surface details to backyard observers at all, the cloud tops of Jupiter display a wealth of changing detail in even modest backyard telescopes.

And this month is a great time to start observing Jupiter, as the largest planet in our solar system just passed opposition on January 5th. Recently, veteran astrophotographer Michael Phillips amazed us here at Universe Today once again with a stunning time-lapse sequence of Jupiter and its moons Ganymede and Io. Now, he’s outdone himself with a new full rotation compilation of the gas giant planet.

The capture is simply mesmerizing to sit and watch. At 9.9 hours, Jupiter has the fastest rotational period of any planet in our solar system. In fact, with Jupiter currently visible low to the east at sunset, it’s possible to follow it through one rotation in the span of a single long January winter night.

We caught up with Michael recently and asked him about this amazing capture. The sequence was actually accomplished over the span of five successive evenings. This made it challenging to stitch together using a sophisticated program known as WINJupos.

“While this is possible on a long winter night when it is darker longer, I typically find it easier to do over multiple nights than one long sleepless night,” Michael told Universe Today. “If you wait too many days between observations, the features will change significantly, and then two nights will not match up clearly. The seams that result from using multiple nights are tricky to stick together. I created multiple non-overlapping seams and tried to blend them out against one another as layers in my image editing software. The result is smoother, but not quite the same as a single observation.”

A 14” f/4.5 Newtonian reflecting telescope was used for the captures. “Similar weather conditions and camera settings help quite a bit to make the multiple nights’ segments match up better,” Michael noted. “Keeping the same settings, using the same location away from my house  in the corner of the yard (to reduce local atmospheric turbulence) night after night gives consistent results after removing the variability of the weather.”

Planetary photography also requires special considerations prior to imaging, such as getting Jupiter high enough in the sky and at specific longitudes to get full coverage in the rotation sequence.

“I try to consider the local weather patterns and atmospheric stability (seeing), but in reality, I pushed myself to get out as much and often as I could,” Michael told Universe Today. “Typically, I try to wait until Jupiter is at the highest in the sky, as the result is looking through less atmosphere and thus more stable conditions. Sometimes, the planets jiggle around and you just want to scream ‘SIT STILL!’ Basically around the time of opposition I go out as often as it’s clear, as those are opportunities that you don’t get back again until next year.”

Jupiter reaches opposition just over once every 13 months, moving roughly one constellation eastward each time. 2013 was an “oppositionless” year for Jupiter, which won’t occur again until 2025. Michael also notes that from his observing location at 35 degrees north latitude, Jupiter currently peaks at an altitude of 77 degrees above the horizon when it transits the local meridian. “I wasn’t going to squander it waiting for perfect conditions!”

In fact, Jupiter is currently in a region in the astronomical constellation of Gemini that will be occupied by the Sun in just over five months time during the June Solstice. Currently at a declination of around 22 degrees 45’ north, Jupiter won’t appear this high in the northern sky near opposition again until 2026.

It’s also amazing to consider the kind of results that backyard observers like Michael Phillips are now routinely accomplishing. It’s an interesting exercise to compare Michael’s capture side-by-side with a sequence captured  by NASA’s New Horizons spacecraft during its 2006 flyby of Jupiter:

Both sequences capture a wealth of detail, including the enormous Great Red Spot, the Northern and Southern Equatorial Belts, and numerous white spots and smaller swirls and eddies in the Jovian atmosphere.

To date, six spacecraft (Pioneer 10 and 11, Voyagers 1 and 2, New Horizons and Cassini) have made flybys of Jupiter, and one, Galileo, orbited the planet until its demise in 2003. Juno is the next in this legacy, and will be inserted into orbit around Jupiter in July 2016.

Now is the time to get out and observe and image Jupiter and its moons, as it moves higher into the sky on successive evenings towards eastern quadrature on April 1st, 2014.

Congrats to Michael Phillips on an amazing sequence!

Posted on by David Dickinson

‘Tis the Season to Spot Jupiter: A Guide to the 2014 Opposition

Jupiter+moon imaged recently by Paul Cotton (@paultbird66) of Lincolnshire, England. Used with permission.

Lovers of planetary action rejoice; the king of the planets is returning to the evening skies.

One of the very first notable astronomical events for 2014 occurs on January 5th, when the planet Jupiter reaches opposition. You can already catch site of Jove in late December, rising in the east about an hour after local sunset. And while Venus will be dropping faster than the ball in Times Square on New Year’s Eve to the west in early 2014, Jupiter will begin to dominate the evening planetary action.

Orbiting the Sun once every 11.9 years, oppositions of Jupiter occur about once every 13 months or about 400 days, as the speedy Earth overtakes the gas giant on the inside track. This means that successive oppositions of the planet move roughly one astronomical constellation eastward. In fact, this year’s opposition is it’s northernmost in 12 years, occurring in the constellation Gemini. “Opposition” means that an outer planet is rising “opposite” to the setting Sun. As this opposition of Jupiter occurs just weeks after the southward solstice, Jupiter now lies in the direction that the Sun will occupy six months from now during the June Solstice.

This all means that Jupiter will ride high in the sky for northern hemisphere observers towards local midnight, a boon for astrophotographers looking to catch the planet high in the sky and out of the low horizon murk.

Jupiter will reach its most northern point for 2014 at a declination of +23.3 degrees on March 11th.

Jupiter also “skipped” 2013, in the sense that it was an “oppositionless year” for the giant world, as said 13 month span fell juuusst right, first on December 2nd, 2012 and then on January 5th, 2014. The next opposition of Jupiter will occur on… you guessed it… February 6th, 2015. The last year missing an opposition of Jupiter was 2001.

Jupiter and Io (arrowed) as imaged on the evening of December 22nd, 2013 by the author.
Jupiter and Io (arrowed) as imaged on the evening of December 22nd, 2013 by the author.

The exact timing of Jupiter’s opposition to the Sun in right ascension occurs at 21:00 UT/4:00 PM EST on January 5th. Its closest approach to Earth, however, arrives 27 hours prior, owing to a slight outward curvature of the approach of the two worlds. Jupiter will then lie about 4.21 astronomical units (AUs) or 629 million kilometres distant. This is just about down the middle of how close it can pass; Jupiter was just under 4 AUs distant in September 2010, and can pass almost 4.5 AUs from Earth, as happened in April 2005.

Jupiter also reaches a maximum brightness of magnitude -2.7 at opposition in 2014 and presents a disk 46.8” arc seconds wide. The coming month also provides a great chance to catch Jupiter in the daytime sky just before sunset, when the waxing gibbous Moon passes 4.9 degrees south of the planet on the evening of January 14th.

The Moon and Jupiter on the evening of January 14th shortly before sunset. (Created by the Author using Stellarium).
The Moon and Jupiter on the evening of January 14th shortly before sunset. (Created by the Author using Stellarium).

The very first thing you’ll notice looking at Jupiter, even at low power with binoculars or a telescope, is it retinue of moons. Though the planet has 67 discovered moons and counting, only the four large Galilean moons of Io, Europa, Ganymede and Callisto are readily apparent in a telescope. It’s fun to see orbital mechanics in action and watch them from night to night as they change position, just as Galileo first did over four centuries ago. This provided him with evidence that there is much more to universe than meets the eye, though we can consider ourselves fortunate that his proposal to name them the “Medician Moons” after his Medici benefactors was never widely adopted.

Crank up the magnification, and you’ll notice the large twin stripes of the northern and southern equatorial cloud belts crossing the disk of Jupiter. While the northern belt is stable, the southern belt has been known to submerge and disappear from view about every decade or so, as last happened in 2009-2010. You’ll also notice the Great Red Spot, a massive storm system over three times larger than the Earth that has been tracked by astronomers since it was recorded by Samuel Schwabe in 1831. The planet has the fastest rotation of any world in our solar system at 9.9 hours, and you’ll notice this swift rotation tracking Jupiter over the course of a single evening.

Transits and occultations of Jupiter’s moons are also always interesting to watch. The variation in the timing of these events at differing distances led Danish astronomer Ole Rømer to make the first attempts at measuring the speed of light in 1676.

Europa just beginning to cast a shadow off to one side shortly after opposition on January 8th at 7:30PM EST. (Created by the author using Stellarium).
Europa just beginning to cast a shadow off to one side shortly after opposition on January 8th at 7:30 PM EST. (Created by the author using Starry Night).

It’s interesting to note that Jupiter and its moons cast a shadow nearly straight back from our line of sight around opposition. You can see this change as the planet heads towards quadrature on April 1st, 2014 and Jupiter and its moons cast shadows off to one side. We’re also in the midst of a plane crossing, as the orbits of the Jovian moons appear edge-on to our line of sight in 2014 headed into early 2015. The outermost Jovian moon Callisto began a series of transits in 2013 and will continue to do so through 2014.

This is a great time to begin following all of the Jovian action, as we head into another exciting year of astronomy!