The JUNO spacecraft continues its mission of very close flybys of the cloud tops of Jupiter. The most recent pass was on 19 May 2017. Images downloaded from the JunoCam instrument were made available to the public. I downloaded two sets in red, green, and blue filtered grayscale. Each set was combined into color versions using Photoshop and techniques described in a previous post. The colors are my interpretation and not necessarily real.
The clear evening sky offered a view of our Moon with Jupiter nearby as shown at left. Near sunset we set up the telescope and camera on tripods for closer looks. Good seeing allowed a photograph of Jupiter showing a few cloud bands as well as 3 of the 4 Galilean Moons. Ganymede was at the upper right. Europa and Io were to the lower left. Callisto was visible farther to the lower left in the telescope view. But, it didn’t show in this photo.
Usually, setting the exposure for Jupiter detail underexposes the Galilean moons and makes them not visible. Setting exposure to show the Galilean moons overexposes Jupiter. This time was a compromise.
Canon PowerShot SX60HS, ISO = 100, Shutter = 1/25s, Raw
Screenshot view via Stellarium
The Juno spacecraft successfully made a third close flyby of Jupiter on 11 Dec 2016. It was initially captured in orbit on 4 July 2016 as I noted in this blog post. The next close pass will be in early February. This brief animation illustrates a close flyby as Juno skims barely above the cloud tops of Jupiter.
On board Juno is a video camera called JunoCam. During the passes, JunoCam captures images which are sent to Earth. They are available to the public for download and processing. NASA hopes the public will use the images in creative projects. The creations can then be uploaded back to the JunoCam site for others to view.
I downloaded three images in Red, Green, and Blue of the south polar region of Jupiter. The video above shows Juno approaching over the north pole, passing very close to the equator, then receding below the south pole with each orbit. My three images were taken when Juno was directly below Jupiter’s south pole.
Using Photoshop, I opened the three RGB files, adjusted them for intensity, them combined them into this color composite. The program allowed me to adjust the saturation of many different colors across the face of the planet for enhancement. I uploaded it back to JunoCam. The colors are not realistic. But they do show the differences and circulations more readily. That was fun.
I offer this peaceful view of the morning sky. The crescent Moon at lower left aligned with Jupiter and the star Spica in a slender triangle at 6:25 am. Jupiter is at the upper right. Spica is almost directly below Jupiter and equidistant from the Moon. Spica is difficult to see because of the twilight. Click for a larger view.
The waning Moon always offers a nice view first thing in the morning from my front window.
On 27 August 2016, Jupiter was involved in two interesting events. At around 7:44 am CDT the Juno spacecraft made a very close and fast flyby of the planet going 130,000 mph. It came within 2600 miles of the cloud tops, the closest to the clouds for the entire mission of 35 more orbits. NASA reported the entire suite of scientific instruments was turned on and functioned well. Data will be returned over the next days and weeks.
The image at left is a view of the north pole of Jupiter just prior to the flyby. The polar orbit is a first for Jupiter exploration.
According to Scott Bolton, principal investigator, “We are getting some intriguing early data returns as we speak. It will take days for all the science data collected during the flyby to be downlinked and even more to begin to comprehend what Juno and Jupiter are trying to tell us. We are in an orbit nobody has ever been in before, and these images give us a whole new perspective on this gas-giant world.”
High resolution images will be released in the next two weeks.
More information and details about the Juno mission are available at this previous post.
At sunset also on the 27th, Jupiter and Venus aligned about 1/2˚ apart low in the western sky. That is the width of a full-moon. The dense cloud cover earlier in the day gave way to some partially clear sky for the evening show. The air was laden with much moisture and cloud remnants. The planets were visible. But, hazy conditions made their images not sharp and clear. I couldn’t wait for darkness because the clouds were approaching. Below is a wide view and a fully zoomed view. Venus is the upper and brightest of the two.
Jupiter aligned with Venus but was much more distant, small and dim.
Galileo used a telescope to cast his eyes upon Jupiter and its moons Io, Europa, Ganymede, and Callisto in 1610. He recorded notebook drawings of their positions nightly. He believed they moved around the planet Jupiter in what appeared to be orbits. His views were but snapshots in time.
Galileo Galilei | Siderius Nuncius | 1610
Telescopes improved over time. Technology brought us better views. Spacecraft Voyager and Galileo gave us marvelous images of the moons. But, those detailed images still gave us only snapshots in time. Those amazing views still lacked the perspective needed to show them in actual orbit about Jupiter.
Our view of the moons changed with the arrival of the Juno spacecraft on 4 July 2016. It approached Jupiter from above the plane of the orbits of Jupiter and its moons. The perspective allowed the JunoCam camera onboard to image the system multiple times for 17 days between 12 June and 29 June. The still images were made into a movie which shows the four moons in orbit several revolutions around the massive Jupiter.
Notice how the innermost moon Io orbits quickly. The farther moons more slowly. The planets of our solar system behave this way. All bodies in the universe orbit other bodies this same way. We are seeing from a unique perspective above the orbit plane. We are witnessing firsthand the effect of the law of gravitation. It is a thing of beauty. In addition, the three inner moons darken briefly as they pass into the shadow of Jupiter in each orbit.
Quoting Scott Bolton, principal investigator of Juno, Southwest Research Institute:
“This is the king of our solar system, and its disciples going around it. It’s also representative of nature. This is how we look, that’s a mini solar system. And so, I think, to me it’s very significant because we’re finally able to see, with real video, real pictures, this motion. And we’ve only been able to imagine it up until today.”
We enjoyed a visit to Cuba between October 21 and 26. Posts about our trip are here. One special event was taking place during that time which I enjoyed each morning before dawn. The bright planets Venus and Jupiter were high in the eastern sky. Because of the orbital movements of Earth and those planets, their relative positions changed each day.
I went out onto the balcony of our hotel room and set the camera the same way each day to get a photo of them over the skyline of Havana. Here is the typical view around 6:20 am. Venus is the brighter of the two in the upper right. It is much closer in orbit to Earth at this date than is Jupiter. The tall buildings don’t really lean that way. It is due to the camera lens. Click for a slightly larger view.
