May 222021
 

Jupiter and Saturn are finally visible over my eastern tree line in the early morning. I have to stay up longer than my usual schedule, but worth the extra time. Saturn is actually the first of the two to rise with Jupiter about an hour behind.

Jupiter
[(V)R:1258×1.3ms; G:1253×1.2ms;B:1257×1.9ms]

This image of Jupiter is, as usual, south up matching the view in most telescopes. The image of Saturn is north up just because I think that orientation looks better.
 

Saturn
[(V)R:3744×4.3ms; G:3698×4.2ms; B:2715×6.8ms]

 Posted by at 12:02
Dec 222020
 

Here is my contribution to the 2020 Great Conjunction hoopla. While it is rare to see a conjunction where both celestial bodies can be seen in the same telescopic field of view, from an astronomical point of view, the event was no big deal. On average, Jupiter and Saturn have a conjunction every 19.76 years. The frenzy was only due to the apparent closeness of the two as viewed from planet Earth.

Jupiter/Saturn conjunction

Even so, I tried to get an image when the two planets were actually closest to each other at 1200 CST but even though they had cleared the trees they were just not bright enough against the sky to get a good photo. The pair would be obscured by trees before it got dark so that meant packing up equipment and heading to another location. In fact, it involved two sets of equipment since my oldest son Chris would be joining in.

I really should have taken my planetary camera off the main telescope and brought it along but that camera would have meant additional cabling, a PC, another power supply, much longer setup and a more precise telescope alignment. My DLSR doesn’t require such an extensive life support system so I brought it instead. I chose poorly. The field of view the camera saw through the telescope was huge. This meant I had to zoom in quite a bit in order to see any detail at all. But since each planet only covered a small patch of pixels, very little detail is apparent.

The annotated image identifies the three Jovian moons that are visible. Ganymede is the one that is missing. It just started to cross in front of the planet and is lost in the glare on Jupiter’s left edge.

Jupiter/Saturn conjunction (annotated).

This photo is a composite of three separate images. Saturn is roughly 500,000,000 miles further from the Sun than Jupiter, so it is much dimmer when photographed. To make it visible, the exposure is lengthened to the point that Jupiter is grossly over exposed. To make the moons visible, the exposure is lengthened even more. So the image is a composite of a long exposure for the moons, a shorter exposure for Saturn and an even shorter exposure for Jupiter.

 Posted by at 19:28
Aug 212020
 

Right now there are three naked eye planets easily seen in the evening / night time sky. Jupiter and Saturn are visible as the sky darkens after sunset. Jupiter will be a bright enough object that it can be viewed during dusk. Saturn will be just east of Jupiter, a little lower, noticeably fainter and will need a darker sky to be seen. Ultimately, Mars will join the other two in the sky around 2200(CDT) when it rises above the eastern horizon.

These pictures were all taken on the evening of the 17th / morning of the 18th of August. Jupiter and Mars are oriented south up; Saturn is north up.

When this image was taken, the GRS was just about to rotate around to the far side of the planet. Just coming on to the near side above the North Temperate Belt (NTB) is the small dark shadow of the Jovian moon Europa. The moon is visible but very hard to identify as it is also in front of the NTB but almost directly below the GRS. To ID the cloud bands see Jupiter’s belts and zones.

The image shows Jupiter with its cloud bands and zones. The great red spot is on the left upper side of the planet and is close to rotating around to the far side. A small sharply defined black spot is at the lower right of the planet denoting the shadow of the Jovian moon Europa.

Jupiter, GRS & Europa’s shadow
[(V)R:1211×1.57ms;
G:1260×1.70ms;
B:1260×2.91ms]

Right now, Saturn is in the portion of its orbit where we are looking down on the ring plane. This is why I rotated the image 180° from the view in the telescope. Now we see the rings as they truly are. Our view of the upper side of the rings will remain until March 2025 when we will see the ring plane edge on. At that time the rings will be nearly invisible. Saturn will continue on in its orbit and our view will shift to the underside of the rings for the next 14.5 years.

If you look closely, you can see a bit of Saturn’s shadow on the far side rings and you can see some of the planet’s disk through the Cassini division and just a bit of it below the rings.

The image shows Saturn with the orientation looking down on the rings. The planet shows subtly colored bands in the atmosphere and a a bit of the planet's shadow on the far side of the rings. There is also a hint of the planet visible both through the main gap in the rings as well as a tiny amount of the planet visible below the rings.

Saturn
[(V) R:3597×2.81ms;
G:3591×7.27ms;
B:1826×16.32ms]

The most obvious object in this image of Mars is the southern ice cap. There is a distinct notch in the lower edge. Mars was at perihelion on the 3rd of August. The southern hemisphere season is heading towards summer and the ice cap we see is starting to shrink.

This image shows the rusty colored planet in the normal orientation with south up. The planet's bright white southern ice cap is not only plainly visible but has an obvious notch in the lower edge. The upper portion of the planet is much darker and with more complex surface markings than the lower.

Mars
[(V) R:6838×0.21ms;
G:6837×0.35ms;
B:6832×0.73ms]

This image is an accurate illustration of Mars matching the picture taken of Mars through the PTO's telescope. The illustration shows Mars' equator, central meridian and a line showing the planet's axis of rotation with North indicated.

The Mars illustration is courtesy of WinJUPOS.

For an explanation of caption information see exposure data.

 Posted by at 21:23
Jul 062020
 

Almanac data shows we are entering the cloudiest part of the year with clear skies only about 12% of the time. This makes it almost impossible to spend an hour taking a series of images necessary for asteroid position analysis. This means the PTO is left configured for planetary imaging with a temporary reconfiguration to cover a random occultation when necessary. On the night of the 2nd I was able to get several RGB sets of Jupiter but only 2 sets of Saturn before the clouds closed back in.

Jupiter & Ganymede
[(V)TR:1254×0.91ms;
TG:1252×1.45ms;
TB:1252×2.18ms]

Saturn
[(V)TR:1743×2.89ms;
TG:1301×7.70ms;
TB:909×13.07ms]

The dark spot on the lower left of Jupiter is the largest moon in the solar system – Ganymede. In fact, Ganymede is larger than the planet Mercury. Clouds prevented an earlier set of images that would have shown the Ganymede’s shadow as well as the GRS. As soon as Jupiter rotated the GRS out of view and the shadow left the planet, the clouds cleared.

Currently, Saturn rises only 23 minutes after Jupiter putting them close to each other in the sky as viewed from Earth.

For an explanation of caption information see exposure data.

 Posted by at 14:17
Jun 012020
 

Jupiter and Saturn now clear my tree line around 0130(L) so I don’t have to stay up too late (early?) for now. Both, for the time being, will be low on the horizon for years to come but we deal with what solar system geometry gives us. It takes Jupiter 12 Earth years to orbit the Sun, so it will be several years before Earth’s tilt puts Jupiter at its highest in the sky again. Saturn takes 29 years to orbit the Sun, we will need to wait a even longer for it to peak in altitude.

Jupiter
[(V)TR:2500×0.89ms;
TG:2490×1.41ms;
TB:2436×2.24ms ]

Saturn
[(V)TR:4436×3.78ms;
TG:4342×6.77ms;
TB:2195×13.55ms]

 Posted by at 11:23