It is rare to have five consecutive nights of clear skies for star gazing. And, even more rare when those nights coincide with a special event I hope to photograph. The gods must have looked favorably on me. It started on 11 July 2019 with this view to the south-southeast at 9:44pm CDT. Far lower left was Saturn emerging from behind the bushes. Jupiter was proud above the trees. The overexposed Moon hovered at the right. I photographed this scene at 9:44pm over the course of the next four nights. The Moon tracked down to the left. Click for a better view.
I like to watch movements of the planets which bring them into close encounters, or conjunctions. Some conjunctions are at a time and position in the sky so images taken over a few days can show their movements. Such was the case June 2019. A big challenge to getting well-timed images is cloud cover. We have had too much of it.
This image is a composite of three evenings of images looking west-northwest at 9:30pm. The camera was on a tripod at the same spot framing two light poles. I cut and pasted the locations of Mercury and Mars from the images taken on June 7 and June 20 onto this image taken on June 11. The dates for each are labeled. Click here or on the image to embiggen in a separate tab.
Note that Mercury, in yellow highlight, moved toward the upper left between June 7 and 11. It moved farther to the upper left by June 20. Mars, in white, moved down to the right between June 7 and 11. It continued down to the right by June 20. I hoped to image the two planets on June 17 or 18 when they appeared very close together, the width of a full moon. But clouds happened.
🔭 Updates an earlier post to include recent changes and new information. 🔭
Desktop planetarium software helps plan viewing sessions and keep track of the planets and Moon. Many products are available for all computer platforms and smartphones. A Google search yields links to many sources. Open source and free Stellarium is on my desktop computer. It can be customized to your location and has a nice look and feel. For Android and Mac phones and tablets, I like SkySafari. It isn’t free but is inexpensive.
Online planetarium sites are popular and offer many features. Below are highlights of a few I like. With multiple features, a unique look and feel, and different levels of detail, they can help satisfy your curiosity about astronomical events. I welcome reader questions or reviews about using these tools or others you find helpful.
It has begun. Mars is making the turn from its usual eastward progress across the sky. It will appear to move westward for the next two months. At the end of August it will slowly turn and head eastward again. Why? How can that be?
The answer is simple. Earth orbits closer to the Sun than Mars. We move faster than Mars. We are passing Mars at this time. It is the same perspective as when passing another car. The passed car appears to move backward relative to your faster car.
In addition, Mars grows in size when viewed through telescopes until the end of July. After that, it will decrease in size. If you have access to a telescope, look for Mars in the east after sunset. You’ll need a high power to see any detail. Let’s hope the dust storm settles to reveal those details.
The graphic below from BinTel illustrates the apparent change in diameter given in arc-seconds (“). At the end of July, the Moon will appear about 24″ wide. For reference, the angular diameter of the Sun, or a full moon, is about 1800”, half a degree. That is the width of your little fingernail seen at arm’s length.
The previous visit by Comet Halley to our part of the inner solar system was in 1986. The time before that was in 1910. The next visit will be in 2061. I have not ruled out seeing it again.
The European Space Agency’s Giotto spacecraft flew within 600 mi (965 km) of Halley and through the tail in March 1986. The dimensions of the comet nucleus were seen as 15×8 km (9×5 mi) and shaped like a potato. Giotto confirmed the existence of organic matter and revealed the surface to be one of the blackest objects in space. Image enhancement was used to brighten the surface to reveal more detail in these fly-by images. Images are from ESA and affiliates.