It was one of those mornings when the sky was full of wonder.
After days and nights of smoke from unfortunate fires burning not far away, including in my favourite national park of Waterton Lakes, the sky cleared enough this morning, September 12, to reveal some fine sights.
At 6 a.m. the waning gibbous Moon passed in front of the star Aldebaran in Taurus. It is performing many such occultations of Aldebaran this year, but most aren’t well seen from any one location. This one was ideal, right from my backyard.
The lead image is a “high dynamic range” stack of several exposures showing the waning Moon and star set in some high haze adding the sky colours.
The star winked out behind the Moon’s bright limb as the Moon advanced from right to left (west to east) against the background sky.
This shows a composite sequence, with images of the star taken every four minutes blended with a single image of the Moon. While it looks like the star is moving, it is really the Moon that is edging closer to Aldebaran.
The star reappeared from behind the dark limb of the Moon, but five minutes after sunrise, with the Moon in a bright blue sky. Still, the star stood out nicely in binoculars and in the telescope for this view.
Aldebaran is the point of light at right, just off the invisible edge of the Moon.
I shot stills and video, and compiled them into this short video.
Enlarge it to full screen to view it properly.
Meanwhile, over to the east the twilight sky was awash in planets.
All the three inner terrestrial worlds were there: Venus, at top, Mercury below Regulus, and Mars lowest of the trio. Of course, a fourth terrestrial world is in the photo, too – Earth!
Mercury was at its greatest western elongation this morning, placing it as far from the Sun and as high in the sky as it gets, with this autumn appearance the best of 2017 for a morning showing for Mercury. Even so, you can see how Mercury is always low and easy to miss. However, this morning it was obvious to the naked eye.
Mars and Mercury will be in close conjunction at dawn on the morning of September 16.
It was a fine morning to be up early and enjoy the solar system show.
— Alan, September 12, 2017 / © 2017 Alan Dyer / amazingsky.com