Very Old Waning Crescent Moon

It was just after 6 am on 16 September. The Sun barely brightened the sky in the east. A thin haze was in the air from forest fires to the west. I live in Iowa. We have had several days of filtered light through the smoke and haze. The Sun rises and sets very orange. On this morning I hoped to photograph the thinnest crescent moon I had ever seen. It was only 24 hours before the next new moon.

I had been up since 5:30 with binoculars scanning the sky close to the horizon. At 6:07 am I spotted the thin crescent through the haze only 5˚ above the horizon. I grabbed several shots then watched as it rose and the sky brightened. Soon the Moon disappeared in the bright sky.

Waning Moon | 28.4 days | 1.44% Illuminated | ISO 1600 | 1 sec

Mars Moon Conjunction | 5 Sep 2020

Mars and the Moon rose in the east just before 10 pm. A few small clouds cleared revealing the pair. This at 9:59 pm.

Canon PowerShot SX60 HS | 9:59pm

I shot 3 more images at 10, 10:23, and 10:32, then aligned them with Photoshop Elements.

Canon PowerShot SX60 HS | Photoshop Elements composite

Also in view but to the south were Jupiter and Saturn. Keep watching J&S until late December. They will be in very close conjunction with each other at that time. It will be a beautiful and rare sight.

Apparent Planetary Magnitudes

Amateur and professional astronomers know that the apparent brightness, or magnitude (V), varies greatly from planet to planet. For example, Venus is high in the morning sky at twilight at this time in its orbit. It is very bright. It has a large apparent magnitude. Neptune has a very low apparent magnitude due to its distance from the Sun. Most people have no idea where to look for it and have never seen it.

This chart is in Computing Apparent Planetary magnitudes for The Astronomical Almanac authored by Anthony Mallama and James L. Hilton of the US Naval Observatory in June 2018. It is an attractive display of the apparent magnitudes of the planets as seen from Earth. Not only is it artistic, there is a lot of science to see if we examine the details contributed by each planet.

A. Mallama,  J. Hilton | USNO

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Cumulative Cumulus

I enjoy using the NightCap app on my iPad. It has several time exposure settings for special night situations such as star trails, ISS passes, and meteors. It also has a light trails setting. One could set the iPad in a dark scene and move a flashlight around painting lines, figures, or words in the time exposure. I wondered if that setting would work in a bright blue sky scene with passing white cumulus clouds.

The iPad was propped up at about 45˚ and the exposure was started. This first photo was for 33 seconds. Notice the tree leaves at the left. They were moving with the breeze and were blurred. The clouds streaked during the exposure from lower left to upper right for a weird and pleasing effect.

NightCap | Light Trails mode | 33 sec

More clouds drifted by in this 323 sec exposure. I think this experiment deserves more trials to see what other interesting effects it can produce. What do you think?

NightCap | Light Trails mode | 323 sec

Daytime Mars With Moon

It was 6:22 am CDT. Sunrise was 6:09. I stepped outside with binoculars to see if Mars was visible near the Moon. Yes, it was easy to see. The Moon will be near Venus the morning of 15 August.

Canon PowerShot SX60 HS | ISO 100 | 1/40 sec