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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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

Comet NEOWISE | Planet Opposition

Sunday evening 19 July 2020 the skies cleared providing another viewing opportunity for C/2020 F3 (NEOWISE). We went just outside our garage door and looked northwest below the Big Dipper. A large River Birch tree shades us from the glare of the nearby streetlamp. We first looked at the comet through our 30x telescope.

I then set my digital camera on the tripod and zoomed all the way in for a photo. It was 9:53 pm local time. Several features are labeled in the resulting photograph. Comets have a core nucleus composed of rock, dust, water ice, and frozen carbon dioxide, carbon monoxide, methane, and ammonia. Some describe them as freeze dried dirty snowballs. Their surface is littered with a thick layer of very dark material. The Sun heats this dark material and causes the ices to vaporize and escape into a cloud of gas around the core called a coma. The pressure of the solar wind forces the gas to stream away from the Sun producing the comet tail. It is very faint extending upward in this photograph. The Sun is out of view far below the bottom of this photo frame. Two reference stars were in view shining through the thin comet tail and coma.

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