April is the month of Venus! See the 'evening star' at its brightest

rod

Oct 22, 2019
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FYI, I was out tonight from 1930 until 2100 EDT viewing Venus et al. Earlier I created star charts using Starry Night and Stellarium 0.20.0 for my views. Here is a note from my log.

"Sunset near 1931 EDT tonight or 7:31 PM. Clear skies, temperature near 10C, NW winds. The waxing gibbous Moon in Cancer was bright. I viewed Venus and the Pleiades using 10x50 binoculars and telescope at 40x. Venus nearly half-moon shape with some 20 or more stars of M45 visible in the eyepiece, especially after 2000 EDT or 8:00 PM. This would have made a great astrophoto. Tomorrow night, Venus is in M45 open star cluster near 2030 EDT. Using the binoculars, I could just see M44, the Beehive cluster in Cancer near the bright Moon. M42 in Orion, I could see four of the six stars in the Trapezium and some nebulosity at 40x with the telescope. The southern region of the Moon full of craters near Longomontanus crater region along the terminator line. Nothing like being under COVID-19 house arrest under the sky that is there tonight 😊---Rod
 
Apr 3, 2020
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I heard the big sunset moon is an illusion before (referring to the video). [redacted]. I've measured it myself often. When the full moon is high overhead, with my hand extended all the way out, I can easily cover it with my thumb. But when it's extra large on the horizon, with my hand fully extended, sometimes it takes 4 fingers to cover it.

It's caused by refraction of the light as it hits our atmosphere, which is more pronounced the lower it is on the horizon. It's also why the moon & the sun are sometimes slightly oval when on the horizon. The refraction may be greater in some areas depending on the humidity, barometer, & pollution.

Many astronomers may not see much refraction because they work in areas with good visibility conditions, like low humidity, clean air, or low barometers, as near mountains or desserts.

Here in my polluted lowland city right next to the Great Lakes where it's often very humid, with a barometer above 30", on a rare extra large moon-set, 4 fingers won't cover it all, but depending on the weather, sometimes 2 fingers will cover it.

In a telescope, I can see Jupiter & Saturn shimmer, expand & contract as I'm watching it because of atmospheric refraction & distortions. We already know light refracts when passing from a vacuum, to dense atmosphere. The curvature of the earth & its atmosphere acts more like a lens when the moon is close to the horizon.

In fact, at the time of moon-set, sometimes the moon is already below the horizon, & what you are seeing is it's refracted image being bent by the atmosphere like a lens & prism. No illusion.

Mind your language.
Refuting a comment with vulgarity isn't productive or civil.
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