- 2936 - MOON - facts from moon-watching? - If you view the crescent moon seen from Mill Valley set behind Mount Tamalpais, Marin County, California, you see the brightness of the portion of the Moon not directly lit by the Sun, but instead illuminated by “Earthshine“. It will change over time, dependent on how reflective the Earth is, which is dependent on a number of factors, including cloud cover, ice cover, the time of day and the Earth's rotation, and even the seasons.
------------------ 2936 - MOON - facts from moon-watching?
- The Moon, as seen from Earth, is the brightest, most easily identifiable object in the night sky. The Moon's phases change from “new” to “crescent” to half-full to “gibbous” to full to gibbous to half-full to crescent to “new” again periodically every 29.53 days. That is how we got our “month“.
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- Beyond its skyward motion and changing phases, naked-eye lunar observations can yield tremendous scientific knowledge. Using the Moon we proved the Earth is round.
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- How latitude affects your perspective and the apparent orientation of the Moon depending on an observer's latitude and perspective, you will see the Moon oriented differently, as their horizon and orientation is determined by their position on a round Earth.
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- Someone at the north pole would see the Moon flipped by 180 degrees from someone at the south pole. Arctic versus Antarctic perspectives are completely flipped, with latitudinal variations indicating Earth’s shape.
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- The Moon as seen during various stages of a lunar eclipse, can be stitched together.
By looking at the curvature of the Earth's shadow that falls on the Moon, we can reconstruct the relative size of the Moon versus the Earth's shadow-cone, allowing us to geometrically reconstruct the Earth-Moon distance. The Earth's shadow falling on the Moon teaches us that our planet is more than 3 but less than 4 times the diameter of the Moon, and spheroidal in shape.
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- Differences between the Moon's apparent diameter based on its distance from us.
Compared to an apogee (most distant) Moon, a perigee (closest) full Moon can be 14% .
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- The Moon’s orbit is elliptical, not circular. Kepler's second law is that planets trace out equal areas in equal times. Before we understood how the law of gravity worked, we were able to establish than any object in orbit around another obeyed Kepler's second law: it traced out equal areas in equal amounts of time, indicating that it must move more slowly when it's farther away and more quickly when it's closer.
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- This effect was clearly visible for the Moon since antiquity, as the smaller angular size and slower speed near apogee and the larger angular size and faster speed near perigee is evident. Changes in the Moon’s apparent size indicate large variations in its distance from Earth.
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- The Lunar Libration cycle from “new Moon” to “full Moon” to new Moon again coincides with increases and decreases in apparent size as the Moon moves along its elliptical orbit. Because it moves faster at perigee and slower at apogee, but has a constant rate of rotation, we see slightly more than 50% of the Moon over the course of a lunar month. Additionally, more than 50% of its face is visible over time, as it orbits Earth quicker when closer and slower when farther.
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- As seen from Earth, a less-than-full Moon will have a portion of its face illuminated by reflected sunshine, but the remainder of the Moon isn't fully dark. Instead, it's lit up by “Earthshine“, the reflected sunlight from Earth that falls on the Moon. By observing the Earth-illuminated portion of the Moon, we can determine the reflectivity of the Earth, known as the Earth's albedo.
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- Observing the light from the unilluminated portion teaches us the reflectivity of Earth. Earthshine illuminates the majority of the Moon, which has only a tiny sliver lit up by the Sun. The light from the Moon passes through the Earth's atmosphere.
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- The moon appears red when its close to the horizon, due to Earth's atmospheric effects.
When observed very close to the horizon, light from the Moon must pass through the maximum amount of Earth's atmosphere. The atmosphere preferentially scatters blue light away while allowing red light to pass through more easily, resulting in a redder appearance near the horizon.
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- As the Moon appears farther away from the horizon, its light passes through less of Earth's atmosphere before reaching our eyes, causing its color to appear truer to its original color: white, that of reflected sunlight. The closer the Moon is to your apparent horizon, the redder it will appear.
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- That red light is bent preferentially illuminating the Moon during lunar eclipses. During most total lunar eclipses, a partial eclipse is followed by a dark red taking over the Moon from one side, with one limb always remaining brighter and whiter than the other.
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- If the Moon passes through the direct center of the Earth's shadow, it may appear to be uniformly red and dim, but more blue light will fall on the Moon the closer the side of the Moon is to the end of Earth's shadow cone.
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- The Moon has mountains, valleys, and high crater walls. As the Moon blocks out nearly all of the Sun, the deepest craters continue to let sunlight through, giving the effect known as Baily's Beads. The amount of time that these beads are visible, along with their intensity, enables us to infer the heights and depths of crater walls and valleys during solar eclipses.
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- When the Moon's shadow falls on the Earth, as it did during the 1999 total solar eclipse, its entire shadow can be seen from the right perspective. Contrary to the expectations of many, the Moon's shadow won't be perfectly spherical, but will be elongated and irregular due to geometric alignments and the cratered and mountainous terrain found on the Moon.
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- 2919 - MOONS - in our solar system? The discovery of moons around another planet left centuries’ worth of astronomers desperate to learn more about what other natural satellites the solar system holds. Increasingly powerful telescopes and interplanetary spacecraft have revealed that there are many of the moons in the solar system and they are far stranger than anyone could have imagined.
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- 2527 - MOON - Take Me to the Moon. - Twin astronauts, Mark Kelly and Scott Kelly, were part of a survival experiment. From March 2015 to March 2016 Scott spent a year on the International Space Station while his brother, Mark, remained on Earth. In April 2019, the results of a 3 year study was published of what changed between them with the two different year experiences. Can we survive on he Moon?
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- 2919 - MOONS - in our solar system? The discovery of moons around another planet left centuries’ worth of astronomers desperate to learn more about what other natural satellites the solar system holds. Increasingly powerful telescopes and interplanetary spacecraft have revealed that there are many of the moons in the solar system and they are far stranger than anyone could have imagined.
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- 2791 - MOON - measuring the distance? - The distance to the Moon is 240,000 miles. I learned that in High School. Today the average distance is measured to be 238,856 miles. Actually that distance can be measured to within less than an inch.
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- 2752 - MOON - mining the Moon? Forty-five years have passed since humans last set foot on an extraterrestrial body. Now, the moon is back at the center of efforts not only to explore space, but to create a permanent, independent space-faring society.
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- 2450 - MOON - new analysis 50 years later. The Apollo missions brought back 200 pounds of rocks and soil samples. Half of these samples were locked in a vacuumed safe to be analyzed 50 years later with more advanced scientific instruments. New sample testing inspired these new theories about the formation of the Moon.
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- 2241 - Some Moon eclipse party trivia. Happened December 20 , 2019.
- 1902 - The Moon and angular momentum.
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- 1901 - Other moons around the planets.
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- 1900 - Moons in our Solar System. Totals 161.
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- 1704 - There are two sides to get a Full Moon. The size of the Moon is 27% the size of the Earth. However, the Moon is only 1.2% the mass of the Earth. To get a rocket to leave the Moon it needs to accelerate to only 5,400 miles per hour.
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- 1681 - Enceladus and Europa might support life? We have 173 moons orbiting our 8 planets. Over 150 asteroids also have orbiting satellites.
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- 1678 - Moon history from the beginning. The Moon has almost no atmosphere. You can count catering yourself on website “NASA Lunar Reconnaissance Orbiter” www.moonzoo.org The Moon is 250,000 miles away but these images are from only 400 miles away.
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- 1450 - Full Moon on Doug’s birthday.
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- 1291 - Two Moons over Miami. The early Universe was a chaotic place.
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- 1243 - What is behind the Man in the Moon? As the Moon cooled it preserved some water in the form of hydroxyl. The Moon is spiraling away in its orbit 1.5 inches each year.
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- 1651 - Moon may be the best habitats for life.
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- 64 - 424 - What you did not know about our Moon.
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- December 15, 2020 MOON - facts from moon-watching 2936
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--------------------- --- Wednesday, December 16, 2020 ---------------------------
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