Chirag Upreti caught this image of the waxing crescent moon on June 25, 2017. He wrote: “The waxing crescent moon illuminated at ~6% descends behind the Eastern Sierra mountains as the radio antennae in the Owens Valley Radio Observatory actively scan the skies to reward human curiosity.”
A waxing crescent moon – sometimes called a young moon – is in the west after sunset in the week following new moon.
Following Monday’s total solar eclipse, many began asking when we’ll see the moon again. The answer is that Monday’s moon was traveling across the sky with the sun during the day. It rose and set approximately when the sun did. Except for the stirring moments of the eclipse itself, Monday’s moon was drowned from view in the glare from the sun. Yet the instant of new moon, when the moon was directly in front of the sun, marked the beginning of a new lunation, or lunar cycle. The moon – moving eastward as it always does in orbit around Earth – was inching across the sky all day yesterday, and, following the eclipse, it was moving away from the sun.
So the question is … when will the moon have moved far enough away from the sun to become visible again?
In the days following new moon, a young moon – a waxing crescent – always appears in the west shortly after sunset. If you live in the Southern Hemisphere, you might see this moon Tuesday evening. If you live in the Northern Hemisphere, you’ll have a greater challenge seeing Tuesday evening’s slim crescent moon after sunset. But we’ll all see the moon by Wednesday evening, when it will have moved farther from the sun’s glare.
Why the difference between different parts of Earth? It’s because we live on a world that tilts on its axis. This tilt causes the path of the sun and moon across our sky to shift with the seasons. Right now, the angle of the ecliptic – or path of the sun and moon – is somewhat narrow with respect to the evening horizon, as seen from the Northern Hemisphere. This fact of nature means the moon’s motion away from the sun on Monday and Tuesday will carry the moon somewhat sideways along the western horizon after sunset. Thus it’ll remain low in the sky.
In contrast, the angle of the ecliptic with respect to the evening horizon as viewed from Earth’s Southern Hemisphere is relatively steep now. So the moon’s motion away from the sun on Monday and Tuesday carries the moon higher above the sunset point, where it’ll be easier to see.
The waxing crescent moon shines in the vicinity of Jupiter (and the star Spica) for several days, centered on or near August 25, 2017. Read more.
Some people think a moon visible in the west after sunset is a rising moon. But it’s not; it’s a setting moon. All objects in our sky rise in the east and set in the west, due to Earth’s spin under the sky. When you see a waxing crescent, you know the Earth, moon and sun are located nearly on a line in space. If they were more precisely on a line, as they are at new moon, we wouldn’t see the moon. The moon would travel across the sky during the day, lost in the sun’s glare.
Note also that a crescent moon has nothing to do with Earth’s shadow on the moon. The only time Earth’s shadow can fall on the moon is at full moon, during a lunar eclipse. There is a shadow on a crescent moon, but it’s the moon’s own shadow. Night on the moon happens on the part of the moon submerged in the moon’s own shadow. Likewise, night on Earth happens on the part of Earth submerged in Earth’s own shadow.
2017 started out with a beautiful waxing crescent moon. This day-lapse composite image combines the earthshine moon from New Year’s Day with the crescent moon from the following day. A wide-field image with Venus at sunset and more information on how to make day-lapse images is available from Robert Pettengill of Austin, Texas.
Because the waxing crescent moon is nearly on a line with the Earth and sun, its illuminated hemisphere – or day side – is facing mostly away from us. We see only a slender fraction of the day side: a crescent moon. Each evening, because the moon is moving eastward in orbit around Earth, the moon appears farther from the sunset glare. It is moving farther from the Earth-sun line in space. Each evening, as the moon’s orbital motion carries it away from the Earth-sun line, we see more of the moon’s day side. Thus the crescent in the west after sunset appears to wax, or grow fatter each evening.
The pale glow on the darkened portion (night side) of a crescent moon is called earthshine. Is caused by light reflected from Earth’s day side onto the moon. After all, when you see a crescent moon in Earth’s sky, any moon people looking back at our world would see a nearly full Earth. Read more: What is earthshine?
As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.
Four keys to understanding moon phases
Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase
Check out EarthSky’s guide to the bright planets.
Photos of the August 21, 2017 eclipse here
How ISS astronauts saw the August 21 eclipse
from EarthSky http://ift.tt/1trITpz
Chirag Upreti caught this image of the waxing crescent moon on June 25, 2017. He wrote: “The waxing crescent moon illuminated at ~6% descends behind the Eastern Sierra mountains as the radio antennae in the Owens Valley Radio Observatory actively scan the skies to reward human curiosity.”
A waxing crescent moon – sometimes called a young moon – is in the west after sunset in the week following new moon.
Following Monday’s total solar eclipse, many began asking when we’ll see the moon again. The answer is that Monday’s moon was traveling across the sky with the sun during the day. It rose and set approximately when the sun did. Except for the stirring moments of the eclipse itself, Monday’s moon was drowned from view in the glare from the sun. Yet the instant of new moon, when the moon was directly in front of the sun, marked the beginning of a new lunation, or lunar cycle. The moon – moving eastward as it always does in orbit around Earth – was inching across the sky all day yesterday, and, following the eclipse, it was moving away from the sun.
So the question is … when will the moon have moved far enough away from the sun to become visible again?
In the days following new moon, a young moon – a waxing crescent – always appears in the west shortly after sunset. If you live in the Southern Hemisphere, you might see this moon Tuesday evening. If you live in the Northern Hemisphere, you’ll have a greater challenge seeing Tuesday evening’s slim crescent moon after sunset. But we’ll all see the moon by Wednesday evening, when it will have moved farther from the sun’s glare.
Why the difference between different parts of Earth? It’s because we live on a world that tilts on its axis. This tilt causes the path of the sun and moon across our sky to shift with the seasons. Right now, the angle of the ecliptic – or path of the sun and moon – is somewhat narrow with respect to the evening horizon, as seen from the Northern Hemisphere. This fact of nature means the moon’s motion away from the sun on Monday and Tuesday will carry the moon somewhat sideways along the western horizon after sunset. Thus it’ll remain low in the sky.
In contrast, the angle of the ecliptic with respect to the evening horizon as viewed from Earth’s Southern Hemisphere is relatively steep now. So the moon’s motion away from the sun on Monday and Tuesday carries the moon higher above the sunset point, where it’ll be easier to see.
The waxing crescent moon shines in the vicinity of Jupiter (and the star Spica) for several days, centered on or near August 25, 2017. Read more.
Some people think a moon visible in the west after sunset is a rising moon. But it’s not; it’s a setting moon. All objects in our sky rise in the east and set in the west, due to Earth’s spin under the sky. When you see a waxing crescent, you know the Earth, moon and sun are located nearly on a line in space. If they were more precisely on a line, as they are at new moon, we wouldn’t see the moon. The moon would travel across the sky during the day, lost in the sun’s glare.
Note also that a crescent moon has nothing to do with Earth’s shadow on the moon. The only time Earth’s shadow can fall on the moon is at full moon, during a lunar eclipse. There is a shadow on a crescent moon, but it’s the moon’s own shadow. Night on the moon happens on the part of the moon submerged in the moon’s own shadow. Likewise, night on Earth happens on the part of Earth submerged in Earth’s own shadow.
2017 started out with a beautiful waxing crescent moon. This day-lapse composite image combines the earthshine moon from New Year’s Day with the crescent moon from the following day. A wide-field image with Venus at sunset and more information on how to make day-lapse images is available from Robert Pettengill of Austin, Texas.
Because the waxing crescent moon is nearly on a line with the Earth and sun, its illuminated hemisphere – or day side – is facing mostly away from us. We see only a slender fraction of the day side: a crescent moon. Each evening, because the moon is moving eastward in orbit around Earth, the moon appears farther from the sunset glare. It is moving farther from the Earth-sun line in space. Each evening, as the moon’s orbital motion carries it away from the Earth-sun line, we see more of the moon’s day side. Thus the crescent in the west after sunset appears to wax, or grow fatter each evening.
The pale glow on the darkened portion (night side) of a crescent moon is called earthshine. Is caused by light reflected from Earth’s day side onto the moon. After all, when you see a crescent moon in Earth’s sky, any moon people looking back at our world would see a nearly full Earth. Read more: What is earthshine?
As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.
Four keys to understanding moon phases
Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase
Check out EarthSky’s guide to the bright planets.
Photos of the August 21, 2017 eclipse here
How ISS astronauts saw the August 21 eclipse
from EarthSky http://ift.tt/1trITpz
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