The terminator.
The line that separates the light and dark portions on Earth is called the terminator line. On the Moon, this line is known as the lunar terminator or dusk line. It is where sunlight transitions into darkness as a result of the rotation of the Earth and the Moon.
The line that separates the dark half from the light half of the Earth is called the terminator. This line represents the boundary between day and night, where the sun's light is directly illuminating one side of the planet while the other side remains in shadow. The position of the terminator changes throughout the day as the Earth rotates on its axis.
The dividing line between light and shadow across the moon's disk is called the terminator. This is the line that separates the illuminated side of the moon from the dark side.
The terminator is the line that separates "day" and "night" (the light and dark part of the Moon). It is interesting to note that close to the terminator, you can see more details, because of the shadows cast by mountains and craters.
The abrupt change (line) between light and dark on the moon is called the terminator. The shadow on the moon is there because the sun only lights up half of the moon (which is a sphere) at a time. Also, people on earth always see the same side of the moon. This is because the moon rotates at the same rate as it orbits (kinda tricky). This phenomenon is called tidal locking. The side of the moon we never see interestingly enough has the biggest impact crater in our solar system. So basically as the moon revolves around the earth and the terminator moves across the moon, more and more of the bright part is 'clipped away' until we eventually end up with a moon that looks totally black. This happens at the end of every month and is called the new moon. Here is the link to the wikipedia article. http://en.wikipedia.org/wiki/Lunar_phase
The line that separates the light and dark portions on Earth is called the terminator line. On the Moon, this line is known as the lunar terminator or dusk line. It is where sunlight transitions into darkness as a result of the rotation of the Earth and the Moon.
The dividing line between light and shadow across the moon's disk is called the terminator. This is the line that separates the illuminated side of the moon from the dark side.
The terminator is the line that separates "day" and "night" (the light and dark part of the Moon). It is interesting to note that close to the terminator, you can see more details, because of the shadows cast by mountains and craters.
dark-line spectrum...
The line is called the terminator
A dark line found in a spectrum is called an absorption line. Absorption lines are created when atoms or molecules absorb specific wavelengths of light, resulting in dark lines in the spectrum where that light is missing.
A line that separates two places is a boundary line.
light and dark
The line that separates the day and night is called the "TERMINATOR". it is a grey moving line
The line that separates the northern and southern hemispheres is called the equator.
It is the solidus line that separates the numerator from the denominator in a fraction
A dark line in a spectrum, also known as an absorption line, represents a specific wavelength of light that has been absorbed by a substance between the source of light and the observer. The presence of dark lines in a spectrum can provide information about the composition and properties of the absorbing material.