Sunset at Copernicus
It's one day past third quarter, and most of the vast western crater fields are safely tucked away for their long night. Now the eastern maria dominate the view, with but a few more recent impacts to mar their seemingly smooth surface. The smoothness is an illusion, though, as shown by the features that become visible, sometimes within the last waning hours of their day. Ridges and rilles, hillocks and slumps, faults and mountains can now be seen if you look for them.
Some of the mountains can even be seen on the dark side of the terminator, their bases in night but their peaks still jutting up into the sharp boundary between light and dark. That boundary is sharp because the moon has no atmosphere to bend the light around the terminator. The beautiful sunset-lit clouds that we enjoy so often, after the sun has sunk below the horizon, are visible primarily because the atmosphere bends the sun's light downward so it will still strike those clouds and color them with the warm colors that the same atmosphere has allowed to pass.
There's no such thing on the moon. If you were to watch a sunset there, you'd see the blindingly brilliant sun touch the horizon. The some hours later, the last blinding bit of the sun's disk would abruptly blink out, leaving you standing in total darkness. Total, that is, unless there was terrain around you that was higher than your head, in which case you'd watch the horizon's shadow slowly creep up those slopes until the last tip of the highest hill blinked out.
After sunset there would be fourteen days of near-total darkness. The only light would be provided by starlight and whatever was reflected from the earth, which would be beautifully blue, hung in the vast, star-filled expanse of space. The stars would not twinkle, because it is the movement of the atmosphere that causes that, and there's no atmosphere there. The faintest stars visible would be more numerous than we could see here, because there's no air, with all its burden of light-attenuating particulates, to squelch their brilliance. Thus, the sky would seem much more dense with stars than we could see when we lived on Earth. The Milky Way would stretch across the expanse of the sky in a glory we'd never seen before.
We'd have but a few minutes to enjoy the spectacle, because the terrain would be quickly radiating away the last remaining heat it had accumulated during the fourteen earth-day long day. It would get very cold, very quickly, and if we didn't carry a source of heat with us, or get into our geothermally heated shelter, we'd freeze. We'd doubtless be very thankful that someone had solved the problem of how to survive the long lunar nights!
Sunrise would begin just as abruptly. The first little bit of the sun would peek over the opposite horizon, abruptly ending the night as if someone had just turned on a billion billion watt lightbulbs somewhere on the horizon. Night ends, and the fourteen day long lunar day begins. At its peak, the surface is heated to hundreds of degrees, because there's no air, no clouds, no water, nothing to turn away the fury of the sun's radiation.
Such is the nature of living on the moon. The challenges are immense. It's not like we can just build a house, put a furnace and air conditioner in it, and that's all there is to it. Oh no. We will eventually live there, but it's a terribly harsh and completely unforgiving environment. Mistakes will be made, and people will die for them. But explore, we must, and those are the costs.
Sunset at Copernicus
It's one day past third quarter, and most of the vast western crater fields are safely tucked away for their long night. Now the eastern maria dominate the view, with but a few more recent impacts to mar their seemingly smooth surface. The smoothness is an illusion, though, as shown by the features that become visible, sometimes within the last waning hours of their day. Ridges and rilles, hillocks and slumps, faults and mountains can now be seen if you look for them.
Some of the mountains can even be seen on the dark side of the terminator, their bases in night but their peaks still jutting up into the sharp boundary between light and dark. That boundary is sharp because the moon has no atmosphere to bend the light around the terminator. The beautiful sunset-lit clouds that we enjoy so often, after the sun has sunk below the horizon, are visible primarily because the atmosphere bends the sun's light downward so it will still strike those clouds and color them with the warm colors that the same atmosphere has allowed to pass.
There's no such thing on the moon. If you were to watch a sunset there, you'd see the blindingly brilliant sun touch the horizon. The some hours later, the last blinding bit of the sun's disk would abruptly blink out, leaving you standing in total darkness. Total, that is, unless there was terrain around you that was higher than your head, in which case you'd watch the horizon's shadow slowly creep up those slopes until the last tip of the highest hill blinked out.
After sunset there would be fourteen days of near-total darkness. The only light would be provided by starlight and whatever was reflected from the earth, which would be beautifully blue, hung in the vast, star-filled expanse of space. The stars would not twinkle, because it is the movement of the atmosphere that causes that, and there's no atmosphere there. The faintest stars visible would be more numerous than we could see here, because there's no air, with all its burden of light-attenuating particulates, to squelch their brilliance. Thus, the sky would seem much more dense with stars than we could see when we lived on Earth. The Milky Way would stretch across the expanse of the sky in a glory we'd never seen before.
We'd have but a few minutes to enjoy the spectacle, because the terrain would be quickly radiating away the last remaining heat it had accumulated during the fourteen earth-day long day. It would get very cold, very quickly, and if we didn't carry a source of heat with us, or get into our geothermally heated shelter, we'd freeze. We'd doubtless be very thankful that someone had solved the problem of how to survive the long lunar nights!
Sunrise would begin just as abruptly. The first little bit of the sun would peek over the opposite horizon, abruptly ending the night as if someone had just turned on a billion billion watt lightbulbs somewhere on the horizon. Night ends, and the fourteen day long lunar day begins. At its peak, the surface is heated to hundreds of degrees, because there's no air, no clouds, no water, nothing to turn away the fury of the sun's radiation.
Such is the nature of living on the moon. The challenges are immense. It's not like we can just build a house, put a furnace and air conditioner in it, and that's all there is to it. Oh no. We will eventually live there, but it's a terribly harsh and completely unforgiving environment. Mistakes will be made, and people will die for them. But explore, we must, and those are the costs.