If you lived in the Moon, you would have to give up many things that you would take for granted on Earth. Feel your legs are firmly on the ground. Your ability to breathe outside without a helmet. And your look at the night sky.
People have spent millennia staring at the moon, watching him rise and set, drawing his phases as it grows and decreases every month. But from the point of view of the Moon, how would Earth look hanging in the sky?
Well, first, that depends on where you stand. [How Does a Black Hole Form?]
The moon is tidally locked with Earth, which means that the moon's orbital period corresponds to its rotational period. It takes about a month for the moon to circulate around Earth and for a month of rotation around its axis. In fact, it means that the same foreign moon always faces our planet. So when you look through the telescope, craters and other features on the Moon's surface are always in the same place.
The first men who directly saw the far side of the moon, that is, the side that always turned from Earth, were the Apollo astronauts 8.
If you were in the camp on the opposite side of the moon, you would never have a look at the Earth. If you were based on the close, you would always see the Earth. It seems that the Earth would indeed pass through the phase for a month, directly opposite the lunar stages where people on earth would witness, said Phil Nicholson, professor and deputy director of the Cornell Center for Astrophysics and Planetary Science at Itaki, New York.
The moon phases arise because one half of the moon always illuminates the sun. The monthly depilation and decay cycle we see is only a long lunar day that turns into the night as the moon turns around the Earth.
While the Earth is staring at a darkened moon (when the moon's moon is not illuminated by the sun), the lunar observer would look into the "full Earth," half of the planet full of sunlight. During the next two weeks, the Moon residents would see the ever-smaller semester of the Earth as the moon was not directly facing the darkened side of the planet. At that moment Earth would enjoy the full moonlight. The person standing on the Moon, full moonlight reflection (and maybe some artificial light), can make the new Earth weakly visible.
"It would not look just dark," said Christine Shupla, head of education and public engagement at NASA's Lunar and Planetary Institute. "You will see potential lights on Earth in the cities."
Your view of the Earth, however, may not be crystal clear. If a part of the moon you are experiencing is a day, your observations of the cosmos can be influenced by the sun glittering from your helmet or the moonlit rocks, Shupla noted. But since the moon has no atmosphere, you can still watch the stars throughout the day.
Earth would also look much bigger than our moon did. (Earth is about four times larger than the Moon, in diameter.) And from the Moon's perspective, the Earth would also always look like it was on a fixed location.
"As the Earth passes through the stages, it does not really move in the sky," said Nicholson Live Science. "It's a little rolling back and forth, because the moon is elliptical, but it does not rise and does not look like a moon for Earth." So if you were standing in what we perceive as the middle of the lunar disc, Earth would always look like it was directly above your head.
However, you will not always see the same features of the Earth from the Moon. You would notice different features like the planet spinning.
"Earth is turning faster than a month," Shupla said. "Sometimes you would see more oceans and sometimes you would see more continents as the hours pass."
The question also prompted Nicholson to reflect on what the eclipse might have seen on the moon.
"If you lived on the Moon, it would be easier to see the sun's shadows because the Earth is so bigger," he said. What we call the lunar eclipse (when the moon is in the sunshine) would be the solar eclipse from the Moon perspective. This would happen two or three times a year. And when the solar eclipse appears from the Earth's point of view (such as the 2017 eclipse, visible on a large part of North America), perhaps with the help of telescopes, you will be able to see how the moon throws its great Earth shadow.
"You will see a small black point," Nicholson said. "It's actually photographed from orbit. It looks like a small black hole trying to swallow the Earth."
Originally posted on the day Live Science.