Skip's House of Chaos

Tuesday, October 20, 2020

TWEETS OF THE WEEK - "What do we way...?"

If the Earth Were the Size of a Grape...

If the Earth Were the Size of a Grape...

The scale of the universe is so immense that it is difficult to imagine the relative distances between celestial objects. The Sun, the Moon, the planets, the stars, and the galaxies - they all seem like distant objects in the sky. It is easy to just think of them all as being very far away, without giving much thought to the great differences in their distances from Earth. In order to grasp the diversity in true distances in the universe it helps to mentally scale things down - to compare with objects and distances we can understand. How far away would these objects be if the Earth, which is actually about 8,000 miles in diameter, were the size of a grape, or about one half inch in diameter.

In true terms, the Moon is about 250,000 miles away from Earth. In our scaled down model in which the Earth is a grape, the Moon would be as large as a green pea and only about 16 inches away, that doesn't seem very far. It would be like the height of about 32 grapes, or Earths, stacked on top of each other. It takes human spacecraft only a few days to get to the moon.

The Sun is actually about 93 million miles away, or roughly 400 times further than the Moon. In astronomical terms it is quite close to us. Light from the Sun takes about 8 minutes to reach us. In our scaled down universe the Sun would be the size of a giant beach ball, about 4 feet wide. It would be about 490 feet away (163 yards), or about as far as one of Mickey Mantles longest home runs.

The largest planet in our solar system, Jupiter, is actually about 400 million miles from Earth when the two planets are closest, and it is about eleven times as wide as Earth. About 100 Earths would fit in it. Its light takes a bit more than a half hour to reach Earth. If the Earth were a grape, Jupiter would be about the size of a grapefruit, and would be about five blocks away - a little less than a half mile.

When we leave our own solar system, the distances to other objects start getting really large.

The nearest star, other than our own Sun, is about four light years away. That means it takes four years for its light to reach us. Since light travels at a speed of 186,000 miles per second, each light year is a great distance. In our scaled down universe the nearest star would be about 24,000 miles away. A much further star, Deneb, which is part of the well-known "Summer Triangle", and is actually 1,800 light years away, would be about one billion miles away if the Earth were a grape.

The galaxy we are part of, the Milky Way, which is about 100,000 light years wide, would be 55 billion miles wide if the Earth were a grape. The Great Andromeda Galaxy, know as the sister galaxy to the Milky Way, and part of our "local group" of galaxies, is actually two million light years away. The light we see now from it left there about the time humans first appeared on Earth. In our scaled down universe the Great Andromeda Galaxy would be about one trillion miles away.

So if the Earth were a grape,

- the Moon would be 16 inches away,

- the Sun - 163 yards away,

- Jupiter - a little under half a mile away,

- the nearest star - 24,000 miles away,

- the star Deneb - one billion miles away, and

- the Great Andromeda Galaxy - one trillion miles away.