A while ago I saw some information which helped to visualize the relative sizes of objects in the Universe, and I expanded on that information a bit here with some additional calculations. I think it’s useful to look at a map of locations that you are familiar with to visualize how far the distances actually are.
— If the Earth was the size of a pea, then the diameter of our Solar System would be about 5.5 miles across (assuming the diameter of Pluto’s orbit is 100 astronomical units.)
The diameter of the Earth is 12,742 km.
The diameter of Pluto’s orbit is about 100 astronomical units across at the farthest distance. An astronomical unit is about the distance from the Earth to the Sun, which is 150 million kilometers, or 150,000,000 km. Therefore, the diameter of Pluto’s orbit is about 15,000,000,000 km.
Therefore, the diameter of our Solar system is 1177209 times larger than the diameter of the Earth.
— If our Solar System was the size of a pea, then the Milky Way Galaxy would be about 300 miles across. And if our Solar System was the size of a mustard seed (about 1 mm diameter), then the Milky Way Galaxy would be about 40 miles across.
The diameter of our solar system (Pluto’s orbit at its farthest) is about 100 astronomical units across (0.00158125 light years.)
The diameter of the Milky Way Galaxy is about 100,000 light years across.
Therefore the Milky Way Galaxy is 63241107 times larger than the solar system.
— If the Milky Way Galaxy was the size of a pea, then the known Universe would be about 2 miles across. And if the Milky Way Galaxy was the size of a mustard seed, then the Universe would be about 510 yards (or about four football fields) across.
The diameter of the Milky Way Galaxy is about 100,000 light years across.
The diameter of the Universe is about 46.5 billion light years across (46,500,000,000 light years)
Therefore the Universe is 465000 times the size of the Milky Way Galaxy.