Size can be measured 3 ways: distance in a straight line, 2-dimensional area, and 3-dimensional volume. For example, the earth's diameter is less than 13,000 kilometers but its circumference around it is about 40,000 kilometers. The cubic size of earth is 1 trillion kilometers. Big difference, huh?
So earth is 13,000 km in diameter and our sun is 1,400,000 km in diameter. That makes the sun about 107 times wider than earth.
This does not reveal how huge the sun really is because it is not 107 times bigger, just 107 times wider. In fact, we can fit 1,300,000 earth spheres inside one sphere the size of the sun. Now we get the difference in size. The sun is 1.3 million times bigger than earth.
The sun is the big boy at 1.4 million km but its own solar system is much bigger at 4.5 BILLION km in diameter.
Billion Trillion Lifeless Planets
The earth is a speck. The sun is a speck. Our solar system is a speck. The Milky Way is a speck so naturally, we have been looking for other intelligent life out there among the billion trillion planets. We have certainly not found insects, fish or birds, reptiles or mammals. We have yet to find even cellular life. In fact, many nations have invested money in reaching out but none as much as the USA.
In 1981 SETI (Search for Extraterrestrial Intelligence) was funded to set up 131,000 channels searching day and night . This was followed in 1985 by a big upgrade to 8.4 million channels reaching out 24/7. Then in 1990, a 2nd one set up in Argentina simultaneously. No response yet, so another upgrade with the ability to receive 250 million simultaneous channels.
With all the movies I've seen with monsters, aliens and super heroes in space, it's almost hard to believe fishing for life at this great expense hasn't achieved one single discovery of any form of life.
EARTH IS NOT THE CENTER BUT CENTRAL IN IMPORTANCE
Does this mean there is no life out there? No. Space is big. But absolutely everyone should agree by now, that earth may be a speck, but it is fantastically unique with flourishing life. Surrounded by cubic light years with stars, systems, planets and universes . . . with all our effort, we cannot find another planet like ours.
In size, we are small compared to space but to be this improbably exclusive in such a vast space is a screaming declaration that earth is an astoundingly important speck.
We are beautifully, perfectly situated for life to exist, so enjoy our spectacularly rare phenomena.
POSTSCRIPT - A True to Scale Solar System Model
Making a model solar system to true scale in anyone's bedroom would be difficult if your sun is the size of a tennis ball. Your solar system must be about 3500 times wider than your sun if you want it to scale. You need to put Neptune (less than 3 millimeter ball) about 212 meters away from your tennis ball. Pluto should be 276 meters away. Remember, the distance from the sun is only the radius, so you need a room at least 276 X 276 meters square with very tiny planets.
The same drama unfolds in space. Usually we hear about how many light years a star is from us. A single light year is 150 million km. But remember, the size of space is neither linear or square light years but cubic light years. Can anyone really imagine one single light year cube that is 150 million kilometers in height, length and width? Light years are inconceivable distances but the cubic mass dwarfs all other measurements.