Average radius = 3,959 miles (6,371 kilometers).
The diameter of Earth varies due to the gravitational forces that interact with Earth from surrounding solar-system bodies—the moon, the sun, neighboring planets, etc.
Earth Mass = 5.52 grams for cubic centimeter.
Data borrowed from Space.com.
Number of beliefs held by humans = impossible to know.
The Kepler Mission—Nasa
“The primary goal of the Kepler mission is to find Earth-sized planets in the habitable zone,” said Francois Fressin of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., lead author of a new study published in the journal Nature. “This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them.” –Nasa.gov
Earth and its Earthlings
Humans and humanity collectively represent the self-proclaimed, highest-intelligence to develop on Earth since the ‘beginning. This forces the question, beginning of what?
Is it the beginning of human life, the beginning of life on Earth, the beginning of life in the Universe, or the beginning of the Universe itself?
- We can calculate the exact mass of Earth.
- We can estimate the diameter of Earth.
- We can try and keep track of the human population of Earth.
We can do these things while searching the Universe for other examples of similar phenomena that will help explain ourselves.
We can also create explanations to the same ends without accounting for what we observe. What I mean, is we can create gods to explain everything—literally everything. Why do we exist? God. Why am I here? God. Why is the Universe here? God Why do storms happen? God. Why do people suffer? God. Why do people win national titles in the NBA? God. Why do the tides go in and go out? God. Why do whales and dogs and birds and bats and dinosaurs share a common skeletal design? God. Why do I do bad things? God. Why do I do good things? God. Why do I know the difference between good and bad things? God.
I think you see the point.
Until we migrate to an entirely new world like the dead planet Mars, our closest, friendliest neighbor, we are all stuck on this one planet Earth together. We live on ONE PLANET. Is it chemically, biologically, and physically possible to terra-form Mars, I am sure it is. What good would that do if we remain bound to silly answers to our biggest questions? We would simply be the virus infecting Mars the way that we infect Earth because every question we ask is answered the same. God.
- Kepler retires from planet-hunting (bbc.co.uk)
- “Are Habitable Worlds Common or Rare in the Milky Way?” –New Kepler Mission Data Holds the Answer (dailygalaxy.com)
- Dreaming in Kepler: Artist Renderings From the Planet-Hunting Spacecraft (geeksugar.com)