What Really Lies Beneath the Earth in Space?

Penulis

KOMPAS.com - If you have ever seen an illustration or model of the solar system, you may notice something interesting: almost all planets orbit the Sun in the same plane and move in the same direction. The solar system looks like a flat disc, not a collection of planets moving on random paths in all directions.

But the question often arises: what is actually above or below that orbital plane? Is there something “below” Earth in space?

To answer, we need to view the solar system not only from Earth’s perspective, but also from galactic scales to cosmological structures that are far larger.

Planets in the solar system move in a plane called the ecliptic plane. This plane is an imaginary plane that follows the path Earth takes while orbiting the Sun. Other planets are also nearly all in the same plane.

Conventionally, astronomers define up and down directions based on this plane.

“Conventionally, we say that from above the ecliptic plane the planets appear to orbit the Sun counterclockwise, whereas from below they appear clockwise.”

However, the concepts of “up” and “down” in space are not absolute.

But the directions do actually vary depending on location on Earth.

Imagine someone standing in North America and pointing down. If the line from their finger passes through the Earth to the other side of a planet, the line would point in the direction considered “up” by someone located in the southern Indian Ocean.

In other words, the downward direction on Earth is local, not universal.

If you travel far enough in that direction, you will encounter interplanetary space, comets, asteroids, and eventually other stars with their own planetary systems.

Interestingly, the concept of a flat plane does not apply only to the solar system.