# How fast is the Earth moving through space?

We all know the feeling of standing on the earth's surface, of perceiving ourselves in a “steady” state. We just stop walking. But the theory of relativity taught us one very important thing, everything is relative to the frame of reference with which to compare. And it turns out that there is no universal reference, not even to determine our position or measure our speed of displacement.

The subjective feeling of standing takes as reference the earth's surface and the objects that surround us. If we go up to the astronomical level and look inside the planet Earth, we will soon realize that we are moving at great speed through space.

## Rotation of the Earth on itself

To get started, the earth rotates on itself completing one lap in 24 hours. This movement, responsible for us having night and day, has a speed of approximately 1670km/h (0.5 km/s) at Earth's equator1. As we move north or south, this speed decreases.

Although it is a considerable speed, because gravity keeps us attached to the Earth, we move with it and do not notice its rotation.

## Translation of the Earth around the Sun

In addition to spinning on itself, the Earth moves within the Solar System following a elliptical orbit around the sun, the central and only star of the system. This movement, called translational movement, is carried out at a speed of 30 km/s (108,000 km/h). The orbit is completed in 365,242 days (1 sidereal year).

If the rotational movement, the translational movement and the displacement of the Sun are combined, the movement of the Earth through space could be similar to the following animation:

## Speed ​​of the Solar System within the Milky Way

If we take the Milky Way as a reference, the Solar System as a whole moves at a speed of approximately 200–220 km/s. The Solar System follows an elliptical orbit around the galactic center that it completes every 220–250 million years.

## Displacement of the Milky Way within the local group

And the Milky Way itself isn't sitting still either. Within the local group of galaxies, the Milky Way moves at an estimated speed of 300 km/s. And if we take as reference the Cosmic Microwave Backgroundthe maximum frame of reference that we know and that was determined by the Big Band, the Milky Way moves at an estimated speed of 552 ± 6 km/s.

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