The motion of the solar system through our galaxy

The solar system cruising through the galaxy. pic.twitter.com/CpBaRjyjau

— Tony Dunn (@tony873004) May 25, 2023

The motion of the solar system

Tony Dunn’s newest simulation, produced on software he created, has garnered more than 8 million views on Twitter. And it’s no wonder! It’s a fascinating look at the planets in our solar system as they move through space. The simulation covers about 20 years, and the viewpoint is approximately 238 astronomical units (AU) from the sun in the direction of the center of the Milky Way Galaxy. That’s outside the Kuiper belt (at 50 AU) but well inside the Oort Cloud (at 2,000 to 100,000 AU).

As can be seen, the inner planets and sun all spiral close together. The outer planets have room for labels, so you can watch Jupiter, for example, complete about two orbits of the sun. (Jupiter’s year is equal to about 12 Earth years.) Plus, Pluto appears to be shooting off on its own, but don’t worry; its stretched-out elliptical orbit will bring it back.

So, just as the sun circles the center of our galaxy, so do the solar system’s planets circle the sun as it barrels through space.

Why don’t the stars move?

In the background, you can see the stars of Orion. If the sun is orbiting the center of the galaxy, why don’t we see other stars moving too? Well, they are moving, but this simulation puts us close to the solar system, so from this position we wouldn’t see the stars move over a short period of time (such as 20 years). However, from farther away or with a much longer simulation, we would be able to see the movement of other stars.

Here’s a look at how the stars of Orion move over many millennia.

Orion has a very slow proper motion compared to other asterisms. That's because its bright stars are very far. pic.twitter.com/hmwxjO5v3p

— Tony Dunn (@tony873004) November 17, 2022

Here’s another fun look at Orion. If you were to fly toward its stars, you can see from this simulation which are closer and which are further away.

Flying to Orion pic.twitter.com/DrGW7K3yUI

— Tony Dunn (@tony873004) November 17, 2022

Bottom line: Tony Dunn has created a simulation of the movement of the solar system through the Milky Way. Learn more about it here.