Our Solar System - Google Arts & Culture (2024)

The Beginning — 4.5 Billion Years Ago

Making a Star

Over time, gravity causes parts of these clouds to collapse. The clumps get denser and hotter, attracting even more material from the cloud, until finally their cores reach the conditions required to begin nuclear fusion—the power source of all stars.

Orion

We can watch this happening in the Orion Nebula. The bright clumps on the right are regions where gigantic, massive stars are forming. The clump that became our Solar System was about 20,000 times as big as the current distance between the Earth and the Sun.

A Closer Look At The Orion Nebula

It was in a place like this that our Sun formed, surrounded by many other stars. Over hundreds of millions of years, these stars drifted apart, leaving little evidence of their original crowding.

Ignition

As a star turns on, it continues to attract dust and gas. Some falls onto the star, but other bits collect into a disk that rotates around it instead. At the same time, the star's magnetic field channels some particles through powerful jets from either north/south pole.

A Planet Crucible

Enter: Planets

Though the dust in this disk is only about a billionth of a meter large to begin with, over thousands of years it coagulates into dust bunnies, then pebbles, then boulders —and eventually, the building blocks of entire planets (called "protoplanets").

486958 Arrokoth

This faraway object, also known as "2014 MU69", is thought to be a leftover of the primitive building blocks that glommed together to form the rocky cores of planets.

Diverging Paths

Depending where and when a planet begins forming, it can end up big or small. It can be made of rock or ice or gas, or some combination of the three. It can end up anywhere between an orbit so far away that it takes centuries, or one so close that it takes less than a day.

The Chaotic Era

At this point, the Solar System went through a period of instability that lasted about a hundred million years. Some protoplanets smashed into each other, like the impact that formed the Earth's moon. Others may have been ejected out of the Solar System entirely.

Haumea

The dwarf planet Haumea, which orbits the Sun from a distance far past Neptune, is thought to have formed through the kind of giant collision that reshaped our Solar System so much.

Moon-making

In this chaotic time, some planets captured others into their orbit, gaining moons. Others had already formed moons early on, from orbiting disks like miniature versions of the one that had surrounded the Sun.

Asteroids Incoming

Most scientists agree that about 500 million years after the Solar System formed, Jupiter began migrating closer to the Sun. Its gravitational influence disturbed the asteroid belt and launched many rocks toward the inner planets, including the Earth.

A Shove From Jupiter

One popular theory says that as Jupiter moved, it eventually interacted with Saturn's orbit, causing a major gravitational disturbance that pushed Uranus and Neptune farther out from the Sun and even switched their order.

The "Final" Product

That brings us to today.

But the Solar System isn't done evolving.

Collision Course?

But by then...

...the Sun will have already made life (and water) on Earth's surface hard to sustain. In a billion years, it'll be too hot.

And as the Sun exhausts the hydrogen it fuses for energy, it will expand, eventually swallowing Mercury. It may also consume Venus and the Earth — some calculations point to yes, others say no.

Boom.

In about 5 billion years, the Sun will exhaust all its fuel and collapse in on itself. The sun isn't massive enough to go supernova or become a black hole, but the collapse will cause an explosion that either destroys any of the remaining planets or ejects them out into space.

Another Kind Of Nebula

The Solar System will then be a "planetary nebula" —a misleading name, since the planets will all be gone. The Sun will have lost about half its mass, and will continue to shine as a small, hot white dwarf.

The End?