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The universe in five levels

How big is the universe? The best way to grasp it is in steps. Each level shows a larger field of view than the one before, until the whole Milky Way is just a dot. In the 3D model you can fly through all the levels.

✨ Our neighbouring stars

Field of view: about 90 light-years

The nearest stars around the Sun. The blue shell around the Sun is the Oort Cloud – the outermost edge of our Solar System. A light-year is the distance light travels in one year: 9.5 trillion kilometres.

If Earth's orbit were the size of a 1-franc coin, Proxima Centauri would be 3 km away – roughly from Zurich main station to the zoo.
The whole Solar System out to Neptune would then be a disc 70 cm across.
Voyager 1, the fastest object ever to fly out there, would need around 75,000 years to reach Proxima Centauri.

🌌 The Milky Way

Field of view: about 130,000 light-years

Our galaxy: a spiral of 100 to 400 billion stars. The Sun lies in the Orion Arm, 26,000 light-years from the centre. All the neighbouring stars from the previous level are inside the tiny dot at “Sun”.

If the Milky Way were the size of Switzerland (350 km), the Solar System out to Neptune would be only 3 mm across – and Proxima Centauri 15 m away.
The Sun takes about 230 million years to travel once around the centre. The last time it was here, the first dinosaurs were alive.
At the centre sits a black hole of 4 million solar masses: Sagittarius A*.

🌀 The Local Group

Field of view: about 10 million light-years

The Milky Way is not alone: together with the Andromeda Galaxy, the Triangulum Galaxy and around 80 small dwarf galaxies it forms the Local Group.

If the Milky Way and Andromeda were two plates (25 cm), they would lie only 6 m apart. Compared with their size, galaxies are close together.
If stars were marbles, on the other hand, the nearest marble would be 430 km away – compared with their size, stars are extremely far apart.
The light from the Andromeda Galaxy that you see today set off 2.5 million years ago – when there were not yet any humans like us.

🕸 The cosmic web

Field of view: about 600 million light-years

Galaxies are spread out like dewdrops on a gigantic spider's web: in clusters and long filaments, with vast voids in between. Here the whole Local Group is a single point of light.

The observable universe is around 93 billion light-years across – this view shows only a small piece of it.
It is estimated to contain around 2 trillion galaxies – about 250 galaxies for every person on Earth.
If the Local Group were a football, the observable universe would be around 2 km across.

🌐 The observable universe

Field of view: about 93 billion light-years

As far as we can see at all. Light needs time – looking into the distance means looking into the past. At the edge glows the oldest light, from 380,000 years after the Big Bang. Right in the middle, invisibly small, is where we are.

If the observable universe were the size of Switzerland, the Milky Way would be a plate 38 cm across – and the Solar System out to Neptune smaller than a virus.
The universe is 13.8 billion years old, yet 93 billion light-years across: while the light was on its way to us, space kept on stretching – like dots on a balloon that is being blown up.
Beyond the edge, the universe probably simply carries on. We just cannot see it, because the light from there has not reached us yet.

The scale ladder

Field of view	Size
Solar System out to Neptune	8.3 light-hours
with the Oort Cloud	3 light-years
Neighbouring stars	90 light-years
Milky Way	100,000 light-years
Local Group	10 million light-years
Cosmic web (section)	600 million light-years
Observable universe	93 billion light-years

A light-year is the distance light travels in one year: about 9.5 trillion kilometres.