108.1 m · Solar system
Saturn
116,460 kmA gas giant whose spectacular rings are broad but astonishingly thin.
116,460 km → ≈38 billion km
Stellar scale
Stars swell, collapse and bend the meaning of size.
Stellar scale ranges from dense remnants to supergiants and event horizons. Many stellar boundaries are variable or model-dependent, so the catalog marks representative values instead of pretending to show fixed surfaces.
Enter this realm in the scale engine
Questions this realm answers
Start with curiosity.
- How big is the Sun compared with Earth?
- Is Betelgeuse larger than the Solar System?
- How wide is a stellar black hole?
21 source-backed coordinates
Every landmark in stellar scale.
Ordered by the actual logarithm of its SI value.
108.1 m · Solar system
Jupiter
139,820 kmThe largest planet, with storms and cloud bands wrapped around a rapidly rotating globe.
108.3 m · Stars
Proxima Centauri
≈214,000 kmThe nearest known star to the Sun is a cool red dwarf only modestly larger than Jupiter.
108.5 m · Distance
One light-second
299,792 kmThe distance light covers in exactly one second in vacuum.
108.6 m · Distance
Earth–Moon distance
≈384,400 kmThe average centre-to-centre distance separating Earth and the Moon.
109.1 m · Stars
The Sun
1.393 million kmThe star containing almost all the solar system’s mass and powering nearly every surface ecosystem.
109.4 m · Stars
Sirius A
≈2.38 million kmThe brightest star in Earth’s night sky is larger, hotter and more luminous than the Sun.
1010.1 m · Stars
Pollux
≈12.25 million kmAn orange giant star that shows how dramatically stars expand after core hydrogen runs low.
1010.4 m · Black holes
Sagittarius A* horizon
≈25.4 million kmThe Milky Way’s central black hole has millions of solar masses inside an event horizon smaller than Mercury’s orbit.
1010.5 m · Stars
Arcturus
≈35.4 million kmA nearby orange giant whose swollen surface dwarfs the Sun.
1010.8 m · Stars
Aldebaran
≈61.2 million kmThe orange eye of Taurus is a giant star with a broad, diffuse visible boundary.
1011.0 m · Stars
Rigel
≈109 million kmA blue supergiant burning with extreme luminosity and a vast stellar surface.
1011.2 m · Distance
One astronomical unit
149.6 million kmThe conventional distance unit based on Earth’s average separation from the Sun.
1012.0 m · Stars
Betelgeuse
≈1 billion kmA pulsating red supergiant with a surface so diffuse that its quoted diameter changes with wavelength and time.
1012.0 m · Distance
One light-hour
≈1.079 billion kmThe distance light crosses during one hour in vacuum.
1012.3 m · Stars
VY Canis Majoris
≈1.98 billion kmAn extreme red hypergiant surrounded by material it has expelled into space.
1013.0 m · Solar system
Solar System to Neptune
≈9 billion kmThe broad diameter of Neptune’s orbit reveals how empty a planetary system really is.
1013.1 m · Solar system
Pluto’s orbit diameter
≈11.8 billion kmPluto’s elongated orbit widens the familiar planetary system beyond Neptune.
1013.4 m · Distance
One light-day
≈25.9 billion kmThe enormous distance light covers during one Earth day.
1013.6 m · Solar system
Heliosphere
≈36 billion kmThe solar wind inflates a vast, asymmetric bubble inside the surrounding interstellar medium.
1013.6 m · Black holes
M87* event horizon
≈38 billion kmA supermassive black hole whose event-horizon scale rivals the width of the heliosphere.
Guided routes
Meet this realm inside a story.
Flight · 5 minLeave the planet without cheating
Climb from mountains through atmospheric layers to orbit, the Moon and the gulf between planets.
Begin expedition →Stars · 7 minHow stars become impossibleFollow stellar scale from a nursery through ordinary stars, giants, remnants and black holes.
Begin expedition →Cosmos · 6 minYour complete cosmic addressLocate yourself inside nested structures from one body to the observable horizon.
Begin expedition →