About Cosmic Scale
Universe size comparison in 3D: see how big planets, stars, black holes and galaxies really are, side by side at true scale.
How big is the Sun next to Earth? How small is the Sun next to the largest stars? What does a black hole do to a star that comes too close? And where are we, inside the Milky Way and beyond?
Cosmic Scale ("the site") is a free web version of the Cosmic Scale app. The site is free and shows ads through Google AdSense.
What is in it
Cosmic Scale lines up 77 objects from smallest to largest, from a 490-metre asteroid to the Solar System and the Oort Cloud, and 123 with the Beyond pack, which adds galaxies, nebulae and the largest structures in the cosmos. Every one is drawn at its true size. Fly through them like a size-comparison video you control. Read about all 123 objects.
Everything, at true size
From the Moon to the Sun, every object drawn at its real size, so you finally feel how big things are.
Fly through the universe
A tour that never leaves your thumb: swipe from an asteroid out to the Oort Cloud, and with the Beyond pack on to the Observable Universe.
Put anything next to anything
Earth beside the Sun. A star beside a black hole. Slide between them and see the real ratio.
Watch the impossible happen
Supernovae, black-hole mergers, pulsars and more, built step by step from real physics and measured numbers.
The tour
Press play and fly from an asteroid past moons, planets, stars and black holes out to the observable universe, with calm music and a bell for every step up in size. At each layer we live inside, the tour dives in to show where we are: Earth in the Solar System, the Solar System in the Milky Way, all the way out.
Compare any two
"The Sun is 109× wider than Earth. About 1.3 million Earths would fit inside it. Light crosses it in 4.6 seconds." Pick any two objects and see them side by side at real scale.
Simulations
Cosmic Scale has 17 simulations: 12 of things that happen in space and 5 theory-only “what if” stories. Each is simulated from real physics and measurements; anything no eye could see, like magnetic fields and radio waves, is drawn and labelled as drawn. Read every simulation's story.
Nothing here has ever been seen. Each idea comes from real physics and says how it could be made, and what it would look like. Light is bent as the equations say it would be; the things themselves are drawn.
Real maps, photos and sounds
Planets and moons wear real maps from NASA missions. Open any object for real photographs, from the Blue Marble to Webb's deep fields, each credited. Listen to the wind on Mars, lightning on Jupiter, Saturn's radio auroras and NASA's sonifications of black holes.
15 languages
English, Español, Português, Français, Deutsch, Türkçe, Bahasa Indonesia, Tiếng Việt, Русский, Oʻzbekcha, العربية, हिन्दी, 简体中文, 日本語, 한국어.
How sizes are drawn
Every object is drawn at its true size relative to the others. Radii are mean radii from NASA/JPL fact sheets and published measurements; supergiant stars and the largest galaxies are uncertain by tens of percent. For black holes the size is the event horizon; nebulae, galaxies and superclusters are artistic renderings at true size.
Image credits
- Mercury, Venus, Earth (day, night lights, clouds), Moon, Mars, Jupiter, Saturn and its rings, Uranus, Neptune — Solar System Scope (solarsystemscope.com), CC BY 4.0
- Io, Europa, Callisto — NASA / JPL / USGS Astrogeology — Galileo and Voyager global mosaics
- Titan — NASA / JPL-Caltech / Space Science Institute — Cassini (PIA19658)
- Enceladus — NASA / JPL-Caltech / Space Science Institute / Lunar and Planetary Institute — Cassini (PIA14937)
- Mimas — NASA / JPL-Caltech / Space Science Institute / Lunar and Planetary Institute — Cassini (PIA17214)
- Pluto — NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute — New Horizons (PIA19858)
- Charon — NASA / JHUAPL / SwRI — New Horizons (PIA19866)
- Triton — NASA / JPL / Universities Space Research Association / Lunar & Planetary Institute — Voyager 2 (PIA18668)
- Ceres — NASA / JPL-Caltech / UCLA / MPS / DLR / IDA — Dawn (PIA20351), reprojected
- Unphotographed areas of Pluto, Charon, Triton, Ceres and Callisto — Filled in by Cosmic Scale from each world's own terrain; not real imagery
Photos are loaded from NASA (public domain), ESA/Hubble, ESA/Webb, ESO, NOIRLab and the Event Horizon Telescope (CC BY 4.0); each shows its own credit. Sounds are streamed from NASA, the Chandra X-ray Center and the University of Iowa, each with its credit. Tour music is generated in the app. Nebulae, galaxies, black holes and stars beyond the Sun are artistic renderings drawn at true size. NASA and ESA do not endorse this app.
Contact
Questions and corrections: ahasankhonov@gmail.com. See also the privacy policy.