Lookback

About

Everything here is at its real size and its real distance.

Earth, the Moon and the planets are where they are right now, from NASA JPL orbital elements. The 109,400 stars are real, from the HYG catalogue, at their measured positions, colours and brightness. The 157,000 galaxies are real, from the Sloan Digital Sky Survey. The asteroids and Kuiper belt objects are real, from the JPL Small-Body Database.

What is an aid, and what is not

• Guides add orbit lines, names, distance rings and a small ring around anything too small to see. Turn them off and nothing is drawn that is not there.
• Long exposure raises brightness as you travel, as a camera would with a longer exposure. Turn it off for the unaided eye: beyond a few light-years, almost everything goes dark.
• The Milky Way is generated from the accepted model of its shape (a bar, four arms, the Sun 26,700 light-years from the centre). Its individual points are not real stars. The soft glows of named galaxies show their position and rough size, not their true shape.
• Beyond the Local Group, “distance” is the distance today, and the light time is how long ago the light left, using the Planck 2018 measurements of the expanding universe.

Keys

↑↓ pull back and move in · ←→ look around · Space play or pause · G guides · E exposure · H home · Esc close

Credits

• Stars: HYG database 4.1, David Nash, CC BY-SA 4.0 (Hipparcos, Yale Bright Star and Gliese catalogues).
• Galaxies: Sloan Digital Sky Survey Data Release 17, public domain.
• Planet positions: NASA JPL Solar System Dynamics. Small bodies: JPL Small-Body Database.
• Planet maps: Solar System Scope, CC BY 4.0, based on NASA imagery; resized.
• Sizes and facts: NASA Planetary Fact Sheets and NASA Science. Rotation: IAU WGCCRE 2015.
• Cosmology: Planck Collaboration 2018. Typeface: Geist, SIL Open Font License.

Made by Pratyush Shivam.