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Planetarium

Solar System · true positions

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Scale

Camera

Show

Controls

1–8Mercury … Neptune
9 / 0Pluto / Sun
Spaceplay / pause
, .slower / faster (also backward)
+ −zoom in / out
← → ↑ ↓rotate camera
G / Btop / side view
Ttoday's date
Escwhole system (stop following)
Hthis help
Mouse / touchdrag — rotate; wheel or pinch — zoom; click — follow; double-click — closer

Planet positions: JPL orbital elements (E. M. Standish, valid 1800–2050) and a solution of Kepler's equation. Moons — approximate orbits. Body sizes are enlarged so they can be seen.

Challenges

0 / 4

They complete themselves: do the task in the planetarium and a ✓ appears here. Progress is saved in this browser.

  1. A year on Mercury

    Follow Mercury (key 1) and let time run until the planet goes once all the way around the Sun. How many Earth days does it take?

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  2. Mars within reach

    Select Mars (key 4) and find a date when it is closer to Earth than 0.40 AU (about 60 million km). The distance is shown in the planet panel. Such great oppositions happen every 15–17 years.

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  3. The Great Conjunction

    Set a date when Jupiter and Saturn, seen from Earth, are less than 1° apart in the sky. It happens roughly every 20 years — take a look at late 2020.

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  4. Neptune to true scale

    In the settings choose “True distance” and fly to Neptune (key 8). Compare how far it is from the Sun with how close Earth is.

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Did you know…?