Where you are
Diameter
Position
Earths across
Light crosses it in
Sizes are diameters. Light travels at 299,792 km per second.
Position on the scale
Type an exponent such as 7.1 (that is 107.1 meters), or a size with units such as 12742 km, 1 AU or 3 ly. The slider is logarithmic: each step is a multiple of size.
Smaller object Larger object
Guided tour
Step through every object
Pauses on each object for a moment, from the smallest to the largest, then starts again.
Zoom and pan the view
Fit the object Reset the view
Hold Ctrl (or pinch on a trackpad or phone) and scroll to zoom toward the pointer. Shift-drag, right-drag or two fingers pan. Double-click to zoom in on a spot, and double-click again to return.
Scene and comparison
Compare with
Draws a dashed outline of the chosen object at true size next to the center object.
Reset the scene
Units
Automatic Meters and km Feet and miles AU and light-years Powers of ten
Classroom display
Presentation mode Hides the panel, enlarges the text and readout, and adds the Earth-widths and light-crossing time to the stage. Press P or Esc to come back.
Text size
Normal Large Extra large
Display
Graphics quality
Auto High Ultra Low
Keys: arrow keys or the mouse wheel move along the scale, plus and minus nudge, [ and ] zoom the view, F fits the object, 0 resets the view, Space plays the tour, 1 to 6 jump to a kind of object, Enter opens details, P presentation mode, D switches light and dark, M shows or hides this panel, Esc closes it. The space scene stays dark in both appearances.