Distance, Brightness, and Size of Planets

How to Use the Planet Chart

• Using the four buttons at the top, select either Distance from the Sun, Distance from the Earth, Size in the Sky, or Brightness to control how the planets are displayed.
• Press the Play button at the bottom of the chart to make time move in fast forward mode. You can also move backward and forwards in time by sliding the hand cursor along the red timeline.
• If the red dot next to NOW is flashing, the chart is showing the current distances, displayed in UTC time. You can always return to this view by clicking NOW.
• Press the calendar icon to choose a different date. Enter the time in the fields to the right of the clock icon, if you want to be very specific. The time is indicated in UTC. Find the time difference between UTC and other locations

Distance from the Sun

• The planets' distance from the Sun varies because all the planets orbit the Sun on different elliptical paths.
• The top row of planets shows the distance in kilometers or miles.
• The second row of planets dotted on a line illustrates their relative distance from the Sun and each other.

Distance from the Earth

• The planets' distance from the Earth varies because all the planets orbit the Sun on different elliptical paths.
• Keeping in mind that you are "seeing" the planets from Earth in this chart, you will notice that the Sun, Mercury, Venus, and Mars swap order as time passes. The distance between Earth and Jupiter, Saturn, Uranus, and Neptune also varies, but they always remain in the same order as they are all so far away from each other and from our planet.

Size in the Sky

See how large the planets appear in the sky. For local times and where to look etc., try the night sky in your location. The planets' apparent size is measured in arcseconds ("). For comparison, the Sun and the Moon measure about 1800 arcseconds.

Brightness

We measure the apparent brightness of celestial bodies in magnitude. The brighter a planet shines, the lower the magnitude value. Negative numbers indicate that the planet is very easy to spot in the night sky, even with ambient light. The planets also have phases, like the Moon, but these are not indicated in this chart. The two planets which are closer to the Sun than Earth, Mercury and Venus, have the most easily visible planetary phases, but you need a telescope to see them.

• The bar below each planet shows brightness.
• The eye icon means that planet is visible with the naked eye, without any equipment, given good conditions on that particular date.
• If the eye icon is crossed out, that planet is too close to the Sun to be seen on the given date.
• The binoculars icon means you need a pair of binoculars to see this planet. To a trained planet spotter, Uranus may sometimes be visible to the naked eye, even though it is marked with binoculars.