Mars at closer distances
Mars is the planet closest to Earth in size and the one people most often imagine standing on. In the real sky it never grows past a bright point. The distance ladder shows what it would take for the rust-coloured surface to become something you could actually read.
- 6,779 km
- 24.62 hours
- planet
How big does Mars actually look from Earth?
At 54,600,000 km, Mars spans 0.01° across your sky — a small fraction of the width of the full Moon. Light crosses that gap in 3.0 minutes.
At its closest real approach Mars is still a point of light. No unaided eye resolves a disc.
How big would Mars look if it replaced the Moon?
At 384,400 km, Mars spans 1.0° across your sky — about 2.0 times the width of the full Moon. Light crosses that gap in 1.3 seconds.
Put Mars where the Moon is and it is the wider of the two, because it is nearly twice the diameter.
How big would Mars look from a hundredth of an astronomical unit?
At 1,495,979 km, Mars spans 0.3° across your sky — about 0.50 times the width of the full Moon. Light crosses that gap in 5.0 seconds.
The disc is unmistakable and the polar cap is visible.
How big would Mars look from a tenth of an astronomical unit?
At 14,959,787 km, Mars spans 0.03° across your sky — a small fraction of the width of the full Moon. Light crosses that gap in 49.9 seconds.
Closer than Mars ever comes to Earth in the real Solar System.
How big would Mars look at one astronomical unit?
At 149,597,871 km, Mars spans 9.35 arcseconds across your sky — a small fraction of the width of the full Moon. Light crosses that gap in 8.3 minutes.
Mars at the distance the Sun sits from Earth.
What Perigee calculates and what it renders
The apparent size on this page is calculated from the published diameter and the distance you choose, using the same geometry the live scene uses. The lighting and surface treatment are an authored visualization.
How Perigee calculates apparent size