guide
How far is Mars from Earth? Distance, dates and light time
The distance to Mars changes as Earth and Mars orbit the Sun. Choose a date below for the separation at 00:00 UTC. Daily samples in our archive range from 56,910,012 km to 400,191,052 km across 2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB; these are sampled archive extremes, not universal limits or a live reading.
Use the existing scientific archive
How far is Mars on your chosen date?
Choose a date for the Earth–Mars distance and one-way light time at 00:00 UTC. This is an archive calculation, not a live spacecraft measurement.
Measured facts
- Distance at the recorded snapshot epoch
- 1.866 AU · 279,189,487 kmThis is the epoch the embedded Solar System state uses.
- One-way light time at that epoch
- 15.52 minutes
- Closest measured approach
- 0.380420 AU on 2035-09-12One-way light time then: 3.16 minutes.
- Farthest measured separation
- 2.675112 AU on 2034-08-20One-way light time then: 22.25 minutes.
- Mean separation across the archive
- 1.675823 AU7,306 daily samples.
- Ratio of farthest to closest
- 7.03×
How these numbers were produced
Cubic-Hermite interpolation of the shipped Earth-centred JPL Horizons state archive, sampled once per day across the declared coverage. Distances are magnitudes of the geometric position vectors; no light-time correction or planetary-orbit averaging is applied.
The archive is the same checksum-verified file the renderer loads: horizons-earth-centered-2020-2040.f64, 2,221,200 bytes, SHA-256 166364deaa7e1c62aa613a8df4c0ab614dd64d101301cb09de61d34798585fa1. Coverage is exactly 2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB, and any request outside it is rejected rather than extrapolated.
Why the distance changes so much
Earth completes an orbit in about a year while Mars takes nearly two, and the two orbits are not the same size. When Earth overtakes Mars on the inside, the separation can fall below half an astronomical unit; when the planets are on opposite sides of the Sun, it can exceed two.
Because the orbits are elliptical rather than circular, successive close approaches are not equally close. The archive range of roughly 0.38 to 2.68 AU is measured, not assumed, and the dates above show when each extreme occurred in this window.
What the explorer does with this
The COSMOS date control re-interpolates every planetary position inside the archive, so travelling from Earth to Mars crosses the real separation at the selected date. Choose a date near the closest approach above and the journey is visibly shorter than at the farthest separation.
The planetary view itself is the historical Viking mosaic, not a dated image: the selected date moves the planets, not the surface imagery.
Questions this page answers
- How far is Mars from Earth right now?
- Use the calculator to choose today's UTC date and calculate the distance at 00:00 UTC from the shipped Horizons archive. It is not a continuously live or apparent telescope distance. Supported dates are 1 January 2020–31 December 2039; the calculator refuses dates outside the archive rather than extrapolating.
- How long does it take light to reach Mars?
- At the recorded snapshot epoch the one-way light time is 15.52 minutes. Across the archive it ranges from 3.16 minutes at closest approach to 22.25 minutes at the farthest separation.
- How much does the Earth–Mars distance vary?
- In this archive the separation ranges from 0.380420 AU to 2.675112 AU, a factor of about 7.03.
- Is the closest approach the same every time?
- No. Both orbits are elliptical, so successive oppositions differ in separation. The dates in this archive are specific close approaches rather than a repeating cycle with a single fixed value.
Content updated 2026-10-25. Every value on this page is computed from the shipped datasets; where a source publishes no value, the page says so instead of estimating one.