Last updated: 11 July 2026
Notes on distance, light, and motion in the solar system — short reads for anyone who uses the calculator and wonders about the "why" behind a number.
Why the Earth–Mars distance changes so much
What "light-time delay" means for a spacecraft
How Mars launch windows are chosen
Why the Moon's distance from Earth changes every month
How far is Jupiter from Earth right now?
How long would it take to travel to Mars?
How far is the Sun from Earth in light-minutes?
Which planet is actually closest to Earth?
How far away is the International Space Station?
How far is Voyager 1 from Earth right now?
Frequently asked questions
How far is it from Earth to Mars right now?
It depends entirely on where each planet currently sits in its orbit. At closest approach the two planets are around 56 million kilometres apart; on opposite sides of the Sun, that stretches past 400 million kilometres. The calculator works out today's figure live. See also: why the distance changes so much.
How long does light take to travel from the Sun to each planet?
About 8 minutes 20 seconds to Earth, roughly 4.3 minutes to Mercury, around 12.5 minutes to Mars, and over 4 hours to Neptune — though the exact figure shifts slightly as each planet moves through its orbit. More detail: how the Sun's light-minutes are worked out.
What planet is closest to Earth right now?
It changes constantly. Venus, Mars, and Mercury each take turns being the nearest planet, depending on where all three bodies happen to be in their orbits on a given day. See which planet is actually closest to Earth on average.
Why does the site show a distance that looks different from what I read elsewhere?
Most published "distance to Mars" figures you see quoted are the average or closest-approach distance, not today's actual distance. This site calculates the current position of each body and reports the real, live distance, which is almost never the same as the average.
How accurate are these numbers?
Planet positions come from the VSOP87 model, accurate to within a few percent of true range. That's precise enough to understand scale and trends, but not precise enough for navigation or scientific publication — see the terms and conditions for the full note.
Articles
Why the Earth–Mars Distance Changes So Much
Earth and Mars orbit the Sun at different speeds, so the gap between them constantly opens and closes — by a factor of more than seven.
What Light-Time Delay Actually Means for a Spacecraft
Even at the speed of light, a command to Mars takes minutes to arrive — which is exactly why Mars rovers make their own driving decisions.
How a Launch Window Is Chosen
Launch windows aren’t about convenience — they’re dictated almost entirely by how much fuel a trajectory needs.
Why the Moon Isn't Always the Same Distance Away
The Moon swings between roughly 356,500 km and 406,700 km from Earth every month — enough to be visible to the naked eye.
How Far Is Jupiter From Earth?
Jupiter's huge orbit means its distance from Earth swings by hundreds of millions of kilometres — and light still takes over half an hour to arrive.
How Long Would It Take to Travel to Mars?
Most Mars missions take 6 to 9 months one-way — but the exact time depends heavily on the trajectory and when you launch.
How Far Is the Sun From Earth, in Light-Minutes?
The Sun's light takes about 8 minutes 20 seconds to reach Earth — and that figure shifts slightly through the year.
Which Planet Is Actually Closest to Earth?
On any single day, Venus or Mars might be nearest — but averaged over time, the answer is surprisingly Mercury.
How Far Away Is the ISS?
The ISS orbits closer to Earth's surface than the distance between many major cities — yet it circles the entire planet every 93 minutes.
How Far Is Voyager 1 From Earth Right Now?
Launched in 1977, Voyager 1 is now the most distant human-made object in existence — and it keeps getting farther every second.