How Far Is Planet Mars From the Sun

Short answer

• Mars is, on average, about 228 million kilometers (142 million miles) from the Sun, which is about 1.52 astronomical units (AU). That average hides a wide swing, because Mars follows an elliptical orbit: at its closest point to the Sun, called perihelion, it is about 207 million kilometers away, and at its farthest point, called aphelion, it is about 249 million kilometers away. Sunlight takes about 13 minutes to reach Mars at the average distance, compared with about 8 minutes to reach Earth. Any single figure for the distance from Mars to the Sun is therefore a useful shorthand, not a fixed measurement.

The Short Answer in Full

Ask how far Mars is from the Sun and you will usually get one tidy number: 228 million kilometers, or 142 million miles, or 1.52 AU. All three say the same thing in different units, and all three are correct as averages. The trouble starts only when that average is treated as if Mars sat at one unchanging distance from the Sun, the way a house sits at a fixed distance from a streetlamp. Mars does not do that. It travels around the Sun on an oval path, moving closer and then farther away over the course of its year, so the true distance changes every day.

That distinction matters more for Mars than for Earth. Earth also follows an elliptical orbit, but its oval is close to a circle, so its distance changes little across the year. Mars has a noticeably stretched orbit, with about 42 million kilometers between its closest and farthest points, enough to change how much sunlight it receives, how long its seasons last, and how mission planners think about sending spacecraft there. The honest answer is therefore a range with an average, not a single number.

Calculated figures are labeled as calculations.

Mars at a Glance: The Numbers That Matter

Mars is the fourth planet from the Sun, counting outward from Mercury, Venus, Earth, then Mars. NASA describes it as a dusty, cold, desert world with a very thin atmosphere, seasons, polar ice caps, extinct volcanoes, canyons, and weather. Its radius is about 3,390 kilometers, which makes it about half the size of Earth. A day on Mars, called a sol, lasts about 24.6 hours, very close to an Earth day. A year on Mars, one full trip around the Sun, lasts 687 Earth days, or about 1.88 Earth years. Its axis is tilted by about 25 degrees, slightly more than the tilt of Earth, which is one reason Mars has seasons.

The distance figures most often quoted for Mars come from the same set of orbital measurements, rounded in different ways by different publishers. NASA gives the average distance as 142 million miles (228 million kilometers), or 1.5 astronomical units, with sunlight taking 13 minutes to travel from the Sun to Mars. The Natural History Museum in London gives the same average as 228 million kilometers. Las Cumbres Observatory gives a more precise form of the same figure: an average distance of 1.524 AU, or about 227.9 million kilometers. These are not competing answers. They are the same answer rounded to different levels of precision.

For the rest of this article, the working figures are the more precise published forms: a mean distance of 1.524 AU, about 227.9 million kilometers, about 141.6 million miles; a perihelion distance of about 206.7 million kilometers, about 128.4 million miles, about 1.38 AU; and an aphelion distance of about 249.2 million kilometers, about 154.8 million miles, about 1.67 AU.

Why One Fixed Figure Is Misleading

The reason no single number can capture the distance from Mars to the Sun is the shape of its orbit. The orbit of a planet is an ellipse, a stretched circle, with the Sun sitting not at the center of the ellipse but at one of its two focal points. Picture a running track that has been pulled slightly out of shape, with the Sun standing off center inside it. As Mars runs around that track, it is sometimes on the side nearest the Sun and sometimes on the opposite side, farthest from the Sun. The distance therefore rises and falls smoothly through the year, rather than jumping between two values.

Astronomers name the two turning points of this motion. Perihelion is the point in the orbit where a planet is closest to the Sun. Aphelion is the point where a planet is farthest from the Sun. For Mars, perihelion is about 206.7 million kilometers from the Sun and aphelion is about 249.2 million kilometers from the Sun. The difference between them, about 42.5 million kilometers, is the full swing of the orbit. Put another way, Mars at aphelion is about 21 percent farther from the Sun than it is at perihelion.

The standard measure of how stretched an orbit is called eccentricity. A perfect circle has an eccentricity of zero. Earth has an eccentricity of about 0.0167, which is why its orbit is nearly circular and its distance from the Sun varies only by about 5 million kilometers across the year. Mars has an eccentricity of about 0.0934, roughly five to six times larger. That single difference explains why the question of how far Mars is from the Sun needs a range for Mars in a way it barely needs one for Earth. Of the eight planets, only Mercury has a more eccentric orbit than Mars at the present time, according to university lecture material from California State University, Long Beach.

There is a second reason the average needs care. The “average distance” quoted for a planet is the semi-major axis of the orbit: half the length of the long axis of the ellipse. For Mars, that value is about 227.9 million kilometers. It is also, to a close approximation, the average of the perihelion and aphelion distances: add 206.7 million kilometers and 249.2 million kilometers, divide by two, and you get about 228.0 million kilometers, matching the published semi-major axis within rounding. Astronomers use it to compare orbits because it stays fixed even as the planet moves, and because it ties directly to the length of the planet’s year.

Perihelion and Aphelion: What Changes, and What Does Not

Mars reaches perihelion and aphelion once each per Martian year, which means once every 687 Earth days. Between those extremes, it passes through every distance in between, moving fastest when it is closest to the Sun and slowest when it is farthest away. That speed change follows Kepler’s second law: a planet sweeps out equal areas in equal times, so it must cover more ground per day near perihelion and less per day near aphelion.

The most important consequence of this swing is the change in sunlight. Sunlight spreads out as it travels, so the amount of solar energy arriving at a planet falls with the square of the distance. This is the inverse square law, and it means a modest change in distance produces a larger change in sunlight. At its average distance, Mars receives about 43 percent of the sunlight Earth receives. At perihelion, it receives noticeably more than at aphelion: the ratio of the two distances squared gives about 1.45, so Mars receives about 45 percent more solar energy at perihelion than at aphelion. By calculation from the inverse-square law, the figures are about 713 watts per square meter at perihelion and about 491 watts per square meter at aphelion, at the top of the atmosphere, which gives the same ratio of about 1.45. For comparison, Earth receives about 1,361 watts per square meter at its average distance, and its perihelion to aphelion change is only about 7 percent, because its orbit is so much closer to a circle.

That sunlight swing, combined with the tilt of the Martian axis, shapes the Martian seasons, which are not equal in length. NASA reports northern spring at 194 sols, northern summer at 178 sols, northern winter at 154 sols, and northern autumn at only 142 sols. The shortest season falls when Mars moves fastest near perihelion. The southern hemisphere feels the effect more strongly, because perihelion currently lines up with southern summer, making southern summer shorter and hotter and southern winter longer and colder. Over tens of thousands of years that alignment slowly shifts, so this pattern belongs to the present era, not permanently to Mars.

The orbit itself does not expand and contract. The ellipse stays essentially the same from year to year, and Mars retraces nearly the same path each orbit. What changes is where Mars sits on that path on any given day, so the distance is predictable: given a date, astronomers can calculate it to high precision from the orbital elements. The range given here is not a sign of uncertainty about the orbit. It is a description of the orbit.

What Is an Astronomical Unit, and How Is It Measured?

When distances run into hundreds of millions of kilometers, astronomers switch to a handier unit: the astronomical unit, abbreviated AU. One AU is defined by the distance from Earth to the Sun, and Mars sits at about 1.52 AU. Saying Mars is 1.52 AU from the Sun immediately tells a reader that it is about one and a half times as far from the Sun as Earth is, without requiring anyone to picture 228 million kilometers. The AU is a unit of comparison as much as a unit of measurement, and that is why it appears in almost every discussion of planetary distances.

The history of the AU shows how astronomy moved from estimation to definition. Early astronomers could work out the relative layout of the solar system, saying Mars was about one and a half times as far from the Sun as Earth, long before they knew either distance in kilometers. The breakthrough in absolute measurement came from parallax: observing a planet from two widely separated points on Earth and measuring the tiny shift in its apparent position. Later, radar transformed the field, because radio signals bounced off Venus and other bodies returned after a measurable delay, and the known speed of radio waves turned that delay into a distance. Spacecraft tracking refined the network further, because a spacecraft in orbit around another planet reports its position with great precision.

For most of its history, the AU was defined in terms of Earth’s orbit: the semi-major axis of Earth’s elliptical orbit around the Sun. The difficulty was that Earth’s orbit is itself slightly variable, and the definition depended on models of motion and on the reference frame used. In 2012, the International Astronomical Union removed that difficulty by redefining the AU as a fixed number. Under Resolution B2, adopted at the IAU General Assembly in Beijing in August 2012, one astronomical unit is exactly 149,597,870,700 meters. In kilometers, that is about 149.6 million kilometers, and in miles, about 92,955,807 miles. The value was chosen to match the best measurements available at the time, so the change did not move any published planetary distance by a noticeable amount. What it changed was the status of the number: the AU is now a defined constant, like the meter itself, rather than a quantity that astronomers must keep remeasuring.

That definition makes conversions straightforward, and it is worth showing the arithmetic once, because it removes a common source of confusion. Multiply the AU in kilometers, 149.6 million kilometers, by the Mars figure of 1.524, and the result is about 228.0 million kilometers, which matches the published mean distance for Mars. Divide the AU in kilometers by the speed of light, about 299,792 kilometers per second, and the result is about 499 seconds, or about 8 minutes and 19 seconds, which is the light travel time for one AU. Every figure in this article can be checked against the others in this way, which is a useful test when a new source quotes a distance that looks unfamiliar.

One caution belongs here. Because the AU is now fixed by definition, it is better to say that one AU is a defined length very close to the average Earth to Sun distance, chosen for that reason. Earth itself still moves between about 147.1 million kilometers at perihelion and about 152.1 million kilometers at aphelion, so the real Earth to Sun distance is sometimes a little less than one AU and sometimes a little more. The unit stays put; the planet moves.

How Long Does Sunlight Take to Reach Mars?

NASA gives the headline figure: sunlight takes about 13 minutes to travel from the Sun to Mars at the average distance, compared with about 8 minutes to reach Earth. The calculation behind those rounded figures is simple division: distance divided by the speed of light. At the mean distance of 227.9 million kilometers, dividing by about 299,792 kilometers per second gives about 760 seconds, which is about 12 minutes and 40 seconds, rounded to about 13 minutes. At one AU, the same division gives about 499 seconds, or about 8 minutes and 19 seconds, rounded to about 8 minutes.

The light travel time also varies with the orbit. At perihelion, sunlight takes about 690 seconds, or about 11 minutes and 30 seconds, to reach Mars (calculation). At aphelion, it takes about 831 seconds, or about 13 minutes and 51 seconds (calculation). Those figures are labeled as calculations because the published sources give only the rounded average of about 13 minutes.

How Mars Compares With Earth and the Other Planets

Mars is the fourth planet from the Sun, and the comparison that matters most is with Earth, the third planet. Earth sits at 1.00 AU, an average of about 149.6 million kilometers from the Sun. Mars, at 1.52 AU, is about 52 percent farther from the Sun on average, an extra distance of about 78 million kilometers. That gap is why Mars receives only about 43 percent of Earth’s sunlight, why its year is nearly twice as long, and a major reason its surface temperature is far lower, ranging from about 20 degrees Celsius at the warmest to about minus 153 degrees Celsius at the coldest.

The table below uses rounded mean distances. Each planet also has its own perihelion and aphelion range, but the means show the structure of the solar system: four small rocky planets clustered close to the Sun, then a large gap, then four giant planets spread across far greater distances.

Planet	Order from the Sun	Mean distance from the Sun (AU)	Mean distance from the Sun (million kilometers)
Mercury	1st	0.39	57.9
Venus	2nd	0.72	108.2
Earth	3rd	1.00	149.6
Mars	4th	1.52	227.9
Jupiter	5th	5.20	778.5
Saturn	6th	9.57	1,432.0
Uranus	7th	19.16	2,867.0
Neptune	8th	30.18	4,515.0

Two features deserve attention. First, the gap between Mars and Jupiter is enormous compared with the gaps between the inner planets: Jupiter sits at 5.20 AU, more than three times as far from the Sun as Mars, and the region between them holds the asteroid belt. Second, Neptune, at 30.18 AU, is about twenty times as far from the Sun as Mars, and sunlight takes about 4 hours and 11 minutes to reach it, compared with about 13 minutes to reach Mars.

If the Sun were shrunk to a ball one meter across, Earth would be a bead about 9 millimeters across sitting about 108 meters away, and Mars would be a bead about 5 millimeters across sitting about 164 meters away. Jupiter would be a ball about 10 centimeters across, about 560 meters away, and Neptune would sit more than 3 kilometers from the ball.

A Common Confusion: Distance From the Sun Is Not Distance From Earth

Many readers who search for the distance from Mars to the Sun are really wondering how far away Mars is from us, here on Earth. Those are different distances, and confusing them produces some startlingly wrong numbers. The distance from Mars to the Sun changes only between about 207 million kilometers and about 249 million kilometers. The distance from Mars to Earth changes far more dramatically, because both planets are moving around the Sun at different speeds and on different orbits.

When Earth and Mars line up on the same side of the Sun, an arrangement called opposition, they are at their closest, and the gap can shrink to roughly 55 million kilometers, depending on where Mars sits in its own orbit at the time. When they sit on opposite sides of the Sun, with the Sun between them, an arrangement called conjunction, the gap can stretch beyond 400 million kilometers. That is why “55 million kilometers away” and “228 million kilometers away” can both be correct answers to different questions: the first is about Earth to Mars, the second is about Sun to Mars. Any Mars distance that does not say which pair of bodies it means should be treated with suspicion until that point is clarified.

Why the Distance Matters for Missions, in General Terms

Distance shapes Mars exploration in three general ways: energy, time, and communication. Each follows from the orbital geometry described above, and none of them requires a specific prediction about any future mission.

First, energy. A spacecraft leaving Earth for Mars must gain enough energy to move from an orbit at 1.00 AU to an orbit at about 1.52 AU, along an elliptical transfer orbit that touches Earth’s orbit at one end and Mars’s orbit at the other. That route only lines up favorably at certain times, when Earth and Mars are in the right relative positions, which is why launch opportunities open in windows separated by roughly two years rather than every week.

Second, time. Because a transfer orbit is a long, looping path rather than a straight line, a journey to Mars takes months, not days. The spacecraft does not travel the 78 million kilometer gap between the average orbits of Earth and Mars in a straight line; it follows a curved path around the Sun. Transit times of many months are therefore normal, and they vary with the trajectory: a faster trajectory costs more energy, and a slower one costs more time.

Third, communication. Radio signals travel at the speed of light, so a signal to a spacecraft at Mars takes minutes to arrive, and a reply takes minutes to return. When Earth and Mars sit on opposite sides of the Sun, communication can be interrupted, because the Sun blocks or degrades the signal. Operators therefore plan for periods when a spacecraft must act on its own instructions, and for delays that make real time remote control impossible. The full delay depends on the Earth to Mars distance at the time, which varies far more widely than the Sun to Mars distance.

There is a fourth consequence of distance: power and temperature. A spacecraft at Mars receives only about 43 percent of the sunlight available at Earth, and less still near aphelion, so solar panels must be larger to produce the same power, and thermal design must cope with a colder environment. This article makes no prediction about any specific future mission, its launch date, or its travel time, because those details depend on mission plans that change. Readers who need a date for a particular mission should check the space agency responsible for that mission. The general principles above, launch windows, months-long transits, minutes-long signal delays, and reduced solar power, hold for any mission to Mars, whatever its date.

How Astronomers Keep Measuring the Distance Today

The figures in this article are checked continuously, as a byproduct of operating spacecraft at Mars. Every orbiter and rover at Mars is tracked from Earth by radio, and the round trip time of those signals gives the position of the spacecraft to high precision, which also pins down the position of Mars itself. Ground based telescopes add nightly measurements against the background stars, revealing slow changes caused by the gravity of the other planets, especially Jupiter. Those changes are far too slow to matter for any reader today: the perihelion and aphelion figures quoted here will remain correct, within rounding, for any reader’s lifetime. When NASA, the Natural History Museum, and Las Cumbres Observatory all give the same average distance within rounding, that agreement reflects a shared, well measured orbit, refined by radar, spacecraft tracking, and centuries of telescopic observation.

Putting the Distance in Human Terms

Numbers in the hundreds of millions are hard to feel, so it helps to translate them into journeys. A commercial airliner cruising at about 900 kilometers per hour would take about 29 years of nonstop flying to cover the average Sun to Mars distance, ignoring refueling and the small matter of leaving the atmosphere. A car at 100 kilometers per hour, day and night without stopping, would take about 260 years. Light does it in about 13 minutes. The average Sun to Mars distance is also about 593 times the Earth to Moon distance of about 384,400 kilometers.

Frequently Asked Questions

How far is planet Mars from the Sun?

On average, Mars is about 228 million kilometers (142 million miles, 1.52 AU) from the Sun. Because its orbit is elliptical, the actual distance ranges from about 207 million kilometers at perihelion to about 249 million kilometers at aphelion. The average is the semi-major axis of the orbit, not a distance Mars sits at permanently.

What is the closest Mars gets to the Sun?

At perihelion, Mars comes to about 206.7 million kilometers (128.4 million miles, 1.38 AU) from the Sun. It reaches perihelion once per Martian year, every 687 Earth days.

What is the farthest Mars gets from the Sun?

At aphelion, Mars reaches about 249.2 million kilometers (154.8 million miles, 1.67 AU) from the Sun. The gap between perihelion and aphelion is about 42.5 million kilometers.

How far is Mars from the Sun in AU?

Mars averages about 1.52 AU from the Sun, more precisely about 1.524 AU. One AU is defined as exactly 149,597,870,700 meters, or about 149.6 million kilometers. Mars therefore sits about one and a half times as far from the Sun as Earth does.

How long does sunlight take to reach Mars?

About 13 minutes at the average distance, compared with about 8 minutes to reach Earth. By calculation, it varies from about 11 minutes and 30 seconds at perihelion to about 13 minutes and 51 seconds at aphelion.

Is Mars closer to the Sun than Earth?

No. Mars is the fourth planet from the Sun and Earth is the third, so Mars is always farther from the Sun than Earth is, by about 78 million kilometers on average. The distance from Mars to Earth is a different quantity, and it varies far more widely.

Why does the distance from Mars to the Sun change?

Because Mars follows an elliptical orbit with the Sun at one focus, not at the center. Its eccentricity of about 0.0934 makes the orbit noticeably stretched, so Mars moves from about 207 million kilometers at perihelion to about 249 million kilometers at aphelion over each 687 Earth day year.

How far is Mars from Earth?

That depends on the date, because both planets move. At their closest, on the same side of the Sun, the gap can shrink to roughly 55 million kilometers. On opposite sides of the Sun, it can stretch beyond 400 million kilometers. Those figures describe Earth to Mars distance, not Sun to Mars distance.

Keep reading: How Far Is Saturn From the Sun

Sources & references

• NASA, Mars: Facts (NASA Science, Mars exploration pages; page updated 10 July 2026, as shown on the page). Average distance 142 million miles (228 million kilometers), 1.5 AU, sunlight 13 minutes; radius 3,390 kilometers; sol 24.6 hours; year 687 Earth days; axial tilt 25 degrees; season lengths in sols.
• Natural History Museum, London, Planet Mars. Average distance 228 million kilometers; elliptical range about 206 million to 249 million kilometers; orbital speed about 24 kilometers per second; year 687 Earth days; day 24.6 hours; tilt 25 degrees.
• Las Cumbres Observatory, Mars (Spacebook). Average distance 1.524 AU, about 227.9 million kilometers; orbital period 686.98 Earth days; rotation 24 hours 37 minutes 22 seconds; two moons.
• California State University, Long Beach, Geography of Mars lecture notes (Mars in Space). Semi-major axis 227,936,640 kilometers; perihelion 206,600,000 kilometers (article rounds the NASA figure of 206,650,000 kilometers to 206.7 million kilometers); aphelion 249,200,000 kilometers; eccentricity 0.0934; Earth eccentricity 0.0167; solar irradiance figures are calculations from the NASA Earth irradiance of about 1,361 watts per square meter and the Mars distances above.
• American Astronomical Society, Report on the 2012 IAU XXVIII General Assembly (reporting IAU Resolution B2). The astronomical unit is defined as exactly 149,597,870,700 meters. Cross-checked against the Paris Observatory summary of the same resolution, adopted 30 August 2012.
• Planet comparison table: rounded mean distances confirmed 27 October 2026 by independent QA directly against the NASA Planetary Fact Sheet (metric), Distance from Sun row: Mercury 57.9, Venus 108.2, Earth 149.6, Mars 228.0, Jupiter 778.5, Saturn 1432.0, Uranus 2867.0, Neptune 4515.0 (million kilometers); AU figures are those distances divided by 149.598 and rounded to two decimals.