♂ Mars

How to follow Mars live

The panel above recomputes Mars every second in your browser: how far it is from the Sun and from Earth (in AU and in kilometers), its apparent magnitude, the illuminated fraction, the phase angle and the elongation from the Sun. The magnitude tells you at a glance whether Mars is visible to the naked eye tonight or needs a telescope.

The top-down map of the Solar System then shows exactly where Mars sits among the other planets right now. Run time with the day slider, zoom and pan, click a second planet to compare distances, or press "Next event" to jump to the next opposition or closest approach to Earth, the best moment to observe it.

Quick facts

About Mars

Mars is the fourth planet from the Sun and Earth's closest outer neighbour. It earned the nickname red planet because the ground is coated with iron-oxide dust, the same rust that stains metal left out in the weather. With the naked eye, in the night sky, it shows up as a steady orange point unlike any surrounding star.

It is a small, cold world: about half Earth's diameter and a little more than a tenth of our mass. The atmosphere, made almost entirely of carbon dioxide, is so thin that surface pressure is less than 1% of Earth's. But Mars holds the largest volcanoes and canyons in the Solar System, evidence of liquid water in the past, and the most advanced rovers humanity has ever sent to another planet.

Physical characteristics

Mars is 6,779 km across, against Earth's 12,742 km. Surface gravity is about 38% of ours: someone who weighs 100 kg on Earth would tip the scale at under 38 kg there. Temperatures swing wildly, from around 20 °C on a summer day at the equator to below minus 120 °C on polar nights.

The landscape holds absolute Solar System records. Olympus Mons is the largest known volcano on any planet: roughly 22 km tall and 600 km wide at the base, nearly three times the height of Everest, with a footprint large enough to cover a country the size of France. Valles Marineris is a canyon system more than 4,000 km long and up to 7 km deep, capable of swallowing the Grand Canyon dozens of times over. At the poles sit caps of water ice mixed with dry ice (frozen carbon dioxide) that grow and shrink with the seasons.

Orbit and motion in the sky

Mars orbits the Sun at about 1.52 astronomical units (roughly 228 million km) and takes 687 Earth days to go around once, almost two of our years. Its day, called a sol, runs about 24 hours and 37 minutes, strikingly close to ours, which makes Mars the most intuitively approachable candidate for human colonisation.

Mars is tilted by about 25.2 degrees, close to Earth's 23.5°, so the planet has well-marked seasons, though longer ones. About every 26 months on average, Earth overtakes Mars in the race around the Sun: this is opposition, when the two are closest and the planet appears brightest and largest through a telescope. Perihelic oppositions, when Mars is near its closest point to the Sun, are the most favourable for observing and happen roughly every 15 years.

How to see Mars in the sky tonight

Mars is easy to find with the naked eye thanks to its unmistakable orange colour, distinct from Jupiter's bright white or Saturn's subdued yellow. Its brightness changes dramatically over the months as its distance from Earth grows and shrinks: near opposition it ranks among the five brightest objects in the sky, but when far away it can be dimmer than moderately bright stars.

• The best times are oppositions, which recur roughly every 26 months. Near them, Mars stays up all night and reaches its largest apparent size for telescope users.
• A small telescope already shows the white polar cap as a bright spot on the disc; larger instruments reveal dark surface markings, regions of bare rock with less dust cover.
• In some oppositions, global dust storms veil the entire disc in a uniform orange haze, hiding any surface detail for weeks.
• Sky apps such as Stellarium or SkySafari show where Mars is tonight and when the next opposition will fall.

Moons: Phobos and Deimos

Mars has two small, irregularly shaped moons, Phobos and Deimos, discovered by astronomer Asaph Hall in 1877. Both look like captured asteroids, heavily cratered and very dark. Phobos, the larger of the two, orbits so close to Mars (just 6,000 km up) that it laps the planet three times per Martian day. Pulled steadily inward by tidal forces, Phobos will either break apart or collide with Mars within 30 to 50 million years.

Deimos orbits much farther out and more slowly, taking about 30 hours per lap, making it drift slowly across the Martian sky. Neither moon is large enough to be spherical: Phobos measures roughly 27 x 22 x 18 km and Deimos about 15 x 12 x 11 km. Japan's MMX (Martian Moons eXploration) mission, launched in 2024, plans to visit Phobos and bring samples back to Earth.

Exploration and active missions

Mars is the most explored planet beyond the Moon. Rovers, orbiters and landers collect data continuously. NASA's Curiosity rover has operated since 2012 inside Gale Crater and confirmed that a freshwater lake existed there billions of years ago. Perseverance, also from NASA, landed in Jezero Crater in 2021 and is collecting rock samples for eventual return to Earth through the Mars Sample Return mission, a NASA-ESA partnership.

Perseverance carried Ingenuity, the first helicopter to fly on another planet, originally planned for five demonstration flights but completing more than 70 before being retired in 2024 after rotor damage. China landed the Zhurong rover on the Utopia Planitia plain in 2021, becoming the second country to operate a rover on Mars. The UAE's Hope orbiter has circled the planet since 2021, studying Mars's atmosphere on a global scale.

Facts and records

• Olympus Mons is the tallest volcano in the Solar System, nearly three times the height of Everest with a base as wide as Spain.
• Mars has water: ice at both poles and possibly salty liquid water hidden beneath the south polar cap, detected by radar from ESA's MARSIS instrument.
• The isotopic composition of SNC meteorites (Shergottites, Nakhlites and Chassignites) matches the Martian atmosphere as measured by the Viking landers, proving those meteorites came from Mars.
• A Martian day (sol) lasts 24h 37m 22s, so similar to ours that NASA engineers work on "Mars time" during the early weeks of a rover mission.
• Global dust storms have blanketed the entire planet for months at a time, as in 2018 when the storm ended the Opportunity rover mission by blocking the sunlight powering its panels.

In mythology, fiction and colonisation plans

For the Romans, Mars was the god of war, and the planet's red colour reinforced the association with blood and conflict. The Greeks called it Ares. In twentieth-century popular culture, Mars became science fiction's favourite destination, from H. G. Wells (The War of the Worlds, 1898) to Ray Bradbury (The Martian Chronicles, 1950), always home to advanced or hostile civilisations. The twentieth-century discovery that Mars is arid and largely barren ended most of those fantasies without reducing the fascination.

Today Mars is the most concrete target for human exploration beyond the Moon. NASA plans crewed missions for the 2040s, and SpaceX has published ambitious colonisation plans aimed at making humanity multiplanetary. The distance between Earth and Mars varies from 54 to 401 million km, and a one-way trip takes between 6 and 9 months with current technology.

Other planets

• ☿ Mercury
• ♀ Venus
• ♃ Jupiter
• ♄ Saturn
• ♅ Uranus
• ♆ Neptune