How Long Does It Take to Get to Each Planet? Distances and Real Mission Times

Solar System · Distances · Updated 2026-07-22

Real spacecraft have reached Mars in about 7 months, Jupiter in roughly 5 years, Saturn in 4 years, Uranus in 8.5 years, Neptune in 12 years and Pluto in 9.5 years. Mercury is the odd one out: Mariner 10 flew past it just 147 days after launch, because falling inward toward the Sun is easy and stopping there is not.

There is no single travel time to a planet, because the distance changes constantly as both worlds orbit the Sun and because no spacecraft flies in a straight line. The table below gives the three numbers people actually mean: how close the planet ever gets, how far it ever gets, and how long a real NASA or ESA mission took to arrive.

Distance and travel time to every planet

Two things in that table surprise people. Venus, not Mars, is Earth's closest neighbour at closest approach - 38.2 million km against Mars's 54.6 million. And Voyager 2 reached Saturn faster than Cassini did, even though Cassini launched twenty years later with better rockets. Cassini had to arrive slowly enough to be captured into orbit. Voyager 2 just flew past.

Why there is no single travel time

• Where the planets are. Mars swings between 54.6 and 401.4 million km from Earth. The same trajectory launched at the wrong moment does not arrive at all.
• Flyby or orbit. A flyby only needs to arrive. An orbiter has to shed speed on arrival, which usually means a slower approach and a longer cruise. Juno's insertion burn slowed it by 542 m/s.
• Gravity assists. Spacecraft borrow energy from planets they pass. Juno flew back past Earth in October 2013 for a boost of more than 3.9 km/s. Galileo used one Venus and two Earth flybys, which is why it took over six years.
• Trajectory type. A fuel-efficient transfer orbit is a long curved arc around the Sun. A fast direct shot burns far more propellant and limits how much science hardware you can carry.

Worked example: why the straight-line number is wrong

Take the Mars Reconnaissance Orbiter. It launched 12 August 2005 and reached Mars 10 March 2006, a cruise of 210 days. Divide Mars's closest approach distance, 54.6 million km, by 210 days and you get an average speed of about 10,800 km/h - slower than some sounding rockets. The number is nonsense, because MRO never flew 54.6 million km. It flew roughly half an ellipse around the Sun while Mars kept moving, covering several hundred million km of arc.

The same trap catches airliner comparisons, which are still worth doing for scale. At a cruising 900 km/h, straight-line and non-stop, Mars at closest approach is about 6.9 years away, Saturn about 152 years, and Neptune about 546 years. Those are lower bounds on a journey no aircraft could make.

Jupiter, four ways

The solar system, one fact a day. StarQuest's Solar System and Space Tech categories cover exactly this territory - rockets, rovers, and the missions that actually made these trips. Tap the heart on the ones worth keeping and they land in Favorites, and a fresh fact appears on your Home Screen, Lock Screen and Apple Watch every day. No ads, no account. Download StarQuest: Daily Cosmos Facts on the App Store.

Launch windows: the reason missions wait

Earth laps Mars roughly every 26 months, so an efficient Mars launch window opens about every two years and stays open for a few weeks. Miss it and the next attempt is two years later, which is why Mars missions cluster: 2005 for MRO, 2013 for MAVEN, 2020 for Perseverance. Outer-planet windows are rarer still. Voyager 2's route past Saturn, Uranus and Neptune relied on an alignment of the outer planets that recurs roughly every 175 years, which is the single reason Uranus and Neptune have each been visited exactly once.

Keeping the numbers straight

Distances and durations like these are easier to remember when they arrive one at a time instead of as a wall of figures. StarQuest is built that way: a single daily fact, curated into collections and ten categories including Solar System and Space Tech, with Favorites for the ones you want to keep and widgets so the next one is waiting the next time you glance at your phone. If this table interested you, the planet size comparison and moon counts are the natural next stops.

Frequently asked questions

How long would it take to travel to Mars?

Real robotic missions have taken roughly 7 to 10 months. The Mars Reconnaissance Orbiter cruised 210 days in 2005 to 2006; MAVEN took about 10 months in 2013 to 2014. Crewed mission studies generally assume 6 to 9 months each way, plus a wait at Mars for the return window.

How long would it take to fly to Saturn?

Voyager 2 reached Saturn 4 years after launch, in August 1981. Cassini took 6 years 8 months because it had to slow down enough to enter orbit rather than fly past. At airliner speed in a straight line, Saturn at closest approach would take about 152 years.

Which planet is closest to Earth?

Venus, at closest approach: 38.2 million km, against Mars's 54.6 million. Averaged over long periods, though, Mercury spends more time near Earth than any other planet, because its tight orbit keeps it from ever wandering far.

How long does it take to get to Pluto?

New Horizons took 9 years and 6 months, launching in January 2006 and reaching closest approach on 14 July 2015. It was the fastest spacecraft ever launched from Earth and still needed a Jupiter gravity assist, which cut about three years off the trip.

Keep reading

• Planet Size Comparison: Every Planet From Smallest to Largest
• How Many Moons Does Each Planet Have? Current Confirmed Counts
• Hottest and Coldest Planets in the Solar System (Full Temperature Chart)