Putting the planets where they are tonight…

Every planet, moon, dwarf planet and spacecraft here is drawn where it really is right now, worked out from NASA JPL orbit data. Run time forwards or backwards with the bar at the bottom.

The Sun and planets

  • Sun
  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune

Dwarf planets

  • Ceres
  • Pluto
  • Haumea
  • Makemake
  • Eris

Moons

  • Moon
  • Phobos
  • Deimos
  • Io
  • Europa
  • Ganymede
  • Callisto
  • Mimas
  • Enceladus
  • Tethys
  • Dione
  • Rhea
  • Titan
  • Iapetus
  • Miranda
  • Ariel
  • Umbriel
  • Titania
  • Oberon
  • Triton
  • Charon

Belts

  • Asteroid Belt
  • Kuiper Belt

Spacecraft

  • Voyager 1
  • Voyager 2
  • New Horizons
  • Pioneer 10
  • Pioneer 11

Fall inside

  • Inside the Sun
  • Inside Mercury
  • Inside Venus
  • Inside Earth
  • Inside Mars
  • Inside Jupiter
  • Inside Saturn
  • Inside Uranus
  • Inside Neptune
  • Inside the Moon
  • Inside Europa
  • Inside Titan
Right now · live
A moon of Mars ↑

Phobos

A lumpy little moon, slowly spiralling down into Mars.

Phobos is a lumpy rock only about 27 km long. It looks more like a potato than a moon.

It orbits just 6,000 km above Mars, closer to its planet than any other moon, and goes round three times a day. From Mars it rises in the west and sets in the east.

Phobos is slowly spiralling in, a couple of metres closer every century. In tens of millions of years it will either crash into Mars or be torn into a ring.

Its name means fear, after one of the sons of the Greek war god. A Japanese mission called MMX plans to bring a piece of it back to Earth.

If you stood here

Mars would fill a quarter of your sky. You'd weigh less than an egg, so walk gently.

The numbers

Width
22 km
Goes round Mars
every 7.7 hours
One day
The same: it always shows Mars one face
Temperature
−112 °C to −4 °C
70 kg on Earth weighs
41 grams here
Quick answers+

How big is Phobos?

Phobos is 22 km wide, less than 1% of Earth's width.

How long does Phobos take to go round Mars?

Phobos goes once round Mars every 7.7 hours. It spins once in the same time, so it always shows Mars the same face.

How hot or cold is Phobos?

−112 °C to −4 °C.

What is the gravity like on Phobos?

Gravity is 0.0057 m/s², less than 1% of Earth's. Someone who weighs 70 kg on Earth would weigh 41 grams there.