50 Facts About The Asteroid Belt

A giant doughnut of rock and rubble, the Asteroid Belt moves around the Sun silently between the orbits of Mars and Jupiter. Why the Asteroid Belt never formed into a planet is a secret these shadowed rocks may never give up. But that doesn’t mean we can’t learn lots about them. Read on to learn 50 facts about the Asteroid Belt.

Fact 1: The Asteroid Belt isn’t flat. It’s Taurus shaped which is the same as a doughnut.

Fact 2: The Asteroid Belt is located between the orbit of the planet Jupiter and Mars.

Fact 3: Other names for The Asteroid Belt include the “Main Asteroid Belt” and the “Main belt”.

Fact 4: The Asteroid Belt actually orbits closer to Mars than it does to Jupiter.

Fact 5: Of the total distance between Mars’ orbit and Jupiter’s orbit, the asteroid belt is about 1/3 of that total distance from Mars and 2/3 of the distance from Jupiter.

Fact 6: The Asteroid Belt’s total mass is actually comparatively tiny when compared to the planets and the moon that is in the solar system. The belts mass is only 4% of the Moon’s total mass.

Fact 7: The total mass of the asteroid field is only 1/4 the mass of the dwarf planet Pluto.

Fact 8: The largest asteroid in The Asteroid Belt is called Ceres.

Fact 9: Ceres, the largest asteroid in the belt, is about 950 km in diameter. That’s about the same size as France.

Fact 10: Ceres is a dwarf planet just like Pluto.


Fact 11: The Asteroid Belt lost 99.9% of its mass in the first 100 million years of its existence because of gravitational interactions with Jupiter.

Fact 12: Half of the Asteroid Belt’s mass is made up from the four biggest asteroids: Ceres, Vesta, Pallas, and Hygiea.

Fact 13: Asteroid Belts in films are portrayed as packed and chaotic places where space ships have to dodge and weave to avoid collisions with primordial rock and rubble. The real Asteroid Belt is nothing like this. Most asteroids are millions of kilometres apart and very rarely interact with each other.

Fact 14: The smallest particle size in the Asteroid Belt is dust.

Fact 15: The first space probe to pass through The Asteroid Belt was NASA’s Pioneer 10 probe.

Fact 16: At the time of Pioneer 10’s passage through The Asteroid Belt, NASA engineers had no idea how populated the belt was and feared the probe may smash into an asteroid.

Fact 17: 12 space probes have passed through the Asteroid Belt without any problems.

Fact 18: The Asteroid Belt has such a low density of material that it’s estimated that the odds of a space probe crashing into an asteroid while traveling through the belt is about 1 in 1 billion.

Fact 19: NASA’s Dawn probe visited both Vesta and Ceres.

Fact 20: Water vapor has been detected on Ceres.

Fact 21: Vesta, the second largest asteroid in The Asteroid Belt, is 1145.2 km in diameter at its widest point.

Fact 22: Vesta is actually classified as a minor planet.

Fact 23: Vesta contributes about 9% of the total mass of The Asteroid Belt.

Fact 24: Pallas, the third largest object in the Asteroid Belt, has a diameter of 1100 km at its widest point.

Fact 25: Pallas is thought to make up just over 7% of the total mass of the Asteroid Belt.

Fact 26: Hygiea, is the fourth largest body in the Asteroid Belt with a maximum diameter of 900 km.

Fact 27: Hygiea is classed as a minor planet like Vesta and Pallas.

Fact 28: Hygiea may be reclassified as a dwarf planet because of its spherical shape.

Fact 29: Johannes Kepler, a German astronomer and mathematician, predicted that a planet should exist between the orbits of Mars and Jupiter.

Fact 30: Ceres, the largest object in the Asteroid Belt, was discovered by Italian astronomer Giuseppe Piazzi on January 1st, 1801.

Fact 31: Ceres is named after the patron saint of Sicily and the Roman goddess of the harvest.

Fact 32: The word asteroid means “star-like” and was first thought up by William Herschel in 1802.

Fact 33: The Astroid belt sits at a distance between 329,100,000 km and 493,700,000 km away from the Sun. That’s between 2 and 3 times the distance Earth is from the Sun.

Fact 34: The asteroid field is about 150,000,000 km deep from the closest asteroid from the Sun to the furthest.

Fact 35: The asteroids in the Asteroid Belt take between 3 to 6 years to complete a single orbit.

Fact 36: The Asteroid Belt is thought to contain billions of objects ranging in size from 1000 km to a metre in diameter.

Fact 37: We currently know of over 200 asteroids with diameters over 100 km in the Asteroid Belt.

Fact 38: There are as many as 1.7 million asteroids, with a diameter of 1 km or more, in the belt.

Fact 39: The four largest asteroid’s in the Asteroid Belt make up 40% of the belt’s total mass.

Fact 40: There are three types of asteroid in the Asteroid Belt. They are:

  • Metalic Iron-rich, M-Type, Asteroids
  • Carbonaceous, C-Type, Asteroids
  • Silicate, S-Type, Asteroids

Fact 41: Every 10 million years or so, there’ll be a mammoth collision between two asteroids that are over 10 km in diameter in the Asteroid Belt.

Fact 42: The Asteroid Belt formed 4.5 billion years ago.

Fact 43: It only took 10 million years for the Belt to take shape after the solar system was created.

Fact 44: The Asteroid Belt used to contain a huge amount more mass. Its total mass was once thought to be about the same as the planet Earth. Now it’s thousands of times less.

Fact 45: The average distance between any two asteroids in The Belt is 1,000,000 km. That’s about 2.5 times the distance between Earth and the Moon.

Fact 46: About 99.999% of the asteroid’s in The Belt are the size of a Child’s fist or smaller.

Fact 47: Many companies and businesses have explored the possibility of mining asteroids in The Belt. Many asteroids are packed full of minerals and metals that are rare on Earth.

Fact 48: Many of the asteroids have very eccentric orbits and move far outside the orbital plane of the planets.

Fact 49: Many of the asteroids are in an orbital resonance with Jupiter.

Fact 50: The Asteroid belt never formed into a planet because of Jupiter’s gravitational influence.


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