Arguably the most famous comet is Halley's Comet, which is due to return to our skies in July 2061.Ĭomet 67P/C-G, known as the “rubber duck” taken by Rosetta’s NavCam. This causes the solid ice to turn into gas, which is swept into the distinctive comet tail. When their orbit brings them close to the Sun, they heat up.

These icy bodies of frozen gases, rocks and dust orbit the Sun on highly elliptical paths, often tumbling as they go. CometĬomets are the snowballs of the cosmos. After that, the spacecraft will head out again, this time to study the near-Earth asteroid Apophis, under a new mission name OSIRIS-APEX. It's most likely a piece of a much larger carbon-rich asteroid, breaking off around 700 million to 2 billion years ago and making a close approach to Earth every six years.īut astronomers must be patient for a little while longer as the spacecraft is still on its way back home, due to swing by on 24 September 2023 to deliver the precious cargo. It was an impressive achievement, and one which smashed the original target of 60g.īennu is estimated to be around 4.5 billion years old, forming just after the formation of our Solar System. Not ideal viewing conditions.Īsteroid Bennu (shown in the above video by NASA's Scientific Visualization Studio) made the news in 2020 when NASA’s OSIRIS-REx mission successfully landed on the asteroid's surface and collected over 400g worth of samples. There are two trojan asteroids for Earth, however, both are difficult to see as they are leading the Earth in our orbit around the Sun, and therefore appear on the horizon, close to the Sun at sunrise. When an asteroid shares its orbit with a planet, it's known as a Trojan asteroid. Asteroids are rocky remnants left over from the early formation of the Solar System. There are over a million known asteroids, and most can be found in the main asteroid belt between Mars and Jupiter. Most asteroids are irregularly shaped, although there are a few that are nearly spherical. Meteorite: Meteoroids that survive the journey through the Earth's atmosphere and fall to the surfaceĭwarf planet: A small spherical (or near-spherical) celestial body in orbit around the Sun, that lacks sufficient mass to clear its neighbourhood of debris AsteroidĪsteroids are small, rocky objects that orbit the Sun. Meteor shower: Multiple meteoroids burning up in the Earth's atmosphereįireball: An exceptionally bright meteor that can be seen over a wide area Meteoroid: Fragments and debris from asteroids and comets What's that space rock? Asteroids: Small, rocky objects, often irregularly shaped, leftover from the formation of the Solar SystemĬomets: Large, icy bodies of frozen gases, dust and rock, with a frozen nucleus

Meteorite rock types