Our solar system has over a million asteroids. These are rocky lumps that orbit the sun. They’re too small to be planets, but are sometimes called ‘minor planets’.
Most asteroids are in a region – the asteroid belt – between the orbits of Mars and Jupiter, but some are in other parts of the solar system.
| Asteroids factfile | Ryugu | Vesta |
|---|---|---|
| Position from the sun | near Earth orbit | in the asteroid belt |
| Diameter | 865 metres | 530 kilometres |
| Distance from sun | 178,500,000 km | 354,000,000 km |
| Day length | 7.6 hours | 5.3 hours |
| Year length | 474 days | 3.63 years |
| Type of asteroid | C-type | V-type/minor planet |
| Surface temperature | -50 °C to 60 °C | -188 °C to -18 °C |
| Gravity | Approx. 0.00013 m/s2 | 0.25 m/s2 |
| Atmosphere | none | none |
Asteroids may seem a bit small and boring compared with colourful and active planets and moons. However, asteroids are rich in a lot of useful minerals (including silver, gold and platinum!) In future, we might send mining missions to them, especially those close to Earth’s orbit like Ryugu.
Image credit: JAXA, University of Tokyo & collaborators
This asteroid, Ryugu, was visited by the Japanese Hayabashu 2 Mission in 2019. The probe then returned to Earth with samples taken from the asteroid.
The capsule containing the samples was dropped to Earth as the space probe flew past in December 2020. In the picture, you can see the sample capsule where it landed in the South Australian desert.
Picture Credit: JAXA
The Project Team is fascinated by the appearance of Ryugu and morale is rising at the prospect of this challenge. Together with all of you, we have become the first eyewitnesses to see asteroid Ryugu. I feel this amazing honor as we proceed with the mission operations.
Hyabusu2 Project Manager, Yuichi Tsuda, 25th june 2018
Activity
Vesta is an amazing asteroid. If it had been further away from Jupiter, it might have grown into another planet!
Do some research to find out all about the amazing history, geography, geology and exploration of Vesta. When you search online for ‘vesta asteroid’, make sure you take information from several different sources, to help you check how accurate each fact is.
Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Make a poster to communicate all your findings about Vesta. Include at least one image of the asteroid, which could be a sketch that you draw, or you might print pictures from the Internet. Then add blocks of text that explain the different things you found out about Vesta.
You can go to the previous secret pages by clicking the planets below.
