Discovery of asteroids
In 1801, Giuseppe Piazzi discovered what he believed to be a new planet. He named the newfound object Ceres, after the Roman goddess of the harvest. Soon after Ceres’ discovery similar objects were found. It was soon realized that these new objects were not, in fact, planets, but some other type of celestial body. One characteristic these objects shared was their resemblance to distant stars as viewed through the telescopes of the time. As a result of their similar appearance to stars the objects were named asteroids, meaning “star shaped.”
Although there are hundreds of thousands of asteroids in the Asteroid Belt, there are only around 200 known that exceed 100 km in diameter, making the majority of the asteroids realtively small objects.
Current theories suggests that the asteroids found in the Asoteroid Belt are the remnants of a planet that failed to form during the development of the Solar System. More specifically, it is believed that when Jupiter formed its huge mass and gravitational pull disrupted the material in the Asteroid Belt to accrete, or join together, to form into a planet. If all the material in the Asteroid Belt were to be combined, the resulting object’s diameter is projected to be at most about half that of Earth’s moon.
Facts about asteroids
- Asteroids are small, rocky objects that orbit the Sun.
- The first asteroid was Ceres, discovered by Giuseppe Piazzi in 1801.
- There are currently over 600,000 known asteroids in our solar system.
- Most asteroids are found orbiting in the Asteroid Belt, a series of rings located between the orbits of Mars and Jupiter.
- Astronomer William Herschel first coined the word asteroid, which means “star like” in 1802.
- As well as being the first asteroid discovered, Ceres is also the largest known asteroid at 933 kilometers (580 miles) across. The smallest known asteroid, 1991 BA, is only 6 meters (20 feet) across.
- Current theory suggest that asteroids are planetisimals – the building blocks of planets – that were never incorporated into one of the eight planets in our solar system.
- Apollo objects are asteroids whose orbit crosses the orbit of Earth.
- An asteroid impact around 65 million years ago caused a chain reaction that led to the extinction of the dinosaurs and affected all life on Earth, according to scientists.
- An asteroid about .15 kilometers (.1 miles) in width is believed to have exploded over Siberia, causing damage within a radius of hundreds of kilometers (miles).
- Most asteroids are irregular in shape because they are too small to exert enough gravitational pull to become spherical in shape.
- Some asteroids are blown out comets. When the ice is gone, all that remains is the rocky material.
- A meteoroid (piece of asteroid) the size of a car falls into the Earth’s atmosphere on average once every year. This creates a bright fireball effect, but it usually burns up in the atmosphere before it reaches the ground.