In 1801, Giuseppe Piazzi was discovered a new planet. He called the new object Ceres, in honor of the Roman goddess of the harvest. Similar objects were found shortly after the discovery of Ceres. He soon realized that these new objects were not, in fact, planets, but some other type of celestial body.
A characteristic that these objects shared was their resemblance to distant stars seen through the telescopes of the time. As a result of their star-like appearance, the objects were called asteroids, which means “star-shaped.
Most known asteroids in the Solar System orbit around the Sun in a band between the orbits of Mars and Jupiter. This band is commonly known as the asteroid belt.
Although there are hundreds of thousands of asteroids in the Asteroid Belt, only about 200 are known that exceed 100 km in diameter, which makes most asteroids really small objects.
Current theories suggest that the asteroids found in the asteroid belt are the remains of a planet that was not formed during the development of the Solar System.
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 more than 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. In addition to being the first asteroid discovered, Ceres is also the largest known asteroid with 933 kilometers (580 miles) in diameter.
The smallest known asteroid, 1991 BA, is only 6 meters (20 feet) wide.
Current theory suggests that asteroids are planetesimals, the basic components of planets, that were never incorporated into one of the eight planets in our solar system.
Apollo objects are asteroids whose orbit crosses Earth’s orbit. An item of an asteroid about 65 million years ago caused a chain reaction that led to the extinction of dinosaurs and affected all life on Earth, according to scientists. It is believed that an asteroid of approximately .15 kilometers wide exploded over Siberia. It causing damage within a radius of hundreds of kilometers.
Another facts, Most asteroids are irregular in shape because they are too small to exert enough gravitational force to have a spherical shape. Some asteroids are flying kites. When the ice leaves, all that is left is the rocky material.
A meteoroid (asteroid piece) the size of a car falls into the Earth’s atmosphere on average once a year. This creates a bright fireball effect but generally burns in the atmosphere before reaching the ground.
Asteroids Impact Near-Earth
Earth and the other planets formed as objects in the primitive system struck and formed larger worlds. The collision and impact process continues to this day, although with smaller objects (since all the larger ones became the planets we know).
The asteroids continue to approach Earth in their orbits. They are called near-Earth objects (NEO) or potentially dangerous asteroids (PHAs). If the orbital conditions are correct, it is possible that a NEO will crash against the Earth’s surface.
Depending on the size of the impactor, the damage to our planet (and us) could vary from very little to catastrophic. It is likely that a small incoming object will break in our atmosphere. A larger one could rain very large pieces on the surface or in the oceans.
There are groups of astronomers who search and map the positions of these NEOs to predict possible impacts weeks, months or years in advance. Several organizations are making plans in case something hits and causes damage. The chances of something hitting the Earth are very small. They also depend on the size and orbit of the object.
The best-known asteroids are 1 Ceres, which is 952 kilometers in diameter, 2 Pallas (with a diameter of 544 kilometers) and 4 Vesta (approximately 580 km in diameter). These are minor rocky planets, and astronomers have observed them since the 19th century.
Ceres is a differentiated asteroid. That means it has a rocky core and an icy outer crust. It can have an inner ocean. Pallas has a very irregular shape and maybe what remains of an early protoplanet. Vesta is very bright and is probably the remnant of a rocky protoplanet.