Introduction
As early as the 19th century, astronomers believed there was an "invisible planet" in our solar system. According to a mathematical theory called Bode's Law, there should have been a planet between Mars and Jupiter. What these astronomers found instead was an enormous band formed from millions of rocks orbiting the Sun. They called these objects asteroids.
Killer asteroids
Most asteroids drift harmlessly in their around the sun for billions of years. However, occasionally an asteroid may be knocked out of its orbit and sent on a collision course with a planet. If an asteroid collided with Earth, the impact would be powerful enough to annihilate all forms of life. Vast waves of fire, water and dust would engulf the planet instantly. Those who survived this would gradually freeze to death in "nuclear winter" that would follow. This is when billions of tonnes of rubble would be blasted into the atmosphere, blocking out the Sun's light for hundreds of years.
Asteroid belt
There are billions of asteroids in the Solar System, most of which orbit the Sun in a band nearly 550 million km wide-larger than the distance from Earth to the Sun. This band is located between Mars and Jupiter, and is called the asteroid belt. Theories about how this belt developed differ. Some think that it is the remains of planet that was torn apart millions of years ago. Others believe the opposite, claiming that these rocks are a planet that never formed.According to this theory, Jupiter's immense gravity prevented these rocks from joining together.
Asteroid uses
Some scientists are taking interest in asteroid because of their potential value to Earth in the future. Many asteroids are thought to contain useful minerals and metals. In a few decades, expeditions may be launched to mine asteroids in space. The giant rocks could even be brought back to Earth to be harvested. Until then, the Near Earth Asteroid Rendezvous (NEAR) space probe is surveying nearby asteroids so that we can learn more about them.
Some important facts
1) Bode's law states that there is a mathematical pattern in the way the planets are spaced from the Sun. In the 18th century, two astronomers noticed this pattern. They started with 0 and began doubling : 0, 3, 6, 12, 24, 48, 96, 384, 768. Then they added four to each number and divided by ten. The numbers they discovered were similar to planetary distance from the Sun in astronomical units. According to this theory, there should be a planet between Mars and Jupiter.
2) If the asteroids could overcome the gravitational battle between the Sun and Jupiter they might form a planet about the same size of our moon.
3) Most asteroids are believed to be smaller than 25km in diameter. However, millions of these pieces of debris are orbiting the Sun in asteroid belt.
4) Astronomers think that in the early years of the Solar System there were fewer than 1,000 asteroids in the belt. These were all larger than Ceres, but continuous collisions broke them into smaller pieces.
5) Astronomers have found that even asteroids can have satellites. Ida is orbited by a tiny asteroid moon called Dactyl.
As early as the 19th century, astronomers believed there was an "invisible planet" in our solar system. According to a mathematical theory called Bode's Law, there should have been a planet between Mars and Jupiter. What these astronomers found instead was an enormous band formed from millions of rocks orbiting the Sun. They called these objects asteroids.
Killer asteroids
Most asteroids drift harmlessly in their around the sun for billions of years. However, occasionally an asteroid may be knocked out of its orbit and sent on a collision course with a planet. If an asteroid collided with Earth, the impact would be powerful enough to annihilate all forms of life. Vast waves of fire, water and dust would engulf the planet instantly. Those who survived this would gradually freeze to death in "nuclear winter" that would follow. This is when billions of tonnes of rubble would be blasted into the atmosphere, blocking out the Sun's light for hundreds of years.
Asteroid belt
There are billions of asteroids in the Solar System, most of which orbit the Sun in a band nearly 550 million km wide-larger than the distance from Earth to the Sun. This band is located between Mars and Jupiter, and is called the asteroid belt. Theories about how this belt developed differ. Some think that it is the remains of planet that was torn apart millions of years ago. Others believe the opposite, claiming that these rocks are a planet that never formed.According to this theory, Jupiter's immense gravity prevented these rocks from joining together.
Asteroid uses
Some scientists are taking interest in asteroid because of their potential value to Earth in the future. Many asteroids are thought to contain useful minerals and metals. In a few decades, expeditions may be launched to mine asteroids in space. The giant rocks could even be brought back to Earth to be harvested. Until then, the Near Earth Asteroid Rendezvous (NEAR) space probe is surveying nearby asteroids so that we can learn more about them.
Some important facts
1) Bode's law states that there is a mathematical pattern in the way the planets are spaced from the Sun. In the 18th century, two astronomers noticed this pattern. They started with 0 and began doubling : 0, 3, 6, 12, 24, 48, 96, 384, 768. Then they added four to each number and divided by ten. The numbers they discovered were similar to planetary distance from the Sun in astronomical units. According to this theory, there should be a planet between Mars and Jupiter.
2) If the asteroids could overcome the gravitational battle between the Sun and Jupiter they might form a planet about the same size of our moon.
3) Most asteroids are believed to be smaller than 25km in diameter. However, millions of these pieces of debris are orbiting the Sun in asteroid belt.
4) Astronomers think that in the early years of the Solar System there were fewer than 1,000 asteroids in the belt. These were all larger than Ceres, but continuous collisions broke them into smaller pieces.
5) Astronomers have found that even asteroids can have satellites. Ida is orbited by a tiny asteroid moon called Dactyl.
0 comments:
Speak up your mind
Tell us what you're thinking... !