SPACE
SPACEFILES - The Universe Unveiled
Inner Solar System Files 1 to 7 | Outer Solar System Files 8 to 13
Earth-Space Files 14 to 9 | Cosmos Files 20 to 26
8. Asteroid
Asteroids, Meteors and Impacts
Between the orbits of Mars and Jupiter is the asteroid belt, a swarm of rocky bodies. Every so often, perturbed perhaps by the gravitational tug of Jupiter, asteroids collide and tumble towards the Sun. If they pass Mars, they can threaten Earth. 65 million years ago an asteroid impact most probably killed the dinosaurs. That threat from space continues. How do we protect our planet? To get to know our enemy, robot spacecraft visit asteroids.
9. King Planet
Jupiter
Jupiter, bigger than all the other planets combined, could swallow Earth 1,323 times. Yet this giant ball of gas has no solid surface. Comprising 90 per cent hydrogen and ten per cent helium and orbited by more than 60 moons, Jupiter is a mini solar system. Four of them are big enough to make small planets. The moon Europa has an icy crust that may conceal an ocean. Primitive life may lurk there - evolved, as in seas on Earth, around hydro-thermal vents.
10. Lord Of The Rings
Saturn
Saturn, second largest of the giant gas planets, rules a dazzling domain. Forming a halo that would stretch from Earth to the Moon, the rings of Saturn are billions of moonlets - from grains of dust to rocks the size of tanks. The planet is so light it would float in water. Titan, Saturn’s greatest moon, is bigger than the planet Mercury. Shrouded in cloud, Titan resembles early Earth in deep-freeze. To check out the probability of land and seas, a spaceprobe landed on Titan.
11. Uranus & Neptune
Outer Gas Giants
In the cold, dark outer reaches, orbit the giant gas planets of Uranus and Neptune. Uranus is twice as far from the Sun as Saturn. Neptune is so distant it takes 165 years to orbit the Sun. Uranus rotates on its side - possibly knocked over in a collision that may also have shattered and re-assembled the craggy moon Miranda. Neptune is a very windy planet. Its only large moon, Triton, is the coldest place in the Solar System. Dusty gas plumes spurt like oil wells.
12. Pluto
Farthest Planet from the Sun
Farthest planet from the Sun, Pluto is so remote and small, it was not found until 1930. The discovery was made by a 24-year-old farmer’s son, Clyde Tombaugh. At the Lowell Observatory, in Flagstaff, Arizona, USA, Tombaugh photographed 45-million objects in the cosmos before spotting Pluto. And it was not until 1978 that Pluto’s huge moon Charon was discovered by Jim Christie. It was named after his wife. “Most men promise their wives the moon”, she says. “Jim delivered”.
13. Comet
Kuiper, Oort and Comets
The nomads of the Solar System, comets swing through the planets on wild eccentric orbits. Comets plunge into the Sun, some just graze it. Others, like Halley’s Comet every 76 years, make regular periodic appearance in our skies. Comets are from the Kuiper Belt and the Oort Cloud, a vast halo of debris that stretches a third of the way to the nearest star. These exotic visitors, with tails always pointing away from the Sun, are fascinating remnants of the early Solar System.