Реферат: Solar System Essay Research Paper The Sun

by about 40%.

The Sun is about 4.5 billion years old. Since its birth it has used up about half of

the hydrogen in its core. It will continue to radiate “peacefully” for another 5 billion

years or so (although its luminosity will approximately double in that time). But

eventually it will run out of hydrogen fuel. It will then be forced into radical changes

which, though commonplace by stellar standards, will result in the total destruction

of the Earth (and probably the creation of a planetary nebula).

The Sun’s satellites

There are nine planets and a large number of smaller objects orbiting the Sun. (Exactly which

bodies should be classified as planets and which as “smaller objects” has been the source of some

controversy, but in the end it is really only a matter of definition.)

Distance Radius Mass

Planet (000 km) (km) (kg) Discoverer Date

——— ——— —— ——- ———- —–

Mercury 57,910 2439 3.30e23

Venus 108,200 6052 4.87e24

Earth 149,600 6378 5.98e24

Mars 227,940 3397 6.42e23

Jupiter 778,330 71492 1.90e27

Saturn 1,426,940 60268 5.69e26

Uranus 2,870,990 25559 8.69e25 Herschel 1781

Neptune 4,497,070 24764 1.02e26 Galle 1846

Pluto 5,913,520 1160 1.31e22 Tombaugh 1930