Page 104 - BBC Sky at Night Beginners Guide to Astronomy - 2017 UK

At 60 tonnes, the Hoba
meteorite in Namibia is the
largest known on Earth

LOOK OUT!

METEORITES

SOME OF Right now, out there in the Solar System, millions showers that we see each year, such as the Perseids
THESE CHUNKS of tiny bits of rock are fl ying around. They all go in August, or the Orionids in October. These
showers are produced by tiny, dust-like particles
unnoticed, until our planet gets in their path. These
OF SPACE particles, which can be as small as a grain of sand, that are too small to reach the ground and are left
ROCK LEAVE travel at such a high speed that they burn and glow around the Solar System by comets.
Most meteorites, the chunks of rock that reach
KILOMETRE- as they shoot through the upper atmosphere. And if Earth’s surface, come from the asteroid belt, the
they’re large enough, they may even make it down
WIDE CRATERS, to the ground. area of the Solar System between the orbits of
In astro-speak, these bits of rock have three
WHILE OTHERS different names depending on where they are. Mars and Jupiter where there are thousands of
large rocky objects. These asteroids occasionally
ALLOW US When they’re in space they’re meteoroids; once hit each other, sending debris fl ying out into space.
TO TOUCH they’re in the atmosphere and we see them racing It may be millions of years later that one chunk
OTHER WORLDS across the night sky they become meteors; and if from such an incident, maybe helped by the vast
gravity of Jupiter, encounters Earth.
any of them reach the ground without burning up,
they are known as meteorites. They are not all made of the same stuff: 94 per
At this point it’s worth mentioning that we do cent are stony, about fi ve per cent are a mix of
not get any meteorites from the famous meteor stone and iron, while just one per cent are pure
104 skyatnightmagazine.com 2012