Why is this crater so big (ground hit by meteorite travelling at high speed; try throwing a stone into soft sand at an angle to see how the hole it leaves is bigger than the object)? What exactly is a meteorite (space debris, usually from asteroids, stone andor iron)? How big are they (many are quite small as they burn up in the atmosphere, but one in Namibia weighs 60 tonnes, the equivalent of several lorries)? Why is the Moon so pockmarked with craters (thinner atmosphere than Earth so more meteorites and comets get through; also volcanic activity)?
What is the asteroid belt (a 100 million-mile wide ring of large space bodies some, like Ceres, hundreds of miles across, orbiting between Mars and Jupiter; possibly a disintegrated or unformed 10th planet)? What are the nine planets of the solar system (four small and dense "inner planets", Mercury, Venus, Earth and Mars; four larger outer "gas giants", Jupiter, Saturn, Uranus and Neptune; the distant Pluto, about which little is known)? What is the effect of the Sun (holds planets in orbit around it by a powerful gravitational pull; supplies energy through constant nuclear reactions in its core)?
If a meteorite did land on Earth, would it be fate (what do you understand by the word fate)? Do you believe in free will, or is everything predetermined and, if so, by whom or what? Is the notion of predestination a hopeless philosophy, nothing you can do, no purpose in life? Do you believe in good and bad luck, or is it just an excuse people put forward for failing to do something ("You make your own luck" is an old saying in sport and business)?
(a) Describe what happens when you are walking along with friends and you suddenly hear a hissing sound, a loud bang, and a meteorite lands a mile away; (b) find out what you can about space debris and write an explanation to someone who does not know what it is; (c) imagine going into a crater formed by a meteorite and say how you feel - is it exciting, scary, surprising or eerie?
Ted Wragg is professor of education at Exeter University
One day a large meteorite may hit Earth. Should we be worrying about it?
A large lump of iron or stone hitting Earth at high speed would be like a bomb, and it could land on a populated area, killing thousands. We need to track every possibility and blow up any that might threaten us. There are trillions of pieces of debris in space so the problem cannot be ignored.
Most meteorites burn up in the Earth's atmosphere, or land in remote areas or the sea, so there is no point fretting about an unlikely event. Scary books and films exaggerate the probability of disaster. With modern tracking methods any real threat could be identified and blown off course by missiles.