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12 Cards in this Set
- Front
- Back
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Our solar system Comets have very elliptical orbits. What is meant by an elliptical orbit? |
A path that follows an ellipse; a flattened circle shape. - they pass inside the orbit of mercury and outside passed the orbit of Pluto |
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What is a meteor and what is it made up of? |
A meteor is bright flashes in the sky caused by rocks burning in earths atmosphere. It is made out of grains of dust that burn through earths atmosphere |
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How does a meteor burn up through earths atmosphere? π |
They heat the air around them which glows up which forms a streak known as a shooting starπ |
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Where are black holes formed?π |
Where large stars used to be.β |
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Name 2 properties of a black hole. |
- you cannot see it as light can not escape from it - it is very small but has a large mass |
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1. Moons orbit _____ and planets orbit ____ because ________ ______ acts on them. 2. What is centripetal force? |
Planets Stars Centripetal force 2. Force acting on a body, travelling in a circle, which acts towards the centre of the circle and keeps the body moving in a circle |
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Centripetal force acts towards the centre of the circular orbit |
Gravitational attraction is the source of the centripetal force u |
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Exploring planets Why do we use unmanned probes? |
Because they can travel anywhere that is deadly to humans |
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Spacesuits Dark visor- stops astronaut being blinded Suit- pressurised and has oxygen supply |
Surface of suit facing towards sun can reach up to 120 C π Surface of suit facing away from sun can reach as cold as -160 C π |
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What are the advantages of unmanned probes? |
- cost less - do not put humans at risk They have to be very reliable as there is no help if they break down |
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A long way to go π Light travels at 300 000 km/s 1. How long does it take light from the sun to reach us? America - manned mission in 2020 to cost Β£400 billπ· |
1. 8 minutes Light from the next star takes 4.22years (proxima centauri) |
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What is a light year? ππππ |
The distance light travels in a year |
