Simplified P2 - Exploring our solar system Flashcards
What kind of orbit do comets have?
Comets have very elliptical orbits.
- They pass inside the orbit of mercury and and go out well beyond the orbit of Pluto.
What is a Meteor made from?
A meteor is made from grains of dust that burn up as they pass through the Earth’s atmosphere
How do meteor’s get their streak?
They heat the air around them which glows and the streak is known as a shooting star.
Where are black holes formed?
Black holes are formed where stars used to be.
Why an you not see a black hole?
You cannot see a black hole because light cannot escape from it.
They also have a very large mass but a very small size.
Why do moons orbit planets, and planets orbit stars?
Moons orbit planets, and planets orbit stars because centripetal force acts on them.
- Centripetal force acts towards the centre of the circular orbit.
What is the source of the centripetal force?
Gravitational attraction is the source of the centripetal force.
In what conditions would you send an unmanned probe?
You would send an unmanned probe to conditions too dangerous for humans.
What is an issue with Spacecraft carrying humans?
They would have to travel with large amounts of food, water and oxygen aboard.
How are space-suits designed to protect humans?
- Dark visor stops the astronaut being blinded.
- Suit is pressurised and has oxygen supply for breathing
- Surface of the suit facing the sun can reach 120c
- Surface of the suit facing away from the sun can reach -160c
What is an issue with unmanned space-craft?
If they break down, in most cases there is no way of repairing them, therefore they would have to be very reliable.
What are the advantages of unmanned spacecraft?
Unmanned spacecraft cost less and do not put astronaut lives at risk.
What speed does light travel at?
300,000 km/s
How long does light take to reach the Earth from the sun?
Light from the sun takes about eight minutes to reach us on Earth.
How long does light take to reach Earth from the next nearest star ( Proxima Centauri )?
It takes 4.22 years.
