Space And The Solar System

Question 1

What are dwarf planets?

Answer 1

Planet like objects that aren’t big enough to be called planets

Question 2

What are moons?

Answer 2

Moons orbit planets in an almost circular orbit

Question 3

What are artificial satellites?

Answer 3

Human built satellites that orbit the earth in fairly circular orbits.

Question 4

What are asteroids?

Answer 4

Lumps of rock and metal that orbit the sun - they are usually find in the asteroid belt

Question 5

What are comets?

Answer 5

Lumps of ice and dust that orbit the sun - they have highly elliptical orbits

Question 6

What are meteors?

Answer 6

Particles broken off from a comet or asteroid that orbit the sun. It burns up as it enters the earth’s atmosphere, creating the effect of a shooting star

Question 7

What is a planet?

Answer 7

Large objects that orbit our sun

Mercury, Venus, Earth, mars, Jupiter, Saturn, Uranus, Neptune,

Question 8

What force causes the planets to move around the sun in almost circular orbits and to be constantly accelerating?

Answer 8

The Centripetal force which acts towards the centre of the circle.
This force would cause the object to fall towards whatever it is orbiting, but as it is already moving it just cause it to change direction.

Question 9

What causes the object orbiting to travel in a circle?

Answer 9

The instantaneous velocity (right angle to the acceleration)
The force that allows this to happen is provided by the gravitational force (gravity) between the planet and the sun or plant and the satellite

Question 10

What does gravitational field strength depend on?

Answer 10

The greater the mass and the smaller readies to surface area, the stronger the gravitational field strength
It also varies with distance as the closer you get to a star or planet the stronger the g force.

Question 11

How do orbits remain stable?

Answer 11

The stronger the force, the larger the instantaneous velocity needed to balance it. So the closer you get to a star or planet,the faster you need to go to remain in orbit.
Faster moving objects will move in a stable orbit with a smaller radius that slower moving ones(what happens to one happens to the other)

Question 12

What did Ptolemy think about the solar system?

Answer 12

A Greek astronomer who thought the solar system was geocentric. This suggested that everything orbited earth in perfect circles. The idea arose as people didn’t have telescopes but saw the sun and moon travel across the sky in the same way daily

Question 13

What did Corpenicus think about the solar system?

Answer 13

A polish astronomer who thought the solar system was heliocentric - planets orbiter the sun in perfect circles

Question 14

What was Galileo able to prove?

Answer 14

That the geocentric model was incorrect. Whilst looking at Jupiter through a telescope he realised moon orbited it - proving not everything orbited the Earth. Therefore our current accepted model is heliocentric but orbits are elliptical

Question 15

What is the steady state theory?

Answer 15

That the universe has always existed as it is now and it always will do. It is based off the idea that the u inverse appears pretty much the same everywhere. As the universe expands, new matter is constantly being created to fill the gaps - so density remains roughly constant

Question 16

What is the Big Bang theory?

Answer 16

Initially all the matter in the universe occupied a very small space which was extremely hot and dense- was a singularity
This then exploded producing energy, time and the creation of space. It started to expand and still is - giving the universe a finite age

Question 17

What is the red-shift?

Answer 17

Red-shift/blue-shift is the process by which wavelengths of light from distant stars is lengthened or shortened. This is because stars more between emitting waves of light causing contractions of lengthening in the wavelength of light we observe

Question 18

What wavelength is blue shift and which is red shift?

Answer 18

Long wavelength, lower frequency = red shift
Shorter wavelength = higher frequent = blue shift
Because almost all distant stars are red shifted, showing they are moving away from us, it is evidence for the universe expanding

Question 19

What is the red shift evidence for?

Answer 19

Both the Big Bang and steady state theory support the idea that the universe is expanding and in doing so moving away from the observer, so as a singular piece of evidence is supports both theories.

Question 20

What is CMBR?

Answer 20

Scientists have detected low frequency electromagnetic radiation coming from all parts of the universe. It is though to be left over heat and energy from the original explosion

Question 21

What does CMBR support?

Answer 21

Supports the idea that the universe had a beginning and is why the Big Bang theory is currently our accepted model. The steady state theory also didn’t predict CMBR so is discredited

Question 22

What are optical telescopes used for?

Answer 22

To see distant objects clearly by detecting visible light by using reflection and refraction
-to improve quality, increase the aperture and use a higher quality objective lens

Question 23

Why is it hard to detect light?

Answer 23

The earth’s atmosphere gets in the way and absorbs wavelengths as does light pollution. It can also cause atmospheric distortion

Question 24

What do more advanced telescopes do?

Answer 24

Detect different kinds of EM waves

• X-ray telescopes are a good way to ‘see’ violent high temperature events in space like exploding stars, radio telescope detected CMBR
• better quality lens, clearer image and larger aperture to allow more light in

Question 25

How do you improve images from telescopes?

Answer 25

• enhance by using a computer hand in hand
• high up in dark places
• view from space
• better resolution and magnification
• bigger telescopes let in more light to ‘see’ further into space

Question 26

What is a nebula/ the first stage of the life cycle of stars?

Answer 26

Stars initially form a cloud of ash and dust called a nebula

Question 27

How does a nebula get to a protostar?

Answer 27

The force of gravity pulls and dust and ash together to form a protostar. The temperate rises as the star gets denser and more particles collide, when the temperature gets high enough, hydrogen nuclei undergo nuclear fusion to form helium nuclei. Giving out huge amounts of energy to keep the core of the star hot.

Question 28

How does a protostar turn to a main sequence star?

Answer 28

The star enters a stable period in which the outward pressure caused by thermal expansion balances the force of gravity pulling everything inwards. This lasts serval billion years ( the heavier the star the shorter time it takes)

Question 29

How does a main sequence star turn into a red giant/ red supergiant?

Answer 29

Eventually, hydrogen in the core begins to run out and the force due to gravity is larger than the outward force of radiation pressure. The star is then compressed till it is dense and hot enough that energy created makes the outer layers of stars expand

Question 30

What is the next stage for a red giant?

Answer 30

A small to medium sized star like the sun becomes unstable and ejects its outer gas and dust layer, this leaves being a hit dense solid core known as a white dwarf.

Question 31

What is the next stage for a red supergiant?

Answer 31

Much bigger stars start to glow brightly again and undergo more fusion to make heavier elements. They expand and contact several times as the balance shifts between gravity and radiation pressure, they explode into a supernova

Question 32

What us the stage for large stars after a supernova?

Answer 32

• forms a black hole if the star is massive enough as it will collapse to form a super dense hole in space
• or forms a neutron star when the exploding supernova throws outer layers of dust and gas into space leaving a very dense star

Question 33

What happens to a satellite if it looses speed?

Answer 33

It’s orbit gets smaller as gravity is now bigger than the centripetal force required so it is attracted to the object