Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physics > Topic 4 - Astronomy > Flashcards

Topic 4 - Astronomy Flashcards

(61 cards)

Start Studying
1
Q

What is a satellite?

A

Any object that orbits a celestial body such as a star or planet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List all the planets in our solar system from closest to furthers from the sun

A

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What shape is the orbit of a comet?

A

Elliptical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What two planets is the asteroid belt of our solar system found between?

A

Mars and Jupiter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an asteroid belt?

A

A region of space that contains millions of asteroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a comet mostly made of?

A

Ice and dust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an asteroid mostly made of?

A

Rock and metal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a galaxy and how does it stay together?

A

A galaxy is a collection of billions of stars that are held together by gravity and that orbit the centre of the galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is an orbit?

A

The curved path of a spacecraft or celestial object around another celestial object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is Newton’s 1st law?

A

An object travelling at a certain velocity will continue tot ravel at that velocity unless acted on by a resultant force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is instantaneous velocity?

A

The velocity of an object at a specific point in time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What quantity of velocity (a vector quantity) of an object in orbit is always changing?

A

Direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is true about the speed and velocity of objects in orbit?

A

The speed remains constant and the velocity is changing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Does an orbiting object’s acceleration change and why?

A

The acceleration of an object in orbit is accelerating because the velocity is changing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens if an object moves closer to what it is orbiting and can it stay in orbit?

A

The object will experience a greater force of gravitational attraction and its velocity will need to increase for it to stay in orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What provides the force needed to keep a satellite in orbit?

A

Gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does CMBR stand for and what is it ?

A

CMBR stands for cosmic microwave background radiation and is electromagnetic radiation that has dropped in frequency from the big bang since the big bang as the universe expanded and cooled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the Steady State Theory and why WAS it supported?

A

A theory that suggests the universe has always been the same as we see it now. It was supported by red-shift seen from distant galaxies but is no longer supported because of CMBR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the equation for red-shift?

A

The difference between the observed and original wavelengths divided by the original wavelength of light = the recessional velocity of the galaxy divided by the speed of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the red-shift equation allow us to calculate?

A

The recessional velocity of the galaxy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which side of the absorption spectra has the highest wavelength?

A

The red side on the left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why are some wavelengths on the absorption spectra missing?

A

A star emits light of all wavelengths, but some are absorbed by chemicals in the star’s atmosphere, therefore light that reaches Earth has some wavelengths missing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Out of red-shift, blue-shift and the doppler effect, which supports the Big Bang Theory and why?

A

Red-shift because it demonstrates that the universe is expanding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How many galaxies show a red-shift?

A

Nearly all of them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is red-shift?
When light from distant galaxies show an absorption pattern that has been shifted to the red side of the spectra
26
Why does red shift occur?
The light emitted by an object moving away from us will be stretched. This causes the lights wavelength to increase. The faster an object moves away from us, the larger the red shift
27
Why are galaxies moving away from each other?
Space and the universe itself is expanding and this makes galaxies further apart
28
What is the basic idea of the Big Bang Theory?
The universe expanded from a point of high density and pressure
29
Why do we believe the big bang theory?
Light that reaches earth from other galaxies shows red-shift, which suggests that all galaxies are moving away from us and each other, suggesting the universe is expanding and that it must have expanded from a point, which is where the big bang comes in
30
What is a nebula?
A large cloud of dust and gas
31
What pulls a nebula together to form a protostar?
Gravity
32
As a protostar grows what could happen?
The temperature could increase, nuclear fusion could start and it could become more dense
33
What happens when nuclear fusion starts in a protostar?
It becomes a main sequence star
34
How does a star stay together?
The outward pressure created by nuclear fusion balances against the inward pressure from gravity
35
After a main sequence what star could a main sequence star become?
It could become a red giant or red super giant
36
What fusion occurs in a main sequence star?
Hydrogen to helium nuclei
37
What fusion occurs in a red giant or red super giant?
Fusion that forms heavier nuclei up to iron
38
What fusion occurs in supernovas?
Fusion that forms nuclei heavier than iron
39
What are the stages of a star's lifecycle for a star larger than the sun?
A nebula, protostar, main sequence star, red supergiant, supernova, neutron star/black hole
40
What are the stages of a star's lifecycle for a star the same size as or smaller than the sun?
A nebula, protostar, main sequence star, red giant, white dwarf and then a black dwarf
41
What are 2 advantages of naked eye astronomy?
It is low cost and can be conducted anywhere
42
What are 3 disadvantages of naked eye astronomy?
The naked eye cannot detect faint lights, it is heavily dependent on clear weather and the naked eye can only detect visible light
43
What are 2 advantages and disadvantages of Newton's telescopes?
They can collect more light than naked eye astronomy, meaning more stars can be seen and the light is more focused, producing a better quality image They require a clear day to observe astronomical objects and are only able to detect visible light
44
How did Newton improve telescopes?
He introduced mirrors into telescopes that allowed telescopes to be constructed with lower image distortion and better focusing of light
45
Why do telescopes work better at higher altitude?
As altitude increases the atmosphere's density decreases, which is better for telescopes as that atmosphere also contains certain wavelengths of infrared radiation, UV light and gamma rays. They also are able to detect electromagnetic radiation that would have been absorbed by the atmosphere at ground level
46
What are 3 advantages of space telescopes?
They are unaffected by the Earth's atmosphere, are capable of detecting all wavelengths of electromagnetic radiation and can observe extremely faint light from stars and distant galaxies
47
What are 2 disadvantages of space telescopes?
They are expensive to build and difficult to repair once in orbit
48
Who discovered infrared radiation?
Herschel
49
Why does the distance between the moon and Hubble telescope change?
Because of the change of the relative positions of their orbits, the different radii of their orbits and their different orbital speeds
50
What is meant by the big bang theory?
The expansion of space from a very hot point that is the origin of the universe
51
How does a reflecting telescope form an image of a distant object?
It uses a mirror which is concave
52
What is the eyepiece of a telescope intended to do?
Magnify the image
53
What are 3 pieces of evidence that support the geocentric model?
The sun, moon stars and planets move across the sky in the same direction in a repeating pattern that appears to be going around the Earth and is the same every day
54
What are 3 pieces of evidence that don't support the geocentric model?
The moons of other planets orbit those planets, the movement of the sun isn't the same each day and planets don't move in a simple path
55
How has the sun gone from a nebula to a main sequence star?
Gravity causes the nebula to contract which causes the temperature to increase and forms a protostar. The temperature rises until it is hot enough to start nuclear fusion
56
What is the steady state theory?
That the universe is expanding and did not have a beginning
57
Why do most scientists prefer the big bang theory to the steady state theory?
CMBR - Cosmic Microwave Background Radiation
58
How do scientists search for life on Mars
They use telescopes that have cameras to analyse the atmosphere
59
Why are some telescopes not on the Earth's surface?
On Earth the image is distorted and the planets are too far away
60
Why is knowing the age of the oldest star not enough to tell scientists the age of the universe?
The oldest star had not yet appeared when the big bang happened, stars take time to form and we cannot be certain of this time
61
How does red-shift provide evidence of the universe expanding?
Redshift provides evidence for an expanding universe because the observed light from distant galaxies is shifted towards the red end of the spectrum, indicating they are moving away from us. This shift is proportional to the galaxy's distance, meaning more distant galaxies exhibit greater redshift and are moving away faster. This relationship supports the Big Bang theory and the idea that the universe originated from a singularity and has been expanding ever since

Physics (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions