Space Unit Test Flashcards
1
Q
Where does the moon rise and set?
A
Rises in the East, sets in the West
2
Q
Does the moon rise earlier or later each day?
A
The moon rises 48 min later each day
3
Q
How long does it take for the moon to orbit the Earth?
A
it takes the moon 29.5 days to orbit Earth
4
Q
Where does the sun rise and set?
A
The sun rises in the east and sets in the west
5
Q
When does the sun rise earlier and set later?
A
From december 21 to june 21
6
Q
What is the Sun made of?
A
75% hydrogen, 23% helium
7
Q
what is the core and surface temperature of the sun?
A
core: 15 million degrees C
surface: 5500 or 5505 degrees C
8
Q
What is the order of planets from the sun?
A
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
9
Q
Which is the largest planet?
A
Jupiter
10
Q
What planet has the closest diameter to Earth?
A
Venus
11
Q
What planet as the shortest year?
A
Mercury
12
Q
Which planet has the longest year?
A
Neptune
13
Q
Which planet has the longest day?
A
Venus
14
Q
Which planet has the shortest day?
A
Jupiter
15
Q
Which are the rocky planets?
A
mercury, venus, earth, mars (inner 4)
16
Q
Which are the gaseous planets?
A
jupiter, saturn, uranus, neptune (outer 4)
17
Q
Which planet has the largest ring system?
A
Saturn
18
Q
Which planet looks red?
A
Mars
19
Q
What is the only planet that has liquid water on its surface?
A
Earth!
20
Q
Which planet rotates the opposite direction from the others?
A
Uranus
21
Q
Define: waxing moon
A
a moon that appears to be “growing” as it orbits around the Earth. This happens in the first half of the moons cycle
22
Q
Define: waning moon
A
A moon that appears to be “shrinking” in size. this happens in the last half of the moons cycle
23
Q
Define: geocentric model
A
the idea that Earth is at the center and everything else revolves around it.this came from the church believing that the gods and the people were at the center.
24
Q
Define: heliocentric model
A
when Galileo discovered that the sun was actually at the center of the solar system and that the Earth and other planets orbit around the Sun, but he was punished for believing this against the church
25
Define: Orbit
The curved path of a celestial object or spacecraft around a star planet or moon. They are not perfectly round but are elliptical
26
Define: line spectrum
when each element is excited, it absorbs a certain colour of light, creating a black line in its line spectrum. a full line spectrum looks like a rainbow. The wave lengths vary depending on the type of light.
27
Solar System
The sun with all the planets, and other celestial objects that are held by the Sun's gravitational pull therefore orbit around it
28
Comet
celestial object made of dust and ice that orbits around the sun in an elliptical shape and burns up creating a tail
29
Meteor
s small piece of rock or metal that enters Earth's atmosphere and starts to burn up.
30
Meteorite
A meteor that has fallen to Earth and becomes a meteorite
31
Fusion Reaction
occurs when an element is heated up to the point that they bond together to make a different element (which is found by adding up their atomic numbers and seeing what element that corresponds with). This happens at extremely high temperatures and creates an outward push. For some reason iron resists fusion.
32
Red Giant
the phase in a medium mass star where helium fuses into beryllium (because the temperature is high enough) which causes the star to rapidly expand and cool until it glows red
33
White Dwarf
the phase of a low mass star where hydrogen has fused into helium and the star contracts because there is no hydrogen left, causing the star to heat up again and glow white, but ther is not enough matter for helium to fuse even f the temperatures are high enough.
34
Supernova
Occurs when a star explodes because the elements fused to iron (because iron resists fusion) which build up to the point where it gets so hot and dense that it explodes, ending in a black hole or a neutron star
35
Blackhole
the core formed after a supernova that is so dense from the inward force of the explosion that not even light can escape
36
Nebula
the beginning of all stars- they start as a huge cloud of gas where the particles have been attracted together due to gravity and contracts the gas.
37
Galaxy
a collection of hundreds of billions of stars orbiting around a massive black hole which is held together by gravity
38
Universe
everything that physically exists- it is made up of celestial objects, stars, planets, galaxies, etc. it was formed by the big bang
39
Big Bang theory
A theory about how the universe formed- an infinitely dense point suddenly expanded creating everything. This occurred 13.8 billion years ago.
40
Solar Flare
A massive explosion on the surface of the Sun that sends radiation and particles into space because of a build up of pressure
41
Solar Wind
a steady stream of subatomic particles flowing out of the Sun in all directions in space.
42
Sun Spot
an area on the surface of the sun that is significantly cooler than other areas
43
Light year
a unit of measurement to measure distances outside our solar system- it is the distance light can travel in 1 year (1ly=9.5 trillion km)
44
Astronomical Unit
the distance from Earth to the sun. It is used for measuring extremely long distancs in space.
45
1. Why does the shape of the moon change?
The shape of the moon changes based on the phase that the moon is in. Throughout (about) a month, there are 8 phases (possibly 9 if there is a Blue Moon) that change based on the positioning of the Moon in relation to the Sun and the Earth. If the moon is between the sun and the earth, we see a new moon where it looks like the moon has disappeared from the sky. More of the moon is visible as it moves around the earth until it is on the opposite side of the Earth so the earth is between the moon and the sun. This is when we see a full moon because the sun is able to light up the side of the moon which is visible from earth. The moon appears to grow until it reaches a full moon then appears to shrink until it reaches a new moon, and the cycle starts again.
46
2. Why does a full moon rise exactly at sunset?
For the moon to be full, it has to be on the opposite side of the Earth from the Sun. As the Earth rotates, the Sun starts to set and we don’t see it anymore, but since the Moon is on the opposite side as the sun, we are able to see the moon as soon as we can’t see the sun anymore.
47
3. Why does the face of the moon always look the same?
The face of the moon always looks the same because the moon does not rotate on its own axis; it only orbits around the Earth (no spinning, just orbiting). As the Earth orbits the Sun, the moon orbits around the Earth, so the moon is always with the earth, but the moon doesn’t spin, so the same side is always facing Earth.
48
4. What causes a solar eclipse?
A solar eclipse occurs when the moon blocks the Sun’s light from getting to Earth. For this to happen, the Earth, Sun and Moon would have to perfectly line up so the Moon is exactly between the Earth and the Sun to form a perfect line, making solar eclipses rare.
49
What causes a lunar eclipse?
A lunar eclipse occurs when the Earth blocks the light from reaching the moon, making it look like the moon completely disappeared from the sky. For this to happen, the Earth would have to be directly in between the Sun and the Moon. But, they would have to be in a perfect line, making these eclipses rare.
50
6. What is the significance of the Polaris or North Star?
The North Star is significant because it is the star at which Earth’s axis is almost directly pointed at. When Earth rotates all the other stars appear to be spinning except the North Star because that is the direction the Earth is pointed at. It may slightly waiver as the Earth’s axis waivers, but the axis of the Earth is pointed almost directly at the North Star, making it very important to Earth.
51
7. Why does the tilt of the Earth cause seasons?
The tilt of the Earth causes seasons because the tilt always stays the same and is always pointed in the same direction, but the Earths rotates around the sun. As it does that, the Suns light is focused on certain areas of Earth. The equator is always in sunlight, but the northern and southern hemisphere can go in and out of lots of sun light and not much sun light at all. In the northern hemisphere, December 21 is the first day that the Earth is tilted the furthest away from the sun creating winter and June 21 is the first day that the Earth points the most towards the sun for the northern hemisphere creating summer. The in between stages are fall and spring.
52
8. What is the significance of the summer solstice?
The summer solstice is significant because it is the longest day of the year because of the Earth’s tilt being so direct to the Earth’s northern hemisphere. There aren’t more hours in the day, but there is more sunlight than moonlight on the summer solstice. The summer solstice is also the first day that the Earths tilt is the most direct at the northern hemisphere.
53
9. What causes tides? How often do they occur?
Tides are caused by the moons gravitational pull on the water on Earth. All mass has a gravitational pull on other things with mass, so the moon has a strong pull on Earth’s oceans. There is a bulge in the water levels on the side the moon is on and on the opposite side because water flows. As the moon orbits around the Earth, the placement of the bulge changes with the placement of the moon. There are 12 hours between high tides so therefore there are 6 hours between a high tide and a low tide.
54
10. How do we explain retrograde motion of a planet like Mars?
Retrograde motion occurs because Mars Travels around the Sun slower than Earth does. Mars is always visible from Earth, so as they travel around the Sun we can see Mars travel as well. But Earth eventually meets up with Mars then laps Mars and because of the angle we see Mars at, it appears to travel backwards, even though that is just the way we see it as we travel away from Mars again. When Earth gets further away from Mars, it appears like it travels forward again because the angle we see it at changes.
55
What causes the Northern Lights?
The northern lights are created when solar wind from the sun enters Earth’s atmosphere and the charged particles from the wind enter and get swept toward the poles and trapped because of Earth’s magnetic fields. The reaction between the charged particles and particles on Earth happen because of the magnetic fields which creates the glowing lights.
56
12. Why does the Sun give off light?
The sun gives off light because like a star, it is made of mostly hydrogen. The hydrogen is compressed because of gravity which causes it to heat up. The temperature gets hot enough that the hydrogen can turn into helium which lets the force of the hydrogen and helium fusing and gravity balance each other out so the Sun doesn’t expand or contract (this is where our sun id now). Because of the heat needed to fuse hydrogen, the matter glows red because it is not hot enough to glow white. The sun does not burn because there is no oxygen, but it is so hot it glows.
57
How do we know what stars are made of?
We know what stars are made of because each element gives off a certain pattern of colours called a line spectrum when excited. By examining what line spectrum comes from a star, we can identify the elements in the star.
58
14. What happens to a star during its life?
1 The star starts as a cloud of gases attracted together by gravity. This is the start of a stars life and is called a nebula.
2 The matter of gases, dust and other particles is contracted and starts to heat up. If it is heated up enough (needs to reach 1 million degrees C), the hydrogen will start to fuse to helium. When it does this, the force of the fusion and the force of gravity will keep the star the same size because the forces are balanced.
3 once all the hydrogen is used up, the star will start to contract again because the force of the fusion is not there anymore. Because of the contraction, the star will heat up again. If it heats up enough, helium will fuse to form beryllium.
4 The pattern of expansion and contraction will continue if a) the star can heat up enough or b) until it reaches iron because iron resists fusion.
5 Since iron resists fusion, the star is contracted until it reaches extremely high temperatures which are where fusion forms all the elements in an explosion called a supernova.
6 The core from the supernova is very dense due to the inward force of the explosion and can either form a neutron star (very dense star that is about 15kn across and more dense than steel) or a black hole (it is so dense that not even light can escape).
59
How does gravity affect our solar system?
Gravity affects our solar system in many ways. Gravity keeps the planets in our solar system in orbit around the sun and it also keeps the moons that belong to the planets in orbit around them. Gravity also keeps the asteroid belt evenly between the sun a Jupiter because of the equal gravitational pull between Jupiter and the Sun. In our galaxy, gravity keeps out solar system orbiting around a massive black hole and keeps stars balanced. Just on Earth gravity affects tides, keeps us on the earth, gives us a moon, etc.
60
Explain 2 pieces of evidence of the Big Bang Theory?
The 2 main pieces of evidence that the big bang happened is that the galaxies are constantly moving away from each other. This means that they once would have had to be very close to each other for them to start moving away and even get pushed away from other galaxies. We know they are moving away from each other because a “red shift” happens in the hydrogen elements when it is moving away which make the light waves longer. Another piece of evidence is that the universe is mostly made of hydrogen and as it expanded, it cooled very quickly. This would explain why hydrogen makes up most of our universe because the protons weren’t at a hot enough temperature for long enough for them to organize into anything more complex then hydrogen (it only has 1 proton).
61
What features of Earth and its orbit around the Sun make it unique in its ability to sustain life?
* Earth orbits close enough around the sun for the Earth to be warm enough to sustain life, but it is also far enough away that it isn’t too hot and we are protected from solar flares and solar maxes. We also orbit close enough to keep some water solid and liquid, but some can still evaporate into the atmosphere
* Earth also has a magnetic field to protect itself from solar flares and solar wind
* The orbit of earth is also in a shape where we can have a change in seasons
* We can have an atmosphere that can keep some of the Suns heat in Earth’s atmosphere but some can escape
62
18. Why is Pluto no longer a planet?
Pluto is no longer a planet because it is much smaller than other planets, it does not have the same composition as the other planets and its orbit is tilted compared to all the other planets.
63
19. How do we know a star is moving?
We know how stars are moving because when we look at the line spectrum of an element or star that is moving away from the earth it shifts towards the red end (called a red shift) and the light waves get longer. If the star is moving towards Earth, the line spectrum will shift towards the violet end of the spectrum creating shorter waves. The star may also appear brighter or dimmer as it moves towards or away from Earth.
64
20. What causes a meteor shower?
A meteor shower is caused by a cloud of ice, dust and asteroids that cross paths with Earth to create “shooting stars” this can often come after a comet because as the tail of a comet breaks off, pieces of dust, ice and rock are released.
65
What are the 6 layers of the Sun?
1. The Core
2. Radiative Zone
3. Convective Zone
4. Photosphere
5. Chromosphere
6. Corona
66
What is the core of the Sun?
- 15 million degrees C
| - where fusion occurs
67
What is the Radative Zone?
- radiation is released during fusion and it makes its way ti the surface- radiation is energy travelling as a wave
68
What is the Convective Zone?
- constant circulation of plasma as it heats and cools (plasma is nuclei and electrons that are too hot to sort into atoms)
69
What is the Photosphere?
- it glows yellow
| - 5505 degrees C
70
What is the Chromosphere?
-glows red
71
What is the Corona?
- constantly changing surface due to plasma being ejected into spacethen pulled back due to gravity and magnetic fields
72
What are the features of the surface of the Sun? Define them all.
- sun spots (areas on the the surface of the Sun that are significantly cooler than other areas)
- solar flares (a massive explosion on the surface of the sun that sends radiation and particles into space because of a build up of pressure)
- Coronal Mass Ejection CME (very large solar flares. If pointed at Earth, they cause Northern Lights and could disrupt electrical equipment.
73
Define: Celestial Objects
a natural object outside the Earth’s atmosphere ex. Moon, sun, asteroid, planet, stars, etc.
74
Define: Equinox
the short period of time where the hours of daylight and the hours of night are equal. This happens twice a year during spring and fall
75
Define: Spectroscope
a device used to look at a line spectrum. It shows the series of lines that an element absorbs and reflects when pointed at a light source.
76
Define: Constellation
a collection of stars which formed together and create visible shapes or patterns from Earth.
77
Define:Plasma
nuclei and electrons that are too hot to form into atoms
78
Define: Planet
: a fairly large (but vary in size) celestial objects that orbit a star in an elliptical pattern. They orbit the Sun and reflect its light.
79
Define: Neutron Star
the extremely dense core that is about 15 km across but 1 million times more dense than steel that is left after a supernova.
