Astronomy Flashcards
(86 cards)
1
Q
Define Astronomy.
A
The scientific Study of what exists beyond Earth.
2
Q
Define Celestial Object.
A
Any object that exists in space.
3
Q
Define the Universe.
A
Everything that exists, including all energy, matter, and space.
4
Q
Define a Star.
A
A massive collection of gases held together by its own gravity and emitting huge amounts of energy.
5
Q
Define Luminous.
A
Producing and giving off light; Shining.
6
Q
Define a Planet.
A
A large, round celestial object that travels around a star.
7
Q
Define Solar System.
A
The sun and all the objects that travel around it.
8
Q
Define Satellite.
A
A celestial object that travels around a planet or dwarf planet.
9
Q
Define Orbit.
A
The closed path of a Celestial object or Satellite as it travels around another Celestial object.
10
Q
Define Galaxy.
A
A huge, rotating collection of gas, dust, and billions of stars, planets, and other celestial objects.
11
Q
Define Electromagnetic (EM) Radiation.
A
Energy emitted from matter, consisting of electromagnetic wives that travel at the speed of light.
12
Q
Define Electromagnetic (EM) Radiation.
A
The range of wavelengths of electromagnetic radiation, extending from radio waves to gamma rays, and including visible light.
13
Q
Define Sunspots.
A
Dark Spots appearing on the sun’s surface that are cooler than the surrounding areas.
14
Q
Define Solar Flare.
A
Gases and charged particles expelled above an active sunspot.
15
Q
Define Solar Prominence.
A
Low-Energy gas eruptions from the surface of the Sun’s surface that extend thousands of kilometers into space.
16
Q
Define Aurora Borealis.
A
A display of shifting colours in the northern sky caused by solar particles colliding with matter in Earth’s upper atmosphere.
17
Q
Define Astronomical Unit.
A
Approximately 150 million kilometers; the average distance from the Earth to the Sun.
18
Q
Define Dwarf Planets.
A
A celestial object that orbits the Sun and has a spherical shape but does not dominate its orbit.
19
Q
Define Comet.
A
A chunk of ice and dust that travels in a very long orbit around the sun.
20
Q
Define Orbital Radius.
A
The average distance between an object in the Solar System and the Sun.
21
Q
Define Gravitational Force.
A
The force of attraction between all the masses in the universe.
22
Q
Define Solstice.
A
An astronomical event that occurs two times each year, when the tilt of the Earth’s axis is most inclined toward or away from the Sun, causing the position of the Sun in the sky to appear to reach the northernmost or southernmost extreme.
23
Q
Define equinox.
A
The time of year when the hours of daylight are equal to the hours of darkness.
24
Q
Define precession.
A
The changing position of the Earth’s axis.
25
Define Lunar Cycle.
All the phases of the moon.
26
Define Eclipse.
The darkening of a celestial object due to the position of another celestial object.
27
Define Tide.
The alternate rising and falling of the surface of large bodies of water; caused by the interaction between Earth, the Moon, and the Sun.
28
Define Constellation.
A grouping of stars, as observed from Earth.
29
Define Celestial Sphere.
The imaginary sphere that rotates around Earth, onto which celestial objects are projected.
30
Define Celestial Navigation.
The use of positions of stars to determine location and direction when travelling.
31
Define the Ecliptic.
The path across the sky that the Sun, Moon, and Planets, and Zodiac constellations appear to fallow over the course of a year.
32
Define Retrograde Motion.
The apparent motion of an object in the sky, usually a planet, from east to west, rather than from west to east like normal.
33
Define Azymuth.
The horizontal distance from north measured eastward along the horizon to a point directly below a celestial body.
34
Define the Altitude of a celestial object.
The angular height a celestial object appears to be above the horizon; measured vertically from the horizon.
35
Define a Global Positioning System (GPS).
A group of satellites that work together to determine the positions of given objects on the surface of the Earth.
36
Define Geostationary Orbit.
An orbital path directly over Earth's equator with a period equal to the period of the Earth's rotation.
37
Define a Light Year and give the distance.
The distance that light travels in 1 year (365.25 days). 9.46x10^12 km.
38
Define Parallax.
The apparent change of an object as viewed from two different locations that are not on a line with the object.
39
Define Luminosity.
The total amount of energy produced by a star per second.
40
Define Solar Mass.
A value used to described by masses of galaxies and stars other than the Sun; equal to the mass of the Sun (2x10^30kg)
41
Define a Nebula.
A massive cloud of interstellar gas and dust; the beginning of a star.
42
Define a Protostar.
A massive concentration of gas and dust thought to eventually develop into a star after the nebula collapses.
43
Define the Main Sequence in stars.
The stars (including the sun) that form a narrow band across the H-R diagram from the upper left to the lower right.
44
Define a Red Giant.
A star near the end of it's life cycle with its mass that is equal or smaller than the mass or the sun. The red giant becomes larger and redder as it runs out of hydrogen fuel.
45
Define a Red Supergiant.
A star near the end of its life cycle with a mass that is 10 times (or more) larger than the mass of the sun. The red supergiant becomes larger and redder as it runs of hydrogen fuel.
46
Define a White Dwarf.
A small, hot, dim star created by the remaining material that is left when the red giant dies.
47
Define a Supernova.
A stellar explosion that occurs at the end of a massive star's life.
48
Define a Neutron Star.
An extremely dense star made up of tightly packed neutrons; results when a star over 10 solar masses collapses.
49
Define a Black Hole.
An extremely dense quantity of mater in space which no light or matter can escape.
50
Define a Star Cluster.
A group of stars held together by gravity.
51
Define an Elliptical Galaxy.
A large group of stars together make an elliptical or oval shape.
52
Define a Spiral Galaxy.
A large group of stars that together make an spiral shape, such as the Milky Way.
53
Define a Lenticular Galaxy.
A large group of stars that together make a shape that has a central bulge but no spiral arms.
54
Define an Irregular Galaxy.
A large group of stars that together make an irregular shape.
55
Define the Big Bang theory.
The theory that the universe began in an incredibly hot, dense expansion approximately 13.8 billion years ago.
56
Define Refracting Telescope.
An optical Telescope that uses glass lenses to gather and fucus light
57
Define Reflecting Telescope.
An optical telescope that uses glass lenses to gather and focus light.
58
Define Spacecraft.
A human-occupied or robotic vehicle used to explore space or celestial objects.
59
Define Space Probe.
A robotic spacecraft sent into space to explore celestial objects such as planets, moons, asteroids, and comets.
60
Define a Microgravity Environment.
An environment in which objects behave as though there is very little gravity affecting them.
61
Define Space Junk.
Debris from artificial objects orbiting Earth.
62
In what zone of the sun does fusion take place? Where is this zone in the Sun.
The radioactive zone which is in the layer of the Sun Surrounding the core.
63
What zone is just outside the Radioactive zone or the sun?
The convective zone.
64
What is the layer of the sun below the sun's atmosphere called? What happens in this layer?
The photosphere is the layer below the sun's atmosphere where light and other types of radiation escape the sun.
65
What layer of the sun makes up the sun's inner atmosphere?
The Chromosphere.
66
What layer of the sun makes up the sun's outer atmosphere? How far does this layer extend into space?
The Corona makes up the sun's outer atmosphere and extends millions kilometers into space.
67
In an eclipse, which layer of the sun can you see?
The Corona.
68
What sections of the sun are drawn on the outside in a diagram.
The Chromosphere The Corona The Solar Flare The Solar Prominence
69
Describe the stages in the life cycle of a massive star (30 times the mass of the sun):
1. Protostar forms from the gas clumps in the nebula. 2. Nuclear fusion starts and converts the Hydrogen into Helium. 3. The star runs out of hydrogen and expands into a red supergiant. 4. There is a supernova explosion and the core collapses itself 5. A Black Hole and Nebula forms.
70
Name some differences between stars and planets (of our solar system)?
Stars Planets Stars have nuclear fusion. Planets do not have nuclear fusion. Stars give off their own light Planets do not give off (luminous). their own light. Stars are the centre of the The planets are not the Solar System. centre of the Solar System. Stars produce and give off Planets are cooler and do their own heat to the planets not give off their own in the Solar System and are heat to stars, moons, or very hot (at least 2x10^7C in other planets. the core of the sun).
71
There are four planets called the "gas giants". Which planets are these?
1. Jupiter 2. Saturn 3. Uranus 4. Neptune
72
There are four planets called terrestrial planets. Which planets are these?
1. Mercury 2. Venus 3. Earth 4. Mars
73
Since the Earth is closest to the Sun in January, why is January not the hottest month? What other effects causes it to be cold in January in Ottawa?
1. The Earth is tilted so that the sun shines at 23.5S of the equator so the sun shines at a lower angle in the sky causing the sun rays to scatter and not heat the surface of the earth as much. 2. There is less hours of daylight so there is less time for the daytime heating than nighttime cooling.
74
Why has most of the Solar System been explored by robots instead of sending people in space ships?
1. Humans will not be able to survive in many places in the Solar System for reasons such as too low Oxygen. 2. It costs too much money to send humans to space and places around the solar system 3. In space, humans will not be able to report to the Earth as fast as humans. 4. Human's will die because they will have no source of food or drinks. 5. Humans will get bored and need sleep so they cannot observe all the time.
75
As people have learned about astronomy, we have discovered things at larger and larger distances and sizes. Explain the meaning of the following words. Solar System, Galaxy, Universe.
1. Solar System: A star is in the centre of the Solar System Everything in the Solar System revolves around the Star. The solar system is disk-shaped. Distances in the Solar System are measured in Astronomical Units. 2. Galaxy: A galaxy contains different stays and clusters. The older stars are in the centre of the galaxy and bunched up together. The younger stars are more on the outsides. Galaxies like the Milky-Way contain black holes in the centre. The distances are measured in light years (ly) because galaxies are larger than solar systems. 3. A universe contains everything we know. People thing it is possibly infinitely sized. People can just see a small part of it (up to 13.8 billion light years away). The universe has no edges.
76
I am thinking about building a scale model of the Earth in our cafetorium. The real diameter of the Earth us 12700 km. The height available from the floor to the ceiling is about 650 cm (6.5 m) What scale should I use for this model? Using the same scale, draw on this paper below a cross section the part of the model near the Earth's surface. Calculate and draw how thick the following layers should be. The thickest part of the Lithosphere (the Earth's crust) is 150 km deep. The average ocean depth is 3.7 km. The thickness of the troposphere (lower atmosphere where weather takes place) is 20 km. Mount Everest us 8.4 kilometers high.
Scale
= Real/Drawing
= 12700km/6.5m
=2000km/m
=20km/cm
The thickest part of the Lithosphere (the Earth's crust) is 150 km deep.
=150 km/(2000km/m)
=(150 km/2000 km)m
=0.075m
=7.5cm
The average ocean depth is 3.7 km.
=3.7km/(2000km/m)
=(3.7km/2000km)m
=0.00185m
=0.185cm
Mount Everest us 8.4 kilometers high. =8.4km/(2000km/m)
=(8.4km/2000km)m
=0.0042m
=0.42cm Troposphere
_Lithosphere (150km) | | | |_
Ocean Depth Mt.Everest
77
Draw a cross section of the sun with all the parts of the sun.
Cross Section of the Sun
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78
Draw a labelled diagram for a Solar Eclipse and a labelled diagram for Lunar Eclipse.
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79
What causes the stars to be revolving around the North star?
The Earth is rotating.
80
What causes the moon to change it's position each night?
The moon revolves around the Earth.
81
What causes the Sun's position to gradually change so different constellations are visible at different times of the year?
The Earth orbitin he sun once per year.
82
Why do astronomrtd think that the universe was created in a Big Bang about 13.8 billion years ago?
The universe is expanding.
The far away galaxies are red-shiting.
At one point the universe was much smaller and much more dense.
83
How does the Sun produce energy?
Hygrogen gets converted into helium in a process called nuclear fusion.
84
What is the difference between the Geocentruc and Heliocentric model of our Solar System?
**Geocentric model** of the Solar System
The Sun is the centre of the Solar System
**Heliocentric model** of the Solar System
The sun is the centre of the Solar System
All the planets revolve around the Sun
85
Explain the Solar Nebula theory.
**Solar Nebula theory**
A massive cloud of gas and dust in the nebula began to contract approximately 5 billion years ago
Clumps of gas began to form
One clump became a protostar
The protostar contracted and its temperature increased
The protostar started spinning faster counter clockwise
The star kept increasing in temperature and pressure at the core
The cloud became hot enough for nuclear fusion
A disk of spinning gas formed around the protostar because of the contracting material
When the Sun formed, the lighter gases were pushed away from the sun forming the gas giants
The denser clumps formed the terrestrial inner planets
86
What colour does the moon appear to be in a solar eclipse?
Orange-Red
