Download Astronomy Study Guide

Astronomy Study Guide
Vocabulary
Be able to match these terms with their definitions in multiple-choice questions.
Absolute magnitude
Apparent magnitude
Asteroid
Black hole
Comet
Constellation
Fusion
Galaxy
Geocentric
Heliocentric
Light year
Lunar Eclipse
Meteor
Meteorite
Moon
Nebula
Neutron star
Orbit
Revolution
Rotation
Satellite
Solar Eclipse
Solar system
Solar wind
Summer solstice
Sunspot
Supernova
White dwarf
Winter solstice
Zenith
Concepts
Structure of the Universe
• Put the following in order of increasing size: planet, star, galaxy, universe
• Put the following in order of decreasing size: universe, galaxy, star, planet
• The theory for the formation of the universe is the Big Bang Theory
EVIDENCE:
o The Doppler effect, where objects moving further away produce light that is shifted
to the red end of the spectrum, while objects moving closer produce light that is
shifted to the blue end of the spectrum.
o Light from distant galaxies is red-shifted, proving that they are moving away from
Earth. This shows that the universe is [circle one] expanding / contracting.
• A light-year is used to measure distance between stars & galaxies.
• Matter in space is distributed [evenly / unevenly] in clumps that are [evenly / unevenly]
distributed throughout the universe.
Stars
• All stars & solar systems start their life cycle as nebulae, which are clouds of gas & dust.
• The energy that powers stars & produces the light is called fusion. This is the process
where two nuclei collide to make a single larger element.
• The two main elements that make up stars are hydrogen and helium.
• In the life cycle of a star, what determines which path a particular star will take? mass or
size
• What type of star is our sun currently? Main
sequence star
• What type of star will our sun become next? Red
giant
• What will our star end up as? White dwarf / black
dwarf
• What could a very massive star end up as?
Neutron star or black hole
• What is the difference between apparent magnitude
& absolute magnitude? Apparent magnitude is
how it appears due to distance, absolute
magnitude is how bright it actually is if they are all the same distance
• Our sun has a high apparent magnitude, but a low absolute magnitude. Why?
our sun is very close, so appears brighter even though it is frequently dimmer than
other stars that are further away, just like a flashlight in your face is very bright, but
when further away is definitely not as bright as the sun
• The HR Diagram at right classifies stars by brightness & temperature.
• Rank the following stars by increasing temperature: Barnard’s Star, Betelgeuse,
Aldebaran, Alpha
Centauri, Procyon
B
• Rank the following
stars by increasing
brightness:
Barnard’s Star,
Procyon B, Alpha
Centauri,
Aldebaran,
Betelgeuse
• What determines
the color of a star?
temperature
• The hottest stars are
what color? blue
• The coolest stars are
what color? red
• Spectroscopy uses
the light from a star to tell us: the elements in it & how it is moving or rotating
• The spectrums at right show the ‘fingerprints’ of
carbon, helium & hydrogen. The bottom spectrum is
light from a distant star. Which of the elements
shown is in this unknown star? Hydrogen (has all
the same lines as hydrogen, with a few others)
• Light was received from a distant star & analyzed.
The helium signature from that star is compared
below to the helium signature here on Earth. The
distant light is red-shifted. How is the distant star
moving in relation to us? Away from us
Our Solar System
• Early people on earth believed that Earth was the center of the universe. This is the
geocentric theory.
• Current belief is that the sun is the center of our solar system. This is the heliocentric
theory.
• There are 8 planets in our solar system.
• Write the names of the planets in order starting from the one closest to the sun:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
• The rocky, dense planets are: Mercury, Venus, Earth, Mars – all closest to sun
• The gas giants are: Jupiter, Saturn, Uranus, Neptune – furthest from sun
• Our local star is the sun
• Within the solar system & all large objects (planets, moons & star) in it, the most dense
materials are found in the center / core and the least dense materials are found in the
outside / crust.
• Asteroids are large rocky bodies found between Mars and Jupiter
• Name the planet with these unique characteristics:
Only one with large amounts of liquid water & oxygen: Earth
Tilted on its side so one side gets constant day & the other constant night:
Uranus
Density is so low it would float in water: Saturn
Has a huge hurricane large enough to fit Earth inside: Jupiter
• Comets tails always point away from the sun because of the solar wind.
• Periodically, there are spectacular meteor showers on Earth. These showers usually occur
because the Earth's orbit passes through the remains of which of the following:
a. a star
c. a comet
b. solar flares
d. the rings of Saturn
• Orbits
o The shape of planetary orbits is called an ellipse
o Which orbit below is more eccentric? B – more like an oval
o
o
o
o
o
o
As distance from the sun increases, orbital velocity decreases
Which planet has the fastest orbital velocity: Mercury, Mars or Earth? Mercury
Which planet has the slowest orbital velocity: Mercury, Mars or Earth? Mars
Which planet would have the shortest year, Mercury, Mars or Earth? Mercury
Which planet would have the longest year, Mercury, Mars or Earth? Mars
When would a planet move faster, at aphelion or perihelion? perihelion
Earth, Moon & Sun Interactions
• Rotation: spinning on an axis
o Rotation causes [circle one] day/night OR year
o Rotation causes [circle one] stars to move during the night OR the constellations
to change during the year
o Although the other stars move from Earth’s perspective, Polaris is always still
because it is directly above the North pole.
o Proof that Earth rotates:
Foucault’s pendulum
Coriolis effect
• Revolution: orbiting the sun
o Revolution causes [circle one] day/night OR year
o Revolution causes [circle one] stars to move during the night OR the constellations
to change during the year
o Proof that Earth revolves around the sun:
Seasons changing
Different constellations visible during the year
• Earth’s seasons are caused by Earth’s 23.5°° tilt and revolution around the sun
o Name the day, the season for the Northern Hemisphere, and the season in the
Southern Hemisphere for each diagram.
December 21st
June 21st
North – winter
North – summer
South – summer
South – winter
• These objects appear to move backwards in the sky during some times of the year: planets.
This happens because the Earth passes them. It is called retrograde motion.
• Eclipses
o Solar eclipse: when the Moon’s shadow falls on the Earth & we cannot see the
Sun. Happens during the new moon phase.
o Lunar eclipse: when the Earth’s shadow falls on the Moon & we cannot see the
Moon. Happens during the full moon phase.
o Name the type of eclipse seen in each diagram.
Solar eclipse
Lunar eclipse
o The lunar eclipse can be seen by anyone on the night side of Earth. The solar
eclipse can only be seen by a small portion of people on the day side of Earth.
• Moon phases
o Name the moon phase in each picture.
waxing crescent – waning crescent – waning gibbous – waxing gibbous – 1st quarter – 3rd quarter – full - new
o In the boxes below, draw the phases in order, starting with the new moon.
• Moon
o orbits the Earth in about 27 days
o The moon is currently thought to have formed when a Mars-size object
collided with Earth. The material ejected from Earth’s atmosphere then came
together under the force of gravity to form the moon.
o The moon rotates on its axis at the same rate that it revolves around the Earth. This
causes which of the following?
a. very high tides
b. the phases of the moon
c. partial eclipse of the moon
d. one side of the moon to always face the Earth
• Tides
o caused by the gravitational pull of the moon & sun, but mainly the moon b/c it’s
closer
o The spring tides happen twice a month and have a very large range, going from
very high high tides to very low low tides. They happen at the full and new moon
phases.
o The neap tides happen twice a month and have a very small range, going from
unusually low high tides to unusually high low tides. They happen at the 1st quarter
and 3rd quarter moon phases.
o We have roughly two high tides and two low tides every day.
Exploring Space
• 1st man-made object in space was called Sputnik & was launched in 1957 by the USSR.
• 1st men on the moon were in the mission called Apollo 11. They were from USA & it
happened in 1969.
• The Challenger space shuttle accident in 1986 almost shut down NASA’s space program
because they feared a repeat.
• The Hubble space telescope was initially a financial disaster because of broken parts but
since gave us many incredible pictures of our universe.
• Satellites are used for: military/spying, weather, GPS/mapping, aerial photography,
communications
• Reflecting & refracting telescopes were the first & most common types of telescopes.
• Radio telescopes are good for: observing celestial objects in non-visible wavelengths
(i.e. black holes, galaxies, magnetic fields, alien radio stations)
WARNING: Some questions on mapping may appear on the test, along with questions on scientific method,
measurement & density. Just as the SOL in May will be cumulative, so too are my unit tests.
Test Format: Around 50 multiple-choice questions with 2-3 short answer questions. Periods 1, 2 & 4 take the test on
November 28. Periods 6 & 7 take the test on November 29. Review will be November 21/22. If you miss the review, you will
still be required to take the test when you return, so be prepared!