Astronomy Final Exam

Crater

A bowl-shaped feature formed by the impact of a meteorite.

Rotation of the Earth

The spinning of the Earth that causes us to experience day and night. (24 hours).

Appear to move across the sky from east to west during the day/night.

The rotation of the Earth causes the sun, stars, and moon to...

Revolution

The motion of the Earth orbiting the sun.

365\.25 days.

How many days does revolution last?

Revolution

What causes the stars to be in different positions from one night to the next?

Ecliptic

The path the Sun takes among the stars.

Vernal Equinox

The first day of spring. \n Equal day and equal night. \n March 20.

Autumnal Equinox

The first day of fall. \n Equal day and equal night. \n September 22.

The Summer Solstice

The first day of summer. \n The longest day of the year. \n June 21.

Summer Solstice

When is the Sun at the highest point above the Celestial Equator?

The Winter Solstice

The first day of winter. \n The shortest day of the year. \n December 22.

Winter Solstice

When is the Sun at the lowest position below the Celestial Equator?

The tilt of the Earth and its revolution around the Sun.

The seasons are caused by...

Phases

The changing appearance of the Moon.

On the opposite side of the Earth from the Sun. \n You can see the entire disk of the moon. \n Possibly be a Lunar Eclipse.

During the full moon phase, the moon is...

Between the Sun and the Earth. \n The moon is nearly invisible. \n Possibly have a Solar Eclipse.

During the new moon phase, the moon is...

The Sun, Earth, and Moon form a right angle. \n Happens twice a month.

A quarter moon occurs when...

The positions of the Sun, Earth, and Moon.

The different phases of the moon are caused by...

The moon is directly between the Sun and the Earth. \n It only occurs during the new moon phase. \n Can only be seen from a very small part of the Earth.

A solar eclipse occurs when...

The moon blocks the entire disk of the Sun.

A total solar eclipse occurs when...

The moon blocks part of the disk of the Sun.

A partial solar eclipse occurs when...

The moon is too far from the Earth to block the entire disk of the Sun so a ring is left.

An annular solar eclipse is caused when...

The moon moves into the Earth's shadow.

A lunar eclipse occurs when...

The moon moves completely into the umbrella of the Earth.

A total lunar eclipse occurs when...

The moon moves partially into the umbrella of the Earth.

A partial lunar eclipse occurs when...

Synchronous Rotation

When the rotation rate and revolution rate are equal for a celestial body.

Always keep the same side facing the Earth.

When the moon experiences synchronous rotation, it causes it to...

Maria

Smooth surfaces on the moon that formed when lava flowed on the moon and filled the craters in low lying areas.

The constellations of the zodiac.

The Sun appears to travel through...

Geocentric Model of the Universe

Model based on the belief that the Earth is the center of the universe and that the Sun, planets, and stars revolved around the Earth.

Aristotle and Ptolemy.

Who promoted the Geocentric Model of the Universe?

Retrograde Motion.

What disproved the Geocentric Model of the Universe?

Retrograde Motion

The apparent backward motion of a planet against the background of stars.

Through the epicycle.

How was retrograde motion explained?

Epicycle

A loop in a planet's orbit used to explain retrograde motion in ancient times.

No.

Is epicycle real and a correct model?

Copernicus and Galileo.

Who promoted the Heliocentric Model of the Solar System?

Heliocentric Model of the Solar System

Model that has the Sun at the center of the Solar System with planets revolving around it.

Galileo.

Who famously built the first telescope?

Sunspots on the Sun \n The Four Moons of Jupiter \n The rings of Saturn \n Many more stars than ever imagined \n Craters on the Moon

What are some important discoveries made by the first telescope?

Tycho Brahe.

Who spent 20 years charting the planets and hired Kepler before he died?

Kepler.

Who developed the Three Laws of Planetary Motion?

Kepler.

Who determined that the orbit of the planets was elliptical?

Eccentricity

What tells us the shape of the ellipse?

Eccentricity

The ratio of the distance between the foci to the length of its major axis.

Issac Newton.

Who developed the Three Laws of Motion?

Newton's First Law of Motion

(Inertia) The tendency for an object that is moving to keep moving unless a net force acts on it to stop it.

Law of Universal Gravitation (Newton)

States that there is a force between all objects proportional to their masses and inversely proportional to the square of the distance between them.

Astronomical Unit

The average distance from the Earth to the Sun.

Mercury, Venus, Earth, and Mars.

Which planets are terrestrial?

They both have many craters.

The surface of Mercury is very similar to the surface of the moon because...

It does not have an atmosphere to shield it from the Sun during the day and hold in heat at night.

Mercury has the widest temperature range of any planet because...

It is close to the same size.

Venus is similar to Earth because...

The Greenhouse Effect.

Venus is the hottest planet in the solar system because of...

Two. They most likely came from the asteroid belt.

How many moons does Mars have?

Olympus Mons

Largest (dormant) volcano in the solar system. It is located on Mars.

Auroras

Beautiful displays of light in the atmosphere caused by the solar wind interacting with the magnetic field. This occurs close to the poles of the Earth.

3x10^8 m/s

What is the speed of light?

It can be used to identify elements.

Spectrum is useful because...

Spectrum

How are elements in the chromosphere and the photosphere determined?

Asteroids

Various size rocky objects usually found in the asteroid belt.

Between Mars and Jupiter.

Where is the asteroid belt found?

Meteorites

Larger meteoroids that don't burn up completely in the atmosphere and hot the surface of the Earth.

Meteor

A bright streak in the sky that is often called a shooting star but is really a dust or rock particle that burns up in the atmosphere.

The Kuiper Belt

An area outside the orbit of Neptune where most short-period comets reside.

Ort Cloud

The halo of material surrounding our solar system.

Orbit the Sun \n Be massive enough to keep its spherical shape \n Clear its orbit of debris

For an object to be classified as a planet, it must...

Photosphere

“Sphere of Light” The apparent surface of the Sun.

Chromosphere

"Sphere of color" The layer above the photosphere.

Corona

The outer most layer of the Sun's atmosphere that extends several million kilometers and gradually becomes the solar wind.

Solar Wind

High speed protons and electrons constantly escaping the Sun.

Convection Zone

The layer just under the surface where energy is transferred by convection.

Radiation Zone

The area below the convection zone where energy is transferred by radiation.

75% Hydrogen and 25% Helium.

What elements make up the Sun's interior in what percentages?

The lower layer (chromosphere).

What part of the Sun's atmosphere can only be seen during a total solar eclipse?

The core.

Hydrogen (Nuclear) fusion takes place in what part of the Sun?

Hydrogen fusion in the Radiation Zone.

The Sun's source of energy.

Luminosity

Total energy radiated by the Sun- can be calculated from the fraction of that energy that reaches Earth.

Nuclear Fusion

The process of combining small atomic nuclei into larger nuclei.

When magnetic field lines are distorted by Sun's differential rotation.

How do sunspots form?

Albert Einstein.

Who developed the famous equation E=mc^2?

The speed of light.

What does the "c" in E=mc^2 represent?

Hydrostatic Equilibrium

Inward gravitational force must be balanced by outward pressure from the hydrogen fusion reaction: this means the Sun is not expanding nor contracting at this time.

Weak, always attractive, and has infinite range.

As one of the Four Fundamental Forces of Nature, gravity is...

Stronger than gravity, either attractive or repulsive, and has infinite range.

As one of the Four Fundamental Forces of Nature, electromagnetic is...

The force that keeps the nucleus together, very strong, and has short range.

As one of the Four Fundamental Forces of Nature, strong nuclear force is...

Responsible for beta decay, weak, and has short range.

As one of the Four Fundamental Forces of Nature, weak nuclear force is...

Protostar

A hot nebula that glows because of the pressure from gravity. \n It may or may not become a star.

The protostar has enough mass to fuse hydrogen.

For a protostar, hydrogen fusion begins when...

Brown Dwarf

A protostar that does not have enough mass to fuse hydrogen, so it cools down and is left as a planet-like object.

Main Sequence Star

A young star that has enough mass and pressure to fuse hydrogen. It is in hydrostatic equilibrium and will eventually become a red giant when it fuses helium.

Red Giant

A very large, bright (because it's so large) star that results from the shortage of hydrogen; fuses helium and all other elements up to iron. This star expands and the outer layers glow red.

Eventually cool off until it becomes a black dwarf.

A white dwarf star will...

The Pauli Exclusion Principle

States that two electrons cannot be compressed too close together.

May survive as a neutron star.

After a Supernova explosion, the core of the star...

Neutron Star

A very dense star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons; formed after a supernova.

Compressed very small causing the rotation to speed up only a fraction of a second.

When a Supernova occurs, the neutron star left behind is...

Pulsar

A neutron star that emits regular pulses of energy as it spins rapidly.

Cannot escape due to such a strong force of gravity. Light is also bent as it passes from a distant background star.

With black holes, light...