Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
152 Cards in this Set
- Front
- Back
|
Planet
|
A body in orbit around a star.
|
|
|
Moon
|
A natural satellite of a planet.
|
|
|
Satellite
|
A body orbiting a planet.
|
|
|
Dwarf Planet
|
An object orbiting the Sun that is so massive that its gravity pulls it into a roughly spherical shape but, since it is not the dominant mass in the neighborhood of its orbit, cannot be called a planet. Includes Pluto, Eris, and Ceres.
|
|
|
How much larger than Earth is the Sun, approximately?
|
The diameter of the Sun is 110 times that of Earth's. 1,300,000 Earths would fit inside of it.
|
|
|
What is an AU, and how far is it?
|
Astronomical Unit, a distance unit based on the average distance of the Earth from the Sun; 92 955 887.6 miles/149 598 000km.
|
|
|
How far have the Voyager spacecraft traveled from Earth? How long has it taken them to get that far?
|
The Voyager 2 has traveled for 33 years and has gone 21 billion kilometers (13 billion miles). The Voyager 1 has traveled 34 years and has gone 17.3 billion km (10.8 billion miles).
|
|
|
What is a light year? How far is it?
|
The distance light travels in a year; 10 trillion km (300,000 km/s).
|
|
|
Galaxy
|
A massive system of stars, gas, and dark matter held together by their mutual gravity.
|
|
|
Galactic Group
|
A system of from 2-several dozen galaxies held together by their mutual gravitational attraction.
|
|
|
Galaxy cluster
|
A set of hundreds or thousands of galaxies held together by their mutual gravitational attraction.
|
|
|
True or False – Aristotle is famous as a scientist partly because he was the first to suggest that the planets traveled in elliptical orbits around the sun.
|
False: Kepler did.
|
|
|
True or False – The Jovian planets are characterized by their rocky surfaces.
|
False. Jovian planets are big though.
|
|
|
The sun moves across the sky in a path called the
|
ecliptic
|
|
|
What is an ecliptic?
|
The path the sun moves across the sky in.
|
|
|
A group of stars that form a “picture” like the Big Dipper is called a(n)
|
asterism
|
|
|
Spring tides occur when?
|
Throughout the year.
|
|
|
If you watch the planets move through the night sky night after night, they sometimes move from east to west instead of west to east. This change in motion is called
|
retrograde motion
|
|
|
Which planets have a ring system?
|
All four of the outer planets have rings.
|
|
|
Newton's Third Law of Motion explains
|
that for every action, there is an equal and opposite reaction.
|
|
|
True or False - The umbra is darker than the penumbra.
|
True
|
|
|
The eccentricity of an orbit tells us what?
|
How elliptical the orbit is.
|
|
|
When Mars is on the opposite side of the Sun relative to the Earth (that is, the Sun lies between
Earth and Mars), we say that Mars is in |
Conjunction
|
|
|
The position of our solar system within the Milky Way galaxy is
|
about halfway between the center and the edge.
|
|
|
Which of the following is the largest in size: a lightyear, a parsec, or the distance across the Milky Way?
|
The distance across the Milky Way.
|
|
|
What is the distance of a parsec in lightyears?
|
1 pc = 3.26 ly
|
|
|
What kind of universe did Copernicus devise?
|
Heliocentric
|
|
|
What were Tycho Brahe's major accomplishments?
|
Built instruments to measure the positions of planets very accurately, found that comets moved outside of the Earth’s atmosphere, witnessed a supernova and concluded that it was much farther away than any celestial (planetary) sphere.
|
|
|
Whet were Kepler's major accomplishments?
|
Using Tycho Brahe’s data, Kepler discovered that planets do not move in circles around the Sun. Rather, they follow ellipses with the Sun.
|
|
|
What is Kepler's first law?
|
Planets move in elliptical orbits with the Sun at one focus of the ellipse.
|
|
|
What is Kepler’s Second Law?
|
Planets move faster when near the Sun, and slower when farther from the Sun.
|
|
|
What is Kepler’s Third Law?
|
The amount of time a planet takes to orbit the Sun (its period) P is related to its orbit’s size, a, by p^2 = a^3
|
|
|
What were Galileo's major accomplishments?
|
Observed sunspots, showing that the Sun was not a perfect, immutable sphere, was one of the principal founders of the experimental method for studying scientific problems.
|
|
|
What is a sidereal day?
|
The time for the Earth to rotate through 360 degrees; One sidereal dayis 23 hours, 56 minutes.
|
|
|
What is a penumbra?
|
In a lunar eclipse, the penumbra of the Earth is the part of the shadow where the light from the Sun is only partially blocked. The Moon dims a little as it passes into the penumbra.
|
|
|
What is an umbra?
|
In a lunar eclipse, the Earth’s umbra is the darkest part of the shadow, directly behind the body of the Earth. After the Moon moves into the umbra, its surface becomes very dark, although red. This is a total lunar eclipse.
|
|
|
What is precession?
|
When the Earth rotates on its axis.
|
|
|
What is a pattern of stars called?
|
An asterism.
|
|
|
What is the difference between an asterism and a constellation?
|
??
|
|
|
How old is the visible universe?
|
13.7 billion years
|
|
|
How old is Earth?
|
4.54 billion years
|
|
|
What is azimuth?
|
An angular measurement in a spherical coordinate system.
|
|
|
What is Newton's first law of motion?
|
An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
|
|
|
What is Newton's second law of motion?
|
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
|
|
|
What is Newton's law of gravitation?
|
Newton's law of universal gravitation states that every massive particle in the universe attracts every other massive particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. F = GmM/r^2 where F is the magnitude of the gravitational force between the two point masses, G is the gravitational constant, m1 is the mass of the first point mass, m2 is the mass of the second point mass, and r is the distance between the two point masses.
|
|
|
What is a neap tide?
|
A tide that occurs when the difference between high and low tide is least; the lowest level of high tide. Neap tide comes twice a month, in the first and third quarters of the moon.
|
|
|
What is a spring tide?
|
When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. Spring tides occur during the full moon and the new moon.
|
|
|
Which planets are the terrestrial planets?
|
The rocky inner planets (Mercury, Venus, Earth and Mars).
|
|
|
Where is the Kuiper Belt?
|
Outside the orbit of Neptune
|
|
|
What is The Oort Cloud?
|
A cloud of cometary bodies that surrounds the Solar System.
|
|
|
What is the Coriolis effect?
|
an apparent deflection of moving objects when they are viewed from a rotating reference frame. Causes counterclockwise rotation of weather systems in Northern Hemisphere (incl. tornadoes, hurricanes).
|
|
|
What is the Great Red Spot on Jupiter?
|
The Great Red Spot is a storm caused by the Coriolis Effect that has lasted for at least 300 years.
|
|
|
What are the Galilean satellites?
|
The four largest moons of Jupiter are called the Galilean satellites, in honor of their discoverer.
|
|
|
What is Titan?
|
Titan is Saturn’s largest moon, and is Larger than Mercury.
|
|
|
What are Trans-Neptunian Objects?
|
Small icy bodies orbiting the Sun beyond Neptune’s orbit are called Trans-Neptunian Objects, or TNOs.
|
|
|
What is the coma of a comet?
|
The coma, the cloud of evaporated ices and gases streaming from the surface of the nucleus.
|
|
|
What is sublimation?
|
Going from solid to gas.
|
|
|
What is the radiant?
|
The meteors all appear to be coming from the same point in the sky called the radiant.
|
|
|
What is a meteoroid?
|
When a meteoroid(small chunk of rock in space) enters the Earth’s atmosphere, it heats up and begins to glow. It is now called a meteor.
|
|
|
What is a meteor?
|
When a meteoroid(small chunk of rock in space) enters the Earth’s atmosphere, it heats up and begins to glow. It is now called a meteor.
|
|
|
What is a meteorite?
|
Most meteors burn up in the atmosphere.
Some of them survive all the way to the ground, hitting the surface. These are called meteorites. |
|
|
What is an asteroid?
|
Any of numerous small celestial bodies composed of rock and metal that move around the sun (mainly between the orbits of Mars and Jupiter).
|
|
|
What is the Solar Nebula Theory?
|
The most successful model of Solar System formation is the Solar Nebula Theory:
The Solar System originated from a rotating, disk-shaped cloud of gas and dust, with the outer part of the disk becoming the planets, and the inner part becoming the Sun. |
|
|
What does accreted mean?
|
To stick together.
(In the inner solar system, silicates and metals accreted (stuck together) – initially due to gravity.) |
|
|
What are protoplanets?
|
Planetesimals grew through accretion into protoplanets, which were heated by collisions and by radioactive decay.
|
|
|
What is the transit method for detecting exoplanets?
|
We look for dimming of light from the central star as the planet eclipses the star (passes between us and the star.)
|
|
|
What is Wien's Law?
|
Hotter bodies emit more strongly at shorter wavelengths. The hotter it is, the shorter the wavelengths. Wien’s Law lets us estimate the temperatures of stars easily and fairly accurately.
|
|
|
What is the Stefan-Boltzmann Law?
|
The luminosity of a hot body rises rapidly with temperature.
|
|
|
The science of developing new methods for sensing, focusing and imaging light in astronomy is called
|
instrumentation
|
|
|
What is chromatic aberration?
|
a blurring effect
|
|
|
Most modern telescopes are (reflecting or refracting)
|
reflecting telescopes.
|
|
|
What is diffraction?
|
a “spreading” effect due to the finite size of an aperture. A blurring effect.
|
|
|
What are interferometers?
|
To counter diffraction effects (and obtain higher resolution), astronomers use interferometers. Signals from these arrays of widely-separated telescopes are added together to create images with very high resolution.
|
|
|
What is the corona?
|
The sun's outer atmosphere.
|
|
|
What is the chromosphere?
|
The sun's lower atmosphere.
|
|
|
What is the photosphere?
|
The sun's visible surface.
|
|
|
Where are sunspots found?
|
The photosphere.
|
|
|
What are granules?
|
Regions of rising gas that look like bubbles on the sun.
|
|
|
What is the convection zone?
|
Just below the photosphere is the convection zone. Energy is transported from deeper in the Sun by convection, in patterns similar to those found in a pot of boiling water - hot gas rises, dumps its energy into the photosphere, and, then cooler, sinks back down.
|
|
|
What is the radiative zone?
|
Energy in the convection zone comes from the radiative zone. Energy from the core is transported outward by radiation – the transfer of photons.
|
|
|
What are spicules?
|
Spicules – tall, thin, columns of hot gas.
|
|
|
What is the Ideal Gas Law?
|
Pressure = Constant x Temperature x Density
|
|
|
What is helioseismology?
|
We can probe the interior using helioseismology, the study of “sunquakes”.
|
|
|
Where does the sun's energy come from?
|
The Sun’s energy comes from nuclear fusion –the merging of hydrogen nuclei into helium.
|
|
|
What happens to nuclei in nuclear fusion?
|
The high speeds of the nuclei allow them to collide and fuse via the proton-proton chain.
|
|
|
What are sunspots?
|
Sunspots are highly localized, “cool” regions in the photosphere. "Discovered" by Galileo. They contain intense magnetic fields, as evidenced by the Zeeman effect.
|
|
|
What are prominences?
|
Prominences are large loops of glowing solar plasma, trapped by magnetic fields
|
|
|
What is the Solar Cycle?
|
The number of sunspots seen increases and decreases periodically.
|
|
|
What is the Solar Maximum?
|
Every 11 years or so, the sunspot number peaks. This is called Solar Maximum.
|
|
|
What is the Solar Minimum?
|
Around 5.5 years after Solar Maximum, the sunspot number is at its lowest level. This is called Solar Minimum.
|
|
|
What is differential rotation?
|
Different parts of the sun rotate at different speeds.
|
|
|
What is The Babcock Cycle?
|
The Babcock Model describes a mechanism which can explain magnetic and sunspot patterns observed on the Sun.
|
|
|
What is The Maunder Minimum?
|
Very few sunspots were recorded between 1645 and 1725. Corresponds to relatively lower temperatures here on Earth, a “little ice age”.
|
|
|
What is proper motion?
|
The positions of stars are not fixed relative to Earth. This motion of stars through the sky (independent of the Earth’s rotation or orbit) is called proper motion.
|
|
|
What is radial velocity?
|
The speed of a star’s motion toward or away from the Sun is called its radial velocity. (Doppler shift…)
|
|
|
What is luminosity?
|
The total amount of power a star emits to space is its luminosity, measured in watts.
|
|
|
What is brightness?
|
The amount of light reaching us from a star is its brightness.
|
|
|
What is a standard candle?
|
Some types of stars have a known luminosity, and we can use this standard candle to calculate the distance to the neighborhoods these stars live in.
|
|
|
What are three types of binary stars?
|
Visual, spectroscopic, and eclipsing.
|
|
|
What is a visual binary star?
|
If we can see from pictures taken over time that the stars are orbiting each other, the system is a visual binary.
|
|
|
What is a spectroscopic binary star?
|
If the stars are so close together (or distant from Earth) that their spectra blur together, the system is called a spectroscopic binary.
|
|
|
What is an eclipsing binary star?
|
If the stars are oriented edge-on to the Sun, one star will periodically eclipse the other star in the system. These are called eclipsing binaries.
|
|
|
What is interferometry?
|
We can combine the light from two or more telescopes to pick out more detail – this is called interferometry.
|
|
|
What is The Stefan-Boltzmann Law?
|
The Stefan-Boltzmann Law links a star’s temperature to the amount of light the star emits.
Hotter stars emit more. Larger stars emit more. |
|
|
What is The Hertzsprung-Russell diagram?
|
The Hertzsprung–Russell diagram is a scatter graph of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their spectral types or classifications and effective temperatures. Hertzprung-Russell diagrams are not pictures or maps of the locations of the stars. Rather, they plot each star on a graph measuring the star's absolute magnitude or brightness against its temperature and color.
|
|
|
On the HR diagram, what is The Main Sequence?
|
We see that many stars are located on a diagonal line running from cool, dim stars to hot bright stars.
|
|
|
Stellar parallax is good for measuring distances out to
|
several hundred parsecs.
|
|
|
On an HR diagram, luminosity versus temperature is plotted. Alternatively, one could plot
|
absolute magnitude versus color.
|
|
|
True or False – Objects radiate heat via infrared radiation.
|
True
|
|
|
Analyzing the frequencies of light emitted from an energized element is called
|
spectroscopy.
|
|
|
What is the highest frequency item out of radio, microwave, infrared, visible, ultraviolet, x-ray, gamma ray?
|
Gamma ray.
|
|
|
What is the lowest frequency item out of infrared, radio, visible, ultraviolet, x-ray, microwave, gamma ray?
|
Radio
|
|
|
Order these from lowest to highest frequency: x-ray, infrared, radio, visible, ultraviolet, microwave, gamma ray.
|
radio, microwave, infrared, visible, ultraviolet, x-ray, gamma ray
|
|
|
The unit (of measure) for the apparent magnitude of a star is watts, lumens, watts/m, joules, calories, or none of the above?
|
None of the above.
|
|
|
True or False – When the Sun swells to a red giant, it will become much more massive.
|
False
|
|
|
True or False – Today we know that the asteroid belt contains the dust and particles that
remain from the destruction of a planet that once orbited at that distance from the Sun. |
False
|
|
|
Comets are believed to originate from the
|
Oort Cloud
|
|
|
In Annie Jump Cannon's classification system, what is the order of spectral classes from hottest to coolest?
|
OBAFGKMLT (Oh be a fine girl kiss me, little tease)
|
|
|
What class of star is our sun in Annie Cannon's system?
|
G type (G2)
|
|
|
What is the absolute magnitude of a star?
|
Absolute magnitude is the magnitude of a star "moved" to 10 parsecs away.
|
|
|
The classification for the next coolest star after an F9 star would be
|
K0
|
|
|
How are Annie Jump Cannon's classes subdivided?
|
Each category is further subdivided into 10 subcategories.
|
|
|
What are the four families of stars?
|
Supergiants, giants, main sequence, white dwarves.
|
|
|
How is luminosity related to mass?
|
Luminosity = mass^3.5
|
|
|
What is the inverse square law?
|
Brightness decreases with square of the distance from the star.
|
|
|
What does a magnitude 1 mean?
|
Easily seen.
|
|
|
What does a magnitude 6 mean?
|
Dim; 6 is the limit for magnitude easily seen with the naked eye.
|
|
|
How much brighter is a magnitude 1 star from a magnitude 6?
|
100x, because the magnitude scale is logarithmic.
|
|
|
Why are comets tails blown away from the sun?
|
By radiation.
|
|
|
Deuterium is one of the atoms created in the proton-proton chain. What is it?
|
It's an isotope of hydrogen that contains one proton and one neutron.
|
|
|
The ion tail of a comet always points
|
away from the Sun
|
|
|
True or false: carbon dating is used to find the age of sedimentary rocks dating back millions of years.
|
False
|
|
|
Hubble determined the distance to the Andromeda Galaxy by using the period-luminosity law for pulsating stars called
|
Cepheid variable stars
|
|
|
True or false: "Spectrum" is the plural of "spectra"
|
false; just like millenia is the plural of millenium.
|
|
|
When we refer to the "aperture" of a telescope, we are talking about the
|
diameter of the objective lens or primary mirror
|
|
|
An achromatic lens in a telescope is
|
a lens that corrects for the dispersion of light that otherwise would result in different wavelengths focusing at different locations.
|
|
|
A pulsar is thought to be what?
|
a neutron star; small and extremely dense; rotates very fast and emits regular pulses of polarized radiation
|
|
|
The classification for the next hottest star after an F9 star would be
|
F8
|
|
|
What is the CNO cycle of fusion?
|
The CNO cycle (for carbon-nitrogen-oxygen) is one of two sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton-proton chain. Theoretical models show that the CNO cycle is the dominant source of energy in stars more massive than about 1.3 times the mass of the sun.
|
|
|
What are the two sets of fusion reactions by which stars convert hydrogen to helium?
|
The CNO cycle and the proton-proton chain.
|
|
|
What is the most important information we can get from studying a binary star system?
|
Stellar mass, because you can use one star as a reference, which makes it easier to get mass of other.
|
|
|
Why isn't Jupiter a star?
|
It isn't massive enough.
|
|
|
Star A is 4000K; Star B is 8000K. How much more luminous is star B than A?
|
16 times; 8000/4000 = 2. 2^4 = 16. Luminosity = (difference in temperature)^4
|
|
|
The fusion occurring in the sun primarily takes place in the
|
core
|
|
|
A supergiant star is
|
generally the last stage of a star before its "death"
|
|
|
What does it take for stars dimmer than apparent magnitude 6 to be seen?
|
A telescope.
|
|
|
At what distance is absolute magnitude defined?
|
10 parsecs
|
|
|
Although, the largest four of Jupiter’s moons are known collectively as
|
the Galilean satellites.
|
|
|
What is a coronal hole?
|
Coronal holes are areas where the Sun's corona is darker, colder, and has lower-density plasma than average.
|
|
|
What is Tritium?
|
Tritium is a radioactive isotope of hydrogen. The nucleus of tritium (sometimes
called a triton) contains one proton and two neutrons. |
|
|
What is a blackbody spectrum?
|
A black body is an idealized physical body that absorbs all incident electromagnetic radiation. As the temperature increases past a few hundred degrees Celsius, black bodies start to emit visible wavelengths, appearing red, orange, yellow, white, and blue with increasing temperature. When an object is visually white, it is emitting a substantial fraction as ultraviolet light.
|
|
|
What is room temperature in Kelvin?
|
293 K
|
