Astronomy Chapters 1-2
Europa
A moon orbiting Jupiter that has an unusually smooth, uncratered, ice covered surface is called...
the time for one complete revolution of the earth relative to the celestial reference
A sidereal day is defined as ________.
this is sidereal time, not solar time, a solar day is 24 hours
A statement will sometimes hear people say is that a day is not 24 hours but is really 23 hours =, 56 minutes, and 4 seconds. What does this refer to?
look for the brightest star in the constellation Centaurus
Alpha Centauri is a famous star because it is one of the closest stars to earth (other than the sun of course). where would you look in the night sky for Alpha Centauri?
No, because 2000 years is almost 1/12, or one full sign shift, in the zodiac, so the 2000 year old signs are off by almost one full sign.
Axial precession is sometimes called the precession of equinoxes because it results in a gradual shift, relative to the celestial background, of the position where the Sun crosses the celestial equator at the equinox. Astrology is a mythology based on things like your "sign" which refers to the position of the Sun in the celestial zodiac (the 12 constellations along the ecliptic) on your birthday. This system was established almost two thousand years ago. If this mythology were true (and you believe your horoscope) can you use the dates for your "sign" based on this 2000 year old system?
the ellipticity of the orbit is small so the effect is small; seasons are caused by the tilt of earth's orbit
Earth hits its perihelion position in January. Solar radiation is proportional to the distance squared between the sun and the earth, so why isn't it hot in "winter" perihelion?
sunspots, phases of venus, jupiter's 4 largest moons
Galileo observed several features using the telescope. name them... (3)
They measured the angle of the sun above the horizon at midday in two places with different latitude and used the angle to estimate the circumference of the earth
How did Eratosthenes estimate the size of Earth?
huge impact basins that were nearly filled with basaltic lava flows
How did the lunar maria most likely generated?
1. Mars (Phobos) 2. Jupiter (Callisto) 3. Jupiter (Io) 4. Saturn (Titan) 5. Neptune (Triton) 6. Pluto (Charon) 7. Mars (Deimos)
Identify the planet that goes with each moon listed: 1. Phobos 2. Callisto 3. Io 4. Titan 5. Triton 6. Charon 7. Deimos
magnetic field
In 2012 scientists discovered that Mercury has a(n) ________ that is about 100 times weaker than that on Earth.
Yes, because Olympus Mons and the Tharsus region are higher above the Martian plains than Mt. Everest, so the air would always be dramatically thinner and colder there, even with an Earth atmosphere.
In the science fiction book series "Red Mars, Green Mars, Blue Mars" the author spins a story of "terraforming" Mars with the formation of oceans and a breathable atmosphere by the end of the series. The author describes a scenario, however, where the inhabitants of this fictional world were able to live relatively normally on most of the world but not on Olympus Mons and the Tharsis region. Assuming you could create a breathable atmosphere as described in the books, is the description of where you might live on Mars realistic, or just spinning a yarn?
Their orbits are highly elliptical, off the plane of the ecliptic, and many are retrograde, which is unlikely for satellite formed during planetary accretion.
Jupiter contains a number of small moons that are thought to be captured comets or material ejected by collisions with larger objects. What is the evidence for this theory?
Io is close to Jupiter, and the strong tidal forces on the planet produce frictional heating of the planet.
Jupiter's moon Io is thought to be the volcanically active world in our solar system. What is the inferred source of heat?
planets, sun, elliptical
Kepler said that the _______ go(es) around the ______ on _________ orbits
mercury, venus, earth, mars
List the names of the terrestrial planets below...
Geocentric (Earth-centered)
Most ancient Greeks held a _____________ view of the universe
in the Sun
Most of the mass in the solar system is contained ________.
ellipses
One of the discoveries which led to the modern view of the solar system was that the orbits of the planets are ________.
eastward
Planets appear to move _______ each night, but they occasionally appear to stop and reverse directions
their ejecta, seen as rays, lies across the surface of the maria
Rayed craters like Tyco and Copernicus are known to be younger than the lunar maria because ________.
lacks organic material
Regolith is not a true soil because it
None, all of the Jovian planets have rings
Saturn is famous for its rings. Which of the following Jovian planets does not have rings?
Yes, it is visible in Hawaii during the summer months.
The Southern Cross is a Southern Hemisphere constellation that is as famous the big dipper in the Northern Hemisphere because of the brightness of the stars. It has a Southern Hemisphere declination slightly higher than the big dipper's Northern Hemisphere declination. Is it visible anywhere in the United States?
ecliptic
The apparent path of the sun upon the celestial sphere is called the _______
retrograde motion
The apparent westward "drift" of the planets compared to the background stars is called...
zodiac
The belt of constellations through which all the planets move is called the ________.
Determine when to plant crops or hunt animals based on seasonal changes
The earliest astronomical records appear to have been made by the ancient Chinese, Egyptian, and Babylonians in order to ...
venus
The high surface temperatures of ________ have been attributed to the greenhouse effect.
The move along the zodiac.
The planets are "wanderers" in the night sky because they move relative to the stars. However, there movement is limited to the plane of the solar system, which is disk shaped. So relative to the celestial coordinate system, how do the planets actually move across the sky?
on the Southern Hemisphere summer solstice, around Dec. 21
Think about the correlation of the celestial coordinate system, the tilt of Earth's axis, and the positions on Earth. If you are an observer in the Southern Hemisphere, 2 degrees north of the Tropic of Capricorn, What time of year will you be able to see the North Star?
Aristarchus
This astronomer was the first Greek to profess a sun centered, or heliocentric universe
Galileo
This scientist was the first to use the telescope in astronomy.
he made very precise measurements that were key data used by kepler
Tycho Brahe set out to disprove Copernicus, so why is he famous for developing modern astronomical theory?
Water could not survive as liquid water on the surface because it is too hot
Venus has dense clouds and thick atmosphere, yet there is no evidence for water on the surface. why?
As the air descends on the night side of the planet, it is heated by adiabatic compression to a very high temperatureâ "a grand scale equivalent of Chinook or Santa Ana winds on Earth
Venus is usually described as a runaway greenhouse effect world, which is true in the sense that the atmosphere is mostly CO2. However, the slow rotation of Venus produces a huge heat influx difference from the day to night side of the planet, which produces descending air on the night side and ascending air on the day side. Because the atmosphere is so dense, this means air rises to high elevations on the day side, and descends to surface on the night side. As a result, the night side of the planet is nearly as hot, or even hotter, than the day side. What would be the principal reason for this?
the loose material is mostly micrometeorite fragments and ejecta from impact craters, so it is very different from soil on earth
We know from the Apollo missions and unmanned probes that the moon's surface is covered with loose, unconsolidated material with a texture similar to soil on the earth. How did this material form on the moon?
When Jupiter and Mars align in the sky, and the moon is in the 7th constellation of the zodiac, then peace
What does this quote mean? "When the moon is in the 7th house and jupiter aligns with mars then peace will guide the planets"
High temperatures and solar wind in the inner planets allowed most of the volatiles to be driven off the terrestrial planets, but not the Jovian planets.
What is a popular theory for the difference in atmospheres of the Jovian planets versus terrestrial planets?
stars that go nova or supernova and appear as bright objects during the event and then go away
What is the modern explanation for "guest stars" that appear in the night sky and then disappear?
They are nova or supernova.
What is the modern explanation for what the ancient Chinese called "guest stars"?
A indeterminate, D 90 degrees
What is the right ascension and declination for Polaris, the North Star?
Several degrees from the North Pole position, and Vega will be the North Star instead of Polaris.
Where will the North Star be, relative to the celestial coordinates, 12,000 years from now?
Impact rates were very high in the early history of Earth but dropped off after about the first 1 billion years of Earth history to a nearly constant rate since that time.
Which of the following characterizes the history of impacts on Earth as deduced by impact history on other terrestrial planets?
land sliders and other mass wasting movements along the walls of the depression
Which of the following is most likely to be associated with impact craters and with volcanic calderas that originate by collapse?
Nicolaus Copernicus
Who wrote the book entitled Of the Revolutions of Celestial Spheres (De Revolutionibus)?
It demonstrated that Venus could not be in orbit around earth between earth and the sun because it shows "full" and "new" phases that would never occur with geocentric geometry
Why did Galileo's observation that venus show phases like the moon indicate that the geocentric theory of the solar system was not possible?
They are moving in the same rotation sense as the earth around the Sun, but as the earth moves faster (or slower, depending on the planet) the motion appears to be backwards.
Why do the planets "drift" east relative to the stars and then move west for periods of time?
the air pressure at the surface is equivalent to a water depth of nearly 1km on Earth, and temperatures are very high, which tends to destroy the probes.
Why has it been so difficult to examine the surface of Venus with unmanned probes?
they move relative to the stars.
Why were planets called "wanderers" by early astronomers?
Saturn's moon Titan
________ has atmospheric pressures at its surface that are roughly comparable to those at Earth's surface.
Jupiter
________ has the great, dark spot on its surface.
Carbon dioxide
________ is the principal gas in the Venusian atmosphere and also a minor component of the atmospheres of Earth and Mars
axial precession
a very slow motion of Earth's axis that requires 26,000 years to complete is called ______________ ______________
seven
according to Ptotmaic (Greek) model of the universe, how mnay "heavenly" bodies could be observed "wandering" around the universe?
perturnation
any variance in the orbit of a planet from its predicted path is referred to as ___________
0
at the beginning of spring, the vernal equinox, what is the right ascension of the Sun?
they are different. Lunar regolith is mostly ejecta from impacts whereas martian regolith is primarily wind-blown dust and sand on older surfaces that vary from water laid surfaces to volcanic surfaces
both earths moon and mars have thick layers or loose surface materials. How are they different?
0.1 times those on Earth, major gases are water vapor and carbon dioxide
compared to earth's atmosphere, the atmosphere of Mars has surface pressures that are...
a year measured in sidereal time would be about one day longer than a year based on solar time
if you determine the number of days in a year with solar time and sidereal time how would they vary?
celestial sphere
in the Ptolemaic (greek) model of the universe, the stars are attached to the ...
their orbits are highly elliptical, off the plane of the ecliptic, and many are retrograde, which is unlikely for satellite formed during planetary accretion.
jupiter contains a number of small moons that are thought to be captured comets or material ejected by collisions with larger objects. What is the evidence for this theory?
6
mercury reflects ___ percent of the sunlight that hits it into space
impacts by meteoroids
most of the moon's craters were produced by...
they contain methane ice in their atmosphere which causes the color
neptune and uranus both appear bluish in sunlight whereas jupiter and saturn are multicolored. Why are Neptune and Uranus blue?
ice volcanoes
several of the moons of saturn uranus and neptune display evidence of volcanic activity. What is the most common type of volcano on these moons?
North
the Big Dipper is near the _______ celestial pole
nebular hypothesis
the ______ explains how our solar system probably formed from a giant cloud of gases and dispersed solid particles
Olympus Mons on Mars
the largest known volcano in the solar system is?
the early earth and a planet the size of Mars collided and the ejected material coalesced to form earth's moon
the most popular theory for the origin of the moon today is...
Johannes Kepler
the three laws of planetary motion were discovered by?
Johannes Kepler
the true shape of the planetary orbits was discovered by?
Nicolaus Copernicus
this early astronomer concluded the earth was a planet. He constructed a model that put the sun at the center of the universe but he used this circular orbits for the planets
Sir Isaac Newton
this scientist determined the nature of the forces that kept the planets in their orbits.
deferents and epicycle
to explain retrograde motion, Ptolemy used two motions for the planets. They are _________ and ________
very large impact craters filled with basaltic lava
vast circular to elliptical dark colored areas on the moon called maria represent...
dating of lunar maria basalts collected by apollo astronauts , and then calculated back in time by relative chronology
we know the age of the lunar highlands from?
polar ice caps, sand dunes, extinct volcanoes
what are some things found on mars... (3)
hydrogen
what atmospheric gas is common in the outer planets but rare in the inner planets?
the rover found sedimentary rocks that contained minerals that could only have formed by precipitation from water
what did the mars rover Opportunity discover on Mars that relates to questions about the existence of water on mars?
erosional features related to flowing water
what is found on both mars and earth?
hydrogen
what is the most abundant element in the atmosphere of jupiter and saturn?
the planets move around the sun in approximately the same plane of the ecliptic
which observation supports the theory that the planets form a disk shaped nebula?
lunar highlands
which of these features is the oldest?
venus
which planet rotates the opposite direction it revolves around the sun?
Sir Isaac Newton
who formulated the Law of Universal Gravitation?
Galileo Galilei
who wrote a book entitled Dialogue of the Great World Systems that compared the Earth centered system with the Sun centered system?
the lunar highlands contain large amounts of rock anorthosite which is the light material that "floated' on the top of the magma ocean
why do lunar scientists think the surface of the moon was once a magma ocean?
bc earth has a much stronger atmosphere, it is not covered in regolith
why would you not expect to see a similar landscape of a crater that is on the moon on earth?
