Astronomy - Test 1
What is the altitude of the horizon in the local sky?
0 degrees; parallel with the ground.
What does a last quarter waning moon look like?
left half of moon is lit up by sun.
What happens at higher latitudes on Earth?
length of daylight & darkness become more extreme.
Beyond the Local Group, what are all galaxies doing?
moving away from us.
What does the celestial sphere show? (4 things)
north celestial pole, south celestial pole, celestial equator, & ecliptic.
What is a distinguishing feature of a star?
nuclear fusion.
When is the equator have the highest Sun?
on the equinoxes.
How many times per day does Earth rotate around its axis?
once per day.
How many times per year does the Earth orbit around the Sun?
once per year.
How long does precession take?
one time every 26,000 years.
What is a moon (or satellite)?
orbits a planet.
What is a planet?
orbits a star & reflects starlight.
What is our place in the universe defined by?
our "cosmic address".
What is umbra & penumbra?
penumbra is outer shadow of Earth casting over moon; umbra is inner shadow of Earth casting over moon.
What are 4 types of force carriers that astronomers deal with?
photon, gluon, Z boson, & W boson.
What is our cosmic address?
planet Earth in the solar system, which is in the Milky Way Galaxy, which is in the Local Group, which is the Local Super Cluster.
What is the zodiac made up of?
the constellations that lie on the ecliptic makes up this.
What is a light-year?
the distance light travels in one year.
On a 1 to 10 billion scale of the solar system, what is the size of Pluto?
the size of a dust speck.
On a 1 to 10 billion scale of the solar system, what is the size of the sun?
the size of a large grapefruit (14 cm).
On a 1 to 10 billion scale of the solar system, what is the size of the Jupiter?
the size of a marble.
On a 1 to 10 billion scale of the solar system, what is the size of the Earth?
the size of a tip of a ball point pen.
When we look in any direction into the galactic plane, what do we see?
the stars & interstellar clouds that make up the Milky Way in the night sky.
What is the solar system comprised of?
the sun & all that orbits it.
Since all galaxies are moving away from us, beyond the Local Group, what does that mean?
the universe is expanding.
What do Local Group galaxies orbit?
their common center-of-mass.
According to the scientific method, what happens if the test supports the hypothesis?
then, make additional predictions and test them.
According to the scientific method, what happens if the test does not support the hypothesis?
then, revise hypothesis or choose new hypothesis; then make a new prediction, & test it.
What are 6 types of quarks that astronomers deal with?
up, charm, top, down, strange, & bottom.
What is the scope of General Relativity?
very strong gravity.
What is a lunar eclipse?
Moon is in Earth's shadow (full moon lined up on the ecliptic plane); Earth is in between Sun & Moon.
What is new moon?
Moon is in middle of Earth & Sun; moon can appear high in the sky, low in the sky, or on the ecliptic plane, which is a solar eclipse.
What is the scope of Newton's Laws?
Most types of motion: very strong gravity, very high speeds, & very small scales.
Are we ever sitting still?
No.
What is the scope of Kepler's Laws?
Objects orbiting the Sun, which includes most types of motion: very strong gravity, very high speeds, & very small scales.
What is the universe comprised of?
everything.
How far is 1 astronomical unit (AU)?
150 million kilometers.
How many elementary particles are there that astronomers deal with?
16.
How long does light travel from sun to Earth?
8 minutes.
How long does light travel from Sirius to Earth?
8 years.
What is the altitude of the zenith?
90 degrees; straight up.
What are 4 special points for seasons of Earth?
(1.) summer solstice. (2.) winter solstice. (3.) spring (vernal) equinox. (4.) fall (autumnal) equinox.
How does the Sun's path at different times differ on the local sky? (4 things)
(1.) sun has largest path on summer solstice. (2.) smaller path on equinoxes. (3.) smallest path on winter solstice. (4.) smallest & largest swap for southern hemisphere.
What are 4 fundamental forces that astronomers deal with?
(1.) Gravity. (2.) Electromagnetism. (3.) Strong force. (4.) Weak force.
What are 3 families of matter that astronomers deal with?
(1.) Leptons. (2.) Quarks. (3.) Force Carriers.
What are 4 things that a good scientific theory & hypothesis must be?
(1.) a clearly defined scope. (2.) falsifiable (usually means testable). (3.) has to make precise predictions. (4.) supported by more data than competing theories & hypotheses.
What are 2 measures of the local sky?
(1.) altitude (measured in degrees). (2.) direction (measured by 8 cardinal directions: N,S,E,W,NE,NW,SE,SW).
How did we come to be? (2 things)
(1.) from the Big Bang that made hydrogen & helium. (2.) elements heavier than helium came from normal & dying stars.
In Europe before the Rennaissance, Ptolemy existed between 90 & 168 C.E., what was his contribution? (2 things)
(1.) geocentric model. (2.) epicycles to explain retrograde motion.
If he universe were 1 year old, what is the timeline of events for humans? (3 things)
(1.) human beings have been around for about 2 minutes. (2.) the pyramids were built 11 seconds ago. (3.) you were born about 0.05 seconds ago.
What is the pattern of testing a hypothesis or theory to be good & worthy?
(1.) is it testable? yes. (2.) does it make precise predictions? yes. (3.) are the predictions consistently confirmed? yes. (4.) is it supported by more data than other theories & hypotheses?
What are 2 conditions for an eclipse?
(1.) it must be a full moon (for a lunar eclipse) or a new moon (for a solar eclipse). (2.) the moon must lie on the ecliptic plane.
What is the sequence of the scientific method?
(1.) make observations. (2.) ask a question. (3.) suggest a hypothesis. (4.) make a prediction. (5.) perform a test: experiment or additional observation.
What is the sequence of cycles? (8 things)
(1.) new. (2.) waxing crescent. (3.) 1st quarter waxing. (4.) waxing gibbous. (5.) full. (6.) waning gibbous. (7.) last quarter waning. (8.) waning crescent.
How fast does the Earth rotate around its axis at various locations? (5 things)
(1.) north pole = 0 kilometers per hour. (2.) 25% south longitudinally = 1,275 kilometers per hour. (3.) equator = 1,650 kilometers per hour. (4.) 25% south longitudinally = 1,275 kilometers per hour. (5.) south pole = 0 kilometers per hour.
How long does light travel from moon to Earth?
1 second.
How many roughly stars are in the observable universe?
10 to the 22nd stars (10 to the 11th stars per galaxies times 10 to the 11th galaxies).
How far does light travel in one year?
10 trillion kilometers or 6 trillion miles.
On a 1 to 10 billion scale of the solar system, how far Saturn from the sun?
143 meters away.
On a 1 to 10 billion scale of the solar system, how far Earth from the sun?
15 meters away.
How long does light travel from Andromeda Galaxy to Earth?
2.5 million years.
On a 1 to 10 billion scale of the solar system, how far Mars from the sun?
23 meters away.
How long does it take for the Sun to orbit the Milky Way Galaxy once?
230 million years.
How far is the Sun from the center of the Milky Way Galaxy?
28,000 light years.
On a 1 to 10 billion scale of the solar system, how far Uranus from the sun?
287 meters away.
How long is the moon cycles?
29.5 days.
What is the speed of light?
300,000 kilometers per second.
What small forces do astronomers deal with?
4 fundamental forces.
On a 1 to 10 billion scale of the solar system, how far pluto from the sun?
450 meters away.
How much is moon's orbit tilted to ecliptic plane?
5 degrees.
What does a waning gibbous look like?
75% of the left side of moon is lit up.
What does a waxing gibbous moon look like?
75% of the right side of moon is lit up.
On a 1 to 10 billion scale of the solar system, how far Jupiter from the sun?
78 meters away.
Why may stars that appear close in the sky not actually be close in space?
Because what we see is projected on the sky; there is also depth involved. What we see is in 2 dimensions. The 3rd dimension is depth.
What is a solar eclipse?
Earth is in Moon's shadow (new moon lined up on the ecliptic plane); Moon is in between Earth & Sun.
What does a full moon look like?
Earth is in middle of Sun & Moon; moon can appear high in the sky, low in the sky, or on the ecliptic plane, which is a lunar eclipse.
What is the Cosmic Calendar?
History of the universe compressed into 1 year.
According to the scientific method, what 2 things can happen after performing a test with an experiment or additional observation?
Test can either support hypothesis or not support hypothesis.
What is the scope of Special Relativity?
Very high speeds.
What is the scope of Quantum Physics?
Very small scales.
What is a key question of the birth of modern astronomy?
What is our place in the universe?
When we look out of the galactic plane, what do we see?
a clear view of to the distant universe.
What must a good scientific theory have, like General Relativity, Special Relativity, Quantum Physics, Newton's Laws, & Keplar's Laws?
a clearly defined scope.
What is a constellation?
a region of the sky.
What happens to the Sun at the Arctic Circle?
a sine wave; low at Midnight due north; high at noon due south.
How do we see Andromeda Galaxy look to us?
as it did 2.5 million years ago.
What is a galaxy composed of?
billions of star systems & gas & dust.
What are 6 types of leptons that astronomers deal with?
electron neutrino, muon neutrino, tau neutrino, electron, muon, & tau.
What is the comparative change for the tropics, like that of the 4 seasons from temperate latitudes?
rainy & dry seasons (rain when Sun is higher in sky, i.e. summer for temperate climates).
What does a 1st quarter waxing moon look like?
right half of moon is lit up by sun.
How many galaxies are in the observable universe?
roughly 100 billion galaxies.
How many stars are in the Milky Way Galaxy?
roughly 100 billion stars.
What does a waning crescent moon look like?
sliver of light on the left side of moon.
What does a waxing crescent moon look like?
sliver of light on the right side of moon.
What is a comet?
small, icy, & orbits a star.
What is an asteroid?
small, rocky, & orbits a star.
Where are the characteristics of the 4 seasons on Earth?
temperate latitudes.
What is precession?
the 23.5 degree axial tilt changes directions; & the north star changes from Polaris to Vega.
What covers the celestial sphere?
the 88 official constellations cover this.
What causes the seasons of Earth?
the axial tilt.