Astro 7N Exam 1
Earth pt 2
"Greenhouse Effect": Energy from Sun heats Earth. Earth's surface radiates this heat back towards space by giving off infrared radiation. • - Particular gases (including water vapor and CO2) in the Earth's atmosphere recapture and redirect this heat back towards the surface, preventing it from escaping to space. - This trapped heat is redistributed back on Earth. The naturally abundant greenhouse gases in the Earth's atmosphere act like a thermal blanket keeping Earth warm. - Without greenhouse gases Earth's surface would be about 33 degrees Centigrade cooler. When humans produce large amounts of greenhouse gases, it leads to extra heating, potential extra reinforcing feedback loops — i.e., global warming — beyond stabilized longer-term temperatures.
Uranus' moon Miranda
- Miranda (one of the larger moons): heavily-cratered, with weird valleys and cliffs; appearance caused by upwelling of ices
Formation of the Solar System
1. the Solar System formed 4.5 billion years ago 2. starting with cloud of gas and dust, it collapses due to its own gravity 3. as it collapses, the spinning cloud flattens and forms a disk 4. the Sun forms at center 5. "lumps" in the disk become planets 6. the regions around these proto-planetary clumps clear out (or material is absorbed) 7. only rocks and metals survive in inner region; outside, ices and gases also survive 8. takes a few tens of millions of years to form
Kepler's Laws
1st law: The planets orbit the Sun in elliptical orbits with the Sun at one focus. These ellipses tend to be nearly circular for the planets in our Solar System. 2nd law: "A line joining a planet and its star sweeps out equal areas during equal intervals of time." Or, a planet's speed is fastest when the planet is closest to the Sun (at a point called perihelion), and slowest when it is farthest away (aphelion). 3rd law: P^2 = a 3, where P is the orbital period (a planet's year, given as a mulitple of Earth years) and a is the semimajor axis (average distance from Sun, given in AU).
There are a total of 88 constellations. Roughly how many of these can be seen at any given time from a single location on a clear night?
44
photon
A "particle of light"
6
A Moon phase rises about ___ hours before it is overhead, and then sets about ___ hours later.
Comets
A few kilometers in size • Made of ice (both water ice and "dry ice") and dust — remnants of Solar System formation • Tails pointing away from the Sun develop due to the solar wind • Shine by reflected sunlight — i.e., comets do not produce light of their own • Highly-elliptical orbits that take them far from the Sun; as would be predicted by Kepler's 2nd Law, comets spend most of their time in the outer reaches of the Solar System — they zip by the inner Solar System and travel back out very quickly • Comets move slowly across the sky from our perspective on Earth • Short-period comets have periods < 200 years • long-period comets have much longer periods (can be 1,000s of years) and come from the Oort cloud, as much as 50,000 AU from Sun • Halley's Comet is a famous short-period comet that returns every 76 years — its last visit to the inner Solar System was in 1986; the next return will be in 206
bending different wavelengths by different angles
A prism splits light into different colors by...
speed of light
All forms of radiation travel at the...
electrons
An absorption line is produced when the __________ in atoms absorb photons and remove light of specific energies from the spectrum
electrons jump from higher to lower energy levels, and emit photons of those specific energies
An emission line is produced when...
Newton's First Law
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. ex: if the sun suddenly disappeared, the Earth would continue in the direction that it was traveling in its orbit at that time
Why don't we see the constellation Orion at night throughout the year?
As the earth orbits the sun, its nighttime side points to different constellations at different points along its orbit
Mass
As the mass of the planet increases, the jump height does decreases by the same factor As the mass of the planet decreases, the jump height does increases by the same factor
venus
Closest planet to Earth; visible in western sky in evenings near the Sun, and in the eastern sky just before sunrise; looks like a very bright star. Also shows phases, like the Moon. Just slightly smaller than Earth in mass (82%) and in radius (95%)• Venus has a longer rotational period (243 days) than its year (225 Earth days) - Venus' rotation is in the opposite direction to its orbit around the Sun — i.e., it rotates clockwise when viewed from above (Earth & most other planets rotate counter-clockwise). - The combination of these factors leads to a day/night cycle on Venus of about 117 Earth days; also, the Sun travels "west to east" ("backwards") across the sky. Dense atmosphere — mostly carbon dioxide — of gases produced by volcanic outgassing, but not dissolved in ocean like on Earth, also sulfuric acid in clouds Venus' surface is very hot (> 700 K, hotter than Mercury), because of the presence of large amounts of greenhouse gases (mostly CO2) in its atmosphere to contain heat. Density of Venus is about 5.2 grams per cubic centimeter — similar to Mercury — and made of metals/rock Active volcanoes, huge lava flows and channels, some large craters, but small meteors burn up in the thick atmosphere before they can impact to leave small craters.
energy levels
Different chemical elements have different _________ ________ that their electrons can occupy, and thus give rise to different placements and patterns of lines in their spectra; in other words, each chemical element has its own spectral fingerprint.
year
Different constellations are visible at different times of...
Neptune
Discovered in 1846 (do not need to memorize exact date), based on the orbit of Uranus not looking quite right Similar to Uranus, but a deeper blue color; atmosphere of hydrogen, helium, and methane (causes blue color); a solid core the size of earth; surrounded by a mantle of semi-fluid ices Rapid winds and large storms/vortices; include Great Dark Spots, big storms that can come and go over the timescale of a decade Ring structure, faint and dark; made of clumps of dust 14 known moons • Triton (largest): thin atmosphere made of nitrogen and methane; rocky composition; reflective icy surface; ice volcanoes with liquid nitrogen, dust, or methane coming out of them; • unusual orbit suggests Triton may be a captured Kuiper Belt object
angular resolution
Earth's atmosphere limits _________ __________, or "seeing," for ground-based telescopes — makes stars twinkle
september 21st
Fall begins on or about...
Newton's Third Law
For every action there is an equal and opposite reaction The Sun exerts force on planets, and they orbit it - he planets exert equal force on Sun, but it only moves slightly because of its very large mass relative to the planets
gamma ray > X-ray > ultraviolet (UV) > visible > infrared (IR) > microwave > radio
Forms of light, from high-energy to low-energy
Saturn
Galileo discovered its rings (although he did not know what they were, at the time). - the rings are incredibly thin; made of trillions of individual orbiting objects composed of dusty water-ice crystals, of various sizes • Saturn's mass is about 100 x Earth's (about 1/3 Jupiter); diameter about 10 x Earth's. - overall average density is 0.7 grams per cubic centimeter, which is less than that of water — "Saturn could float!" - the spin axis of Saturn is tilted about the same as Earth's - like Jupiter, Saturn is mostly made of Hydrogen and Helium; clouds arranged into belts and zones; temperatures cooler than on Jupiter. - More than 50 moons; by far the largest is Titan (remember this one) — second largest moon in Solar System; very thick nitrogen-rich atmosphere like the young Earth, but perhaps too cold for life.
Sun — Earth — Moon (as in a full Moon).
How are the Sun, Earth, and Moon positioned when it is a lunar eclipse, and what phase is the Moon in?
Sun — Moon — Earth (as in a new Moon).
How are the Sun, Earth, and Moon positioned when it is a solar eclipse?
Sun — Earth — Moon
How are the Sun, Earth, and Moon positioned when it is full Moon?
in a straight line: Sun — Moon — Earth
How are the Sun, Earth, and Moon positioned when it is new Moon?
East to West, because of Earth's rotation. The stars and planets move in the same way from our point of view, also, because of Earth's rotation.
How does the Sun appear to move in the sky in the course of a day?
With the North pole toward the Sun.
How is the Earth's axis tilted when we have summer in the Northern hemisphere?
88
How many constellations are there?
light-gathering power, angular resolution, and the quality of the instruments
Important qualities of telescopes
what time of year is it dark all (and night) at the south pole of earth?
June
the longest day of the year in the Northern Hemisphere is on or about____ and the shortest is, again, six months later near___, when the earth is at the opposite point in its orbit around the sun
June 21 and December 21 These are called summer solstice and winter solstice
Jupiter pt 2
Jupiter has more than 50 moons; - the four largest were discovered by Galileo in the early 17th century CE; they looked like stars, but were found to orbit Jupiter — important because it helped demonstrate that Earth is not the center of Universe - Using Kepler's laws, the mass of Jupiter can be measured using the periods and semimajor axes of the orbits of Jupiter's moons; periods range from 1.8 to 17 Earth days, and Jupiter's mass is about 317 Earth masses. - You should remember the names and basic information (below) for these four largest "Galilean" moons of Jupiter
wave; particle
Light has some properties of a ________ and other properties of a ________.
Two dates are on opposite sides of the earth's orbit near
March 21 and September 21 these are called the Vernal Equinox and Autumnal equinox (equal night)
mars
Mars' days and nights are similar in length to those on Earth About half Earth's diameter; 1/10th Earth's mass > 12 spacecraft have visited Mars; rovers explored surface No thick atmosphere, but does have thin one that causes orangish sky; mostly carbon dioxide; only modest Greenhouse effect because the atmosphere is so thin • Average surface temperature about -65 ˚C, but can be warmer at its equator • Iron oxide ("rust") in surface rocks gives Mars its red color Has two moons, Phobos and Deimos, but they are tiny — only 0.3 % of Mars' size Olympus Mons (large volcano on Mars; do not need to remember name) is 3 times higher than Earth's highest mountain; Martian volcanos appear dormant • Valles Marineris (do not need to remember name) is the deepest canyon in Solar System — about 300 times size of the "Grand Canyon" on Earth • Water once existed on the surface of Mars, but it is not flowing regularly there at present; permafrosts = water ice locked beneath Martian soil Dust storms are common; occasionally make it hard to see surface features.
If Earth's Moon was Full on May 1,2007. When was it next in the First Quarter phase after this Full Moon?
May 22
Pluto and charon
Pluto was discovered in 1930; NASA's New Horizons probe passed it in July 2015 - 248 Earth-year period of orbit - orbit more highly-elliptical than any of the 8 planets, and not in the same plane; briefly intersects orbit of Neptune - icy ball of rock • Pluto is very small compared to the planets; Earth's Moon is 7 times as massive Despite its size, Pluto has 5 moons; largest is Charon, over half diameter of Pluto Pluto not considered a "planet" anymore, because ... 1. other similar objects were found farther from the Sun — Quaoar, Sedna, Eris 2. not like other outer planets / small; referred to as an "ice dwarf", which are very abundant beyond the orbit of Neptune Pluto is now considered a dwarf planet, in the Kuiper belt - The Kuiper belt is a disk-shaped region beyond Neptune, ranges 30 - 55 AU. • The - Oort cloud (houses long-period comets) is out beyond the Kuiper belt. In order to be considered a planet, now, an object must 1. orbit the Sun (not be a moon around another object); 2. be massive enough to be nearly round; 3. clear the region around its orbit (Pluto does not; many other objects there).
Telescopes
Reflecting telescopes — use a mirror to collect and focus light Refracting telescopes — use a lens to collect and focus light Important qualities of telescopes: light-gathering power, angular resolution, and the quality of the instruments. The magnification is not so important. light-gathering power: Telescopes collect light in proportion to the area of their mirrors: - The area of circle is proportional to its diameter squared. example: a 2m-diameter telescope collects 2 x 2 = 4 times as much light as a 1m-diameter telescope (1 x 1 = 1) - or, a a 2m-diameter telescope collects the same amount of light as a 1m-diameter telescope in 1/4 the time angular resolution: the ability to distinguish or separate two nearby light sources (with good angular resolution) • Earth's atmosphere limits angular resolution, or "seeing," for ground-based telescopes — makes stars twinkle
300
Room temperature is about _____ degrees Kelvin
titan
Saturated orange color (as opposed to Venus' pale yellow). Complete cloud cover; cannot see sharp surface features. Like with Venus, the lack of rings is a hint to help not mistake this for a gas giant.
tilted
Seasons would not happen if the Earth's axis were not...
what would the density of mercury be most like?
Solids like iron and aluminum
march 21st
Spring begins on or about...
distances
Stars in the same constellation are likely to be at very different ____________ from us.
june 21st
Summer begins on or about...
from earth, in which constellation might you find the planet Saturn
Tarus
certain kinds of radiation cannot get through atmosphere all the way to the surface; conditions give clearer images without atmospheric blurring; i.e., better seeing
Telescopes above Earth's atmosphere are better because...
it is hard (and expensive) to get a very large light-collecting area launched into space
Telescopes above Earth's atmosphere are worse because...
light-gathering power
Telescopes collect light in proportion to the area of their mirrors
month
The Sun is inside a Zodiac constellation at all times = in each one for about a ________, each year.
5800 degrees Kelvin
The Sun's surface temperature is about...
Compare frequency of x-ray versus regular light
The X-ray has a larger frequency than visible light.
Newton's Second Law
The acceleration of a body due to a force will be in the same direction as the force, with magnitude directly proportional to its mass Force = mass x acceleration A smaller mas will move faster, if the same force is applied to it
diameter
The area of circle is proportional to its ___________ squared
The force of gravity by the Sun keeps the planet in orbit around it, but how do the planets affect the sun?
They exert an equally strong pull on the sun, causing it move slightly
Uranus
Third-largest planet, after Jupiter (1st) and Saturn (2nd). Orbital period is about 84 Earth years. Uranus' thick atmosphere is made of gas, mostly hydrogen and helium, but some methane too that gives it the blue-green color - atmosphere does not have as continually prominent belts or zones, or bright clouds, like Jupiter - has liquid, icy core surrounding a smaller rocky core Spin axis is nearly in plane of orbit around Sun (it is kind of "rolling on its side"); probably caused by collision early in its history; leads to continual near-darkness or light for 42 Earth years in a row, at its poles Uranus has many thin, faint, dark rings made of carbon ("soot"). 27 known moons - Miranda (one of the larger moons): heavily-cratered, with weird valleys and cliffs; appearance caused by upwelling of ices
Newton's Universal Law of Gravitation
This law gives the force of gravity between any two objects in the Universe. The force of gravity is proportional to (mass of object 1) × (mass of object 2) divided by the distance between the two objects squared: F M1 x M2 / d 2 Again, more mass = stronger gravity. If the objects were moved 2 times closer (or, to half of their initial distance between), ... F M1 x M2 / (1/2) 2 = M1 x M2 / (1/4) = 4 (M1 x M2) ... so, the gravitational attraction would become 4 times as great.
A star(sun) has a surface area temperature of 50,000 kelvin, in which region of electromagnetic spectrum does its peak brightness occur?
Ultraviolet
What would you expect an object at 600 kelvin to radiate the most energy.
Visible light b/c humans are about 310 kelvin
Mars has two small moons, Phobos and Deimos. Relative to Earth's Moon, they are tiny, and closer to their planet and orbiting faster — and closer to the orbital plane of Mars around the Sun. This leads to more frequent eclipses visible from Mars.
What about eclipses of the moons of Mars?
Rotation of the Earth on its axis.
What causes day and night?
The Sun is lighting up different fractions of the part of the Moon we see from Earth.
What causes the phases of the Moon?
It orbits the Sun, once (also referred to as one complete revolution about the Sun).
What happens to the Earth in one year?
It moves once around the Earth.
What happens to the moon in 1 month?
Earth's shadow passes across the Moon.
What is a lunar eclipse?
The Moon is blocking the Sun's light, or a location on the Earth's surface is passing under the Moon's shadow.
What is a solar eclipse?
New - Waxing Crescent - First Quarter - Waxing Gibbous - Full - - Waning Gibbous - Third Quarter - Waning Crescent - New (and repeat...)
What is the order of the phases of the Moon?
visible and radio
What kinds of radiation get through the Earth's atmosphere?
winter
What season is it in the Southern hemisphere when it is summer in the Northern hemisphere?
Only at night. It transits (is highest in the sky, or overhead) at midnight; the full moon rises 6 hours earlier (at sunset), and sets 6 hours later (at sunrise).
When is the full moon visible?
The new moon is visible during the day. It transits at noon; it rises 6 hours earlier (at sunrise), and sets 6 hours later (at sunset)
When is the new moon visible?
The Moon orbits the Earth in a slightly different plane than the Earth orbits the Sun.
Why do eclipses not occur every month on Earth?
The tilt of the Earth's axis of rotation, with respect to the plane of its orbit around the Sun (and not because of changing distance from Sun). The Earth's tilt is about 23 degrees.
Why do we have seasons?
december 21st
Winter begins on or about...
winter
__________ Zodiac constellations = ones opposite the Sun in the winter
summer
____________ Zodiac constellations = ones opposite the Sun in the summer
infrared (IR) region of light
a "blackbody" at room temperature peaks in the...
Where rainbows come from?
a rainbow is a result of white light being split into its component parts of visible light spectrum through mist droplets
Asterisms
a small group of stars that are used to form a picture or represent an object Ibig dipper) drawn by connecting the brightest, easiest-to-see, starts as seen from earth brightest start tends to be the one closest to earth
According to Newton's Second law of motion, if the net force acting on the object increases while the mass of the object remains constant, what happens to acceleration
acceleration increases
gas cloud in front of a light source
an absorption spectrum is produced by a...
Vesta
an asteroid
emission of photons from atoms in gas that have electrons in elevated levels
an emission spectrum is due to the...
region
anything visibly within that __________ is considered "in" that constellation
When does the waxing crescent moon rise
at 9 am
when does the waning gibbous set
at 9am
Where are aurorae likely to be seen most frequently?
at locations near the pole
Constellations
constellation = large defined areas of the sky (like states in a map of a country) - anything visibly within that region is considered "in" that constellation - there are 88 of them, in all (dividing up the total celestial sphere) • Stars in the same constellation are likely to be at very different distances from us. Not necessarily close to each other, though they appear close projected on our sky. • Different constellations are visible at different times of year; e.g., "Orion the Hunter" is prominent in the Winter — because as the Earth travels around the Sun, its nighttime side faces different regions of space. • ecliptic = the apparent path of the Sun over the course of a year, with respect to the distant stars — also refers to the plane in which the Earth orbits the Sun. • Zodiac constellations = the 12 (or 13) constellations that lie along the ecliptic. • The Sun is inside a Zodiac constellation at all times = in each one for about a month, each year. - During that time you cannot see that constellation since it is behind the Sun all day and not on the nighttime side of Earth. • The Sun was in the constellation of your Zodiac "sign" during the month you were born. (You cannot see it at night at that time of year; you must wait six months.) • Winter Zodiac constellations = ones opposite the Sun in the winter • Summer Zodiac constellations = ones opposite the Sun in the summer
Spectroscopy
continuum spectrum: light at all wavelengths absorption spectrum: shows absorption lines — dark lines in the spectrum at certain wavelengths, superimposed on a continuum spectrum— produced by a (less-energetic) gas cloud in front of a light source An absorption line is produced when the electrons in atoms absorb photons and remove light of specific energies from the spectrum. Then the electrons move from a lower to a higher energy level. emission spectrum: shows emission lines — bright lines at specific wavelengths, in an otherwise empty (dark) spectrum, due to emission of photons from atoms in gas that have electrons in elevated levels (i.e., an "excited" gas) An emission line is produced when electrons jump from higher to lower energy levels, and emit photons of those specific energies. Different chemical elements have different energy levels that their electrons can occupy, and thus give rise to different placements and patterns of lines in their spectra; in other words, each chemical element has its own spectral fingerprint.
And, on the opposite site of the orbit, when the northern hemisphere is tilted the farther away from the sun, the average daily temperature is marked as____, suggesting that the norther hemisphere is experiencing___
cool;winter
longer
days ___________ than nights in the North in the summer
equal
days and nights have _______ length in the spring
if earth rotated on it axis more slowly than it does now;
days would be longer
mass x acceleration
equation for force
g = m/r^2
equation for the strength of gravity
proportional equation for force of gravity
f = (m1)(m2)/d^2
Earth
fairly thick atmosphere, mostly composed of nitrogen and oxygen molecules; atmosphere causes sky to appear bright during the daytime; this is the scattered light from the Sun — otherwise the sky would appear dark aurora caused by solar wind particles that hit atmospheric gas and lead to emission of different colors; they are prominent near the north and south poles plate tectonics = rocky plates on the surface of Earth float on denser but more-fluid rocky material, and move around — leads to continental drift, mountains caused by collisions of plates; plates sliding past each other cause faults, quakes ozone (three oxygen atoms bonded together) layer (in stratosphere at 6 - 30 miles above the surface) protects Earth from solar
approximately two weeks after a solar eclipse, what phase will the moon be in?
full moon it takes about a month to get a new moon - so a full moon is the half mark (2 weeks)
sunset occurs 6 hours before the full moon transits. Now, when does the full moon set?
full moon will set at 6am (sunrise) - sun rises at the moon sets
Compare the frequency and wavelength of a gamma ray with visible light:
gamma ray frequency is higher and its wavelength is lower
Mercury
greyish w/ numerous craters looks a like Earth's moon, but does not have prominent maria, the dark "seas," like the Moon does • Can only see close to Sun — and hard to do with the naked eye. Displays phases. Mercury is much smaller than Earth. It is similar to Mars in mass and radius, and only a bit bigger than Earth's Moon; surface gravity less than on Earth Temperature is extremely high on the day side and extremely low on the night side, due to lack of an atmosphere to distribute heat evenly around the planet (or to retain that heat on the night side) Many craters, like the Moon, including a few permanently-shadowed craters near the poles that are cold enough all the time as to hold persistent ice deposits; shadows in other craters may be cold, even on the hot/daytime side Rotates very slowly — 59 Earth days to rotate; has a short year — 88 Earth days to orbit the Sun Mercury has no significant atmosphere; the sky appears black (can see in to deep space), even in daytime — except for the exact position of the Sun Density = mass / volume - density is related to what substance(s) something is made of - Mercury's average density is 5 grams per cubic centimeter, similar to metals and rock
If the frequency of radiation is twice as large then its wavelength is
half as large
high; short; bluer
high-energy light = ______ frequency = _________ wavelength = a ________ color
blackbody spectrum
higher temperature = more light in total, and a peak intensity at a shorter wavelength (or at a bluer color)
half
how much of the moon is always illuminated
What is the relationship between wavelength and frequency?
if the frequency increases the wavelength decreases
longer
in the Northern hemisphere, the nights are _____________ than days in the winter
equal
in the fall, days and nights have _________ length
Which types of radiation have the lowest energy?
infrared radiation and radio
If the Earth were moved to half its current distance from the sun, how would the force of gravity by the sun on the earth change?
it would become 4 times weaker
If the earth were moves to half its current distance from the Sun, how would the force of gravity by the Sun on the Earth change
it would become four times weaker
what would happen to the earth sun's gravity somehow turned off instantaneously
it would continue to move in the line in the same direction it was moving when the gravity turned off
constellation
large defined areas of the sky (like states in a map of a country)
less
larger separation = ______ gravity
Jupiter's moon Ganymede
largest moon in the Solar System (larger than the planet Mercury); icy crust; has craters so not active now, but cracks show it once was more active
continuum spectrum
light at all wavelengths
low; long; redder
low-energy light = _____ frequency = _________ wavelength = a _______ color
Telescopes pt 2
magnification: zooms in on a smaller portion of the sky, to see more detail (but also observes a smaller overall area of the sky) Telescopes above Earth's atmosphere are better because: - certain kinds of radiation cannot get through atmosphere all the way to the surface (X-ray, gamma-ray, UV, IR) - conditions give clearer images without atmospheric blurring; i.e., better seeing • Telescopes above Earth's atmosphere are worse because: - it is hard (and expensive) to get a very large light-collecting area launched into space
4/10
mars has a surface gravity of ______ that of earth
waning gibbous
moon phase that is overhead at 3 am
waxing crescent
moon phase that is overhead at 3 pm
last quarter
moon phase that is overhead at 6 am
first quarter
moon phase that is overhead at 6 pm
waning crescent
moon phase that is overhead at 9 am
waxing gibbous
moon phase that is overhead at 9pm
full moon
moon phase that is overhead at midnight
new moon
moon phase that is overhead at noon
more
more mass = _______ gravity
the density of water is 1 gram per cubic cm. What about the density of most gases?
much less than 1 gram per cubic cm
A moon orbits is exactly the same plane as the planet orbits its star. How often does this planet experience a solar eclipse?
once every orbit of its moon (its month)
How much of the total surface area of the Moon is illuminated by Sunlight during the Full Moon phase?
one half
in what region of the electromagnetic spectrum would an object near Absolute Zero radiate the most?
radio
At winter solstice, december 21, at noon, the sun is in
sagittarius
Which one requires more energy? Long or short waves?
short waves require more energy to generate
absorption spectrum
shows absorption lines- dark lines in the spectrum at certain wavelengths, superimposed on a continuum spectrum
emission spectrum
shows emission lines — bright lines at specific wavelengths, in an otherwise empty (dark) spectrum
Meteors
streak across the sky very quickly — they are also called "shooting / falling stars" (they can travel up to a hundred thousand kilometers per hour) • most meteors are tiny dust particles or grains — less than a centimeter in size — that rapidly burn up in Earth's atmosphere; pieces of Solar System debris • meteors occur when an asteroid crosses Earth's orbit, or when Earth passes through a cloud of debris left behind by a comet passing through the inner Solar System (the famous Halley's Comet is reponsible for the "Orionids" annual meteor shower) • a "fireball" = very bright meteor due to larger-than-usual chunk of debris • a "meteorite" = piece of meteor that survives atmospheric entry, hits Earth's surface • asteroid collisions were more common in the younger Solar System • 65 million years ago a large meteor collision with Earth contributed to the extinction of dinosaurs (the "K/T event"); dust and smoke thrown into the atmosphere was greater cause of extinction — not so much the initial impact itself
At approximately what time does the third quarter Moon rise?
sunrise 6am
refracting telescopes
telescopes that use a lens to collect and focus light
Reflecting telescopes
telescopes that use a mirror to collect and focus light
Earth's moon (luna)
terra (Latin for "land"): light-colored features, heavily-cratered, high peaks; geologically older; highlands uplifted from impacts in early solar system maria (Latin for "seas"): dark-colored, less cratered, valleys; geologically younger; filled by lava 1 to 4 billion years ago regolith = powdery dust and rocky debris that covers the Moon; broken apart by small meteorites hitting moon continuously impact craters = gouged out from explosions, asteroids or comets that hit the moon The Moon rotates on its own axis with exactly the same period that it takes to travel once around the Earth; consequentially, the same side of the Moon always faces Earth — this is known as "tidal locking" Moon lacks as much high-density material such as iron — no large iron core 1/4 diameter of Earth Moon has no atmosphere; daytime sky is dark Surface gravity is 6 times stronger on the Earth than on the Moon.
Zodiac constellations
the 12 (or 13) constellations that lie along the ecliptic.
angular resolution
the ability to distinguish or separate two nearby light sources
ecliptic
the apparent path of the Sun over the course of a year, with respect to the distant stars — also refers to the plane in which the Earth orbits the Sun.
Jupiter's moon Io
the closest; mostly coppery-yellow with black dots, which are active volcanic sites; overall very volcanically active, due to "tidal heating" from Jupiter; low crater density; yellow color from sulfur
Jupiter's moon Callisto
the farthest out of the four large Galilean moons; very heavily cratered — many young craters; does not get heated much, and has not changed much since its formation; about the size of the planet Mercury
What did newton's law of universal gravitation tell us about how gravity works
the force of gravity from the sun will be stronger on object with more mass
moon and earth
the moon's orbit around earth is actually tipped about 5 degrees to earth's orbit around the sun so the moon isnt always in the right plane for an eclipse to occur Phobos eclipses: every orbit Mars had a one degree inclination, which is different from Earth's Moon's inclination of 5 degrees. That inclination of Earth's Moon's orbit explain why eclipses are very rare on earth
a new planet orbits its star faster than the earth orbits the sun and it rotates more slowly than he earth rotates. which is true
the new planet has a shorter year than earth and a longer day than earth
If I apply exactly the same amount of force to a pebble and a boulder, what will happen
the pebble will move faster
Both the mood and the sun rise for the same reason, it is b/c of:
the rotation of the earth
visible light region
the sun's spectrum peaks in the...
The densities of the 4 terrestrial planets are similar to each other. This means
they are made of similar substances
if earth had its orbit changed so that all points along its orbit it were always the same distance from the sun (circular orbit), how would this affect the seasons on earth?
they would be the same as they are now
what would happen if the ozone layer was completely destroyed?
uv radiation from the sun would get through the atmosphere and cause damage to life
At midnight on March 21, we would be looking at___assuming the sky is clear
virgo
so what time must the moon be so the observers on earth will see the mood overhead at 9am. And where on the sky does the moon set?
waning crescent the moon sets on the west side, and rises on the east side (east to west)
When the northern hemisphere is tilted TOWARDS the Sun the average daily temperature is marked as____, suggested that the northern hemisphere is experiencing____
warm;summer
Jupiter's moon Europa
water-ice surface; no craters — ice movement wiped them out; liquid water ocean below icy crust
nanometers down to picometers
wavelengths of X-rays are measured in...
meters/centimeters
wavelengths of radio waves are measured in...
ten-billionths of a meter
wavelengths of visible light are measured in...
A photon's___can be measured to determine its energy
wavelengths or frequency
lower; higher
when an absorption line is produced, the electrons move from a ________ to a ________ energy level
in the southern hemisphere its___in late june, and__is in late december
winter;summer
If you were to sit on the ground, there would be a force due to gravity pulling you toward the earth. which of the following is true according to newton's third law
you are pushing the earth away from yourself with the same force
magnification
zooms in on a smaller portion of the sky, to see more detail (but also observes a smaller overall area of the sky)
Jupiter
• Jupiter is about 300 times the mass of the Earth, but is on average far less dense — overall about 1.3 grams per cubic centimeter (about the density of milk); it has a radius of 11 times that of the Earth. Jupiter has a small ring system. Jupiter is made mostly of hydrogen and helium gas. - Gaseous molecules of ammonia, methane, and water vapor also present; these lead to different colors in Jupiter's stripey, swirling appearance. - Clouds of different colors are also at different altitudes. Windspeeds can reach 360 km/hr; the "Great Red Spot" is a giant storm larger than Earth — like an anticyclone on Earth — and has lasted for at least 300 years Jupiter rotates rapidly (once every 10 hours), which stretches the clouds into long bands. It takes Jupiter 12 Earth years to orbit the Sun. Interior temperatures and pressures get very high, deep inside Jupiter's gaseous body - Hydrogen gets compressed into a liquid-metallic form. - In its very center, Jupiter is likely to have a rocky/metallic core. Magnetic fields are 10 times stronger than Earth's due to the rotating liquid-metallic region; interaction between this magnetic field, the solar wind, and Jupiter's atmosphere leads to aurora like we see on Earth Methane can convert to carbon soot, and high pressures inside Jupiter can compress that into diamonds (leading to "diamond rain" in Jupiter's atmosphere). Life forms in Jupiter's atmosphere were proposed to exist by astronomers Carl Sagan and Edwin Salpeter; these speculative creatures were referred to as "sinkers," "floaters," and "hunters."
born
• The Sun was in the constellation of your Zodiac "sign" during the month you were...
neptune moon triton
• Triton (largest): thin atmosphere made of nitrogen and methane; rocky composition; reflective icy surface; ice volcanoes with liquid nitrogen, dust, or methane coming out of them; • unusual orbit suggests Triton may be a captured Kuiper Belt object
Asteriods
• remnants of the Solar System's formation — rocks left over when the planets form • many are in the "Asteroid Belt" between Mars and Jupiter • asteroid orbits are typically slightly elliptical • a few major types exist: carbon-rich, metallic, and silicate (stony) • we see asteroids by reflected sunlight; they do not shine visibly on their own • the orbits of some asteroids intersect Earth's orbit, and lead to meteors • most are less than 1 kilometer in size, but some are bigger • like comets, asteroids tend to move very slowly across the sky to a viewer on Earth
