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;
51 Cards in this Set
- Front
- Back
Galileo
|
Observation w/ first telescopes that supported heliocentric view.
1st to use telescope for astronomy. More stars, nebulous blurs(Milky Way) made of many stars. Jupiter satellites orbit. Phases of Venus support heliocentric. Moon rough & irregular. Sunspots = imperfect. Persecuted by Roman Inquisition. |
|
Isaac Newton
|
"Marvelous Year"
Calculus, theory of gravity (Principia), explanation for nature of light, invented reflecting telescope. |
|
Newton's Laws
|
1. Inertia - a body continues in a stte of motion or rest unless made to change by an outside force.
2. F=ma - the amount of acceleration that a force produces depends on the mass being accelerated. 3.Action-Reaction: when two bodies interact, they create equal and opposite forces on each other. Universal Law of Gravity: F=GMm/r^2 |
|
What causes tidal bulge?
|
Differential gravitational force the Moon exerts on Earth's waters.A portion of the Earth's surface is always 8,000 mi closer to the Moon than the opposite surface.
|
|
Spring vs neap tides?
|
Spring tides: new and full moon phases. (Max tides)
Neap tides: near quarter moon phases.(Min. tides) |
|
High & low tides?
|
High tide on side of Earth near Moon results from water being pulled away from the Earth & toward Moon, the high tide of the opposite side of the Moon results from Earth being pulled away from the water & toward Moon.
Low tide occurs between high tides. Cycles high to low every 6 hrs 12 mins |
|
Wax vs Wane
|
Wax - increasing illumination w/ time
Wane - decreasing illumination w/ time |
|
New Moon
|
unilluminated, rises at sunrise
between new and 1st quarter is waxing crescent |
|
First Quarter
|
half illuminated
bet. 1st Q & Full is waxing gibbous |
|
Full Moon
|
fully illuminated, rises at sunset
between full & 3rd Q is waning gibbous |
|
Solar eclipse
|
occur at time of New Moon if Moon lies directly between Earth and Sun
Partial - moon doesn't completely cover sun Total - moon completely covers Sun. Lasts less than 3-7 mins at any one place. Annular - moon nearly perfectly eclipses sun but is at a larger than normal distance from earth. Ring of sunlight around dark Moon. |
|
Lunar eclipse
|
occur at full moon when earth lies between moon & sun.
|
|
What are seasons caused by?
|
the plane of the Earth's rotation is not aligned w/ the plane of Earth's revolution about the Sun. This is called obliquity of the ecliptic.Opposite seasons in northern & southern hemispheres.
|
|
Examples of gravity(dominant force in solar system)
|
1.Holds sun together, pressure from high temperatures tries to push sun apart.
2. causes planets,asteroids,and comets to orbit Sun. 3. Earth-Moon system causes tides. |
|
celestial coordinates
|
locations of stars in sky.
longitude = right ascension latitude=declination local sidereal time = tells when a star of a particular right ascension will be at its highest point zenith = point in sky directly overhead ecliptic = apparent path of the sun through the sky. all planets & moon found here. constellations along this are "constellations of the zodiac." |
|
Aurora
|
arise when charged particles are produced by a solar storm. Charged particles become part of the solar wind, when particles encounter Earth's magnetic field, they are guided to the poles. Once it hits the molecules in the atmosphere a glow is produced.
|
|
time zones
|
24, each 15 degrees wide in longitude. Time is adjusted in each so the sun will be highest pt in sky within ~ 1/2 hr of noon each day.
|
|
precession of the equinox
|
earth's axis of rotation changes the direction it's pointed w/ a cyclic period of 26,000 yrs.
|
|
electromagnetic radiation
|
astronomers observe astronomical objects by observing how they emit & absorb EM radiation.
photons |
|
photons (EM radiation)
|
wave-like & carry energy.
diffract (spread out) when they pass by the edge of an opaque body. wavelength of photon inversely proportional to its energy(shorter wavelength, greater energy). When separated into their component wavelengths/energies, EM spectrum formed. |
|
Types of EM radiation. Dec. order of energy (short to long wavelength)
|
Gamma Rays - energetic processes. observed w/ space telescopes cuz ozone absorbs most.
X-rays - energetic processes & absorbed by ozone. UV radiation - most emitted by energetic processes & hot stars. mostly absorbed by ozone. Visible rad. - moderate temp stars like sun emit large fraction of their energy @ visible wavelengths. Passes through atmosphere. IR rad - most emitted by cool stars, most wavelengths absorbed by water vapor in atmosphere. Radio Waves - smallest eng & longest wavelengths. Most emitted by plasmas associated w/ magnetic fields. Generally pass thru but shorter length radio waves bounce off ionosphere |
|
Visible light
|
ROY G BIV
Red = longest wavelength Violet = shortest wavelength |
|
Telescope collecting area
|
determines how much em rad. from an object can be collected & focused in a given interval of time. Larger area = further objects.
|
|
focal length
|
determine scale of image formed. magnification depends on scope focal length & eyepiece focal length. f-value (length/diameter) = image brightness.
|
|
Optical telescope types
|
Refracting: focuses light w/ lenses. Expensive & suffer from chromatic aberration.
Reflecting: focus light w/ mirrors. vary in cost aberrations determined by the design. Some use both, usually expensive. |
|
Photometry
|
measuring of the strength(magnitude) of light. Done w/ photographic plates as detectors or CCDs (charged couple deviced)
|
|
Magnitude scale
|
invented by Hipparchus.
magnitude of a star decreases by 1 unit, star is 2.5x brighter. If dec. by 5 units, star is 100x brighter. |
|
Keck 10-m telescopes
|
largest ground-based telescopes. Low cost design to achieve large collecting areas.
|
|
Spectroscopy
|
break up UV, optical, & IR light into its component wavelengths or energies using prisms or diffraction gratings. Used to study details of the spectrum of an object.
|
|
Solar nebula hypothesis
|
planets formed out of a rotating disk of gas & dust around the protostar that formed the Sun.
|
|
Planet Order
|
mercury, venus, earth,mars,jupiter,saturn,uranus,neptune
|
|
Terrestrial planets
|
dense rocky bodies ~ diameter of Earth or smaller which may have a gaseous atmosphere
Mercury,venus,earth,mars |
|
Jovian Planets
|
giant gaseous many times the diameter of Earth. large & low density. All have ring systems & moons.
jupiter,saturn,uranus,neptune |
|
Asteroids
|
orbit around sun.
most confined to an orbit between mars & jupiter. non-luminous chunks of rock smaller than a planet. most small enough that gravity doesn't force them into spheres. |
|
Comets
|
asteroid-sized bodies that contain ice & travel in elongated orbits around Sun. absorbed energy from sun and melt & evaporate the ice and producing a huge cloud and a tail of gas and dust that reflect sunlight while near the Sun.Meteor showers occur when earth passes through the debris trail.
tail points away from sun |
|
Meteoroids
|
non-luminous chunks of rock before they enter Earth's atmosphere. Friction from atmosphere causes them to burn and as they streak across sky they are METEORS (luminous object).
When meteor does not burn up completely and impacts earth it is a meteorite |
|
Yucatan Peninsula meteorite
|
65 million yrs ago, cloud raised by impact covered Earth for many years and a layer of clay containing iridium settled. 75% of species wiped out, like dinosaurs.
|
|
Planetesimal
|
one of the small bodies formed from solar nebula and came together w/ others to form a protoplanet
|
|
Differentiation
|
when planetesimals grew to large enough size, release of energy by radioactivity caused layering of light & heavier materials in protoplanet
|
|
outgassing
|
process by which gasses released from planet's interior during differentiation, creating an atmosphere
|
|
Oort Cloud
|
spherical shell of comet nuclei whose orbits lie in realm out past the planets in SS.
|
|
Models
|
understand physical processed & make predictions.
|
|
Aristotle
|
developed geocentric model, dominated cosmological thought for ~1800 yrs. Used logic and detailed reasons (i.e. stellar parallax).
Earth's shadow, moon shape, earth-centered cuz everything falls, stellar parallax. |
|
Quintessence
|
5th element in Greek model.
unchanging transparent element that formed the crystalline spheres that held the stars & planets(wanderers) in place. |
|
Greeks
|
used invented & developed scientific theory
believed moon revolved around earth and sun more distant than moon. Earth & moon reflective, sun creates light. Conceptual understanding of moon phases & eclipses. Could predict accurately. |
|
Light year
|
speed of light = 186,000mps. time it takes light travel A to B indicates distance.
5.88 x 10^12 miles = 1 light year |
|
Copernicus
|
catholic clergy
proposed heliocentric theory in 1512. delayed publication of Commentariolus until death. |
|
Astrology vs Astronomy
|
astrology - believe each part of human anatomy controlled by a specific sign of the Zodiac.
Astronomy - the scientific study of celestial objects and phenomena that originate outside the Earth's atmosphere |
|
Johannes Kepler
|
scientist,mathematician,philospher, and mystic.
Difficult life - protect mom from being burned at stake as a witch (aunt was). Had myopia and multiple vision. Very religious but persecuted by Catholics & Protestants for Copernican views. Worked w/ Tycho Brahe 3 laws of planetary motion. Paved way for Newtons theory of gravity. |
|
Kepler's Laws of Planetary Motion
|
1. Planetary orbits are ellipses not circles.
2.Planet in its orbital plane sweeps out equal areas in equal amounts of time. Closer a planet is to the Sun, faster it moves. 3.P^2 = D^3. P is period of a planet's revolution around sun in yrs and D is planet's distance from Sun in AU (astronomical units) |
|
AU
|
astronomical units = avg distance from Earth to the Sun. 93,000,000 mi.
|