Download ASTRONOMY WORKSHOP

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Einstein's special theory of relativity - a physical theory of relativity based on the
assumption that the speed of light in a vacuum is a constant and the assumption that
the laws of physics are invariant in all inertial systems
Time slows down (when objects move quickly) and it is different to each observer.
Time is relative, so it depends on where you are. The faster you move, the slower
time moves.
Mass appears to increase: If an object is moving at high speed relative to you, the
object will appear to behave strangely. Its mass will increase, so that it becomes
harder and harder to accelerate as it approaches the speed of light. E=mc^2 Energy
contained in an object is the mass times spend of light squared.
3. Length decreases: It will appear to shrink in its direction of motion, becoming more
and more distorted as it travels faster. The object's time will also become distorted; if
there is a clock on the object, it will appear to tick more slowly. These effects happen
to every object, but they only become noticeable once objects approach the speed of
light.
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*Time slows, mass warps space, and there is a gravitational redshift (caused by
photons traveling through space and time).
Clocks run more slowly in regions of lower gravitational potential.[8] This is called
gravitational time dilation.
Orbits precess in a way unexpected in Newton's theory of gravity. (This has been
observed in the orbit of Mercury and in binary pulsars).
Rays of light bend in the presence of a gravitational field.
In general relativity, the presence of matter (energy density) can curve space-time,
and the path of a light ray will be deflected as a result.
Rotating masses "drag along" the spacetime around them; a phenomenon termed
"frame-dragging".
The Universe is expanding, causing a gravitational redshift, and it is moving away
from us faster than the speed of light.
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•The Cosmic Background Explorer (COBE) took pictures which explained the
jumpiness of the MBR.
* Wilkinson Microwave Anisotropy Probe (WMAP) confirms cosmic neutrinos
fill the Universe, showing the first stars took more than a half-billion years to
create a cosmic fog.
* CMB's discovery, in 1964, by American radio astronomers Arno Penzias and Robert
Wilson was due to the culmination of work by Gamow (initiated in the 1940s) and
Dicke’s radiometer and hypothesis.
-This discovery earned Penzias and Wilson the 1978 Nobel Prize.
*explains radiation left from the Big Bang Theory
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Density is denoted as “d,” while “dc” stands for critical density. The 'critical density' is
the average density of matter required for the Universe to just halt its expansion, but
only after an infinite time.
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* BIG BANG:
-Hubble discovered the redshift is proportional to its distance. This means there was
an initial high density and high temperature state.
-galaxies move/recede from each other since they have no center
-CMBR is spread over entire sky and is evidence for this theory
* STEADY-STATE:
-new particles are formed to fill in the space of the expanding galaxy
-universe looks the same daily
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*what we can account for in the Universe:
72% dark energy (repels), 23% dark matter(attracts), 5% bright matter
*explains why the universe is expanding out of control at an accelerated rate
*cosmological constant
*quintessence (new force)
*outcome: big rip or big crunch
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*Terrestrial Planets:
-formed slowly from accretion disks
-high density
- inner four planets
-smaller, rocky
-no rings, few moons
*Jovial Planets:
-formed by gravitational collapse
-low density
-outer four planets
-larger, gaseous
-ring systems, lots of moons
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Solar system:
Must describe why moons/planets are cratered
Condensation and Accretion disks:
*Condensation (gas to liquid state) in a solar nebula converts some
gasses into solids,
which accretes to form billions of planetesimals, or an object formed
from dust, rock, and other materials.
*planets> protoplanets> protoplanet at 15+earth masses=
gravitational collapse which pulls in gas from solar nebula
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* separation of material by density- the denser materials are closer to the mantle
while the core remains a liquid because the less denser materials sank
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*Wegner found that continents were one body due to rock specimen similarities.
*Glomar Challenger mapped the ridges of the earth and found samples of the core
that showed seafloor spreading.
*Igneous-(“fire”) solidified from a molten state and cooled slowly forming large
crystals; ex: pumice, basalt, obsidian, granite
*Metamorphic- has been changed due to extreme heat/compression: ex: marble
*Sedimentary- in layers of sediment corroded by water/liquid; ex: limestone and
sandstone
Explain the cause and possible consequences of a depletion of earth’s ozone layer.
*man-made clorofluorcarbons(CFC’s) cause the increase of UV Rays which cause
skin cancers and gentic mutations
*global warming is caused by the release of excessive CO2 which leads to the green
house effect and the temperature rising. This melts the polar ice caps and causes
coastal cities to flood, thereby endangering certain species.
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The pros and cons of three major theories of the origin of the moon, including the
current theory are:
1.)Fission Hypothesis- moon broke off from rapidly spinning proto-earth
2.)Condensation Hypothesis- the moon & earth condensed from the same cloud of
matter
3.)Large-Impact Hypothesis- moon formed a planetismal as large as Mars and
smashed into proto-earth and ejected a cloud of debris into a disk around earth,
where it formed the moon
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*FAR SIDE- no seas, has craters, Orientalis(impact basin)
*impacts on the near side thin the crust for volcanic flow.
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*cratering-caused by impacts of celestial bodies like meteorites
*lunar lowlands- dark seas that are smooth such as maria, or mare
*highlands- bright mountainous areas which are rough
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-breccia- rock fragments blended together due to heat and pressure and cemented
by impacts
-vesicular basalt- bubbles frozen into rock that was molten
-anorthosite-red rock
-pumice-volcanic rock
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*it suffered a major impact like the moon
*-it has lobate scarps, or long curved ridges,
-terrains like the Weird Terrain caused by the impact and formation of the Caloris
Basin
-size: 1/3 of earth
-orbit: ~ 88 days
-rotation: ~ 58 days
-The Caloris Basin was caused by an impact which created the Weird Terrain on the
other side of Mercury
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Describe the appearance of Venus:
(a) as seen through a telescope from the earth; white dot
(b) as seen in photographs using ultraviolet light; cloud patterns
(c) as seen in photographs taken by the Russian Venera landers; fresh rocks
What is meant by the “runaway greenhouse effect” that makes Venus so hot? How
does it work?
*an effect which amplifies itself
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*cloudy, thick winds, 900degrees F, sulfuric acid rain
*arachnoids- spiderlike corona
*corona- group of round cracks
*volcanoes-lava flow
*craters-wind streaks
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*Moons include: Phobos (Fear) and Deimos (Dread). Phobos- large crater= STICKNEY,
and Deimos- smooth and smaller.
*low temperature and low atmosphere, and presence of water, martian rock types
indicating the presence of water
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*belts-dark bands
*zones- bright bands of clouds
*Giant Red Spot-giant circulating hurricane
-size:11x larger than earth
-comp.: mostly ammonia, hydrogen, helium
-rotation: ~10hours
-atmos.: hydrogen rich, storms
-Magnetic Frield: holds back solar winds, high energy particles for giant belts
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*Ganymede- largest
*Callisto-Valhalla surface feature is like the Caloris Basin of Mercury
*Europa- ice covered, white
*Io- sulfuric and volcanically active
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Saturn:
*size:9x the size of earth
*appearance: oblate
*composition: ice particles consisting of hydrogen and helium
*motion: 10hours and 40mins
Saturn’s Rings:
What is meant by the concept of “resonance” and what role has it played in the
formation of Saturn’s rings and the asteroid belt?
*keeps the orbits slightly elliptical and drives tidal heating. Without the moon’s
gravity, there wouldn’t be any rings.
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*size: 4x the size of earth
*comp.: H, He
*appear.: Blue-green
*rotation:17hours 14 mins
*Atmos: 100degrees cooler than Jupiter; cloudy
*MF: none
Describe and explain the appearance of Uranus’ moon Miranda.
*ovoids-oval-shaped grooves caused by internal heat driving convection in the icy
mantle
How were the rings discovered?
The rings were discovered from the Earth in 1977 when Uranus occulted (passed in
front of) a star and it was noticed that there were dips in the brightness of the star
before and after it passed behind the body of Uranus.
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How does Neptune differ from Uranus in terms of atmospheric phenomena and
overall appearance?
*Neptune has a more dramatic methane atmosphere and it had a GREAT DARK SPOT
which has since disappeared.
Describe and explain the appearance and surface features of Neptune’s moon Triton.
*huge, multi-colored, and consists of liquid nitrogen
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According to http://www.solarviews.com/eng/pluto.htm, “From its discovery in 1930
until 2006, Pluto was considered the Solar System's ninth planet. In the late 1970s,
following the discovery of minor planet 2060 Chiron in the outer Solar System and
the recognition of Pluto's relatively low mass, its status as a major planet began to be
questioned.. On August 24, 2006, the International Astronomical Union (IAU) defined
what it means to be a "planet" within the Solar System. This definition excluded Pluto
as a planet and added it as a member of the new category "dwarf planet" along with
Eris and Ceres. A number of scientists continue to hold that Pluto should be classified
as a planet.”
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Describe the probable origin of comets and their motion around the sun.
*icy bodies around an elliptical orbit
*they develop tails which point away from the sun
Comets:
*icy bodies around an elliptical orbit
*they develop tails which point away from the sun
*comets leave behind meteors creating meteor showers
*Located around Kuiper Belt
(which extends beyond Neptune)
Describe asteroids.
Asteroids:
•Small, irregular bodies
•located between Mars and Jupiter
•In the asteroid belt
•The further away, the colder
•located roughly between
the orbits of the planets Mars and Jupiter
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1. What chemical elements are people mainly made of, and how were those elements
originally formed?
- Hydrogen, Carbon, Oxygen
- Carbon is formed for the core of a Red Giant star
2. Briefly discuss Darwin’s theory of the evolution of the human species.
* Darwin's Theory of Evolution is the widely held notion that all life is related and has
descended from a common ancestor
3. How does the Miller-Urey experiment in 1952 encourage us to expect to find life on
other planets?
*was an experiment that simulated hypothetical conditions thought at the time to be present on
the early Earth, and tested for the occurrence of chemical origins of life.
4. Explain the nature and function of DNA, and how it relates to mutations.
* DNA is gentetic coding, eventually, there is a sequence which goes wrong and genes mutate
5.) Explain how the Drake equation is used to determine the number of possible
extraterrestrial civilizations in the galaxy.
*The Drake Equation was developed by Frank Drake in 1961 as a way to focus on the factors
which determine how many intelligent, communicating civilizations there are in our galaxy.
The Drake Equation is:
N = N* fp ne fl fi fc fL
6. Describe some of the tactics used by project SETI in searching for life in other stellar
systems.
*look for new planets
*send signals
*looking for electromagnetic signals
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