Front Back
Scientific Method
Methodical approach to explore the universe in an objective manner
Theory
A framework of ideas and assumptions used to explain particular observations and construct theoritcal models that make predictions
Constellations
Projection of the stars in the celestial sphere centered on Earth The stars of a particular constellation are not gravitationally connected, which means that they can be at completely different distances
Rotation
The cause of the motion of the stars during one night in the sky
Revolution
The cause of the motion of the stars during one year in the sky
Seasons
Experienced because Earth's rotation axis is inclined to the ecliptic plane
Summer/Winter Solstice
The sun is the highest/lowestin the sky and the length of the day is greatest/shortest
Equinox
Day and night are of equal length
Earth's Precession
Slow "wobble" of Earth's axis due to the influence of the Moon; Duration: 26,000 years
The Moon
Reflects the light from the Sun; As the moon orbits Earth we see Lunar Phases
Eclipse Seasons
Because the Moon's orbit around Earth is slightly inclined with respect to the ecliptic, solar and lunar eclipses do not occur every month--> only during eclipse seasons
Geocentric Model
Ptolomaic model where Earth is in the center of the universe; predicted that planets moved on small circles (epicycles) whose centers orbited Earth on larger circles (deferents)
Heliocentric Model
Earth and other planets orbit the Sun; model accounts for retrograde motion and the observed size and variations in brightness of the planets in a straightforward way (Copernicus)
Heliocentric Model (additional observations)
Galileo observed moons orbiting Jupiter; Kepler modeled the observational data of Brahe deriving the three laws of planetary motion
Keplers 1st Law of Planetary Motion
Planetary orbits are eclipses with the Sun at one focus
Keplers 2nd Law of Planety Motion
A planet moves faster as its orbit takes it closer to the Sun
Keplers 3rd Law of Planetary Motion
The semimajor axis of the orbit is related to the orbital period
Isaac Newton
Physical principles to explain the planetary motion
Newtons 1st Law of Motion
The change the body's velocity, a force must be applied
Newtons 2nd Law of Motion
Acceleration is equal to the applied foce divided by the body's mass
Newtons 3rd Law of Motion
When bodies interact, the forces between them are always equal and opposite to one another
Newtons Law of Gravity
Gravitational force is always attractive and depends of the masses and the distance between the bodies; F=-G(M1M2/r^2)
Space Exploration
All the planets have been visited, as well as numerous comets and asteroids
Typles of Planetary Visits
Flyby, orbits, and landing
Gravity Assist in Planetary Visitation
Spacecraft approaches a planet, passes close by, and then escapes along a new trajectory
Mercury (Mariner)
Density of the planet
Venus (Venera)
Atmospheric conditions are too extreme, first soft landing
Mars (Viking, Curiosity, etc.)
Most visited planet, looking for evidence of life, found strong evidence for underground ice
Jupiter (Pioneer, Voyager, Galileo)
Volcanoes on Jupiters moon, liquid under ice surface of Europa, indications of liquid salt water under the surfaces of Ganymede and Calisto
Saturn (Voyager, Cassini-Huygens)
Complex organic chemicals in Enceladus and Titan, methane lakes and hydrocarbon sand dunes on Titan
Uranus and Neptune
Visited only by Voyager 2
Pluto and Kuiper Belt Objects
Will be visited by New Horizons
Interstellar Mission (Voyager)
Measure interstellar fields, particles and waves unaffected by the Sun
1961 Yuri Gagarin
1 orbit around the Earth, Vostok 1
1965 Alexei Leonov
1st spacewalk Voskhod 2
1969 Neil Armstrong and Buzz Aldrin
First men on the moon Apollo 11
1971 Saluvt
1st space station
Apollo Program
6 landings on the moon
Space Stations
Skylab, Mir, ISS (now)
Space Tourist Era
2001-present
Biosphere 2 (1990s)
Possibility of enclosed biosphere in space colonization
Mars 500 (2011)
Psychological and physiological effects of being in an eclosed environment for 520 days, simulating a trip to Mars
Theories of Planet Formation
Cloud of gas and dust contracts; fragment flattens into a disk; planets inherit properties from the rotating disk; There is differentiation of the planets of the Solar System
Irregularities of the Solar System
Late collisions
Formation of Planets Stop
When the star forms and blows away the dust from the disk
Core Accretion Theory
Form inner planets, plantertimals collide and form protoplanets
Gravitational Instability
Planets form directly from nebular gas, form 4 giant planets
Giant Planet Migration
Planets formed at lower temperatures and migrated inwards

Access the best Study Guides, Lecture Notes and Practice Exams

Login

Join to view and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?