Chapter 2 Flashcards
Number of galaxies in the universe
125
Our galaxy
Milky way
Location of our solar system
on the trailing edge of the milky way
Light years in diameter?
100,000
We are ______ light years from the center
30,000
Milky Way
flattened disk shaped collection of stars, barrel shaped
Whats at the very center of the milky way galaxy?
a black hole
Formation of the solar system
- large rotating cloud of gas and dust
- nebula cloud flattened into a disk shape
- gravity pulled matter proportional to its mass together, forming a protosun
- the proto sun grew in mass, drawing more mass to it
- meanwhile, material accreted together creating protoplanets, which in turn drew more mass towards them to create planets
Gravity
mutual force exerted by the mass of objects that are attracted one another and produced in an amount proportional to each object’s mass
Planetesmal hypothesis
suggests a process by which early protoplanets formed from the condensing masses of a nebular cloud of dust, gas and icy comets
Moons in our solar system
165 (around 6 planets)
Planets in our solar system
8
Speed of light
300,000 km per second
How long does it take for light to travel the diameter of our solar system?
11 hours
Earth orbits around the sun in a _______ (_____) path
elliptical (oval) path
Perihelion
when the Sun and Earth are closest in distance (January 3)
Aphelion
when Sun and Earth are farthest apart (July 4 )
Plane of the Ecliptic
a plane touching all points of Earth’s orbit
Cause of sun spots
Visible surface disturbances on the sun caused by magnetic storms
What causes the auroras?
When solar wind reacts with the magnetosphere and is directed above the poles, where they interact with gases in the ionosphere
Magnetosphere
Earth’s magnetic force field, which is generated by dynamo-like motions within the planet’s outer core; deflects the solar wind flow toward the upper atmosphere above each pole
Aurora
Coronal mass ejections ( and solar flares and solar winds) interact with the magnetosphere and gases in the ionosphere to create a light display at the poles
Frequency (
number of waves passing a fixed point per second
Wein’s Displacement Law
all objects radiate energy in wavelengths related to their individual surface temperatures (the hotter the object, the more shortwave radiation emitted)
Wavelength
The distance between two corresponding point on any two successive waves
Stefan Boltzman Law
Objects that are efficient absorbers or radiation are good emitters too
Solar minimum
period during which FEW sunspots are visible
Solar maximum
period during which sunspots are numerous.
Sun spot cycle
11 years between solar maximums, where magnetic activity (solar flares, CME’s, magnetic storms, prominence flares)
- most of the flares are pulled back into the sun because of magnetic force, some are released in the form of solar wind
Solar Wind
Clouds of electrically charged particles?
Wavelength unit
Micrometers μm
1
