P8.3 Beyond Earth Flashcards
Red-shift
Wavelength of light moving away from you increases and the frequency decreases
It shifts more towards the red side of the absorption spectrum
Blue-shift
Opposite of red shift
When an object moves closer, the visible light moves to the blue end of the spectrum, as its wavelengths appear shorter
When an object is moving faster than you
Bigger red-shift
When an object is moving slower than you
Blue-shift
Hubble’s constant or galaxy speed
1/10 × distance
Universe’s age
1 / Hubble’s constant
Cosmic microwave background radiation (CMBR)
Residual energy from the Big Bang
Very high energy radiation with high frequency stretched out over time until it became a microwave on the electromagnetic spectrum
The Sun
The star at the centre of the Solar System
Planets
Spherical objects orbiting the Sun due to gravity
Moons
Objects orbiting planets
Comets
Made of dust and ice
Orbit the Sun with long and thin orbits
Minor planets
Anything orbiting the Sun other than planets or comets, i.e. asteroids, dwarf planets
Inner planets
Mercury, Venus, Earth, Mars
Rocky planets
Have an atmosphere
Outer planets
Jupiter, Saturn, Uranus, Neptune
First two = gas giants
Second two = ice giants
All have rings and lots of moons
Asteroids
Rock fragments leftover from the creation of the Solar System
The asteroid belt is between Mars and Jupiter
Star life cycle of a less massive star
Star birth from dust and gas (nebula) → nebula condenses into a protostar → nuclear fusion → main sequence star → hydrogen runs out and fusion starts again → red giant → white dwarf → cools down → black dwarf
Life cycle of a more massive star
Star birth from dust and gas (nebula) → nebula condenses into a protostar → nuclear fusion → main sequence star → hydrogen runs out and fusion starts again → red super giant→ explodes → supernova → neutron star (if big)/black hole (really massive)
Natural satellite
Non-man-made objects that orbit a planet
Example: the Moon
Artificial satellite
Man-made objects that orbit a planet
They have two types of orbits:
- geostationary orbit
- low polar orbit
Geostationary orbit
Takes 24hrs to complete one orbit.
Around 36,000 km above the Earth’s surface.
They remain fixed over the equator
Used for communication and satellite television
Low polar orbit
Takes around 2 hrs to complete one orbit.
Can reach up to 2,000 km above the Earth’s surface.
They orbit over the poles.
Used for weather, military, and Earth observation
If an orbiting object speeds up…
…it’ll fly away due to too much gravitational energy
If an orbiting object slows down…
…it’ll accelerate and crash into the object it’s orbiting
If an object emits more radiation than it absorbs…
Its temperature decreases
If an object emits less radiation than it absorbs…
Its temperature increases
If an object emits the same amount of radiation that it absorbs…
It stays at constant temperature
The Earth’s contents (going outwards)
Solid inner core, liquid outer core, Mostly solid mantle (but it can flow), solid crust
Seismic waves
Waves from an earthquake
How do we use seismic waves
Measured on seismometers
Plotted on seismographs
P-waves
Primary (seismic) wave
Arrives at the surface first in an earthquake
Longitudinal waves, can travel through solids and liquids
S-waves
Secondary (seismic) wave
Arrives at the surface second in an earthquake
Transverse waves, can only travel through solids → proves that outer core must be liquid
Order of planets of distance from sun
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
