Units 1-5 Flashcards
Astronomy
study of the universe
Earth
reference for other astronomical objects
Radius: 6371 km
Satellite
an object that orbits another
Earth’s moon
1/80th the mass of earth therefore less able to retain internal heat or atmosphere
The sun
100x earths radius
Generates energy by the nuclear reaction converting H to He in the core
AU
Earth’s distance from the sun ~150 mil km
Exploded Stars
lead to new stars
- white dwarfs
- neutron stars
- black holes
Light year
the distance light travels in one year
The milky way galaxy
collection of several hundred billion stars, gas and dust all in a disk shape
Virgo Cluster
central cluster of galaxies in relation to milky way
Supercluster
collections of many galaxy clusters
Order of orbit
- satellites around planets
- planets around stars
- stars around galaxies
- galaxies in clusters
- clusters in superclusters
Big Bang
theory of an all encompassing explosion resulting in galaxies flying away from one another
space is always expanding
Dark Matter
mass made from strange substances that cannot form stars or planets
Parsec
invented as a unit to simplify the formula for the primary method we have for finding stars distances
parsec= 3.09 x 10^16 m
universality
the idea that we can apply what we learn about nature on earth to the universe at large
electromagnetic force
electric charges generate fields of magnetic force
infinite range
strong force
binds protons and neutrons together, acts over short distances
Radioactive decay
an atomic nucleus splits into two smaller nuclei, with the release of radiation
Quarks
makes up atomic particles
Particles that make up known universe
up quarks
down quarks
electrons
neutrinos
constellation
recognized group of stars
asterisms
unofficial names for groupings of stars
celestial poles
celestial sphere rotates around these points
