BCS9 Chapter 11 Flashcards
black hole
a large sphere of incredibly tightly packed material with an extraordinary amount of gravitational pull created when a star collapses into itself; called “black” because nothing, not even light, can escape the powerful gravitational field
Doppler effect
the change in wavelengths of electromagnetic radiation or sound that occurs because of the movement of the source relative to an observer
fusion
the process in which the nuclei of atoms fuse together to form larger single atoms, creating an enormous amount of energy
interstellar matter
the material that fills space, made up of gas (mostly hydrogen) and dust
star
a celestial body of hot gases with a core like a furnace that makes its own thermal energy
supernova
a dramatic, massive explosion that occurs when a large,high mass star collapses in on itself
asteroids
small rocky bodies in our solar system, most of which orbit the Sun between Mars and Jupiter
axis
an imaginary line through Earth, extending from the North Pole to the South Pole; Earth spins on its axis at a speed of 1670 km/h, or 0.5 km/s
comet
a small body made up of rocky material and ice that occurs in the Kuiper Belt and the Oort Cloud; when a comet is bumped into the inner solar system, the Sun’s light may make the comet’s tail visible from Earth
moons
celestial bodies that orbit aplanet
planet
a celestial body that orbits one or more stars, is large enough that its own gravity holds it in a spherical shape, and is the only body occupying the orbital path
revolution
the motion of Earth as it orbits the Sun at 30 km/s; one full revolution takes almost a year
rotation
the motion of Earth as it spins on its axis from west to east at 1670 km/h; one full rotation takes almost a day
solar system
a group of planets circling one or more stars
light-year
the distance that light, which moves at 300 000 km/s, travels in a year; equals about 9.5 trillion km
