Space Unit Review Flashcards
frame of reference
a system of objects that are not moving with respect to one another
celestial bodies
any natural body outside of the Earth’s atmosphere
constellation
A group of stars that form a pattern in the sky
azimuth
A horizontal angle measured clockwise from north or south.
altitude
height above sea level
astrolabe
an instrument formerly used to make astronomical measurements
compass
an instrument that shows the direction of magnetic north
geocentric
A model of the universe in which Earth is at the center of the revolving planets and stars.
retrograde motion
a planet’s apparent backward movement in the sky.
heliocentric
A model of the solar system in which Earth and the other planets revolve around the sun
ellipse
A elongated circle, or oval shape, the shape of the planets orbit.
universal gravitation
force of attraction that acts on all objects in the universe.
resolving power
A measure of the clarity of an image; the ability of an optical instrument to show two objects as separate.
refracting
A telescope that uses convex lenses to gather and focus light
reflecting
A telescope that uses a curved mirror to collect and focus light
spectrum
colored band produced when a beam of light passes through a prism or diffraction grating
spectral lines
dark lines or bright lines observed in the spectra of stars
spectroscopy
the branch of science concerned with the investigation and measurement of spectra produced when matter interacts with or emits electromagnetic radiation.
diffraction grating
a device made of thousands of closely spaced slits through which light is passed in order to produce a spectrum
spectral analysis
method of charting and analyzing the chemical properties of matter by looking at the bands in their visible spectrum of light
Doppler effect
A change in sound frequency caused by motion of the sound source, motion of the listener, or both.
red shifted
moving away, spectral lines shifted towards the red end of the spectrum
adaptive optics
Rapid changes in mirror shape compensate for atmospheric distortions.
triangulation
Using a baseline and measured angles to create a scale drawing to find the distance to an object.
astronomical unit
The average distance between Earth and the sun, about 150 million kilometers
light-year
the distance light travels in one year
electromagnetic radiation
The energy transferred through space by electromagnetic waves. Includes radiowaves to gamma waves
radio astronomy
The study of celestial objects that emit radio waves.
interferometry
A technique that uses the images from several telescopes to produce a single image
ballistic missile
a rocket with a bomb as a payload, launched in a trajectory that sends it up into space and down onto its target
gravitational assist
a method of acceleration which enables spacecraft to change speed by using the gravity of a planet
charged coupled device
A solid-state image sensor used in digital imaging (CCD)
artificial satellite
any human-made object placed in orbit around a body in space
low earth orbit
an orbit located a few hundred kilometers above the earth’s surface
geosynchronous orbit
the orbit of a satellite that revolves around Earth at the same rate that Earth rotates
global positioning system
A system that determines the precise position of something on Earth through a series of satellites, tracking stations, and receivers.
solar wind
A stream of electrically charged particles produced by the sun’s corona
inner planets
Small, rocky (terrestrial) planets that orbit closest to the sun including Mercury, Venus, Earth, & Mars
outer planets
Jupiter, Saturn, Uranus, & Neptune. Called Gas Giants.
nebula
A cloud of gas and dust in space. Stars form in nebulae.
galaxy
A collection of stars, dust, and gas bound together by gravity
suborbital trajectory
a spacecraft is boosted above the atmosphere and then falls back to Earth without going into orbit.
microgravity
the condition of experiencing weightlessness in orbit
