Definitions 1
astronomical unit
A unit of distance based on the average distance between the earth and sun
fission
a process where a large atom fissions or breaks into smaller atoms, releasing a lot of energy
Why was the astronomical unit created?
Miles and kilometers are impractical for vast areas
How does the appearance of rings around Jovian planets point to a young universe?
The gravitational pull of the moon would have torn Saturn's rings apart if it were millions or billions of years old
Why do sunspots appear in pairs?
They are regions of magnetic fields, and the sunspots in the pair have opposite polarity.
density
measure of how closely packed matter is (in grams)
fusion
smaller atoms combining into larger atoms, creating energy
Which 2 planets rotate backward, or clockwise?
Venus and Uranus
How does the presence of CO2 in the atmosphere of Venus keep the planet hot?
It traps the infrared radiation rather than letting it radiate away
What are 2 basic types of telescopes?
refractors and reflectors
rotation period
the period of time it takes an object to spin on its axis once
wavelengths
refers to how long a light wave is
What are the 2 classifications or planets?
terrestrial and Jovian
Which planet has the largest known volcanoes in the solar system?
Mars
How does using the spectra of astronomical bodies help tell us what substances for these bodies?
Different elements form different spectral lines, so they can be used to tell the composition of the body.
Galilean satellites
refers to the 4 largest moons of Jupiter
electromagnetic radiation
the name for invisible wavelengths of light
Which type of planet it closer to the sun?
terrestrial
Do scientists think earth was a lot colder in the past?
No
What 3 discoveries by Galileo proved the geocentric theory was incorrect?
1. the phases of Venus
2. craters on the moon
3. four moons orbiting Jupiter
parallax
the visual shift back and forth each year of the stars, based on where we are viewing it from either side of earth's orbit
infrared radiation
refers to the radiation that has wavelengths longer than what is visible to the human eye
What type of planet has a lot of satellites and rings and are larger, with less density?
Jovian
From which part of the sun do we receive almost all of our radiation?
Photosphere
Who measured the earth's size in 200 B.C., and how was it measured?
Eratosthenes; by measuring how high the sun was in the sky on the same date from two locations running along the north and south line