The systematic study of the properties and evolution of stars, galaxies, and the universe is known as:
Kepler proposed that:
Planets orbit the sun in elliptical orbits.
Planets move in elliptical orbits.
An astronomical unit (A.U.) is defined as
Understanding the Universe
Video Worksheet Answer Key
WHERE ARE WE?
The universe may be billions of years too young
The universe contains, dark stars, dwarf stars, stars that eat each other, stars clumped in galaxies, and galaxies clumped in larger st
1- About two-thirds of all chemical elements have been observed in solar spectrum. The
elements other than hydrogen and helium observed in the solar spectrum:
Were produced by fusion in other stars.
Were produced in other stars.
2- The sun has a tempera
the systematic study of the properties and evolution of stars, galaxies, and the universe is known as
kepler proposed that
planets move in elliptical orbits
Aristarchus used the size of the earth's shadow during a lunar eclipse to compute