Astronomy Part 3

Front

How many planets in the solar system are there?

Back

8

Front

What process heated the early solar nebula as it slowly condensed toward a central protosun? Options: thermonuclear fusion in the protosun, followed by radiative heating of the material of the nebula, release of heat from the kinetic energy in collisions of particles as they fall toward the center of the nebula, release of heat as molecules such as CO₂ and NH₃ form from atoms and ices condense from gases such as H₂O

Back

release of heat from the kinetic energy in collisions of particles as they fall toward the center of the nebula

Front

How old is the Earth?

Back

about 4.6 billion years old

Front

What is the smallest planet?

Back

Mercury

Front

Where did the heavy elements in the universe originate?

Back

in nuclear fusion deep in the interiors of stars

Front

How are most planets orbiting other stars detected? Options: the planets are observed directly, by the alternating Doppler shifts of the stars, by the change in color of the star as the planet passes in front of it, by the motions of moons around these planets

Back

by the alternating Doppler shifts of the stars

Front

The planets that have been discovered outside the solar system are typically most similar in mass to which of the following? Options: the Sun, the Earth, Pluto, Jupiter

Back

Jupiter

Front

Rock and metal debris smaller than asteroids is called:

Back

meteoroids

Front

Planetesimals collide and stick together to form protoplanets because

Back

of their mutually attractive gravitation.

Front

Which aspect of the early solar nebula controlled the early evolution and place of formation of the terrestrial and the Jovian planets? Options: The rotation of the nebula, Distribution of hydrogen in the nebula, Distribution of silicates in the nebula, Temperature distribution within the nebula

Back

Temperature distribution within the nebula