Astronomy Chapter 7
One piece of evidence that can help astronomers sort out how the planets in our solar system formed is
finding circumstellar disks of material around nearby stars
All the planets (without exception)
revolve around the Sun in the same direction
A planet in our solar system whose composition resembles that of our Sun is:
Jupiter
Besides the Sun where is most of the mass of the solar system?
Jupiter
How do asteroids differ from comets?
Asteroids are rocky bodies and are denser than the comets, which are made of icy material.
Which planet other than the Earth has visible water ice on it?
Mars
The most metal-rich planet is
Mercury
Which of the following statements is not an observed pattern of motion in our solar system?
Most planets orbit at the same speed
Which planet was discovered using mathematics before it was seen in a telescope?
Neptune
The first trans-Neptunian object astronomers found (in 1930) is called
Pluto
What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter?
The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft
Which of the following observations indicates that conditions on Mars may have been suitable for life in the past?
There is liquid water as well as a significant number of dried up river beds on mars
Which of the following is not a characteristic of the outer planets?
They have very few satellites
What planet does not have satellites?
Venus
Which of the following is farthest from the Sun?
a comet in the Kuiper belt
Radioactive dating techniques have revealed that our Earth and Moon are approximately how old?
about 4.5 billion years
The smaller objects in the solar system made of rock and metal are called:
asteroids
Which of these is a way to date a planetary surface?
counting the craters
In radioactive dating, the measure scientists use to note how long (on average) a particular radioactive nucleus will take to decay is called its
half-life
If you were to look at the four giant planets the most common element you would find would be:
hydrogen
In studying the surfaces of solid bodies in the solar system, astronomers have learned that the number of craters (per unit area):
is roughly proportional to the age of the surface we are examining
The inner planets are made mostly of rock and metal because
it was hot where the inner planets formed that the lighter materials evaporated
Which of the following ways that jovian (giant) planets differ from the terrestrial planets is NOT corret?
jovians have more mass than terrestrial planets
Astronomers have decided that rather than being a planet Pluto is really just a large member of
the Kuiper belt
The smaller objects in the solar system composed mainly of ices that usually orbit far from the Sun are called:
the comets
Which of these would be considered the coldest location?
the moons of Neptune
Which of the following is not an exception to the general patterns in the solar system?
the rings of Saturn
Our best evidence and theoretical calculations indicate that the solar system began with a giant spinning system of gas and dust that scientists call:
the solar nebula
