Astro Ch. 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
Which is not a terrestrial planet, Jupiter, Venus, Earth, or Mars?
Jupiter
Which of these objects have we sent a probe to land on the surface of, Venus, Mars, the Moon, none of the above, or all of the above?
All of the above
How do asteroids differ from comets?
Asteroids are rocky bodies and are denser than the comets, which are made of icy material.
True or false: most planets orbit at the same speed is an observed pattern of motion in solar system
False
If you were to look at the four giant planets the most common element you would find would be
Hydrogen
Which planet other than Earth has visible water ice on it?
Mars
The most metal-rich planet is
Mercury
Which planet is the closest to the Sun?
Mercury
Which planets were known to the ancient people?
Mercury, Venus, Earth, Mars, Jupiter
Which planet was discovered using mathematics before it was seen in a telescope?
Neptune
Which planet in the solar system has not been examined by spacecraft instruments that have either flown by or orbited them?
Planet X
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
What are the exceptions to the general patterns in the solar system?
The large size of Earth's moon, the counterclockwise rotation of Venus, the extreme axis tilt of Uranus
What 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 riverbeds on Mars
Of the following which do NOT have satellites, Venus, Mars, Jupiter, or Earth?
Venus
Which is farthest from the sun, an asteroid in the asteroid belt, Pluto, Neptune, or a comet in the Kuiper belt?
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
The smaller objects in the solar system composed mainly of ices that usually orbit far from the Sun are called
comets
What is a way to date a planetary surface?
counting the craters
True or false: Having very few satellites is a characteristic of the outer planets
false
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
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
How do jovian (giant) planets differ from the terrestrial planets?
jovians have more mass than the terrestrials, jovians are further from the Sun than terrestrials, jovians are made of lighter elements on average that terrestrials, jovians have rings while terrestrials do not
Astronomers have decided that rather than being a planet Pluto is really just a large member of
the Kuiper belt
Which of these is not part of our solar system?
the Milky Way
What would be considered the coldest location?
the moons of Neptune
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
