Chapter 8

Which of the following parts of the formal definition of a planet does Pluto fail to meet?

It has cleared the neighborhood around its orbit

A gas particle will escape a planet's atmosphere if it moves faster than the ...

"escape speed"

Almost the entirety of Jupiter's size is made up of ...

gas

What two factors influence whether gas particles stay or leave a planet's atmosphere?

gravity and heat

The Jovian planets are composed mostly of _______ and _________.

hydrogen .... helium

The planets closest to the Sun are known as the ...

terrestrial planets

As the solar nebula cooled, which compounds were the first to condense from a gas to a solid?

metals

How many millimeters will a 17 mm wavelength radiowave be shifted if the source is traveling away from the observer at 12,000,000 m/s?

0.68 Δλ / λ = v / c λ = 17 mmv = 12,000,000 m/sc = 300,000,000 m/s Δλ = λ * v / c Δλ = 17 * (12,000,000 / 300,000,000) = 0.68 Since Δλ is the change in lambda, this would be the amount that the radio wave is shifted. So the answer to this question is simply 0.68 mm.

If the peak wavelength of a star at rest is 830 nm, but astronomers on earth observer that is has been shifted by 3.2 nm. Then how fast is the star moving relative to the earth?

1,156,630

If the peak wavelength of a star at rest is 1375 nm, then what peak wavelength is observed when the star is traveling 975,000 m/s away from the Earth.

1,379.4688

If the peak wavelength of a star at rest is 350 nm, but astronomers on earth observer that is has been shifted by 2.25 nm. Then how fast is the star moving relative to the earth?

1,928,571 Δλ / λ = v / c λ = 350 mmΔλ = 2.25 nmc = 300,000,000 m/s v = c * Δλ / λ v = 300,000,000 * (2.25 / 350) = 1,928,571 m/s

The gas in the solar nebula began at a temperature of about ....

2000 K

How many asteroids (that we know of) are on a potential collision course with Earth?

300 - 500

If the peak wavelength of a star at rest is 660 nm, but astronomers on earth observer that is has been shifted by 0.001 nm. Then how fast is the star moving relative to the earth?

454 Δλ / λ = v / c λ = 660 mmΔλ = 0.001 nmc = 300,000,000 m/s v = c * Δλ / λ v = 300,000,000 * (0.001 / 660) = 454 m/s

If the peak wavelength of a star at rest is 550 nm, then what peak wavelength is observed when the star is traveling 150,000 m/s away from the Earth.

550.275 Δλ / λ = v / c λ = 550 nmv = 150,000 m/sc = 300,000,000 m/s Δλ = λ * v / c Δλ = 550 * (150,000 / 300,000,000) = 0.275 Since Δλ is the change in lambda, this must be added or subtracted from the original λ. Since the star is moving away, it must be added. So, the answer is 550 nm + 0.275 nm = 550.275 nm

If the peak wavelength of a star at rest is 615 nm, then what peak wavelength is observed when the star is traveling 2,500,000 m/s toward the Earth.

609.875

If the peak wavelength of a star at rest is 725 nm, then what peak wavelength is observed when the star is traveling 800,000 m/s toward the Earth.

723.067 Δλ / λ = v / c λ = 725 nmv = 800,000 m/sc = 300,000,000 m/s Δλ = λ * v / c Δλ = 725 * (800,000 / 300,000,000) = 1.93 Since Δλ is the change in lambda, this must be added or subtracted from the original λ. Since the star is moving toward, it must be subtracted (blueshift). So, the answer is 725 nm - 1.93 nm = 723.07 nm

Why do some astronomers object to the new definition of a planet that was adopted in 2006?

By this definition, Earth, Jupiter, and other planets should not be considered planets.

The discovery of _________ prompted astronomers to reconsider whether Pluto should really be called a planet.

Eris

If we could capture the spectrum of an exoplanet, we may find evidence for life on that planet in the form of ....

biosignatures

If a star is traveling toward you, its observed spectrum will be ....

blue-shifted

An explosion the size of the Tunguska Event is likely to happen every ....

few centuries

A planet will keep a large atmosphere if it _________ or __________.

is cold .... has a ton of gravity

The moon Titan is special because....

its surface is wet

Jupiter weighs roughly ....

twice as much as all the other planets combined