Goldilocks Zone
Math
Exoplanet Detection
Asteroids
Chemical Habitability
100
What is the "Goldilocks Zone"?
The distance(s) from a star where liquid water can exist on a planet.
100
The Earth's albedo is about 0.31. What is Earth's emissivity if we assume it's opaque?
0.69
100
What are the three main methods of exoplanet detection?
Transits, radial velocity, and direct imaging.
100
What is the most common asteroid type?
C-type
100
What are the CHNOPS elements?
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, and Sulfur.
200
In what direction does the Goldilocks Zone move as a star ages?
Outward
200
Scientists have discovered a new star called Zeta that's around the same mass as our Sun. Zeta has a planet called Sigma that's the same mass as Earth and orbits 4AU away from its host star. How long does a year last on Sigma?
8 Earth years
200
A transit light curve can tell us an exoplanet's _ relative to its star and its _.
size, orbital period
200
Where in a planet's orbit can you find its Trojan asteroids?
60 degrees ahead/behind OR L4 & L5
200
The CHNOPS elements make up roughly __% of living matter on Earth.
98
300
Which star type has the closest habitable zone?
M-type / Red Dwarf
300
A star emits light at 600 nm. A scientist on Earth observes it at 606 nm. How many times faster is the speed of light than the velocity of the star moving towards us?
101 times
300
What is a coronograph(center) 's main purpose in direct imaging?
To block out the star's light
300
Name 3 differences between asteroids & comets.
Composition: rock & metal vs ice, dust, rock, and frozen gases.
Appearance: no tail vs tail and coma
Location: asteroid belt vs outer solar system (Kuiper Belt & Oort Cloud)
Orbit: more circular vs more elliptical & farther from the Sun
300
Carbon is essential for life due to its _, or its ability to form long chains with its own atoms.
catenation
400
Both Earth and Mars are located in the Goldilocks Zone. Name one reason why Earth can sustain life but Mars can't.
Significantly weaker greenhouse effect keeps water trapped in ice caps, lack of magnetic field, high solar radiation, toxic soil.
400
The equilibrium temperature formula tells us that Earth's equilibrium temperature should be around -19*C. Why then is Earth's average temperature 15*C?
The equilibrium temperature formula doesn't account for greenhouse effect / internal heat (formation leftovers, radioactive decay).
400
Match each image to an exoplanet detection method.
Top- transit
Middle- direct imaging
Bottom- Radial velocity
400
The Widmanstatten (Thompson) structure is found in which type of meteorite?
Iron
400
Phosphorous is found in the energy compound called ___.
ATP
500
What is the effective temperature of the Sun's photosphere
5,770 +- 10 K
500
The kinetic energy of an orbit is 1/2*mv^2. The gravitational potential energy of the orbit is -GMm/r. The total energy of the orbit is -GMm/2r. Use this information to prove the vis-viva equation (formula for orbital velocity).
50: Law of Conservation of Mechanical Energy- The energy of a trajectory is the same at every point.
450: KE+PE=TE
mv^2/2 - GMm/r = -GMm/2r [multiply by 2/m]
v^2 - 2GM/r = -GM/r [add 2GM/r]
v^2 = GM/r [square root both sides]
vis-viva: |v = (GM/r)^0.5|
500
An alien measures Earth's emission spectra but finds two thick lines at 588 and 589 nm (yellow) that aren't supposed to be there! What error did they most likely make?
Extra credit for naming the gases!
500: The alien forgot to subtract the sun's spectra from their measurement. The light he's using passed through the Earth AND Sun's atmospheres, so it contains the spectra of both.
250: Sodium & Helium
500
Explain why M-type asteroids only exist from 1.5-3.5 AU.
Hint: M-type asteroids are thought to be the shattered cores of protoplanets.
250: Any protoplanets that existed closer than 1.5 AU were accreted and became part of the 4 terrestrial planets.
250: For a protoplanet to have a dense, metallic core, it must have differentiated. Differentiating requires melting that cannot occur beyond 3.5 AU.
500
Most of the nitrogen on Earth came from meteorites beyond the orbit of _.
Jupiter