moons and planets final

could be incorrect, some of this is opinion based

state 3 factors you consider most important in determining if an exoplanet is earthlike, and 3 additional factors that you consider less important

1: similar rocky composition

2: in habitable zone

3: supports liquid water

• mass

• tidally locked

• planet instead of a moon

list the steps involved in determining the mass of an exoplanet by the doppler method, using words and/or equations. assume we see orbit edge-on

-doppler yeilds orbital period & velocity, so orbit size can be determined

-star spectral type gives mass (M)

-Kepler's 3rd law gives planet orbit size (m)

-m/M can be calculated by comparison

draw light curve of a star that indicates an orbiting exoplanet orbiting moon

study diagram from notes

draw 1-2 diagrams of a star w an exoplanet orbiting it, and an exomoon orbiting the exoplanet that illustrate how the exoplanet transit can be advanced or delayed in time

study diagram from notes + moon can come before or after the planet, or be eclipsed by it, so the dimming of the star when transited will be inconsistent depending on where the exomoon is in its orbit

describe how the 21 cm spectral line is emitted and why we often search in that wavelength for extraterrestrial intelligence

hydrogen electron spin-f;ip emits a 21 cm wavelength, and it's particular enough that we assume other intelligent life would know this as well. if we found that frequency, it would likely be from an artificial source, indicating potential life

describe 1 reason why signal BLC1 suggested an intelligent origin, and 2 reasons why it eventually did not

1: BLC1 had a strong signal that persisted for 2 hours that was only not present in the off-pointing

• signal mimics common electronic instruments

• faint echoes of the signal were eventually found in the off-pointing

in 2 brief sentences, what would cause the presumed solar bow shock?

bow shock is created around planets when their magnetic field meets solar wind. Solar bow shock would follow that principle, but when solar wind meets interstellar wind.

state 2 observations that were expected and 1 that was not from the Voyagers as they left the solar system

expected: drop in solar particles past the heliosphere, sharp trade-off of low to high energy particles

unexpected: the discovery of magnetic foam at termination shock

state 3 proposals for terraforming the martian atmosphere, what paramaters it would "fix," and how long it might take

1: dirty factories would raise temp (1000s of yrs) and pressure slowly (100s of yrs), but it doesn't solve weak magnetic field

2: seed atmosphere with lichen would increase O2 over 100s of years, but no effect on mag field or psi, and lichen may not survive

3: sublimatic polar caps w mirrors (100s of yrs), no effect on mag field, may not have enough ice in the caps to succeed

you plan to design blimps for human habitation in venus's atmosphere. state your 3 most important factors to consider

• proper bouancy to keep blimps afloat at proper level in Venus's atmosphere

• shield from high temps

• keep similar earth-like pressure and conditions

if there is a planet 9, why would it most likely not be detectable in existing imagery, and how have we eliminated sections of its presumed orbit for its present location?

not detectable in current imagery bc it's predicted to most likely be in the middle of the band of the milky way, which would make it extremely dim in comparison to other stars. We've eliminated other places it could be bc we would've already found it with our available space crafts

state 1 observation suggesting that 'Oumuamua is controlled by alien intelligence and one suggesting it is not

strange acceleration pattern could indicate artificial origin, but outgassing has determined to be the probable cause

why could blowing up a weather satellite be a violation of the 1967 outer space treaty?

possible violation bc it could be considered purposefully polluting space

discuss the purpose and current status of OSIRIS-REx, Dart, and Psyche missions

OSIRIS-REx and Dart have been launched, Psyche is planned. They are made to determine if asteroid mining is even possible + how to do it successfully

draw a horizontal line to represent a linear time axis w formation of earth at 0-yd line and present day at 100-yd line. Mark positions of first life forms, first mammals, some extinctions, and appearance of homo sapiens

0 yd: earth forms

20 yd: single-cell life

50 yds: middle

12 yds: cambrain

10 yds: ordovician extinction

5 yds: mammals

100 yds: humans + present day

describe the Milankojitch sycles w the approx period for each

• changes in orbit eccentricity (10,000 year cycles)

• changes in axial precession (26,000 year cycles)

during a rocky exoplanet's transit of its parent star, you see the star appear slightly bluer as well as darker. what does that tell us about the exoplanet atmosphere?

it means that the atmosphere is dense, and that the scattered blue light indicates lots of hydrogen

name 3 atmospheric molecular constituents that we have already detected on exoplanets

-co2

-methane

-dimethyl sulfide

state 2 reasons we are still concerned that an asteroid could destroy an urban area if it collides with earth

city killer asteroids are frequent enough to appear every 10 or so years, so it's important to keep track of where they are and their likelihood of hitting earth (and where), esp as tech develops to eventually divert asteroids.

suppose a 100-meter diameter asteroid is predicted to strike earth in 2 weeks. describe what you think the best way to avoid terrestrial damage + state major pros and cons of that procedure

pulverizing would be the easiest way to divert the asteroid in such a short time frame. In theory, it would break the asteroid up into pieces that would mostly burn up in the atmosphere, but it's not the most reliable method, so there may still be some damage.