EAPS Exam 3
Why the The International Astronomical Union (IAU) felt the need to come up with criteria to demote Pluto
"If you let Pluto stay you logically have to let the number of planets rise to 24 or 25, with the possibility of 50 or 100 within the next decade. Do we want schoolchildren to have to remember so many? No, we want to keep the numbers low."
The size difference between Earth and Jupiter.
- 11 times the diameter of earth - 318 times the mass - 1,300 times the volume
The factors that enabled life to evolve on Earth.
- A stable star - Right distance from sun - Moon's gravitational pull stabilizes our planet's tilt, preventing drastic movements of the poles that could cause massive changes in our climate - Earth's magnetic field helps protect us from solar radiation and cosmic rays - Earth's ozone layer 03 protects us from the sun's ultraviolet radiation - Plate tectonics help scrub CO2 from our atmosphere
The combination of factors that lead to the fastest gas molecule velocities.
- The higher the temperature, the faster gas molecules move. - The lighter its atomic weight, the faster gas molecules move.
The approximate percent of our atmosphere comprised of greenhouse gases.
0.05% of our atmosphere is comprised of greenhouse gasses.
What aerosols are.
Any small particles suspended in the atmosphere.
Why comets have tails.
As a comet approaches the Sun, solar radiation causes the ices to vaporize (sublimate) and stream out of the nucleus, carrying dust and gas away to form two tails
How crowded the asteroid belt is.
Asteroids that are greater than 1 km in diameter are on average over 500,000 km apart
The major differences between the atmospheres of Earth and Venus.
Atmospheric pressure on venus is 90 times greater than on earth, CO2 traps so much heat from the sun that venus has the hottest surface of any planet which is enough to melt lead, there are sulfuric acid clouds.
Why comets are referred to as dirty ice balls.
Because they are made of ice and rock/metal
The differences between Jupiter's belts and zones.
Belts - low, warm clouds. Zones - high, cool clouds Jupiter clouds at diff altitudes are different colors, temp, and composition
Where the main asteroid belt is located.
Between mars and jupiter
Where the Kuiper Belt is located.
Beyond Neptune's orbit
How aerosols influence global temperatures.
Block sunlight and cause global cooling by preventing light from reaching the surface
How we know the Oort cloud extends to more than a light-year from the Sun.
By the elongated shape of the orbits of long-period comets.
The heaviest gas that should be retained by Mars' atmosphere.
Carbon Dioxide
According to this plot, which gases should be retained by Mars' atmosphere
Carbon dioxide
The conditions for a planet that the IAU come up with that Pluto did not meet.
Clear the neighborhood: designed to rule out everything in the asteroid and kuiper belts Must orbit the sun: Designed to kick out moons Nearly rounded in shape: Designed to rule out objects smaller than 700km in diameter. Clear the neighborhood: Designed to rule out everything in the asteroid and kuiper belts
The average density of comets compared to ice and rock.
Comets have average densities much less than that of ice, implying lots of pore (empty) space inside
Why planetary atmospheres become banded.
Convection currents (hot air rises, cool sinks) are organized by the planet's spin into regions of different wind direction as a function of latitude. Atmospheric banding is caused by clouds at different altitudes and therefore different temperatures, compositions, and colors.
How greenhouse gases cause warming of the Earth's atmosphere.
Converts short-wavelength visible light to longer wavelength heat and trapping it
Consequences of Uranus' tilt.
Creates extreme shifts in seasons. All sun for 21-year-long summers and no sun for 21-year-long winters. During spring and fall, days are 17 hours long.
The direction gas moves away from a comet to form a gas tail.
Direction of the solar wind, (opposite direction of the sun)
Why Earth has seasons
Earth's tilt due to different amounts of direct/indirect sunlight during different times
What we have observed with respect to dampness on Mars' surface.
Evidence of water (dampness) has recently been discovered on Mars' surface. This can happen if the water is very salty, which lowers its freezing temperature, enabling shallow permafrost to melt onto the surface during the warmest weather
The presence of storms on the giant planets.
Giant planets have no land beneath the clouds that slow down storms, so they have unlimited heat to fuel its cyclones(very long lived)
The atmospheric environment at the top of Venus' clouds.
Good pressures and temperatures equal to earth's atmosphere, need oxygen though
Why it might be snowing diamonds within the interiors of Uranus and Neptune.
High pressures can strip the hydrogen from methane molecules leading to free carbon which can compress into diamonds and drop down onto the planet's core
Over the past 100 years, how does the average annual emissions of CO2 from volcanoes compare to the average anthropogenic (human) CO2 emissions?
Human emissions are 150 times greater than volcanoes
The main components of a primary atmosphere.
Hydrogen and Helium
How Pluto was discovered.
In 1930 Clyde Tombaugh discovered Pluto by comparing pictures of the night sky taken days apart and looking for anything that moved relative to the fixed background stars.
What most asteroids look like.
Irregularly shaped with smooth surfaces marked by many craters
What happens when warm, moist air cools.
It condenses into droplets and ice crystals-----clouds
What happens when warm, moist air rises.
It expands and cools down
Why Mars is the most explored planet.
It holds the greatest chance of finding evidence of past or present extraterrestrial life. Only other planet with lakes on its surface. Likely sub-surface lakes/glaciers.
The main characteristics of Jupiter's Great Red Spot.
It is 2x the diameter of earth, it is over 350 years old, it is shrinking
Why Haley's comet the most famous of all comets.
It is a short period comet that comes into view about once in a lifetime
How the concentration of CO2 in our atmosphere today compares to the past 800 thousand years.
It is significantly higher than it's ever been.
Why spinning planets are oblate spheroids.
It is what is known as an oblate spheroid, wider at its equator compared to a line through its poles. This is because centripetal forces associated with its fast spin cause the equator to elongate.
The consequences for temperature if the Earth had no greenhouse gases.
It would get very cold, earth would have an average temperature of 0 degrees Fahrenheit instead of the current average temperature of 61 degrees Fahrenheit.
Where most of the water that used to be on the surface of Mars disappear to
It's still there as ice buried beneath the surface. "Permafrost" on earth is similar. Permanent ice.
Why Saturn's colors are muted compared to Jupiter's
Its clouds are thicker due to a more gradual temperature change with altitude, and because sunlight at saturn is dimmer
The planet with the highest escape velocity.
Jupiter (59.54)
The cause of the Kirkwood gaps in the asteroid belt.
Kirkwood gaps are caused by the gravitational interaction between Jupiter and asteroids with these periods.
Where orbits of short-period comet orbits extend to.
Kuiper belt which lies beyond neptune's orbit
What is regolith is.
Layer of dust and small particles left over from many impacts that causes a smooth texture on asteroids
What numerical atmospheric circulation models conclude regarding global warming.
Led to the unequivocal conclusion that human emissions of greenhouse gases are responsible for the current rise in global temperatures
How we know the Oort cloud is a sphere as opposed to a disc.
Long period comets come at us from all directions
The major differences between the atmospheres of Venus and Mars.
Mars and Venus have similar atmospheric chemistry, but Venus' atmosphere is thick, and Mars' is thin
How a Mercury solar day relates to a Mercury year.
Mercury is locked into a 3/2 spin-orbit where it rotates three times(diurnal day) for every two orbits around the sun (mercury year) 2 years = 1 solar day
Where meteor showers arise from.
Meteor showers created when earth passes through remnants of broken up comets.
Why Uranus' and Neptune's atmosphere are blue.
Methane clouds absorb the red light and reflects blue
Where the atmospheres of the giant planets get most of their heat from.
Mostly from the gravitational contraction of the planet below
The best time to view Mercury and Venus from the surface of the Earth.
Near sunrise or near sunset depending on where they are in their orbits
What New Horizons found when it observed Pluto.
New Horizons observed a large, young, heart-shaped region of ice on Pluto and found mountains made of water ice that may float on top of nitrogen ice. It discovered large chasms on Charon and found that its north pole was covered with reddish material that had escaped from Pluto's atmosphere
The atmospheric layers present on Venus and Mars.
No stratosphere, has thermosphere, mesosphere, and troposphere
Is this storm scene on Mars realistic?
No way
The ability of a low-density atmosphere to blow things around.
Not much ability
The presence of dust devils active on Mars.
On any given day about one devil 15-100m wide and 1-20 km high pops up per square km of surface -> meaning there are millions of these all the time moving fine grains of sand and changing the martian surface
Where orbits of long-period comet orbits extend to
Oort cloud
Going strictly by the IAU definition for a planet, which other planets are not planets.
Other planets that don't orbit our sun, they should've made it say "orbit a star" because there are many other galaxies out there that have planets that orbit stars that are not our sun Neptune and Jupiter haven't cleared their orbits and would technically not be planets either.
Why global temperatures have varied greatly throughout Earth's history.
Past global temperature changes have mostly been due to changes in earth's orbital parameters. Eccentricity of the Earth's orbit around the sun.
Whether there is a debate within the scientific community regarding the cause of global warming.
Prof Freed said in the lecture that there is no debate among the scientific community that humans are responsible for the current rise in global temperatures. Approx 97% of peer-reviewed studies have concluded that humans are responsible, according to Prof Freed.
What it means for a planet to be in the habitable zone.
Right distance from the Sun so that the temperature enables liquid water on the surface
What asteroids are primarily comprised of.
Rocks and metals with little ice
The interesting feature around Saturn's north pole.
Saturn's hexagonal cloud pattern around its north pole. Never been seen in any other atmosphere. Still visible after 20 years of detection
What is surmised about water on Venus in the past.
Scientists thought Venus was covered in water clouds, so Venus was imagined as a steamy, swampy jungle world with strange creatures lurking amidst dripping vegetation
Relative wind speeds on the giant planets compared to that on Earth.
Strongest wind in dark spot was 1500mph, avg wind speeds on the giant planets are much greater than that on earth because of higher planet spin rates and no solid surface to slow them down
How Earth obtained most of the oxygen (O2) in its atmosphere.
Sunlight broke down NH3 into N2 and H2 (H2 then escaped). Life (microbes) converted most of the CO2 into O2.
The factors that influence the velocity of an atmospheric gas molecule.
Temperature and atomic weight
What is currently unprecedented regarding Earth's temperature
Temperatures are increasing at a rate that is higher than any rate before, 2 degrees Fahrenheit over last 50 years
Why comets are referred to as rubble piles.
The abundant pore (empty) space within comets implies they are rubble piles -- collections of smaller objects loosely held together by their small gravitational interactions.
How the amount of energy the Earth has received from the Sun has varied over the last 50 years.
The amount of energy from the sun has stayed the same or decreased in the past 50 years.
The major differences between the asteroid belt and the Kuiper belt.
The asteroid belt (within the ice line) and therefore the Kuiper belt (which is beyond the ice line). Difference in composition
What albedo is.
The capacity of a surface to reflect light
The direction dust moves away from a comet to form a dust tail.
The dust tail is swept by pressure from sunlight and falls behind the motion of the comet, separating it from the gas tail.
The evidence for the possible existence of another major planet in the Kuiper Belt.
The elliptical orbits of several kuiper belt objects are all to one side of the sun. This might be explained by the gravitational influence of a Neptune sized planet somewhere in the Kuiper Belt
Which planets have kept their primary atmospheres.
The gas giants: neptune, uranus, jupiter, saturn
The consequences of reducing vehicle exhaust on global warming.
The global temperature would increase if we reduced vehicle exhaust
The factors that influence the escape velocity of a planet
The mass of the planet and the radius of the planet
What will happen to the moist air inside a spaceship if an external door is suddenly blown open?
The pressure will drop The temperature will drop It will become cloudy as the water vapor condenses
What happens to the moist air inside a spaceship if an external door is suddenly blown open
The pressure will drop, the temperature will drop, it will become cloudy as the water vapor condenses
Why the temperature of the troposphere decreases with altitude.
The temperature decreases because warm air rises, it expands since atmospheric pressure decreases with altitude, causing it to cool (same energy in a larger volume).
Why the temperature of the stratosphere increases with altitude.
The temperature increases because Ultraviolet radiation (sunlight) being absorbed by ozone (O3)
What a diurnal day is.
The time it takes to complete a full rotation relative to the fixed stars.
The relative amount of total mass in the asteroid belt.
The total mass of the asteroid belt adds up to just 4% of the mass of the Moon or 0.05% of Earth's mass.
How the size of Pluto compares to other objects found in the Kuiper Belt.
There are all sorts of sizes, some of similar size to Pluto.
How Earth's temperature today compares to the past hundreds of thousands of years.
There have been warmer temperatures over the whole earth in the past, but now we are increasing ten times faster than those increasing intervals in the past
The relationship between global temperatures and greenhouse gas concentrations over Earth's history.
There is a strong relationship between temperature and greenhouse gas concentration, more greenhouse gasses, higher temp.
The influence of an atmosphere on the difference between daytime and nighttime temperatures.
Thicker atmosphere prevents much change in temp from day to night. Thinner atmo allows for more change from day to night in temp
Where orbits of ultra-short-period comet orbits extend to.
To around Mars and the asteroid belt
The atmospheric layer that weather and clouds exist in
Troposphere
How the layers of terrestrial planetary atmospheres defined.
Troposphere: LOW Stratosphere Mesosphere Thermosphere: HIGH Defined by how temp alternates between heating and cooling with altitude
How do wavelengths vary from ultraviolet to infrared light
Ultraviolet light has a shorter wavelength than infrared light
The current source of most greenhouse gas emissions.
Us. Humans. Coal Burning Factories.
Why it be unlikely that Mars lost its atmosphere due to the solar wind.
Venus has stronger solar winds go past it and still has not lost its atmosphere
Mars should have been able to hold onto its carbon dioxide atmosphere - where did it go?
We are not sure
Why Jezero crater is a promising landing site on Mars to find ancient life.
We have observed sediment rock and river channels very near the crater. Deltas are rich ecosystems on Earth, and this location is very similar.
Whether ice is found on Mercury.
Yes, there is permanent ice in the craters on Mercury's poles
When dust jets initiate.
landslides push debris into gas jets
