astronomy test 4

List at least 3 characteristics of Jupiter's Great Red Spot.

1. A storm twice as wide as earth 2. has existed for at least 3 centuries. 3. Winds at its oval edges can reach up to 425 mph

Name 3 interesting things about Pluto and it's moon Charon. Is Charon visible from everywhere from the surface of Pluto? Why?

1. about 1/8 the mass of Pluto. 2. Charon and Pluto are both tidal locked. 3. It and the other moons are thought to have formed from a giant impact with Pluto.

Compare the magnetic fields of the Jovian planets. What do we think is responsible for the magnetic field for each Jovian planet? Roughly how big would Jupiter's appear in our sky if we could see it from earth?

All jovian planets have magnetic fields, Jupiters is the largest. It would look like a full moon if we could see it.

Which color bands are at the highest altitude on Jupiter, which color bands are the hottest?

Ammonia, NH4SH

Define the following terms asteroids, meteoroids, meteors, meteorites, and comets.

Asteroids: Rocky, inner-solar system remnants. Meteoroids: small chunk of asteroid in space. Meteor: Flash of light produced as a small onject enters the atmosphere. Meteorites: is an object that survives its trip through the atmosphere and ends up on the ground. Comets: Icy, Outer-solar system remnants.

How does the appearance of Jupiter compare to that of Saturn? Which one shows more dramatic stripes and why?

Bright and more defined. Jupiter, convection.

What observations with exoplanets have scientists revisiting nebular theory and why?

Discovery of hot jupiters, planetary migration or gravitational encounters may explain how jupiter-like planets moved inward.

What are the 2 most effective indirect methods for identifying exoplanets? (Which have discovered the most) Which is most effective for discovering earth sized planets? Which is most effective for finding large planets with short orbital periods - hot Jupiters?

Doppler and Transit Transit found the most Transit find earth sized planets doppler find large sized planets

Name the Galilean satellites and describe at least one memorable detail of each. How does their size, density, and composition compare?

Europa, LO, Ganymede,and Callisto . Lo's volcanose, Europa's waterworld, Ganymede is the largest moon in our SS, and Callisto "classic" Iceball.

What causes Io and the other Galilean moons orbits to be elliptical?

Every 7 days the moons all line up creating a gravitational tug. The tug adds up making the moons have an elliptical orbit.

List some properties of Saturn's rings. How were the do we think rings formed? What do we call moons that force some particles into narrow rings?

Formed from dust created in impacts on moons orbiting. Shepherd Moons.

What is significant about Saturn's moon Enceladus?

Fountains of ice particles and water vapor from the surface indicate that geological activity is still ongoing.

What is the ideal wavelength of study for direct observation?

Infrared

What evidence supports a mass extinction event that took out the dinosaurs was due to a large impact? Make sure you know the 2 key things here.

Iridium layer, A large crater of that age found in mexico.

Compare the internal structure of the Jovian planets.

Jupiter and Saturn: 1. visible clouds 2. gaseous hydrogen 3. liquid hydrogen 4. metallic hydrogen 5. core of rock, metals, and hydrogen compounds. Uranus and Neptune 1. Visible clouds 2. gaseous hydrogen 3. water, methane, and ammonia 4. rock and metals

Despite being composed of mostly the same stuff, Jupiter is denser than Saturn. Why?

Less H/He proportionately

Why is Io one of the most geologically active satellites in the solar system? Explain the source of how it is heated.

Lo has an elliptical orbit so it's in continual change and is subject to tidal heating.

Compare the physical characteristics (mass, size, density, rotation and revolution rates) of the Jovian planets.

Mass: Jupiter, Saturn, Neptune, Uranus. Size: Jupiter, Saturn, Uranus, Neptune. Density: Neptune, Jupiter, Uranus, Saturn. Rotation: Neptune, Uranus, Saturn, Jupiter. Revolution Rate: Jupiter and Saturn faster, Uranus and Neptune slower.

What space craft recently visited Pluto? Name a few features it discovered.

New Horizons. Vast regions lack craters, Heart shaped Tombaugh Regio smooth ice plains that may be Nitrogen glaciers, and Tall mountains and what appears to be flowing nitrogen ice.

Name the different parts of a comet. Describe how the 2 tails are formed and how they are orientated as a comet travels around the sun.

Nucleus: dirty snowball and source of material for comet's tail. Coma: is atmosphere that comes from heated nucleus. Plasma tail: is gas escaping from coma, pushed by solar wind. Dust tail: is pushed by photons and is always facing away from the Sun

Why are astronomers particularly interested in studying Titan, Saturn's moon? In other words, what are some interesting things about it?

Only moon with a thick atmosphere and no visible light can penetrate the atmosphere. Consists of nitrogen, argon, Methane, and ethane.

What two areas do comets reside? What area do long period comets come from, traditionally what we think of as comets?

Oort Cloud and Kuiper Belt. Kuiper Belt

What are the properties we learn about from the different exoplanet discovery methods? What method or combination of methods can be used to estimate values for each property?

Period, distance, eccentricity, mass, size (radius), density, atmospheric composition, and temperature. Doppler and Transit.

What do we mean by extra solar planets? What are the 4 methods that we discussed that are used to find them and how does each work?

Planets are close to their stars, relative to the distance from us to the star. 1. Direct Detection: Obtain images or spectra of extrasolar Planets 2. Astrometric Mtheod:Infer planet existence from small changes in star's position in sky 3. Doppler Method: Infer planet existence from star's motion towards/ away from us revealed by dopller shifts and its spectrum 4. Transit Method: Infer planet existence from slight changes in star's brightness as a planet passes in front of ( or behind ) it

What are the two major types of meteorites and how are they different?

Primitive: unchanged in composition since they first formed 4.6 billion years ago. Processed: younger; have experienced geologic activity - processes like volcanism or differentiation.

About how often do extinction level impacts occur? How about ones that still can do major damage?

Rare, extinction level events once every mil years, major damage once every tens to hundreds of years

Why is there an asteroid belt? How did it form? How come it never formed a planet?

Rocky planetesimals between mars and jupiter did not excrete due to jupiter's gravity through orbital resonance stirred up asteroid orbits.

What is significant about Neptune's moon Triton? What do we think it is?

Similar to Pluto, but larger and colder because it is more reflective.

How does the appearance of Uranus and Neptune compare? Why do they appear blue?

Their chemical make up is very similar. Mostly Hydrogen compounds such as water, methane, and ammonia.

How must a planetary orbit be orientated to you for the transit method to work? What orientation is the Doppler method limited by? The Astrometric method? (That is what orientation will not yield any detection by these methods.

Transit: edge-on orbit Doppler: close-in orbit Astrometric: orbit far from their star

What causes meteor showers? Explain the process of how they occur and why they are predictable.

comets eject small particles that follow the comet around in its orbit and cause meteor showers when earth crosses the comet's orbit. We calculate to when we will cross a comets orbit.

What evidence exists for the Oort cloud?

comets were once closer to the sun, but they were kicked father out by gravitational interactions with jovian planets.

Why do most of the exoplanets we have found have a short period? Will that change?

small orbits

What causes some of the Jovian planets to budge some at the equator, and not be completely spherical in shape?

their rapid rotation flings the mass near the equator outward

What is some evidence that suggests there is a liquid ocean under the icy crust of Europa?

tidal heating caused by the elliptical orbit would cause the ice to melt deeper in the moons surface.

What two methods are combined to estimate the density of an exoplanet?

transit plus doppler