PH104 Final

What is the general information about Neptune?

- Barely visible to the naked eye. - Is flattened into an oblate shape due to rotation. - Rotates like a giant blob of liquid. - Equatorial plane is highly tilted to the orbit, causing significant seasonal variations. - Emits more energy than it absorbs. - Orbit takes it farther from the sun than Pluto in some locations, its orbit crosses Pluto's. - Blue because of its clouds.

What is the general information about Uranus?

- Extreme axial tilt. - Fine rings that are invisible to the naked eye. - Likely had 2 big hits early on in its formation. - Main magnetic field is tilted away from its spin axis. - No liquid metallic hydrogen core, instead its all slush. - Upper atmosphere comes from external source; likely micrometeoroids. - Little to no heat escaping from its interior to warm upper regions, so little to no convection current.

What is the general information about Pluto?

- High axial tilt. - Follows a highly elliptical orbit that crosses Neptune's. - Completely frozen with cryogeysers erupting on its surface. - Sometimes has an atmosphere, when it is closer to the sun in orbit. - Has seasons and changes colors.

What is the general information about Jupiter?

- Largest planet in the solar system. - High gravity. - Gas giant. - Oblate spheroid. - No core/mantle boundary. - Radiates more energy than it receives. - Very strong magnetic field.

What is the general information about Saturn?

- Lowest density in the solar system, would float in water. - Radiates more energy than it receives. - No hard crust. - Most prominent rings. - Has seasons. - Has a North polar hexagon that rotates but doesn't change shape.

How does NASA define something that is "alive"?

- Something that begins an active existence (forms). - Changes and matures over time (grows). - Replicates through a well-ordered process. - Converts some kind of fuel into life energy, exports waste. - Adapts to environmental conditions or perishes. - Ends its existence at some point.

What kind of things make the Earth unique among planets in our Solar System?

- The only living planet we are aware of. - Most active planet in the solar system. - No other planet has erosion to match Earth's scale. - Earth has soil. - Earth has fire. - Earth has weather. - Earth has water rain & bodies of fresh water. - Earth has liquid water in its atmosphere.

What is the definition of a planet?

1. A body that orbits a star. 2. A body that is big enough its own gravity has pulled it into a round shape. 3. A body that is not the satellite of another body. 4. A body that has cleared its neighborhood and orbit of contending bodies.

How many humans have walked on the Moon?

12.

What happened over Tunguska, Siberia in 1908?

A bolide exploded over it. Pressure wave went twice around Earth. Forest burned for two days. 620 sq miles incinerated.

What is cryovolcanism?

A cryovolcano is a type of volcano that erupts volatiles such as water, ammonia or methane, instead of molten rock. Collectively referred to as cryomagma, cryolava or ice-volcanic melt, these substances are usually liquids and can form plumes, but can also be in vapour form.

What is the difference between a dwarf planet and a plutino?

A dwarf planet is just like a normal planet except that it hasn't cleared other objects from its orbit. A plutino, on the other hand, is any object that orbits the Sun twice for each three orbits of Neptune.

What is the difference between a comet's ion plasma tail and dust tail?

A gas tail is ionized gas carried away by the solar wind and may show effects of the local magnetic field. A dust tail is composed of solid debris blown outward by the pressure of sunlight and may be curved because dust particles follow individual orbits.

Where is the Great Dark Spot and what is it?

A huge spinning storm in the southern atmosphere of Neptune which was about the size of the entire Earth.

What is the Titus-Bode-Phillips Principal?

A hypothesis that the bodies in some orbital systems, including the Sun's, orbit at semi-major axes in a function of planetary sequence. The formula suggests that, extending outward, each planet would be approximately twice as far from the Sun as the one before.

What is lunar regolith?

A layer of fine powder covering the lunar surface.

What are NEOs and EGAs?

A near-Earth object (NEO) is any small solar system body whose orbit brings it into proximity with Earth. By definition, a solar system body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical unit (AU). An Earth Grazing Asteroid (EGA) is a fireball, a very bright meteor that enters Earth's atmosphere and leaves again. Some fragments may impact Earth as meteorites, if the meteor starts to break up or explodes in mid-air. These phenomena are then called Earth-grazing meteor processions and bolides.

What is a "phase diagram" and what can it tell us about water on other planets?

A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases occur and coexist at equilibrium. It can tell us if liquid water is possible on other planets.

What is an exoplanet?

A planet that orbits a star other than the Sun.

What is a tholin?

An abiotic complex organic solid formed by chemistry from energy input into simple, cosmically relevant gases or solids (ices). Tholins are "abiotic complex organic gunk."

What is a Trans-Neptunian Object?

Any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune.

What is the difference between a comet and an asteroid?

Asteroids are made up of metals and rocky material, while comets are made up of ice, dust and rocky material. Asteroids formed much closer to the Sun, where it was too warm for ices to remain solid. Comets formed farther from the Sun where ices would not melt. Comets which approach the Sun lose material with each orbit because some of their ice melts and vaporizes to form a tail.

What are the three basic types of impact craters?

Astron/Multi-ring Basins, complex and simple.

What does a strong magnetic field have to do with auroras?

Charged particles are the "ammunition" of an aurora. The short answer to how the aurora happens is that energetic electrically charged particles (mostly electrons) accelerate along the magnetic field lines into the upper atmosphere, where they collide with gas atoms, causing the atoms to give off light.

Why is Mars red?

Chemical reactions between surface rock and atmospheric oxygen literally rusted the surface.

What is a maria?

Dark, flat areas on the moon.

What is a Van Allen Belt?

Donut shaped zone of energetic charged particles (plasma), held in place by a planet's magnetic field.

What is a plasma torus?

Donut-shaped body around a planet that creates auroras.

What happened to Mars' atmosphere?

Early Mars had a warm core that could support a magnetic field. However, the warm interior caused extensive volcanism and out-gassing. The core solidified, which killed the geodynamo and magnetic field. This also stopped the volcanism and out-gassing. This made the atmosphere thin and unable to hold greenhouse gases.

What is an ELE?

Extinction Level Event

What is the major difference between gas giant and ice giant planets?

Gas Giants consist primarily of the gases hydrogen and helium, with a rocky/iron core. The interiors of Ice Giants consist primarily of what astronomers call 'Ices'. These are compounds like water, methane and ammonia, and are so-named presumably because they are solid at cold temperatures, unlike hydrogen and helium, which remain gaseous up until very close to Absolute Zero.

Who were the "astrochimps"?

Ham and Enos.

What makes the moon Europa unique?

Highest albedo in the solar system and there's water and ice below the surface. Incredibly smooth surface, with a weak magnetic field.

What is hypervelocity?

Hypervelocity is very high velocity, approximately over 3,000 meters per second. In particular, hypervelocity is velocity so high that the strength of materials upon impact is very small compared to inertial stresses. Thus, metals and fluids behave alike under hypervelocity impact.

What is the one way you can tell an impact crater from other holes in the ground?

Impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters range from small, simple, bowl-shaped depressions to large, complex, multi-ringed impact basins.

What is considered the "most thermally unstable body in the Solar System?"

Io, one of Jupiter's moons.

Why is the moon Io important?

It has about 400 active volcanoes making it the most geologically active object in the Solar System.

Why is the Comet Shoemaker-Levy 9 important?

It impacted Jupiter in 1994. Jupiter flings objects that hit it in Earths direction - which could be potentially catastrophic.

What two things make the moon Rhea unique in the Solar System?

It was the first world identified with O2 in its atmosphere. It is also the only moon in the solar system with its own rings.

What is an ablation crust and how does it form on a meteorite?

It's a fusion crust. Fusion crust forms when meteoroids enter the gas atmosphere of our planet. Eventually the hot air causes the exterior of the meteoroid to melt. Once the melt becomes fluid, it is instantly carried away in the gas and plasma jet stream and new material is melted underneath. In this process of ablation, depending on entry angle, entry velocity and mineral composition, the meteoroid loses up to ninety percent of its original mass.

Why is the moon Titan interesting to astronomers and planetary scientists?

It's a smog moon. The only known moon with a big secondary atmosphere, hundreds of miles thick. It's atmosphere is similar to young Earth's. Could harbor life?

What makes Ganymede unique in the Solar System?

It's the largest moon in the solar system. Also the only moon in the solar system with a significant magnetic field.

What is the Great Red Spot and where is it?

Jupiter's Great Red Spot is a gigantic storm that's about twice as wide as Earth, circling the planet in its southern hemisphere. At the storm's center, winds are relatively calm, but on its edges, wind speeds reach 270-425 mph.

What is the Kuiper Belt and the Oort Cloud?

Kuiper belt is a belt of asteroids and comets that circle the Sun. Pluto is in the Kuiper belt. Oort Cloud is an extended shell of icy objects that exist in the outermost reaches of the solar system.

What is the difference between a Kuiper Belt Object and a Scattered Disk Object?

Kuiper belt objects are 50 AU's from the sun or less, anything else floating beyond that is a scattered disk object.

What is a LaGrange point?

Lagrangian points are the points near two large bodies in orbit where a smaller object will maintain its position relative to the large orbiting bodies.

What and who was the first animal in space?

Laika the dog.

Where is the Kraken Mare and why is it so unusual?

Largest body of liquid on the surface of Saturn's moon Titan. It's unusual because it's bigger than the Caspian Sea on Earth.

Why is the moon Triton unique?

Largest moon of Neptune. Only large moon in the Solar System with a retrograde orbit; an orbit in the opposite direction to the planet's rotation.

What is the difference between a meteoroid, meteor, meteorite, and bolide?

Meteoroid: A small body moving in the solar system that would become a meteor if it entered the earth's atmosphere. Meteor: A small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light. Meteorite: A meteor that survives its passage through the earth's atmosphere such that part of it strikes the ground. Bolide: A large meteor which explodes in the atmosphere.

What moon is nicknamed the "Death Star Moon"?

Mimas.

Where did Earth's water come from?

Multiple geochemical studies have concluded that asteroids are most likely the primary source of Earth's water. Carbonaceous chondrites - which are a subclass of the oldest meteorites in the Solar System - have isotopic levels most similar to ocean water.

What is the difference between regular asteroids and Trojan asteroids?

Normal asteroids are in the asteroid belt, between Jupiter and Mars' orbits. Trojan asteroids, on the other hand, are on either side of Jupiter and follow its orbital path in its LaGrange points. Trojan asteroids might be inactive comets.

What is tidal lock?

Occurs when an orbiting astronomical body always has the same face toward the object it is orbiting. This is known as synchronous rotation: the tidally locked body takes just as long to rotate around its own axis as it does to revolve around its partner.

What is the tallest mountain in the Solar System and where is it located?

Olympus Mons - on Mars.

How does Io maintain it volcanism?

Orbital resonance (when two orbiting bodies exert a regular periodic gravity influence on each other) stretches Io's orbit, changing the size and direction of tidal bulges; these flex and heat the moon's interior.

Why are gas and ice giant planets oblate?

Outer layers are not solid(frost line) rotate quickly.

Why are there seasons only on certain planets?

Planetary seasons are caused by two factors: axial tilt and variable distance from the sun (orbital eccentricity).

What is the Fermi Paradox?

Reasonable assumptions predict that a galactic civilization should have already arisen in the Milky Way. Yet, we have absolutely no evidence for it. If aliens exist, why haven't we found each other already?

What is a flux tube?

Region of space containing magnetic field, where aurora is and particles can come in.

Who were Robert Goddard and Werner von Braun?

Robert H. Goddard launched the first successful liquid fueled rocket with Braun's help Americans build their first copies of the German V2 rocket.

What planets have rings? How are Jupiter's rings different from other planets' rings?

Saturn, Jupiter, Uranus, and Neptune all have rings. Jupiter's rings are different - they are very dark and difficult to see. They are made up of small bits of dust. The Galileo spacecraft helped us discover where that dust comes from. Meteors striking the surface of Jupiter's small, inner moons kick up dust which then goes into orbit around Jupiter, forming the rings.

What is SETI and what is its mission?

Search for extraterrestrial intelligence. Collective name for a number of activities undertaken to search for intelligent extraterrestrial life. SETI lost its major funding source in 2011.

What is shock-metamorphism?

Shock wave related deformation and heating during impact events. Rocks act as a liquid.

What is a shepherd moon?

Small moons that orbit near the outer edges of rings or within gaps in the ring.

What is the asteroid belt?

Small planetary bodies that circle the sun in a belt between the orbits of Mars and Jupiter.

Why is 1972 a significant year in space exploration?

That's the last year since humans have been on the moon.

What is the B612 Project?

The B612 Foundation is a private nonprofit foundation headquartered in Mill Valley, California, United States, dedicated to planetary science and planetary defense against asteroids and other near-Earth object (NEO) impacts.

What is the Drake Equation and why is it important?

The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.

What is the Copernican Principle and what does it imply?

The Laws of Nature hold true everywhere in the Universe. Earth is not an exception to the rules. If life formed on Earth because of certain characteristics, then any other planet matching those characteristics has the same chance to support life, too.

Who were the "Mercury 13"?

The Mercury 13 were thirteen American women who, as part of a privately funded program, successfully underwent the same physiological screening tests as had the astronauts selected by NASA on April 9, 1959 for Project Mercury.

What is the difference between the Mercury, Gemini, and Apollo space missions?

The Mercury missions attempted to simply get a man into space, past our atmosphere. The Gemini missions tried to get a man to orbit the Earth. The Apollo missions tried to get a man to the Moon.

What's exobiology (astrobiology)?

The branch of science that deals with the possibility and likely nature of life on other planets or in space.

What was the "space race" really all about?

The competition between the U.S.A. and Russia during the cold war.

What are the Galilean Moons?

The four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto.

What is the Roche Limit?

The maximum distance from a planet at which planetary rings can exist.

Why are there so many craters on the Moon?

The moon has no atmosphere. Also, the Moon has not had tectonics for billions of years. That's a lot more time for craters to form and stay put.

What are the Adams Ring Arcs?

The outermost ring of Neptune. The brightest parts of the Adams ring and were the first elements of Neptune's ring system to be discovered. The Adams ring consists of five bright arcs embedded in a fainter continuous ring. Proceeding counterclockwise, the arcs are: Fraternité, Égalité 1 and 2, Liberté, and Courage. The first three names come from "liberty, equality, fraternity", the motto of the French Revolution and Republic.

What is the "frost line"?

The particular distance in the solar nebula from the central protostar (Sun) where it is cold enough for volatile compounds such as water, ammonia, methane, carbon dioxide, carbon monoxide to condense into solid ice grains.

From what point in the sky do meteorite showers originate?

The radiant.

Why does a comet's tail always point away from the Sun?

The solar winds push the dust and gas away from the comet causing them to stream off into space to form the comet's tail. The solar winds cause the comet's tail to point away from the Sun.

What is the coldest known object in the Solar System?

The surface of Triton, one of Neptune's moons.

What is a unique characteristic of Uranus' moons?

Their surfaces are incredibly diverse and were hit many times.

Why are Uranus and Neptune blue?

Trace amounts of methane reflect a blue color.

What is the largest canyon in the Solar System and where is it located?

Verona Rupes on Miranda (one of Uranus' moons). **Also could be Valles Marineris on Mars??

What is spin compression?

When a planet gives off more energy than it receives caused by the planet contracting under its own gravity (gravitational compression).

What's the difference between a lunar and solar eclipse?

When the Moon passes between Sun and Earth, the lunar shadow is seen as a solar eclipse on Earth. When Earth passes directly between Sun and Moon, its shadow creates a lunar eclipse.

Who were the first two humans into space (leave Earth's atmosphere)?

Yuri Gagarin and Alan Shepard.