ASTR Midterm 2

• 1. largest division between some of the rings
• 2. space caused by gravity of moon mimas

1. minimum radius at which a satellite may orbit without being broken apart by tidal forces

• 1.small angual size
• 2. 4 times the diameter of earth
• 3. no core
• 4. methane in atmosphere makes planet blueish-green
• 5. 10 thin rings,
• 6.retrograde motion bc of its obliquity
• 7. orbital period of 84 yrs
• 8. voyager 2
• 9. shepard moon
• 10. somewhat larger denisty than uranus

Neptune's largest moon; only major moon to revolve around a planet in a retrograde direction

Will crash onto Neptune in future

clyde tombaugh in 1930

blink comparator

• 1. 17 degree tilt to ecliptic
• 2. methane atmosphere
• 3.moon-- Charon
• 4. pluto 1/5 our moon
• 5. small and ecentric orbit: thus maybe a former moon of Neptune

Discorvered asteroids in 1801

• known as minor planets
• ceres is the largest asteroid
• Pallsa and Vesta have diameters greater than 300 km

asteroids that orbit the sun at distanc eof 2.2-3.3 aU

50 asteroids with diameters lager than 1 km tat have eccentric orbits that cross the Earth's orbit

gaps between asteroids in asteroid belt; due to synchronous tugs from Jupiter on the asteroids which used to be located there

two groups of asteroids which are located at Jupiter's distance from the Sun

Asteroids are primordial material that never formed into a planet because of Jupiter's gravitational influence

• Used Newton's methods to calculate orbits of many coments
• corrently predicted next return of what would become Comet Halley

• 1. Head: consists of coma and nucleus
• 2. coma: part of comet's head made up of a diffuse cloud of gas and dust
• 3. Nucleus: comet is solid chunk of a comet, locatd in the head
• 4.tail: gas and/or dust that is swept away from comet's head.

• 1. Ion tail: is a straight tail
• 2. dust tail: curved tail

a dirty snowball (water, ice, frozen carbon dioxide, and small grains

gradual evaporation of their nuclei

trhough evaporationof all volatile material

falling into the sun

jan: proposed comet cloud exists in a spherical shell

these billion of comet nuclei exist in Oort cloud

band of comets and dwarf planets that exists closer to the solar system than the oort cloud

third source of commets (beside kuiper belt, oort cloud) iwhich is larger than Kuiper belt and smaller than Oort cloud

• 1. smallest meteoroids slowed down at top of Earth's atmoshpere---> micro meteorites
• 2. streak in sky from dust grain sized meteroid is heated up by passage through earth's atmoshpere--> meteor
• very brigh meteorr--> fireballs
• 3. Largest meteoroids: able to pass through Earth's atmosphere

meteorite: meteroid after it passes through atmosphere

point in the sky from which the meteors of a shower appear to radiate

1. irons: iron meteorites that are made up of 80%-90% (with some nickel)

2. Stones: stony meteorites that can contain flakes of iron and nickel

3. Stony irons: meteorites that are half stone and half iron

• 1. is a G2 star, that is the main sequence phase of its life
• 2. in 5 billion yrs will become red giant star
• 3. has differential rotation like outer planets
• 4.

1.solar energy striking earth at the rate of 1,380 watts

total rate at which sun releases energy into space in all directions

edge of solar disk

how solar disks look dimmer near their edges,

proof that the temperature decreases with increasing height within the sun's photosphere

divison of the sun's surface into small convection cells

areas where hot material is rising from below and then descending

• 78% hydrogen
• 20% helium

must hold more helium than the photosphere since some of hydrogen that was there has already been converted into helium during lif eof the sun

region of the solar atmoshpere 2,000-3,000 km thick

lies between photosphere and corona

directly above the chromophere, 200 km thick,

narrow jets of gas which are part of the chromosphere but exted through the transition zone into the corona

portion of the solar atmoshpere only visible during a total solar eclipse

above the transition zone

1. shockwaves: produced in solar interior and dump their energy in the corona

2. magnetic reconnection heating: changes in coronal magnetic field

large dark area in the corona

are cooler than the surrounding corona

continous flow of nuclei and electrons from the sun

first person after Galileo to report sunspots

1500 degrees coller than surrounding photosphere

locations where sun's magnetic field passes from its interior through the photosphere into the atmoshpere

measures the sun's magnetic field, by splitting spectral lines by a strong magnetic field

maximum: tie when most sunsposets are visjible on solar surface