Quantitative Astronomy Exam 3

asteroid

a stony or metallic object orbiting the Sun that is smaller than a planet but that shows no evidence of an atmosphere or of other types of activity associated with comets

asteroid belt

the region of the solar system between the orbits of Mars and Jupiter in which most asteroids are located;

the main belt, where the orbits are generally the most stable, extends from 2.2 to 3.3 AU from the Sun

chromosphere

the part of the solar atmosphere that lies immediately above the photospheric layers

coronal mass ejection

a solar flare in which immense quantities of coronal material—mainly protons and electrons—is ejected at high speeds (500–1000 kilometers per second) into interplanetary space

trans-neptunian object

celestial bodies in the Kuiper Belt that have an orbit that intersects the orbit of Neptune

Kupier Belt

a region of space beyond Neptune that is dynamically stable (like the asteroid belt); the source region for most short-period comets

aurora

light radiated by atoms and ions in the ionosphere excited by charged particles from the Sun, mostly seen in the magnetic polar regions

corona

(of the Sun) the outer (hot) atmosphere of the Sun

meteorite

a portion of a meteor that survives passage through an atmosphere and strikes the ground

star

a natural luminous body visible in the sky especially at night

a self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions

Oort Cloud

the large spherical region around the Sun from which most “new” comets come; a reservoir of objects with aphelia at about 50,000 AU

comet

a small body of icy and dusty matter that revolves about the Sun

when it comes near the Sun, some of its material vaporizes, forming a large head of tenuous gas and often a tail

meteor

a small piece of solid matter that enters Earth’s atmosphere and burns up

popularly called a shooting star because it is seen as a small flash of light

photosphere

the region of the solar (or stellar) atmosphere from which continuous radiation escapes into space

fission

breaking up of heavier atomic nuclei into lighter ones

sunspot

large, dark features seen on the surface of the Sun caused by increased magnetic activity

meteoroid

a small asteroid, typically less than a meter across

solar wind

a flow of hot, charged particles leaving the Sun

scarp

a steep cliff or slope, often formed by tectonic activity as a planet or moon cools and its surface contracts

fissure/crack in the surface of a planet

fusion

building up of heavier atomic nuclei from lighter ones

terrestrial planet

any of the planets Mercury, Venus, Earth, or Mars

characteristics of terrestrial planet

close to sun

small

high density

few moons

no rings

rotating slowly

solid surface

weaker winds and storms

jovian planets

any of the planets Jupiter, Saturn, Uranus, and/or Neptune

characteristics of jovian planets

far from sun

large

low density

many moons

circled by rings

rotating rapidly

no solid surface

strong storms

planet

a celestial body that is

1) in orbit around the sun

2) has sufficient mass for itself so that it assumes a hydrostatic equilibrium shape (circular)

3) has cleared the neighborhood around its orbit

dwarf planet

a celestial body that

1) orbits the Sun

2) is nearly round in shape (hydrostatic equilibrium)

3) has not cleared its orbital neighborhood,

4) is not a satellite

atmosphere of mercury

extremely thin, cannot hold greenhouse effect

surface features of mercury

craters

looks similar to our moon

has scarps

daytime and night time temps of mercury

daytime: 800 F

night time: -280 F

which planet is the 3rd brightest object in our sky

venus

does venus have seasons

no

3% axis tilt doesn’t allow for them

which planet is the hottest

Venus (860F day and night)

venus atmosphere

thick

almost entirely CO2 with sulfuric acid clouds that cover entire planet

traces of phosphine gas present in upper atmosphere (linked to microbial life on earth)

runaway greenhouse effect

the process by which the greenhouse effect, rather than remaining stable or being lessened through intervention, continues to grow at an increasing rate

which planet experiences the runaway greenhouse effect

venus

surface features of mars

outflow channels

dust devil tornados

polar ice caps

craters that look like liquid splashed out of the grater

mars atmosphere

very thin

95.3% CO2

moons of mars

Phobos & Demios

why does NASA want to send humans to Mars?

to search for signs of ancient life

to examine the atmosphere to see if it could have sustained life

examine viability of future potential life on the planet

why has NASA not sent humans to Mars yet?

not enough infrastructure to make sure they have enough water on the trip and when they arrive

very long trip to get there

methods of planet exploration for Mars

fly bys

rovers - Sojourner, Spirit & Opportunity, Curiosity

drone

orbiting missions - Mars Reconnaissance Orbiter

what is the 4th brightest object in the night sky and the largest planet

jupiter

jupiter atmosphere

75% hydrogen

24% helium

trace amounts of methane, ammonia, and water vapor

where does jupiter get its magnetic field from

the liquid metallic hydrogen core

moons of jupiter

95 known ones

Io

Europa

Ganymede

Callisto

Io moon

active volcanos

rocky & close with a very strong gravitational pull with Jupiter

experiences tides

Europa moon

entirely water ice surface

theorized may have liquid water oceans underneath

Ganymede and Callisto moons

rocky

craters filled with water ice

how large is jupiter’s magnetic field

20x stronger than earth’s magnetic field

banding on jupiter

light and dark zones from convection constantly changing

is there possibility of life on Jupiter’s 4 Galilean moons?

potentially

Europa, Ganymede, & Callisto all have water ice/are fully water ice & water is key to sustaining life

Saturn atmosphere

92.4% hydrogen

7.4% helium

trace amounts of methane & ammonia

most notable Saturn moon

Titan

could life be possible on Titan?

potentially

methane and ammonia are hydrocarbons, and carbon is the backbone of organic life

what are saturn’s rings considered to be

debris from broken up moons from about 100-400 million years ago

made of mostly water ice

nested with gaps

Titan moon

same size as earth but much cooler

has an atmosphere of methane & ammonia —> hydrocarbons

has lakes on surface & rivers (liquid methane and ammonia)

Tethys moon

one of saturns moons

has crater 280 miles across

at a pole, there is a strange hexagonal cloud formation

what mission to saturn captured data and images of Titan and Tethys

Cassini mission - fly by

Uranus temperature

-350F

Uranus atmosphere

84% hydrogen

14% helium

2-3% methane

no ammonia

degree of axis tilt on uranus

98 degrees

rotates on its side and appears to rotate up & down

does uranus experience seasons

yes it does. takes 84 years to experience all seasons

moons of uranus

28 moons

some may have liquid water under the ice

notable moons of uranus

Oberon

Titania

Umbriel

When did neptune’s great dark spot disappear

1994

what color is neptune

blue

what atmosphere is similar to neptune’s

uranus’s atmosphere

how many moons does neptune have

14

neptune’s largest moon

triton

how long is 1 day on pluto

153 hours

pluto atmosphere

very thin

methane & nitrogen

gravity strength of pluto

6% of earth’sh

moons of pluto

5 known

largest = Charon

Nix

Hydra

largest known TNOs

Pluto

Eris

Makemale

Haumea

Sedna

2007 OR10

Quaoar

Orcus

describe the New Horizons Mission

launched: Jan 2006

arrived at Pluto: July 2015

got close up pictures of Pluto’s moons and images of Pluto’s thin atmosphere

some larger named asteroids

Ceres (dwarf planet)

Vesta

Gaspara (potato shaped)

meteor showers

the sun’s heat breaks up the comet as it passes by and that process leaves a path of debris that sometimes intersects with Earth & it’s atmosphere

that debris enters the atmosphere and burns up as it moves —> shooting stars

impacts on earth

explosion power can be greater than an atomic bomb

notable incident: Russian Meteor Impact event Feb 15, 2013

• 41,000 mph entry

• explosion force 20x stronger than Hiroshima bomb

• 10k metic tons

• 17 m diameter

Tunguska Impact Site - early 1900s siberia

meteorite types

Chondrite (rocky)

iron

comet nucleus

rocky & icy object (water ice and dry ice)

comet halo

a glowing, fuzzy atmosphere of gas and dust surrounding the icy nucleus that forms as it nears the Sun

ion tail of comet

gases release from the nucleus and come into contact with charged particles from solar wind to create blue ion tail

dust tail of comet

white tail that reflects sunlight off material released from the nucleus

orbits of comets

ellipses

parabolas

hyperbolas (2 parabolas that don’t intersect and go opposite directions)

appearance of comets in sky

fuzzy patches of light across the night sky

missions to study comets and asteroids

Stardust Mission

• 2004

• used aerogel to insulate capsule

• visited Comet Wild2

• had particles of comet trapped in aerogel upon return

did comets or asteroids bring water and possibly life to earth?

potentially

contain the materials needed for life from the formation of planets at the beginning of the solar system including water ice —> could’ve collided with Earth during early formation and deposited building blocks of organic life we have today

luminosity

power from spherical starts

hotter stars have more of this

magnetic field of the sun

1-80x the strength of Earth’s magnetic field

away from sunspots & other surface features

core of the sun

150x denser than water

25% inner most portion of sun

15 million degrees C

location of nuclear fusion

photosphere of the sun

“surface” of sun

not solid

density low enough for light generated inside to leave and not get scattered

100 km thick

experiences granulation from the convention process

corona of the sun

outermost layer of sun’s atmosphere

1-10 million degrees C

chromosphere of the sun

part of atmosphere of sun directly above photosphere

7800 degrees F

solar flares

a sudden and temporary outburst of electromagnetic radiation from an extended region of the Sun’s surface

solar loops

hot gasses erupting from the surface of the sun in large arcs

exit and entry points are on the sun

caused by magnetic field changes

22 year cycle of sunspots

magnetic field of the sun flips over an 11 year cycle, creating sunspots during that 11 year portion

next 11 year portion, it goes through the same types of changes in reverse, restoring the magnetic poles to their original spots and leaving a symmetrical magnetic field (at solar minimum)

fusion process in the sun’s core

happens at such a high degree in the core of the sun that vast amount of energy are released every second

hydrogen protons fuse together at about 11 million degrees C to become helium —> releases positrons and neutrinos in process