Unit 10: Astronomy

What is electromagnetic radiation?

  • Radiation from the stars located throughout the universe

What is electromagnetic radiation classified by?

  • Its wavelength

What does a telescope do?

  • Collects and focuses electromagnetic radiation from far-away objects

Three types of telescopes

  • Refracting, reflecting, and radio

Characteristics of a reflecting telescope

  • Can see visible light and uses a curved lens

Characteristics of a reflecting telescope

  • Can see visible light and uses a mirror

Characteristics of a radio telescope

  • Can see radio waves and uses a satellite dish to collect radio waves

What are space-based tools?

  • Instruments sent into space to collect information

Advantages of space-based tools?

  • Atmosphere can not interfere with radiation, and it's closer to the object

How long does it take for the Hubble Space Telescope to orbit Earth?

  • 97 minutes

When was the Hubble Space Telescope launched?

  • 1990

What does the Hubble Space Telescope do?

  • Collects visible, infrared, and UV radiation and has observed galaxies 12 billion light years away

What does the Webb space telescope orbit, and when did it launch?

  • Orbits the sun and was launched in 2021

What is sent directly to space?

  • Spacecrafts

What happened in 1926?

  • 1st liquid fuel rocket, Robert Goddard

What happened in 1957?

  • Sputnik, 1st satellite

What happened in 1961?

  • 1st man in space, Yuri A. Garin, for the U.S., it was Alan Shepard

What happened in 1962?

  • Mercury Friendship 7, John Glenn first man to orbit Earth

What happened in 1965?

  • Gemini 4, 1st American spacewalk, Gemini 6 and 7, 1st space rendezvous

What happened in 1969?

  • Apollo 11, first man on the moon

What happened in 1977?

  • Voyagers 1&2 and, study other planets.

What happened in 1986?

  • Challenger space shuttle disaster

What happened in 1990?

  • Hubble Space Telescope

What is the first day of summer called?

  • Summer sp;stice

When does the summer solstice occur?

  • June 21st in the northern

Why is the summer solstice the longest day of the year?

  • Because it is the day when the sun rises the earliest and sets the latest directly on the tropic of Cancer

What day is the winter solstice?

  • First day of winter, or December 21st, when the sun is directly above the Tropic of Capricorn

Why is the winter solstice the shortest day of the year?

  • The sun rises latest and sets earliest

What is an equinox?

  • When both hemispheres receive the same amount of sunlight, so equal day and night

What dates are the equinoxes?

  • March 20th and September 22nd

How did the moon form?

  • When a huge object hit the Earth, it made debris and gas come together and create the moon..

How long does it take for the moon to revolve around the Earth?

  • One month or 27.3 days

Why can we only see one side of the moon?

  • Because we rotate at the same speed as the moon

Why is the moon lit?

  • It is a reflection of the sun

Define a new moon

  • Darkness occurs when the moon is between Earth and the sun

Define a full moon

  • When the moon is all lit, and occurs when Earth is between the moon and the sun.

Define waxing

  • Get bigger, or the b

Define waning 

  • Getting smaller or the d

Define crescent

  • Less than half is lit

Define gibbous

  • More than half is lit

Define quarter

  • Half moon, it lit

When does an eclipse occur?

  • When the Earth or Moon casts a shadow on the other, and when the sun, Earth, and Moon are lined up

Two types of eclipses

  • Solar and lunar

Define a solar eclipse

  • The moon is new, SME, and it is directly between the sun and Earth, casting a shadow on Earth.

Define a lunar eclipse.

  • Earth is directly between the sun and the moon and causes a shadow on the moon, full moon, SEM.

Describe the Earth-centered model.

  • Early Greeks thought planets, the sun, the Moon, and the stars revolved around the Earth.

Describe the sun-centered model..

  • Copernicus and Galileo observed that the moon revolved around the Earth, and the Earth and other planets around the Sun.

 What is the center of the solar system?

  • The sun

What revolves around the sun?

  • The planets

What does the solar system include?

  • The sun, eight planets, many small objects, and a huge amount of space

Explain the solar nebula theory.

  • A nebula of gas, ice, and dust formed, began to rotate and contract, and squeezed the matter into less space. It became dense and faster, heated up, turned into a disk, and triggered nuclear fusion, creating the sun. Whatever was left over made the planets and asteroids.

What did Copernicus believe?

  • That planet had circular orbits around the sun

What did Kepler discover?

  • Planets have elliptical orbits and don't orbit at the same speed

Characteristics of inner planets

  • First four, small, rocks with iron cores, and few to no moons

4 inner planets

  • Mercury, Venus, Earth, Mars

Characteristics of outer planets

  • Large, lightweight, many moons, mostly gases

4 outer planets

  • Jupiter, Saturn, Uranus, and Neptune are things to are planets

  • Must orbit sunthe, not a satellite, large enough for gravity to keep it round, must dominate its orbit

What are not planets, but close?

  • Dwarf planets

Name of the popular dwarf planets

  • Pluto, Ceres, Eris

Name the planets in order

  • Sun, Mercury, Venus, Earth, Mars, asteroid belt, Jupiter, Saturn, Uranus, Neptune, Pluto

Characteristics of Mercury

  • Smallest, closest to the sun, weak magnetic field, no atmosphere, many craters, and no moons

Characteristics of Venus

  • Second plant, Earth's twin(similar size and mass), very different atmosphere because of atmosphere of carbon dioxide

Characteristics of Earth

  • The third planet, 93 million miles away, has water in solid, liquid, and gas, atmosphere protects it.

Characteristics of Mars

  • Fourth planet, Red planet because of iron oxide in rocks, half the size of Earth, two moons, thin atmosphere, polar ice caps, largest volcano, gullies, strong winds, and seasons

Characteristics of Jupiter

  • Largest planet, atmosphere is hydrogen and helium, solid rocky core, great red spot, 68 moons.

Name some of Jupiter's moons

  • Io, Europa, Ceyx, Callisto

Characteristics of Saturn

  • Second largest planet, lowest density, atmosphere of hydrogen, helium, ammonia, methan and has large rings with ice and rock, 56 moons, large moon bugger tahn mercury is titan.

Characteristics of Uranus

  • Large, made of hydrogen, helium, methane, blue in color, a sideways planet because of its axis, and has 27 moons.

Characteristics of Neptune

  • 8th planet, blushish green, atmosphere like Uranus and creates storms with high winds, ring system, 13 moons

Characteristics of Pluto

  • Dwarf planet, a ball of rock, water, ice, and methane gas, orbits towards sun, and first object in the Kuiper belt.

What are comets?

  • Like dirty snowballs, or a mass of dust, rocks, and ice

Describe a tail on a comet

  • When the tail forms, it always points away from the sun as the comet approaches.

Where can a comet come from?

  • An outer cloud

What is an Oort cloud?

  • A mass of comets and gas surrounds the solar system

Define Meteoroid

  • A space rock orbiting the sun

Define meteors

  • A piece of space rock burning in our atmosphere (shooting stars)

Define meteorite

  • Space rock that hits the Earth

Define a meteor shower

  • When Earth passes through a cloud of dirt and dust from old comets

Define asteroid

  • A large piece of space rock that is mainly orbiting the sun, mainly in the asteroid belt between Mars and Jupiter

What is a Light year?

  • The distance light travels in one year.

How fast does light travel?

  • 300,000km/sec or 9.5 trillion km

What is used to determine the distance of stars?

  • A parallax

Key concepts of parallax

  • A shift in position when viewed from two different angles, and the nearer the object, the greater the parallax.

What are constellations?

  • A group of stars that change position throughout the year as the Earth rotates on its axis and revolves around the Sun

What circles around Polaris and are visible all year?

  • Circumpolar stars

 How many constellations do astronomers study?

  • 88 stars

What measures the stars' brightness?

  • Magnitude

What is the measure of the amount of light a star gives off?

  • Absolute magnitude

What is the measure of the amount of light a star receives on Earth?

  • Apparent magnitude

How does someone determine the temperature of the star?

  • The color

Describe the temperature scale of color

  • Hot stars are blue-white and cool stars are orange and red, and yellow stars are medium temperature, like the su.n

What does a spectroscope do?

  • Gets the composition of stars

How does spectrography determine the composition of stars?

  • By having every chemical element produce a unique pattern of dark lines, almost like a fingerprint. 

Describe the sun

  • Middle-aged star, typical magnitude with yellow not and not part of multiple star systems or clusters

What do the sun's layers do?

  • Produces energy in its core by nuclear fusion 

How does energy move in the sun?

  • Like convection currents

Layers of the sun's atmosphere

  • Photosphere, Chromosphere, Corona, and core

Which lowest layer of the Sun's atmosphere?

  • The photosphere

What does the Corona do?

  • Releases charged particles  as solar winds

What are sunspots?

  • Dark areas are cooler than their surroundings, but are temporary features

Name of the pattern of sunspots of 10-11 years

  • Solar activity cycle

How do we classify stars?

  • By using the Herzprung and russell diagram of temperature and absolute magnitude

Define the main sequence of the stars diagram

  • Diagonal band on H-R diagram

Key features of the H-R diagram

  • Upper left(hot, blue, bright), lower right(cool, red, dim stars), and middle(average yellow)

The categories that don't fall into the main sequence go into what?

  • The dwarfs and giants

How do all-stars begin?

  • As a nebula

What is a nebula?

  • A cloud of interstellar gas and dust 

What forms from a nebula?

  • A prostar forms as the cloud contracts and rotates

What happens in the prostar phase?

  • Temperatures increase, and nuclear fusion begins.

What happens in the main sequence?

  • Begins to balance pressure from fusion with gravity

How and what happens when balance is lost in a main sequence?

  • How- uses all hydrogen fuel, and now helium is burning, and the stars' outer layers expand and cool

How does a star become a red giant?

  • When it expands and cools, and now has a core of carbon

How does a white dwarf form?

  • From a red giant, when the helium runs out and creates a carbon core, making it hot, dense, and small

How does a super red giant form?

  • In massive stars, fusion causes higher temperatures and greater expansion

What will happen to a super red giant when fusion stops?

  • The core crashes inward, causing the outer part to explode as an incredibly bright supernova.

Two things can a supernova create?

  • A neutron star or a black hole

Why is a black hole special?

  • Gravity is so strong that nothing can escape it, but gravity operates normally, like before it collapses.d

What can turn into a new nebula?

  • Matter emitted by a star over its lifetime

What is a galaxy?

  • A large collection of stars, gas, and dust held together by gravity.

What is Earth's galaxy?

  • The Milky Way, which is a part of a galaxy cluster named the Local Group

Three types of galaxies

  • Spiral, elliptical, and irregular

Explain a spiral galaxy

  • Disklike galaxies with spiral arms

Explain an elliptical galaxy

  • Not disk-like with spiral arms, but a three-dimensional ellipse is most common

Explain an irregular galaxy

  • They have various shapes and are less common

Scale of the Milky Way galaxy

  • 100,00 light years wide, and has more than 200 billion stars.

Explain the theory of the steady state.

  • The universe has always existed just as now

Explain the theory of the oscillating model

  • The universe expands and contracts repeatedly over time

Explain the theory of the Big Bang.

  • The universe began 12-15 billion years ago with a huge explosion that caused expansion everywhere at the same time.me

What is the universe doing?

  • Expanding, like in the Doppler shift

What is the Doppler shift

  • Light changes as it moves toward or away from an object

What happens to starlight as it moves toward the Earth?

  • Blue-violet end of the spectrum

What happens to starlight as it moves away from the Earth?

  • Red end of the spectrum