Astronomy 101 - Lecture Notes

Flashcards reviewing key concepts from Astronomy 101 lecture notes, designed to help students prepare for exams.

What is a wormhole?

A hypothetical tunnel through space-time, potentially allowing passage between spatial locations.

What celestial bodies comprise the solar system?

Planets, moons, asteroids and the Sun.

When did the solar system form?

4.5 and 4.7 billion years ago.

What is astronomy?

The scientific study of objects in the universe and the events that shape them.

What objects populate the cosmos?

Stars, planets, galaxies and galaxy clusters.

What unit do astronomers use to measure distances inside the solar system?

An astronomical unit-AU

How does an astronomer calculate a light-year?

Multiplying the speed of light by the total seconds in a year.

What is the name of the star cluster located about 350-460 light-years away?

The Pleiades Star Cluster

What is the name of the nearest spiral galaxy to the Milky Way?

The Andromeda Galaxy

What is the most basic property studied in astronomy?

Studying the light emitted, reflected, or absorbed by an object.

What is the speed of light in a vacuum?

299,792,458 meters (186,282 miles) per second.

What colors are visible in the visible light spectrum?

Red, orange, yellow, green, blue, indigo, and violet.

What is it called when an object moves toward us in the spectrum?

Blueshifted

What is it called when an object moves away from us in the spectrum?

Redshifted

What is our local place in space?

The solar system

What are the components of the solar system?

Sun, eight planets, dwarf planets, comets, moons and asteroids

What planets are located in the inner solar system?

Mercury, Venus, Earth, Mars

What planets make up the outer solar system?

Jupiter, Saturn, Uranus, Neptune

What gas giant is located in a region that extends well beyond 50 AU from the sun?

Kuiper Belt

What are terrestrial planets?

Inner worlds

What are gas giants?

Outer worlds

What comprises ice giants?

Supercold forms of oxygen, carbon, nitrogen, sulfur, and possibly even water.

What is the name of the shell of frozen bits of ice and rock that surround the solar system?

The Oort Cloud

What is the shape of planetary paths?

Elongated

What is the term when volcanoes spew mineral-rich lava?

Volcanism

What is the term when icy material erupts from beneath the surface?

Cryovolcanism

What is the term when the surface layers on a planet or moon are warped, driven by heat from below?

Tectonism

What is the biggest source of heat and light in our solar system?

The Sun

What is the study of the physics of the Sun called?

Solar physics

What is the outer solar atmosphere called?

Corona

The actual surface you see when you look at the Sun is called what?

Photosphere

What is the solar core called?

Nuclear furnace

What are sunspots?

Areas threaded with magnetic fields

What are flares?

Bright outbursts

What are solar explosions called?

Coronal mass ejections

What is the phenomenon that occurs throughout the solar system because of solar activity?

Space weather

What is the bubble’s inner edge surrounding the solar system called?

The heliopause

What special instruments are used to peer inside the sun by focusing on sound waves moving through the Sun, a science called helioseismology?

Global Oscillations Network Group (GONG)

What is space weather?

Changes in the near-Earth space environment due to activity originating at the Sun.

What is one manifestation of a constant connection between Earth and the Sun?

The aurorae

What is the constant stream of charged particles called that the sun produces?

The solar wind

What is the region of space around Earth bound by our magnetic field?

The magnetosphere

What is the aurora over the north pole called?

The aurora borealis.

What is the aurora over the south pole called?

The aurora australis.

What are ionospheric disturbances?

Geomagnetic storms

What are the affects of space weather on Earth and technology?

Damage spacecraft electronics, cause power outages, and disrupt telecommunications.

Who takes a keen interest in studying the Sun’s activity?

Atmospheric scientists and solar researchers

What planet has a cratered, cracked and wrinkled landscape?

Mercury

How hot is Mercury's surface?

430°C (800°F)

What was the name of the Mercury Surface, Space Environment, Geochemistry and Ranging spacecraft that planetary scientists sent on a multi-year mission of exploration?

MESSENGER

What planet is referred to as Earth’s Evil Twin?

Venus

What can be found under Venus's clouds?

A rugged desert.

A planet is defined by the International Astronomical Union

A planet is defined by the International Astronomical Union (IAU) as a celestial body that has its primary orbit around the Sun, has sufficient mass for its own gravity to mold it into a round shape, and has cleared the neighborhood around its orbit by sweeping up all the planetesimals, which means that it’s the only body of its size in its orbit

What world lies in a safe warm zone around the sun, and is home to nearly 9 million known species of life?

The Earth

What happened after Earth's crust began to cool?

The first forms of life appeared and began to fill the atmosphere with oxygen.

Where is a protective blanket absorbing most solar ultraviolet light while also keeping temperatures warm through the greenhouse effect?

Earth’s Atmosphere

Where did Earth’s oceans come from

Cometary nulcei

What is Earth’s natural satellite?

The Moon

How many astronauts flew to the Moon?

24

How many astronauts walked on the Moon’s surface?

12

What is the only other world that humans have walked on?

The Moon

Refers to the Moon’s surface or structure, or missions to the Moon

Lunar Fact

How did the Moon formed

In a titanic collision between the newborn Earth and a Mars-sized object referred to as Theia

What is the fourth rock from the Sun?

Mars

What are the names of Mars' two moons?

Phobos and Deimos.

What is the most important reason that we keep sending missions to Mars?

To search for evidence of life

What planet is a world of superlatives?

Jupiter

What are the Galilean moons of Jupiter?

Io, Europa, Ganymede, and Callisto

What is the original ring world?

Saturn

What is the world beneath Saturn’s rings?

Is a layered world, with a rocky core smothered in layers of liquid metallic hydrogen and liquid helium

What lander settled onto the surface of Titan in 2005, revealing a surface of frozen methane ice and methane lakes?

Huygens lander

What makes of most of Saturn?

Molecular hydrogen gas

What planet orbits the sun on its side?

Uranus

What is the outermost planet in our solar system?

Neptune

What makes Triton the active moon?

Triton has a mottled surface made of nitrogen, water and methane ices and has internal activity that drives nitrogen geysers up into its thin atmosphere.

What planet was demoted to a dwarf planet?

Pluto

what is a solar system object in orbit around the Sun that consists of a central core, called a nucleus—which is a combination of ices and dust?

Comets

That vast collection of icy objects at the outer limits of our solar system is called the Oort Cloud. Who does it name credit

Jan Oort

Comets have been called __

dirty snowballs

the rocky bits left if the rock pieces survive the trip and fell to the ground, what are those called?

Meteorites

Each day and night, our planet is showered with more than a hundred tons of material from “out there.” Where are those from

Earth

Collisions still take place regularly where?

the Asteroid Belt

A general object called solar system debris are orbiting the planets

Asteroids

asteroids represent what class of objects?

Planetisimals

How are Asteroids classified?

Spectra of their reflected light

stars classified by what?

Astronomer classification

stars primarily formed by a what?

Luminous sphere of superheated matter

What are two types of a star

Globular and open