Sun and Stars Flashcards
Universe
All of space and everything in it.
Solar System
Our sun and everything that orbits it.
What are the names of the eight planets?
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Galaxy
A system of stars, planets, dust, gas and other objects held together by gravity.
Milky Way
Our galaxy.
What shape is the Milky Way?
A barred spiral shape.
Is there sound in space? Why or why not?
No, because sound travels through air and there is no air in space.
Why is space dark?
We can only see light when it bounces off of something. In space there are not many things for light to bounce off of.
Why is our galaxy called the Milky Way
It looks milky in the night sky.
How big is the Milky Way compared to other galaxies
It is a medium sized galaxy.
How many stars are in the Milky Way
100-400 billion
What do scientists think is in the center of the Milky Way?
A black hole.
Have any man made objects left our solar system?
Yes. The Voyager 1 and Voyager 2
Does the Milky Way sit still?
No. It is constantly rotating.
Telescope
A device that collects light from far away objects and provides a magnified image.
Aperture
The opening on the end of a telescope that light enters.
How does the size of aperture affect the image
A bigger aperture makes a sharper image.
Refracting Telescope
Uses a lens to collect and focus light.
Reflecting Telescope
Uses a curved mirror to collect light
Compound telescope
Uses both mirrors and lenses to collect light.
How does Earths atmosphere affect the pictures of telescopes?
Heat causes turbulent air that distorts light causing images to be blurry.
What other types of telescopes are there?
Infrared, x-ray, radio waves
What is a star?
A huge fiery ball of gas.
What is the closest star to us?
Our sun.
How far away is the sun?
93 million milles.
How are stars formed?
Gravity pulls gas and dust together. As it becomes more compressed friction causes the ball to heat up until it undergoes nuclear reaction.
Luminosity
A measure of how bright a star is.
What factors affect how bright a star looks from Earth?
How far away it is, how big it is, how hot it is.
Where is the worlds largest astronomical observatory?
Mauna Kea in Hawaii
Why are stars different colors?
They are different temperature.
Hotter stars are what color?
Blue and white.
Cooler stars are what color?
Red and yellow.
What are the big stars called?
Giants
What are the smaller stars called?
Dwarfs.
What type of star is our sun?
A medium sized yellow star.
Some supergiant stars are as big as?
Our entire solar system.
Why do stars twinkle?
Because their light has to pass through many layers of our atmosphere and other things in the universe to get to us.
What other objects in the sky appear to be stars?
Planets and satellites.
When do stars die?
When they burn up all of their fuel.
How is a stars size related to how long it lives?
Large stars burn their fuel faster and smaller stars burn it slower.
As a star burns all of its fuel it will expand and cool into a?
Red Giant
A red giant will either turn into a ___________ or a __________ depending on its size.
White dwarf or supernova.
Supernova
A huge explosion at the end of a stars life.
A supernova will turn into a __________ or a __________.
Black hole or a neutron star.
Neutron Star
A small dense fast rotating star.
Why are neutron stars sometimes called pulsars?
The rapid rotation of a neutron star sweeps
the magnetic fields of its poles across space like a
lighthouse, creating a radio wave pulsing effect.
Constellation
A group of stars that make a picture.
Exoplanet
Planets that do not orbit our sun.
Exo means what in Greek?
Outside.
Chthonian [THON-ee-un]
The baked rocky core of a gas planet whos atmosphere was blown away by being too close to its star.
Goldilocks planet
A planet that is within it’s suns “habitable” zone.
Orbit
The path followed by an object around another object. Caused by gravity.
How fast do you have to go to achieve orbit around the Earth?
Five miles per second.
What shape are orbits?
Elliptical
What do we call the time it takes for a planet to travel around its star?
A planetary year.
How does a planets distance from the sun affect it’s orbit?
The closer a planet is to the sun the faster it moves and the shorter distance it has to travel to go around the sun.
What three conditions have scientists decided make a planet a planet?
It must be a natural celestial body that orbits a sun.
It must have enough mass and gravity to make itself round.
It must have enough mass and gravity to clear objects out of its orbital path.
Mass
How much matter is in an object.
The sun is so large it contains _____ % of the solar systems mass.
99.8%
Why doesn’t the suns gravity pull the planets into it?
The planets all have forward motion that keep them in orbit.
How does a planets closeness to the sun affect it’s tempature
Planets closer to the sun are hotter. Planets farther away are colder.
Asteroid
A small celestial body made of rock, metal or ice.
Astronomer
A scientist that studies stars and planets.
Atmosphere
Gasses that surround a planet.
Atom
One of the basic units of matter.
Carbon
A nonmetallic chemical element.
Comet
A small body made of dirt and ice that orbits the sun.
Core
Center part of the inside of a planet or star.
Coronal Mass Ejection
When large amounts of material from the suns corona erupts into space.
Electron
A negatively charged particle that forms part of an atom.
Gravity
The pull of an object on other objects.
Helium
The second most abundant chemical element in the universe.
Hydrogen
The most abundant chemical element in the universe.
Ion
An atom or a group of atoms that has an electric charge.
Kelvin
A metric unit to measure temperature.
Light-year
The distance that light travels in one year.
How far is a light-year?
5.8 trillion miles
Magnetic Field
The space around a magnetized object where its power of attraction works.
Main-sequence Phase
Stage in a stars life where it gets all of its energy from hydrogen fusion reactions in its core.
Matter
The material of which all objects are made.
Molecule
The basic units of matter.
Nuclear Fusion Reaction
Process by which two atomic nuclei join to create a new, larger nucleus.
Plasma
A form of matter, similar to gas made up of positively charged ions and electrons.
Probe
An unpiloted device sent to explore space.
Radiation
Energy given off in the form of waves or small particles of matter.
Radius
A line going from the center to the outside of a circle or sphere.
Satellite
An object that orbits a body.
Solar Flare
A sudden bightening of a part of
