Bigger Than Big - Science Flashcards - Nakita

What is a planet?

A round and massive object which orbits a star and has cleared its orbital path of debris.

What is gravity?

An attractive force between objects that have mass.

What is orbit?

The path taken by one object around another because of gravity.

What is a satellite?

An object in space that orbits a larger body.

What are terrestrial planets?

Planets mainly composed of rocks and metals with a solid surface.

What are gas planets?

Planets mainly composed of gases.

What is a galaxy?

A cluster of stars, dust, and gas held together by gravity.

For something to be classified as a planet, what must it do?

Orbit a star, be large enough to be round, and have cleared its orbit of debris.

What is a star?

A celestial body that produces heat and light, held together by gravity, made of plasma.

What is the universe?

All of space and time and the matter and energy they contain.

What is galaxy?

A group of billions of stars, gas and dust held together by gravity.

What does the Observable Universe refer to?

the part of the universe that we can see or detect from Earth.

Why can't we see some celestial bodies?

Because their light hasn't had enough time to reach Earth in the 4.5 billion years it's existed.

What are the three types of galaxies?

Spiral, Elliptical, and Irregular.

What are features of spiral galaxies?

Long curling arms that look like whirlpools

What are features of elliptical galaxies?

More uniform, round shape, smooth, bright.

What are features of irregular galaxies?

Twisted shapes, usually caused by collisions between galaxies.

What are electrons?

Subatomic particles with a negative charge.

What are protons?

Subatomic particles with a positive charge.

What are neutrons?

Subatomic particles with no charge.

What is a nucleus?

The core of an atom, made up of protons and neutrons.

What is Nuclear Fusion?

A type of nuclear reaction in which two atomic nuclei fuse together to produce heat and light.

What element is converted into helium in a star?

Hydrogen

What are the counter-forces that prevents a star from blowing apart in nuclear fusion

Balance between gravity and outward pressure.

Where do stars form?

nebulas

What is nebula gas mostly made of?

Hydrogen

What is a protostar?

A ball of gas, primarily hydrogen, that is contracting under gravity. It has not yet begun nuclear fusion but is on its way to becoming a star.

What 3 things are needed to make a star?

Hydrogen, gravity, and time

What do red giants become when they have planetary nebula?

White dwarf

What are white dwarfs mostly comprised of?

Carbon and Oxygen

What do stars that are at least 8 times bigger turn into?

Red Supergiants

What do smaller red giants form?

White dwarfs and planetary nebulas

What is a supernova?

a massive explosion of a star, occurring during the final stages of a massive star's life

What elements are formed by Supernova explosions?

Heavier elements than Iron, such as gold and uranium.

What are neutron stars?

The remains of the core of a large star, made up of densely packed neutrons.

What are black holes?

An object with gravity so strong that even light can't escape it.

What happens to large stars in their final stages?

They are able to fuse carbon and oxygen to form heavier elements due to more mass, more gravity, and compressed core making higher temperatures.

What is a black hole's event horizon?

The imaginary sphere around the singularity from which light cannot escape.

What do black holes have at their centre?

A tiny, incredibly dense point called a singularity

What is a light-year?

A measure of distance, the distance light travels in one year

What is an Astronomical Unit (AU)

The distance between Earth and the Sun.

What is a Stellar Parallax

Use of trigonometry to solve for the distance between the Sun and a distant star based on the parallax angle which is determined from 2 points in Earth's orbit.

What is Hubble Telescope?

a telescope orbiting Earth providing clear, detailed images of distant astronomical objects

What is a gravitational field?

The space around an object where another object will experience the effect of gravity.

How long ago do astronomers believe the universe formed?

14 billion years ago.

What is the Big Bang?

how astronomers explain the way the universe began

What happened in the second after the Big Bang?

The universe expanded from smaller than an atom to bigger than a galaxy.

What happened roughly 380,000 years after the Big Bang?

Electrons combined with nuclei to form simple atoms - hydrogen & helium.

What Scientific Evidence backs the Big Bang theory?

Red Shift, Cosmic Microwave Background Radiation, and Composition of Stars

What is the Doppler Effect?

Change in wavelength due to motion of a light source

What does Redshift show us?

The universe is expanding, the more redshifted a galaxy's light is, the faster it's moving away, this helped disprove the old idea of a Static universe.

How does the composition of stars help prove the big band theory?

What is the Big Bang Theory?

The leading theory for how the universe began about 13.8 billion years ago.

What are Gravitational Fields?

The space surrounding every object where another object will experience the force of gravity.

What is Force measured in?

Newtons (N) so gravitational field strength is measured in newtons per kilogram (N/kg).

What is Mass?

How much matter an object contains, measured in kg.

What is Weight?

The gravitational force on an object, measured in newtons.

What is the gravitational field strength at Earth's surface?

9.8 N/kg.

What long-term effects are due to Human impact?

Greenhouse effect, ozone layer depletion, effect of climate on sea levels, waste management and loss of biodiversity.

What implicates Industrial Revolution?

Global Surface upward temperature trend.