Key Concepts in Astronomy and Ecosystems

Astronomy

Scientific study of what is beyond earth

Celestial Object

Any object that exists in space

Universe

Everything that exists; including, space, matter and space.

Star

Massive collection of gases, held together by emitting huge amounts of energy

Luminous

producing and giving off light; shining

Planet

large round celestial object that travels around a star

Solar System

The sun and other planets that travel around it

Satellite

a celestial object that travels around a planet/dwarf planet

Orbit

the closed path of a celestial object or satellite as it travels around another celestial object

Galaxy

a huge, rotating collection of gas, dust, and billions of stars, planets, and other celestial objects

Electromagnetic (EM) radiation

energy emitted from matter, consisting of electromagnetic waves that travels at the speed of light

Electromagnetic (EM) spectrum

the range of wavelengths of electromagnetic radiation, extending from radio waves to gamma rays, and including visible light

Sunspots

Dark spots appearing on the sun's surface that are cooler than the area surrounding them

Solar flare

sudden burst of radiation released from the Sun, essentially a large explosion on its surface

Solar Prominence

low-energy gas eruptions from the Sun's surface that extend thousands of kilometers into space

Aurora borealis

A display of shifting colors in the northern sky caused by solar particles colliding with matter in earth's upper atmosphere

Astronomical unit

approximately 150 million kilometers; average distance from Earth to the Sun

Dwarf Planet

objects that orbit the Sun, and are nearly round, but does not properly orbit

Comet

a chunk of ice and dust that travels in a very long orbit around the Sun

Orbital radius

Average Distance between an object in the solar system

Gravitational force

The force of attraction between all masses in the universe

Solstice

event that happens twice a year when the Earth's tilt makes the Sun appear at its highest or lowest point in the sky.

Equinox

The time of year when the hours of daylight equals the hours of darkness

Precession

The changing direction of earth's axis

Lunar cycle

All phases of the moon

Eclipse

a darkening of a celestial object due to the position of another celestial object

Tide

Tides are the regular rising and falling of ocean water, caused by the pull of the Moon and the Sun on Earth.

Celestial sphere

the imaginary sphere that rotates around Earth, onto which all celestial objects are projected

Celestial navigation

The use of positions of stars to determine location and direction when travelling

Ecliptic

Path in the sky that the Sun, Moon, planets, and zodiac constellations seem to follow during the year.

Retrograde motion

when a planet appears to move backward in the sky, from east to west, instead of its usual west to east direction.

Azimuth

the direction along the horizon, measured from the north going east, to a point below a star or planet.

Altitude

how high a star or planet appears in the sky, measured upward from the horizon.

Global Positioning system (GPS)

group of satellites that help find the exact location of objects on Earth.

Geostationary orbit

Is a path around Earth above the equator where a satellite moves at the same speed as Earth's rotation, so it stays over the same spot.

atmosphere

the layer of gases surrounding Earth

Lithosphere

earth's solid outer layer

hydrosphere

all of earth's water in solid

biosphere

the zone around earth where life can exist

Ecosystem

All the living organisms and their physical and chemical environment

Biotic factors

Living things their remains and features, such as nests, associated with their activities

abiotic factor

the non-living physical and chemical components of an ecosystem

sustainability

The ability to maintain an ecological balance

sustainable ecosystem

an ecosystem that is maintained through natural processes

radiant energy

energy that travels through empty space

light energy

visible forms of radiant energy

thermal energy

the form of energy transferred during heating or cooling

photosynthesis

the process in which the sun's energy is converted into chemical energy

producer

an organism that makes its own energy-rich food compounds using the Sun's energy

cellular respiration

the process by which sugar and oxygen are converted into carbon dioxide and water, to provide energy for the cell

consumer

an organism that obtains its energy from consuming other organisms

ecological niche

the function a species serves in its ecosystem, including what it eats, what eats it, and how it behaves

food chain

a sequence of organisms, each feeding on the next, showing how energy is transferred

food web

a representation of the feeding relationships within a community

Ecological pyramid

a representation of energy, numbers, or biomass relationships in ecosystems

biomass

the mass of living organisms in a given area

biogeochemical cycle

the movement of matter through the biotic and abiotic environment

Water cycle

the series of processes that cycle water through the environment

carbon cycle

the biogeochemical cycle in which carbon is cycled through the lithosphere, atmosphere, hydrosphere, and biosphere

nitrogen cycle

the series of processes in which nitrogen compounds are moved through the biotic and abiotic environments

limiting factor

any factor that restricts the size of a population

tolerance range

The abiotic conditions within which a species can survive

carrying capacity

the maximum population size of a particular species that a given ecosystem can sustain.

Biome

A large geographical region defined by climate (precipitation and temperature) with a specific set of biotic and abiotic features

oligotrophic

a body of water that is low in nutrients

eutrophic

a body of water that is rich in nutrients

watershed

the land area drained by a particular river; also called a drainage basin

Biogeochemical cycles

Matter is continuously consumed, rearranged, stored, and used while moving between the biotic and the abiotic environment.

Carbon sinks

Carbon is stored for long periods of time in carbon sinks and deposits.

Fossil fuels and deforestation

Burning fossil fuels and deforestation release carbon dioxide into the atmosphere.

Human influence on water cycle

Humans influence the water cycle when they construct dams and use irrigation systems.

Ecosystems

Ecosystems are composed of biotic and abiotic components.

Ecosystem characteristics

Ecosystems are characterized by their biotic and abiotic features.

Natural ecosystems

Natural ecosystems are generally sustainable, maintaining a relatively constant set of biotic and abiotic characteristics.

Artificial ecosystems

Artificially created ecosystems are not usually sustainable.

Species interactions

Species interactions include competition, predation, mutualism, parasitism, and commensalism.

Terrestrial biomes

Terrestrial biomes are largely determined by temperature and precipitation patterns.

Canada's major biomes

Canada's major biomes are tundra, boreal forest, grassland, and temperate deciduous forest and mountain forest.

Aquatic ecosystems

Aquatic ecosystems are determined by factors such as salt content, light, nutrient and oxygen availability, and the movement of water.

Earth's orbit

Earth orbits the Sun at about 150 million km distance.

Earth's appearance from space

From space, Earth looks like a pale blue dot, surrounded by clouds.

Earth's surface composition

Earth's surface is covered by oceans, land, and ice.

Atmospheric composition

The atmosphere is made of 78% nitrogen, 21% oxygen, and less than 1% other gases (argon, water vapour, carbon dioxide, etc.).

Atmospheric functions

The atmosphere acts like a blanket, regulating temperature, preventing extreme heating in the day and cooling at night.

Average temperature regulation

The atmosphere keeps Earth's average temperature around 15°C instead of 18°C.

Protection from solar radiation

The atmosphere blocks harmful solar radiation, including UV rays linked to skin cancer.

Lithosphere thickness

The thickness of the lithosphere ranges from 50 to 150 km.

Water distribution

97% of Earth's water is found in the oceans.

Competition for resources

Life on Earth is in a constant competition for limited resources: space, water, and nutrients.

Gaia Hypothesis

The Gaia Hypothesis, proposed by James Lovelock in the 1960s, suggests Earth acts like a living organism, maintaining stable conditions.

Sustainability of ecosystems

Sustainability is the ability to maintain natural conditions without disruption or loss.

Sun

The main energy source for all life (radiant energy).

Chemical energy

Energy stored in cells, powers growth, movement, reproduction, and must be replenished.

Producers

Organisms that make their own food using light energy.

Food chains

Diagrams that show who eats whom in an ecosystem and represent the flow of energy from one organism to another.

Trophic levels

Levels in a food chain, including producers (1st level), herbivores (2nd level), and carnivores (3rd & 4th levels).

Food webs

Complex feeding relationships that show interconnected food chains.

Energy Pyramid

A type of ecological pyramid that always decreases in size going up and shows energy flow.

Pyramid of Numbers

An ecological pyramid that shows the number of individuals per trophic level.

Pyramid of Biomass

An ecological pyramid that shows the total mass of organisms at each level.