Space Chapter 7

Revolution occurs when one object moves around another object. An example of this occurs when the Earth moves around the Sun.

Astronomers are people who are experts in the study of stars. They study how the stars have evolved. They study the the sun, our star, the moon, our solar system, and what has happened and what will happen as time goes on.

Rotation occurs when an object revolves. It is the cause to turn around a center point, or an axis. This is when the Earth revolves around its axis.

Constellations are groups of stars that make an imaginary shape, but form a recognizable pattern. They are usually named after mythological characters, people, animals and objects.

A Celestial object is an that is a natural object that is located outside of the Earth’s atmosphere. For example, the sun, an asteroid, the moon, or a star.

A light year is a unit of distance, not time. It measures the distance that light travels in one year, and it how astronomers measure distance in space.

Astronomers use the term apparent magnitude to measure how bright an object appears from Earth. It is the way of measuring the brightness of an object as seen from Earth

Asterism are groups of stars that form some kind of pattern, but are smaller than or part of a constellation. For example, the summer triangle is an example of Asterism, as well as the little dipper and the big dipper.

Pointer stars point to something to help find another important star. For example, the stars Dubhe and Merak (the two outermost stars from the big dippers bowl) point to the Northern star, Polaris.

Zenith is that star that can be seen when looking straight up. If you were right under a star, the star would be your zenith.

Circumpolar stars are constellations that never set below the horizon. They are constellations that can always be seen year-round. Depending on when you are, Circumpolar constellations may change.

Tides are the rise and fall of the ocean. They are caused by the gravitational pull of the Moon as well as the rotation of the Earth.

The phase of the moon is how much of the moon appears to us on Earth to be lit up by the sun. Half of the moon is always lit up by the sun, except during an eclipse, but we only see a portion that's lit up. There are 8 phases of the moon

A lunar eclipse occurs when the Moon passes directly behind Earth and into its shadow. This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned, with Earth between the other two. A lunar eclipse can occur only on the night of a full moon. It occurs about twice a year.

A solar eclipse occurs when a portion of the Earth is engulfed in a shadow cast by the Moon which fully or partially blocks sunlight. This occurs when the Sun, Moon and Earth are aligned. For this to be seen, the moon must be in between the two, and because the moon is smaller than the Earth, it cannot be seen although it also occurs about twice a year.

We have seasons because the earth is tilted either towards or away from the Sun. The Earth's axis is tilted at an angle of 23.5 degrees. This means that the Earth is always "pointing" to one side as it goes around the Sun. While that side is experiencing summer, the other will be experiencing winter, while all other in between experience spring and fall.

A comet is a ball of mostly ice that moves around in outer space. They release gas or dust. They have a tail that points away from the Sun.

A celestial body that orbits around a star. In our solar system, there are 8 planets. The four planets that are closest to the sun (Mercury, Venus, Earth and Mars) are the inner planets, also called the terrestrial planets because they are similar to Earth. The inner planets either do not have moons or have just one or two. The inner planets are called the inner planets because their orbits lie inside the asteroid belt. The ones outside are the outer planets, like Jupiter, Saturn, Uranus and Neptune. They are commonly known as gas giants, and are made primarily of hydrogen and helium. The outer planets have faster orbits and rotations, a composition of gases and liquids, numerous moons, and rings.

The solar system is made up of the sun and everything that orbits, or moves around the sun. This includes the eight planets and their moons, dwarf planets, and countless asteroids, comets, and other small, icy objects. However, even with all these things, most of the solar system is empty space.

Retrograde motion is an illusion caused by the Earth’s movement and the planets around the sun. Astronomers use the term to refer to the occasional backwards motion of the planets as seen in Earth’s sky.

A unit of measurement equal to 149.6 million kilometers, the mean distance from the center of the earth to the center of the sun.

A planet's orbital radius is its average distance from the sun.

The geocentric model was a model that led people to believe that everything revolved around the Earth.

The Heliocentric Model is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System

Asteroids are minor planets, especially of the inner Solar System. Larger asteroids have also been called planetoids they are rocky bodies that revolve around the sun

A meteoroid is a small rocky or metallic body in outer space, that would become a meteor if entered space. Meteoroids are significantly smaller than asteroids, and range in size from small grains to one-meter-wide objects. Objects smaller than this are classified as micrometeoroids or space dust

If a meteoroid enters the Earth's atmosphere and vaporizes, it becomes a meteor, which is often called a shooting star. It is seen as bright streaks of light.

If a small asteroid or large meteoroid survives its fiery passage through the Earth's atmosphere and lands on Earth's surface, it is then called a meteorite. A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originated in outer space and survived its passage through the atmosphere to reach the surface of a planet or moon.

A Trans-Neptunium object is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune. A commonly known example of a Trans Neptunium object is Pluto.

An inner planet, closest to the sun. It has no atmosphere. Slightly larger than the Earth's moon, and the closest to the sun. there are huge differences between day and night surface temperatures, which cause it to expand and contract, creating cracks

Atmosphere contains carbon dioxide and nitrogen, the atmosphere traps the heat, making it hotter than Mercury. Size and composition is close to Earth. Thick clouds prevent us from seeing Venus's surface. Sulfur mixes with moisture resulting in acid rain. 1990’s Magellan's radar reveals Venus to have large flat areas, while others are full of volcano’s lava flows and cracks called rifts.

Only one with suitable atmosphere and temperatures for life to survive, mainly contains nitrogen, oxygen and water vapor. Home to the only life scientists have discovered. ONLY a planet to have liquid solid and gas water form. Running water wind and Earth;s tectonic plates constantly shape the Earth. Water covers nearly 3/4 of Earth’s surface.

Very thin atmosphere, made up of mainly carbon dioxide. Iron in the surface gives it a rusty colour, hence the name “red planet”. Has a mountain 3x higher than mount Everest

An outer planet, the largest planet. Has small rings made up of ice particles. Days are 10 hours, shorter than any other in our system. 100x bigger, small faint star. Atmosphere is made up of hydrogen and helium.

Made up of mostly hydrogen, and some helium, just like the planet itself. Elaborate system of rings, which are made up of ice particles and can be 250 000km to 10m wide

Greenish blue colour due to methane gas. Also contains hydrogen and helium in the classroom. The fourth biggest planet in our solar system. Has a ring made up of ice and dust. Unusual rotation, it’s flipped on its side. It is a gas giant.

Similar to Uranus, but a darker blue colour. The outermost planet, and the third biggest. Dark blue colour, very thin rings made up of ice particles

The solar nebular describes how stars and planets formed from contracting, spinning disks of gas and dust

A celestial body made of hot gases, mainly made of hydrogen and some helium

A cloud of gas and dust in outer space, which may be the birthplace of stars and planets

A contracting mass of gas which represents an early stage in the formation of a star, before nucleosynthesis has begun

A nuclear reaction in which energy is produced when hydrogen nuclei combine to form helium nuclei

The surface layer of the sun

A spot or patch appearing from time to time on the sun's surface, appearing dark by contrast with its surroundings. An area of strong magnetic fields on the photosphere

The continuous flow of charged particles from the sun which permeates the solar system.

When high energy charged particles are carried past Earth’s magnetic field generating electric currents that flow toward the poles

Without the Sun's heat and light, the Earth would be a lifeless ball of ice-coated rock. The Sun warms our seas, stirs our atmosphere, generates our weather patterns, and gives energy to the growing green plants that provide the food and oxygen for life on Earth. Warms Earth’s surface, solar energy powers the wind, ocean currents, and our weather.

A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously

a telescope which uses a lens to collect the light.

a telescope in which a mirror is used to collect and focus light.

An artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.