atmosphere: The outer layer of gas that surrounds Earth or another planet or moon.
atom: The basic unit of a chemical element. An atom consists of a dense nucleus containing positively charged protons and uncharged neutrons. A cloud of negatively charged electrons orbits the nucleus.
Aurora: A light show in the sky caused by high-energy particles from the Sun colliding with gas molecules in a planet’s upper atmosphere. The best known is Earth’s Aurora Borealis, or Northern Lights. Some of the outer gas planets, such as Jupiter and Saturn, have fast rotation speeds and strong magnetic fields that generate high electrical currents in the upper atmosphere at the planet’s poles. This, too, can cause an Aurora “light” show in the upper atmosphere.
Aurora: Also known as the Aurora Borealis, this light show in the Northern Hemisphere sky is caused by high-energy particles from the sun colliding with gas molecules in the Earth’s upper atmosphere.
core: The center of an object, usually round in shape. (geology) The innermost layer of the Earth; or a long, tubular sample obtained by drilling into ice, soil, or rock. Scientists use cores to examine layers of sediment, dissolved chemicals, rocks, and fossils to learn how the environment of a place has changed over hundreds or thousands of years or longer.
Cosmic rays: Extremely energetic particles (mainly protons) that bombard Earth from all directions. These particles originate outside the solar system. They are the equivalent of atomic nuclei. They travel at high speeds through space (often close to the speed of light).
drag: The slowing force exerted by air or other fluids around a moving object. It involves friction, but unlike simple friction, it increases with the object’s speed.
Excite: (in chemistry and physics) The transfer of energy to one or more outer electrons in an atom. The electrons remain in this higher-energy state until they give off the extra energy by emitting some type of radiation, such as light.
iron: A metallic element common in minerals in the Earth’s crust and hot core. It is also found in space dust and many meteorites.
Jupiter: (astronomy) The largest planet in the solar system, with the shortest day length (9 hours 55 minutes). It is a gas giant, and its low density means that it is composed mainly of the light elements hydrogen and helium. The planet also gives off more heat than it receives from the Sun, due to the compression of its mass by gravity (and the slow shrinking of the planet).
magnetic field: A field of influence created by certain substances called magnets, or by the movement of electric charges.
Mars: It is the fourth planet from the Sun, just one planet away from Earth. Like Earth, it has seasons and humidity, but its diameter is only about half that of Earth.
mercury: (capitalized in astronomy) The smallest planet in the solar system, and the planet whose orbit is closest to the Sun. Named after the Roman god (Mercury), its year is 88 Earth days, which is shorter than a planetary day, and each day is 175.97 times longer than an Earth day.
metal: Something that conducts electricity well, is shiny (reflective), and malleable (i.e. can be reshaped with heat and without excessive force or pressure).
Melted: A word used to describe molten material, such as the liquid rock that makes up lava.
oxygen: A gas that makes up about 21 percent of Earth’s atmosphere. All animals and many microorganisms require oxygen to fuel their growth (and metabolism).
particle: A trace of something.
planet: They are large celestial bodies that orbit stars, but unlike stars, they do not produce any visible light.
radius: (plural: radii) A straight line from the center of a circle or sphere to its circumference.
Saturn: The sixth planet from the Sun in the Solar System. One of two gas giants, it takes 10.6 hours (one day) to rotate on its axis and 29.5 Earth years to complete one orbit around the Sun. It has at least 82 moons. However, the most distinctive feature of this planet is the large, bright, flat surface that orbits it.
Solar wind: A stream of charged particles (including atomic nuclei) emitted from the surface of a star, such as the Sun, that permeates the entire solar system. When it comes from a star other than the Sun, this radiation is called the stellar wind.
solar: The star at the center of Earth’s solar system, about 27,000 light-years away from the center of the Milky Way galaxy. Also a term used to refer to all stars like the Sun.
Source: www.snexplores.org
