astronomer: A scientist who works within the area of analysis that offers with celestial objects, house and the bodily universe.
atom: The essential unit of a chemical ingredient. Atoms are made up of a dense nucleus that accommodates positively charged protons and uncharged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.
Large Bang: The speedy growth of dense matter that, based on present concept, marked the origin of the universe. It’s supported by astronomers’ present understanding of the composition and construction of the universe.
black gap: A area of house having a gravitational area so intense that regardless of or radiation (together with gentle) can escape.
brown dwarf: A would-be star that by no means turned huge sufficient to maintain nuclear fusion.
celestial object: Any naturally shaped objects of considerable dimension in house. Examples embody comets, asteroids, planets, moons, stars and galaxies.
constituent: An ingredient or constructing block of some materials. (in politics) Somebody represented by an elected political chief, similar to a mayor, governor or senator.
core: One thing — normally round-shaped — within the middle of an object.
particles: Scattered fragments, usually of trash or of one thing that has been destroyed. Area particles, for example, consists of the wreckage of defunct satellites and spacecraft.
electrical cost: The bodily property accountable for electrical drive; it may be unfavourable or optimistic.
electron: A negatively charged particle, normally discovered orbiting the outer areas of an atom; additionally, the service of electrical energy inside solids.
ingredient: A constructing block of some bigger construction. (in chemistry) Every of a couple of hundred substances for which the smallest unit of every is a single atom. Examples embody hydrogen, oxygen, carbon, lithium and uranium.
gas: Any materials that may launch power throughout a managed chemical or nuclear response.
fusion: (v. to fuse) The merging of two issues to kind a brand new mixed entity. (in physics) The method of forcing collectively the nuclei of atoms. This nuclear fusion is the phenomenon that powers the solar and most different stars, producing warmth and forging the creation of latest, heavier parts.
galaxy: A bunch of stars — and normally darkish matter — all held collectively by gravity. Large galaxies, such because the Milky Means, usually have greater than 100 billion stars. The dimmest galaxies could have just some thousand. Some galaxies even have gasoline and mud from which they make new stars.
galaxy cluster: A gathering of many galaxies held shut to at least one one other by gravity.
gravity: The drive that pulls something with mass, or bulk, towards another factor with mass. The extra mass that one thing has, the higher its gravity.
hydrogen: The lightest ingredient within the universe. As a gasoline, it’s colorless, odorless and extremely flammable. It’s an integral a part of many fuels, fat and chemical compounds that make up residing tissues. It’s fabricated from a single proton (which serves as its nucleus) orbited by a single electron.
iron: A metallic ingredient that’s widespread inside minerals in Earth’s crust and in its sizzling core. This metallic is also present in cosmic mud and in lots of meteorites.
kelvin: A temperature scale that has models the scale of these on the Celsius scale. The distinction, zero kelvin is absolute zero. So zero kelvin is the same as -273.15 Celsius. Meaning zero Celsius is the same as 273.15 kelvins. NOTE: Not like with the Celsius and Fahrenheit scales, there isn’t any use of the time period “levels” for numbers on the kelvin scale.
light-year: The space gentle travels in a single 12 months, about 9.46 trillion kilometers (nearly 6 trillion miles). To get some thought of this size, think about a rope lengthy sufficient to wrap across the Earth. It will be slightly over 40,000 kilometers (24,900 miles) lengthy. Lay it out straight. Now lay one other 236 million extra which are the identical size, end-to-end, proper after the primary. The overall distance they now span would equal one light-year.
Mars: The fourth planet from the solar, only one planet out from Earth. Like Earth, it has seasons and moisture. However its diameter is barely about half as massive as Earth’s.
mass: A quantity that exhibits how a lot an object resists rushing up and slowing down — principally a measure of how a lot matter that object is constructed from.
matter: One thing that occupies house and has mass. Something on Earth with matter can have a property described as “weight.”
Milky Means: The galaxy by which Earth’s photo voltaic system resides.
nuclear response: Occasions that bodily alter the nucleus of an atom. (That is in distinction to chemical reactions that have an effect on the electrons orbiting an atom.) Some nuclear reactions will transmute an atom, change it into a unique chemical ingredient, similar to by means of fission (also called atom splitting). Others could contain the seize of power by bombardment with electromagnetic radiation or subatomic particles.
nucleus: Plural is nuclei. (in biology) A dense construction current in lots of cells. Usually a single rounded construction encased inside a membrane, the nucleus accommodates the genetic data. (in astronomy) The rocky physique of a comet, generally carrying a jacket of ice or frozen gases. (in physics) The central core of an atom, containing most of its mass.
neutron: A subatomic particle carrying no electrical cost that is without doubt one of the fundamental items of matter. Neutrons belong to the household of particles generally known as hadrons.
neutron star: The very dense corpse of what had as soon as been a large star. Because the star died in a supernova explosion, its outer layers shot out into house. Its core then collapsed below its intense gravity, inflicting protons and electrons in its atoms to fuse into neutrons (therefore the star’s identify). A single teaspoonful of a neutron star, on Earth, would weigh greater than a billion tons.
orbit: The curved path of a celestial object or spacecraft round a galaxy, star, planet or moon. One full circuit round a celestial physique.
particle: A minute quantity of one thing.
planet: A big celestial object that orbits a star however not like a star doesn’t generate any seen gentle.
proton: A subatomic particle that is without doubt one of the fundamental constructing blocks of the atoms that make up matter. Protons belong to the household of particles generally known as hadrons.
purple dwarf: A kind of small star that’s comparatively cool (and therefore emits reddish gentle). Pink dwarfs are the most typical stars within the Milky Means.
Saturn: The sixth planet out from the solar in our photo voltaic system. One of many two gasoline giants, this planet takes 10.6 hours to rotate (finishing a day) and 29.5 Earth years to finish one orbit of the solar. It has at the very least 82 moons. However what most distinguishes this planet is the broad and flat aircraft of vivid rings that orbit it.
star: The essential constructing block from which galaxies are made. Stars develop when gravity compacts clouds of gasoline. Once they develop into sizzling sufficient, stars will emit gentle and generally different types of electromagnetic radiation. The solar is our closest star.
subatomic: Something smaller than an atom, which is the smallest little bit of matter that has all of the properties of no matter chemical ingredient it’s (like hydrogen, iron or calcium).
solar: The star on the middle of Earth’s photo voltaic system. It’s about 27,000 light-years from the middle of the Milky Means galaxy. Additionally a time period for any sunlike star.
supernova: (plural: supernovae or supernovas) A star that out of the blue will increase tremendously in brightness due to a catastrophic explosion that ejects most (or generally all) of its mass.
telescope: Often a light-collecting instrument that makes distant objects seem nearer by means of using lenses or a mix of curved mirrors and lenses. Some, nonetheless, accumulate radio emissions (power from a unique portion of the electromagnetic spectrum) by means of a community of antennas.
trillion: A quantity representing 1,000,000 million — or 1,000,000,000,000 — of one thing.
universe: Your complete cosmos: All issues that exist all through house and time. It has been increasing since its formation throughout an occasion generally known as the Large Bang, some 13.eight billion years in the past (give or take just a few hundred million years).
white dwarf: A small, very dense star that’s the dimension of a planet. It’s what’s left when a star with a mass about the identical as our solar’s has exhausted its nuclear gas of hydrogen and solid off its outer layers.