How did ancient astronomers know the difference between planets and stars?
Ancient astronomers can tell the difference the same way you can tell now - the planets move, while the stars stay in the same patterns. The word "planet" comes from the Greek word for "wanderer". The 'planets' were the lights in the sky that moved. Originally the Greeks included the Sun and Moon as planets, because they were light's that moved through the sky. Also, the closer and bigger planets, Jupiter, Mars & Venus are also MUCH brighter than stars. The smaller planets and the ones that are far, far away (Mercury & Saturn) are also bright - but not much brighter than the brightest stars in the sky. They also all travel in the same narrow path in the sky - the ecliptic. It's the same path the sun & moon follow in the sky through the months & year. These 7 lights were visible in the sky without telescopes - Sun, Moon, Mars, Mercury, Jupiter, Venus & Saturn - which is how we got our 7 days of the week.
4 people found this useful
Difference Between a Planet and a Star A star contains much more mass than a planet, enough that gravitational forces have compressed the matter enough to start a fusion rea…ction at the nuclear level, radiating the resultant energy out. A planet orbits a star in a regular manner. The sum of a star and it's orbiting planets is called a Solar System. Stars are always much bigger than planets. Also, their content is different. stars are made of mostly hydrogen, which they push together to form helium. this is then pushed together to form other elements which are blown into space. (although one star nicknamed Lucy has got alot of carbon in its core, which because of the pressure has formed a diamond which is a billion billion carats.) planets are different. although they may be made of gas, like Jupiter, they are different gases to the ones in stars. also, it is actually very unlikely that it is made from gases. it is usually molten iron and rock. A star is a burning mass of (mainly) hydrogen and helium. The outer planets are also made out of hydrogen and helium. Neptune and Uranus theirs also have methane,hydrogen, and helium in it that's why both planets are blue. A planet is a body which moves in an orbit around a star. A planet (of any sort, dwarf or other) is defined as "any celestial body which orbits a star." The earth is a planet. A star is typically a big, burning, ball of gas around which planets tend to orbit. (except when it goes out, then it is a black hole or a neutron star.) The sun is a star. Fun fact: The only place gold comes from is supernovas. All gold is made in supernovas.
The short answer: A star is a massive nuclear reactor floating in space, a planet is a smaller rock or gas ball that commonly orbits a star. The detailed answer: To fu…lly understand the difference between a star and a planet, one must first understand what each is. A star is a mass of chemicals large enough to sustain a stable fusion reaction. Stars are usually composed mostly of hydrogen, deuterium, tritium, helium, and lithium. The older the star, typically, the more variety in elements it contains. Because they conduct nuclear fusion, stars emit massive amounts of electromagnetic radiation (light). The wavelengths (and type) of the light released by a star largely depends on its composition, which is why stars change color with age. There are several common misconceptions about stars, including that they are on fire, that they are static, and that they are small beads of light. The first one is understandable, since stars emit light and heat, and so does fire. However, stars produce their light through nuclear fusion, not combustion. The second misconception is largely derived from the erroneous belief that stars are the largest single objects in space. However, stars often orbit eachother, black holes, quasars, pulsars, and other objects. Even lone stars often move. The third misconception, that stars are small, is simply derived from perspective; from Earth, the sun (a 'sun' is a star with a solar system orbiting it) appears to be much smaller than Earth. However, that is simply due to the relatively large [from our perspective] distance between Earth and Sol (the name of our sun). Unlike a star, a planet is usually relatively cool and stable, and much smaller. Planets may be small, rocky bodies, such as terrestrial planets, dwarf planets, and asteroids (minor planets). They may also be larger, and composed of gases and ice, such as gas giants and ice giants. However, it is true of all planets that they are massive enough to influence the balance of gravity in a system, and large enough, usually, to attain hydrostatic equilibrium, but not large enough for the planet's pressure due to mass to initiate a fusion reaction. Planets, being less massive, often orbit stars, forming solar systems. Planets are therefore commonly the natural satellites of stars, just as moons are the natural satellites of planets. There are sometimes cases in which a star may be similar to a planet, and vice versa. For example, a gas giant, a very large planet comprised mostly of gases, often of composition to said planet's parent star, upon accumulating enough mass, may initiate fusion and become an infant star (it has been theorized that if Jupiter were to gain 40 times its current mass, it could become a star). There is also a class of stars, termed Brown Dwarves, that are very small and cool, and are very similar to gas giants.
A star generates its own heat and light and is generally much moremassive than a planet which only orbits round a star and reflectsits light.
Stars are made up of primarily hydrogen, with some helium and a tiny bit of other elements mixed in. They generate energy in their cores through nuclear fusion, combining hydr…ogen nuclei into helium nuclei, and converting some of the matter into energy. Our Sun is a perfectly ordinary star, which seems so large and hot because it is the closest star to us. . Planets are made of all kinds of matter, and most planets are a tiny fraction as large as any star. Our Earth is a planet, made up of hydrogen, oxygen, iron, and all the other elements, but while the Sun is mostly hydrogen, the Earth is primarily rock and iron with some hydrogen and oxygen mixed together as water on the outside. . Some planets like Jupiter are more gaseous, containing more hydrogen and other gasses like ammonia, nitrogen and others. . The Sun is about 1 million times heavier and 1,000 times bigger than the Earth. In fact, the Sun is about 99.8% of all the mass in our solar system. (Most of the rest is Jupiter.)
A Star converts hydrogen into energy by nuclear fusion. A planet does not
The planets move in their own trajectory which is different than the stars in the background. All the stars appear to circle the North star.
The difference between a star an a planet is that a star radiates light and light shines off of planets. also planets can have many different types of gasses and stars have he…lium and specific gasses that make them produce energy.
A planet is any collection of rock or gas that has enough gravity to pull itself into a spherical shape. A star is hundreds or thousands of times more massive than any given p…lanet, and is a ball of plasma with nuclear fusion occuring at the core
Planets are masses of dirt and rock packed tightly together, while stars are balls of gas that burn for centuries until they explode BOOOOOOOOOOOMMMMMMMMMMMMMMMMMMMMMMMMMMMMM…MMMMMMMMMM BICTHEZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
Stars are nuclear furnaces fusing hydrogen into helium to generate energy and shine. Planets don't shine and orbit stars, and moons don't shine and orbit planets.
A star is a hot burning mass of hydrogen, helium and other stuff. A planet is a collection of material that orbits a star. A galaxy is a massive collection of stars, plane…ts and other detritus.
An astronomical planet it a real object that exists outside theEarth's atmosphere. An astrological planet takes this real object and attributescertain myths and characteristic…s with it that influence life onEarth.
They named all the planets after gods. For example, they named Mars after the god of war.
A star is a burning ball of fire and a planet is a part of the solar system. Additional answer A star is much bigger than a planet and emits serious amounts of heat and li…ght from the reactions going on within it. A planet is much colder and smaller and orbits its sun.
A planet does not admit light or heat.
Almost nothing was different, except our understanding of things. The stars have been shining for millions or billions of years; all the planets have been pretty much just whe…re they are for about 4 billion years or more. "Ancient" times in our human history is anything more than 2000 years ago.
a star is a hot flaming ball of gas and dust and emits heat and light while a planet is compsed of metal and rock and doesnt emit light. a plant is also alot smaller than star…. think of the sun compared to earth