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Workbook IAC
Workbook IAC

... asteroid and half comet. Centaurs have transient orbits that cross or have crossed the orbits of one or more of the giant planets, and have dynamical lifetimes of a few million years. The first centaur-like object to be discovered was 944 Hidalgo in 1920. However, they were not recognized as a disti ...
Neptune
Neptune

ASTR 104.3 - University of Saskatchewan
ASTR 104.3 - University of Saskatchewan

... discuss the nature of science and the development of the scientific method through the earliest descriptions of celestial motions. We will examine how continued efforts to better describe and explain those motions revolutionized our understanding of Earth and its place in the Universe. You will then ...
Pitt County Schools
Pitt County Schools

... objects move they way they do. Distinguish between mass and weight. Use these laws in the description of physical phenomena. 1.11 State Newton’s Law of Gravity in own words and describe what Law of Inverse-Square means.  Explain why gravity is needed to keep one object orbiting around another by u ...
the atmosphere
the atmosphere

... ________________________________________________________________________________ 2. What is the Earth’s atmosphere?____________________________________________________ ________________________________________________________________________________ 3. What makes conditions on Earth suitable for livi ...
How to Directly Image a Habitable Planet Around Alpha Centauri
How to Directly Image a Habitable Planet Around Alpha Centauri

... contrast space telescopes (blue region in Figure 1) appear to be necessary. High contrast space telescopes in the 1 - 2.4m size range are realistic for launch in the 2020 decade, such as NASA’s planned WFIRST-AFTA mission [1], as well as the Exo-C and Exo-S concept studies [2, 3]. Such telescopes ca ...
IS Chapter 14 Notes
IS Chapter 14 Notes

Document
Document

... such science was simply not possible.” Of course, not long ago, there was skepticism about whether worlds even existed beyond the reaches of our Solar System. Now, with a continually expanding catalogue of exoplanets – more than 2,500 to date – our expectations have grown in ambition and we are seek ...
models
models

... 1. Stars are so far away that stellar parallax is too small to notice with the naked eye. 2. Earth does not orbit the Sun; it is the center of the universe. With rare exceptions such as Aristarchus, the Greeks rejected the correct explanation (1) because they did not think the stars could be that fa ...
PDF Format
PDF Format

... helium (27%), it also contains traces of nearly all the other chemical elements – It is the most massive object in the Solar System – 700 times the mass of the rest of the Solar System combined – It’s large mass provides the gravitational force to hold all the Solar System bodies in their orbital pa ...
Asteroids and Comets
Asteroids and Comets

... Nucleus: relatively solid and stable, composed mostly of ice and gas, with a small amount of dust and other solids Coma: a dense cloud of water, carbon dioxide, and other neutral gases sublimed off of the nucleus Hydrogen cloud: a huge (millions of km in diameter), but very sparse, envelope of neutr ...
Document
Document

... with the Sun at one focus.(1609) 2) Line joining the planet to the Sun sweeps out equal areas in equal times. 3) The square of a planet’s orbital period is proportional to the cube of its semimajor axis ...
SS-Ch7
SS-Ch7

... helium (27%), it also contains traces of nearly all the other chemical elements – It is the most massive object in the Solar System – 700 times the mass of the rest of the Solar System combined – It’s large mass provides the gravitational force to hold all the Solar System bodies in their orbital pa ...
KS1 Education Guide - Immersive Theatres
KS1 Education Guide - Immersive Theatres

... The Earth is the third planet from the Sun in a system that includes the Moon, the Sun, seven other planets and their moons, and smaller objects, such as asteroids and comets. The Sun, an average star, is the central and largest body in the Solar System. (5 – 8 Standard) ...
Opakování z minulého cvičení
Opakování z minulého cvičení

... The solid nucleus of typical comet is quite small – Halley’s Comet, for example, has a nukleus about 15 km by 10 km by 10 km – but the surrounding coma may be hundrets of thousands of kilometres across and the tail may stretch for 100 milion km. The material to make the coma and tail all comes from ...
Saturn
Saturn

... 15. Two small moons _Hyperion _ and _Phobe__ share the same orbit, and play a game of celestial tag. 16. Most of the moons are probably made entirely of Water Ice__. But at these low temperatures, it would be as hard as a rock. Craters would form. Page 315 ...
Real World Science: The Solar System
Real World Science: The Solar System

... planets revolving around the sun. The planets are attracted to the sun because of a force known as gravity. The hottest part of the sun is about 25 million degrees Fahrenheit. The planets closest to the sun are called the inner planets. They include Mercury, Venus, Earth and Mars. The outer planets ...
Northrop Grumman Space Primer
Northrop Grumman Space Primer

... c. Students know how to use astronomical units and light years as measures of distances between the sun, stars, and Earth. d. Students know that stars are the source of light for all bright objects in outer space and that the moon and planets shine by reflected sunlight, not by their own light. e. S ...
Space Jeopardy
Space Jeopardy

... Question:Planets that are close to the sun…. a)move through the asteroid belt b)orbit faster than the outer planets c)orbit slower than the outer planets d)move closer and closer to the sun ...
Solar system - Wikimedia Commons
Solar system - Wikimedia Commons

... bodies. Other objects that may become classified as dwarf planets are Sedna, Orcus, and Quaoar. From the time of its discovery in 1930 until 2006, Pluto was considered the Solar System's ninth planet. But in the late 20th and early 21st centuries, many objects similar to Pluto were discovered in the ...
Exploration Strategy for the Ice Dwarf Planets 2013-2022
Exploration Strategy for the Ice Dwarf Planets 2013-2022

... raising a host of new questions, and attracting new researchers to investigate this type of planet. However, New Horizons will only provide a snapshot of one such system at one point in its 2.5 century seasonal cycle. The real advances in understanding ice dwarfs as a class will come from long term ...
American Scientist
American Scientist

... the center of the Kepler-32 system, yet it is orbited by five exoplanets within a distance a third the size of Mercury’s orbit. Perhaps the most puzzling case study comes from the Kepler-36 system. Two planets are found at roughly the same distance from the star: one with a density less than that of ...
Hubble - 15 Years of Discovery
Hubble - 15 Years of Discovery

... Since Pluto’s discovery in the 1930s, and its satellite Charon’s in the 1970s, astronomers have tried to figure out if there’s anything else out there, beyond the ninth planet. In 2003, Hubble spotted something moving fast enough across the background of faraway stars to be an object within the Sola ...
Moons in our Solar System
Moons in our Solar System

... Phobos is 27 km (17 mi) wide and completes its orbit of Mars in 8 hours  Deimos, at 14 km (9 mi), is one of the smallest moons in the Solar System ...
doc - Discover Earth Science
doc - Discover Earth Science

... B. The movements of planets across the nighttime sky is not uniform 1. The reason planets have non-uniform motion is that they really are moving in space - stars only look like they’re moving ...
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Definition of planet



The definition of planet, since the word was coined by the ancient Greeks, has included within its scope a wide range of celestial bodies. Greek astronomers employed the term asteres planetai (ἀστέρες πλανῆται), ""wandering stars"", for star-like objects which apparently moved over the sky. Over the millennia, the term has included a variety of different objects, from the Sun and the Moon to satellites and asteroids.By the end of the 19th century the word planet, though it had yet to be defined, had become a working term applied only to a small set of objects in the Solar System. After 1992, however, astronomers began to discover many additional objects beyond the orbit of Neptune, as well as hundreds of objects orbiting other stars. These discoveries not only increased the number of potential planets, but also expanded their variety and peculiarity. Some were nearly large enough to be stars, while others were smaller than Earth's moon. These discoveries challenged long-perceived notions of what a planet could be.The issue of a clear definition for planet came to a head in 2005 with the discovery of the trans-Neptunian object Eris, a body more massive than the smallest then-accepted planet, Pluto. In its 2006 response, the International Astronomical Union (IAU), recognised by astronomers as the world body responsible for resolving issues of nomenclature, released its decision on the matter. This definition, which applies only to the Solar System, states that a planet is a body that orbits the Sun, is massive enough for its own gravity to make it round, and has ""cleared its neighbourhood"" of smaller objects around its orbit. Under this new definition, Pluto and the other trans-Neptunian objects do not qualify as planets. The IAU's decision has not resolved all controversies, and while many scientists have accepted the definition, some in the astronomical community have rejected it outright.
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