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Become a Member - Department of Physics and Astronomy
Become a Member - Department of Physics and Astronomy

RTF - Digitalis Education
RTF - Digitalis Education

... Northwestern area of the USA, saw the stars of Orion as a canoe race between Chinook Wind and Cold Wind. Share the following legend with students, and ask them what it tells them about the Wasco's values. Once there was an old grandfather who always caught many salmon in Big River. His grandson Chin ...
Unit 13 The Solar System
Unit 13 The Solar System

... Unit 13 The Solar System Which is the correct order of the planets from the Sun? a. ...
The Life Cycle of Stars Webquest
The Life Cycle of Stars Webquest

... Task #7: Galaxies: The Big Picture Continue to read on to the section “The Big Picture” on the same webpage http://www.seasky.org/celestialobjects/galaxies.html and answer the following questions: 1. How many stars are in our ...
Winter 2014
Winter 2014

... Pleiades star cluster is close enough that we can see the brightest several stars by eye. Returning to Orion, we can follow the Belt down and to the left and find ourselves at the brightest star in Earth’s night sky, Sirius. Sirius is one of the closest stars to the Earth, which is why it appears so ...
The Mass Assembly of Galaxies
The Mass Assembly of Galaxies

Science - State Goal 12: Understand the fundamental concepts
Science - State Goal 12: Understand the fundamental concepts

science - Amazon Web Services
science - Amazon Web Services

... stood between Mars and Jupiter, the Bode number being 2.8. No known planet exists at this distance from the sun. The actual distances for Mercury, Venus, Earth, Mars, Jupiter, and Saturn are so close to Bode’s numbers that his “law” became accepted as indicating a precise mathematical relationship i ...
File - greenscapes4you
File - greenscapes4you

... M-Sun star has 30 times more H than the Sun, but burns it with a luminosity that is 30,000 times greater. It’s lifetime is 30/30,000 = 1/10,000 as long as the Sun – corresponding to a lifetime of only a few million years. This is a very short time, cosmically speaking. This is one reason why massive ...
Earth In Space - Hicksville Public Schools / Homepage
Earth In Space - Hicksville Public Schools / Homepage

Astronomy 103 – Midterm 2 – October 29, 2014
Astronomy 103 – Midterm 2 – October 29, 2014

... a) A is hotter than B b) B is hotter than A c) A and B have approximately the same temperature d) We do not have enough information to derive their temperatures. ...
A Star is
A Star is

... • The most common elements in stars are hydrogen and helium, in that order. • Small quantities of carbon, oxygen, and nitrogen are also found in stars, but stars are primarily composed of…. • HYDROGEN and HELIUM ...
Stars, Galaxies & Universe
Stars, Galaxies & Universe

... Death of a Star • Stars use up their hydrogen and expand their atmosphere. • Stars that are less than 1.4 solar masses will shrink to a white dwarf. • Stars between 1.4 -3.0 solar masses will produce a supernova and leave a neutron star. • Stars more than 3.0 solar masses will produce a supernova a ...
THE 3-D UNIVERSE CONCEPTS
THE 3-D UNIVERSE CONCEPTS

... Some kinds of stars can be used as landmarks even at very great distances. These stars are known as standard candles. Certain types of supernovas, for example, always explode at a predictable luminosity. Because these supernovas glow at a standard brightness, their distance can be estimated even whe ...
Earth Science
Earth Science

... reactions, primarily the fusion of hydrogen to form helium. f. Students know the evidence for the dramatic effects that asteroid impacts have had in shaping the surface of planets and their moons and in mass extinctions of life on Earth. g.*Students know the evidence for the existence of planets orb ...
The Milky Way Galaxy
The Milky Way Galaxy

PDF only - at www.arxiv.org.
PDF only - at www.arxiv.org.

... when we inhibit the photolysis of O3, H2O2, and HO2 in the solar UV case, ...
The Family of Stars
The Family of Stars

MilkyWay
MilkyWay

... •10kpc diameter and 2kpc thick with the Sun less than a kpc from the center (rather heliocentric) •Tried to estimate scattering due to ISM gas but determined it to be insignificant (most obscuration is due to dust absorption ...
Stars and gravity - Hyde Park 3rd Grade
Stars and gravity - Hyde Park 3rd Grade

... Celsius. The center is millions of degrees hot. It is so hot that gas particles that have a positive charge collide and join. This releases a lot of energy. Energy that travels from the Sun through space includes sunlight. ...
PH607lec10
PH607lec10

printer-friendly version of benchmark
printer-friendly version of benchmark

... 2. Students have a misconception that nighttime visible stars are located within our solar system. Such a notion has been considered since the times of the ancient Greeks. Aristotle proposed a geocentric model of the solar system with Earth at the center. Crystalline spheres surrounded Earth. Each o ...
Deep Space (PDF: 224k)
Deep Space (PDF: 224k)

... a slowly cooling ball of gas that fades from a dull red glow into the infrared as it cools in a few tens of millions of years. A graph of the luminosity versus temperature (called a Hertzsprung-Russell diagram) of all stars show that most of the stars in the sky, about 90 percent, fall in a line cal ...
Detecting the glint of starlight on the oceans of distant planets
Detecting the glint of starlight on the oceans of distant planets

... Fig. 2. Phase cycles of planets as a function of orbital inclination i and orbital longitude θ . Thick black lines denote regions where a planet is a thin crescent (fA < 0.25), and the lines are truncated where a planet orbiting at 1 AU from its star reaches the inner working angle ∼ 4λ/D = 0.057 ...
Chapter 1 Our Place in the Universe
Chapter 1 Our Place in the Universe

... – The observable universe is 14 billion light-years in radius (no it is considerably bigger and depends upon the expansion rate and the history of the expansion rate which has changed) and contains over 100 billion galaxies with a total number of stars comparable to the number of grains of sand on a ...
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Rare Earth hypothesis



In planetary astronomy and astrobiology, the Rare Earth Hypothesis argues that the origin of life and the evolution of biological complexity such as sexually reproducing, multicellular organisms on Earth (and, subsequently, human intelligence) required an improbable combination of astrophysical and geological events and circumstances. The hypothesis argues that complex extraterrestrial life is a very improbable phenomenon and likely to be extremely rare. The term ""Rare Earth"" originates from Rare Earth: Why Complex Life Is Uncommon in the Universe (2000), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist, both faculty members at the University of Washington.An alternative view point was argued by Carl Sagan and Frank Drake, among others. It holds that Earth is a typical rocky planet in a typical planetary system, located in a non-exceptional region of a common barred-spiral galaxy. Given the principle of mediocrity (also called the Copernican principle), it is probable that the universe teems with complex life. Ward and Brownlee argue to the contrary: that planets, planetary systems, and galactic regions that are as friendly to complex life as are the Earth, the Solar System, and our region of the Milky Way are very rare.
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