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The Milky Way Galaxy
The Milky Way Galaxy

... Besides the relative importance of disc and bulge, early-and late-type galaxies differ in their rates of star formation and the mean age of their stars: early-type galaxies have little or no cold, dense gas from which stars can form, so their rates of star formation are small and nearly all their st ...
Stars, Galaxies, and the Universe Section 1 Section 1
Stars, Galaxies, and the Universe Section 1 Section 1

... • Most stars have several types of actual motion. • Stars move across the sky (seen only for close stars). • Some stars may revolve around another star. • Stars either move away from or toward our solar system. ...
PARALLAX EXERCISE1 The goal of this exercise is to introduce the
PARALLAX EXERCISE1 The goal of this exercise is to introduce the

... Determining distances to celestial objects is one of the most important and most difficult measurements in astronomy. Compare the Sun to another star in the sky. They look completely different, and it was once believed that they were different types of objects. In fact, the Sun was once considered a ...
Lectures 14 & 15 powerpoint (neutron stars & black holes)
Lectures 14 & 15 powerpoint (neutron stars & black holes)

20 – N10/4/PHYSI/SP3/ENG/TZ0/XX Option E
20 – N10/4/PHYSI/SP3/ENG/TZ0/XX Option E

... (iii) State why the method of parallax can only be used for stars at a distance of less than a few hundred parsecs from Earth. ...
Beyond the Solar System By Patti Hutchison ANSWER THE
Beyond the Solar System By Patti Hutchison ANSWER THE

... There are billions of galaxies in space. A galaxy is a group of stars, gas, and dust that are bound together by gravity. If you look into the sky on a dark night, you can see our galaxy, the Milky Way. It is a shimmering belt that stretches across the sky. The Milky Way contains the solar system we ...
Hubble`s Expansion of the Universe
Hubble`s Expansion of the Universe

Death of the Stars
Death of the Stars

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... wavelengths? 13. What is a blackbody? What does it mean to say that a star appears almost like a black body? … 15. What is Wien’s Law? How could you use it to determine the temperature of a star’s surface? 16. What is the Stefan-Boltzmann law? How do Astronomers us it? ...
“Breakthroughs” of the 20th Century
“Breakthroughs” of the 20th Century

... Astronomy was revolutionized in the 20th century. The electron was discovered in 1897 and this transformed spectroscopy and introduced plasma and magnetohydrodynamic physics and astro-chemistry. Einstein’s E = mc2, solved the problem of stellar energy generation and spawned the study of elemental nu ...
Chapter 2. Discovering the Universe for Yourself
Chapter 2. Discovering the Universe for Yourself

... The Think About It and See It For Yourself questions are not numbered in the book, so we list them in the order in which they appear, keyed by section number. ...
The Stars education kit - Student activities 5-10
The Stars education kit - Student activities 5-10

... Some stars then become variable stars. The brightness of these stars varies by up to 10% over a few days to months. The brightness changes because the star is expanding and contracting periodically. Astronomers can use the period of the star (or the time it takes to vary) and its luminosity to measu ...
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eratoshenes_earth_measurement

The celestial sphere, the coordinates system, seasons, phases of
The celestial sphere, the coordinates system, seasons, phases of

... Total eclipse: The Moon’s umbra touches a small area of Earth’s surface, no more than 270 km diameter. Because the Earth and the Moon are moving, this area drift across the Earth’s surface and may cover a total of 7,000 km. An observer located inside this strip will see a total solar eclipse. Partia ...
planetary temperatures, albedos, and the greenhouse effect
planetary temperatures, albedos, and the greenhouse effect

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Meet the Dwarf Planets Pluto: The Demoted Former Planet
Meet the Dwarf Planets Pluto: The Demoted Former Planet

... Meet the Dwarf Planets Article by Mike Wall, From Space.com For three-quarters of a century, schoolkids learned that our solar system has nine planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. But things changed five years ago. On Aug. 24, 2006, the International Astr ...
A Planetary Overview
A Planetary Overview

... occurs about once every 177 years. During this time the large outer planets Jupiter, Saturn, Uranus, and Neptune were bunched closely together looking out from Earth, as they traveled their orbits around the Sun. This had not happened since the time of Napoleon. Starting in 1972, NASA scientists and ...
Stellar Characteristics and Evolution
Stellar Characteristics and Evolution

... Star (and their attendant planets, if there are any) condense out of a protostellar nebula, a vast cloud of gas and dust that may be hundreds of AU in diameter initially. The cloud flattens into a disk due to its own rotation, spinning around a growing central mass of hydrogen and helium. Eventually ...
The Sun
The Sun

... There are billions of stars in the universe. But there is only one star that scientists have been able to study in great detail. It is our Sun. Imagine feeling the effects of an explosion 93 million miles away from its source. One November afternoon in 1960, astronomers noted a brilliant explosion o ...
constellation.
constellation.

... c. How are astronomical units and light years use to measure the distances between the Sun, stars, and Earth. (Your project should include: how many kilometers there are in 1 AU and 1 light year along with some interesting distances in space using these measurements, such as, distance from the Sun t ...
Earth Science pacing guide
Earth Science pacing guide

...  the sun as a star; structure, processes, variations and their ...
SOL Review Questions Page 1 Earth Science Name
SOL Review Questions Page 1 Earth Science Name

... D. There is no connection between study time and grades/ 13. _____ Which statement about a hypothesis is valid? A. A hypothesis is believe until it can be disproved B. A hypothesis cannot be tested and proved until a conclusion is reached C. A hypothesis is only reached after many experiments are pe ...
Stellar Lives (continued). Galaxies.
Stellar Lives (continued). Galaxies.

Astronomy
Astronomy

... Unlike the others (which are the same apparent size at arm’s length), a tennis ball does not belong. Which Doesn’t Belong & Why? ...
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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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