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Stars and Planets Credits and Acknowledgements
Stars and Planets Credits and Acknowledgements

... • Low mass stars have less hydrogen to convert to helium than do high mass stars, but live much longer. • Our sun has lived about half of its life as a main sequence star. • For most of the history of the Earth (and the sun), bacteria and other microorganisms were the only form of life on our planet ...
The View from New Horizons: A Full Day on Pluto
The View from New Horizons: A Full Day on Pluto

... After dusk at this time of year, four carnivore constellations climb upward low in a row across the northeast to southeast. They're all seen in profile, with their noses pointed to the upper right and their feet (if any) to the right: Ursa Major in the northeast with the Big Dipper as its brightest ...
(Download from http://astronomy.nmsu.edu/astro/) c NMSU
(Download from http://astronomy.nmsu.edu/astro/) c NMSU

... from the Earth to the Moon is 384,000,000 meters or 384,000 kilometers (km). The distances found in astronomy are usually so large that we have to switch to a unit of measurement that is much larger than the meter, or even the kilometer. In and around the solar system, astronomers use “Astronomical ...
PDF - NMSU Astronomy
PDF - NMSU Astronomy

... from the Earth to the Moon is 384,000,000 meters or 384,000 kilometers (km). The distances found in astronomy are usually so large that we have to switch to a unit of measurement that is much larger than the meter, or even the kilometer. In and around the solar system, astronomers use “Astronomical ...
Detection of Earth-impacting asteroids with the next generation all
Detection of Earth-impacting asteroids with the next generation all

... changes have serious consequences for the survival and evolution of life on the planet. But in the past ∼50 years more than 170 impact structures have been identified on the surface of the Earth (Earth-impact database 2008). Were it not for the Earth’s protective atmosphere, oceans, erosion and plat ...
ASPEN WORKSHOP 2003
ASPEN WORKSHOP 2003

... CMD needs off-source target subtraction to show MSTO and HB of Sag dwarf, so much larger number of stars available at 0.1
Galactic Chemical Evolution and the Oxygen Isotopic Composition
Galactic Chemical Evolution and the Oxygen Isotopic Composition

... ratios lie along a line of slope one in a three-isotope plot and were used by Young et al. (2011) in their discussion of O-isotope GCE and the solar composition. However, they are not commonly used in the astronomical literature, and for large deviations from zero their quantitative meaning is not a ...
Chap 16: Galaxies
Chap 16: Galaxies

... currently being born at a very high rate. ...
Chapter 15 THE MILKY WAY IN RELATION TO OTHER GALAXIES
Chapter 15 THE MILKY WAY IN RELATION TO OTHER GALAXIES

Astronomical Picture of the Day
Astronomical Picture of the Day

Document
Document

1 Introduction - Wiley-VCH
1 Introduction - Wiley-VCH

... gas, dust, and other forms of matter. They span a large range in dimension, luminosity, and mass. Dwarf galaxies are composed of  107 stars, while massive galaxies can have up to  1012 . Massive galaxies have been classified according to their morphology into two main classes, ellipticals (E) and ...
Answers to Chapter Review Questions and Problems for The
Answers to Chapter Review Questions and Problems for The

... Answer: The origin is the point at which all distance measurements along the reference lines begin. While the origin is usually labeled with a zero (0) and located at the center of the coordinate space, these conditions are not required. 2. How many dimensions (coordinates) are required to map the s ...
Project Description - SDSS-III
Project Description - SDSS-III

... Universe imprint a characteristic scale on the clustering of dark matter, galaxies, and intergalactic gas. By measuring this scale with tracers seen at different redshifts, we can create a “Hubble diagram” of unprecedented precision covering most of cosmic history and can thereby pin down the prope ...
File 11 - School of Astronomy, IPM
File 11 - School of Astronomy, IPM

... Often low surface brightness, so hard to find. More than one family of objects: • Gas-poor, passive (dE and dSph) • Gas rich, star forming • Why are dwarf galaxies important? • Majority of galaxies are dwarfs! • Dwarf galaxies may be remnants of galaxy formation process: “proto-dwarf” gas clouds cam ...
Galaxies - WordPress.com
Galaxies - WordPress.com

... A galaxies occasionally collide with one another, particularly within cluster of galaxies B galaxies are so closely packed in the universe that they are always interacting with one another C galaxies are so widely separated that they never interact or collide D the universe is composed of one giant ...
Tycho Brahe
Tycho Brahe

Influence of the Gould Belt on Interstellar Extinction
Influence of the Gould Belt on Interstellar Extinction

... objects, and the extinction for a typical large region of space can be determined as, say, 5.0m ± 0.5m , i.e., with an accuracy of 10%. An analytical model of extinction within the nearest kiloparsec with a relative accuracy higher than that of the model by Arenou et al. (1992) is unlikely to be po ...
Carbon, nitrogen, oxygen and lithium abundances of six
Carbon, nitrogen, oxygen and lithium abundances of six

... –0.15 dex indicates a slight deficiency in carbon plus nitrogen with respect to the Sun, similar to the deficiencies found in Galactic supergiants and Orion. Lithium has been detected in all the program stars, reaching (Li)=0.6 dex for two stars. Key words: stars: abundances; supergiants – galaxies ...
Nucleosynthesis and Chemical Evolution of Oxygen
Nucleosynthesis and Chemical Evolution of Oxygen

... To analyze the yields from massive stars, we consider a single model. While this is only one particular model, its yields are fairly representative of the ejecta from any star more than ten times the mass of the Sun. Chemical evolution models using detailed stellar model yields have long shown that ...
Astronomy and Astrophysics (ASTRO)
Astronomy and Astrophysics (ASTRO)

... ASTROPHYSICS (ASTRO) Courses primarily for undergraduates: ASTRO 102: North Star Astronomy Cr. 1. F.S. An entirely web-based course covering topics in observing the sky and navigation by the stars for students with little or no previous experience. The course combines material on common naked-eye ph ...
13 Universal Gravitation
13 Universal Gravitation

... • A 6-ton lead sphere was rolled beneath the mercury flask. • The flask was pulled slightly downward. • The gravitational force F, between the lead mass and the mercury, was equal to the weight that had to be placed on the opposite end of the balance to restore equilibrium. F, m1, m2, and d were all ...
Ch13 - Southwest High School
Ch13 - Southwest High School

Universal Gravitation Chap 13 Hewitt
Universal Gravitation Chap 13 Hewitt

... • A 6-ton lead sphere was rolled beneath the mercury flask. • The flask was pulled slightly downward. • The gravitational force F, between the lead mass and the mercury, was equal to the weight that had to be placed on the opposite end of the balance to restore equilibrium. F, m1, m2, and d were all ...
A Map of the Universe
A Map of the Universe

... last picture in the sequence shows galaxies out to a distance of 750 million light years. A further sequence of pictures labeled 0, −1, −2, ... − 13, starting with a life size picture of the girl’s hand, shows a sequence of microscopic views, each ten times larger in size, ending with a view of the ...
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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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