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Light Years Away - Sitka School District
Light Years Away - Sitka School District

... The star outside of our solar system that is closest to us is Alpha Centauri C, also called Alpha Proxima. It is 40,000,000,000,000 (40 trillion) km away. How many light years is that? ...
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Space by Clare and Emma D.C.

... Mars is the fourth planet from the sun and is the second smallest planet in the solar system. ...
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Class 11 and 12 lecture slides (giant planets)

... • Process accelerated until nebular gas was lost • So initial accretion was rapid (few Myr) • Uranus and Neptune didn’t acquire so much gas because they were further out and accreted more slowly • Planets will have initially been hot (gravitational energy) and subsequently cooled and contracted • We ...
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The astronauts in the upper left of this photo are working on the

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... •Since no known process significantly changes this H/He ratio, it is taken to be the ratio which existed at the time when the deuteron became stable in the expansion of the universe. ...
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... trans-Neptunian objects are made of ice and rock. All are remnants left over from the formation of the planets. Most asteroids are found in the asteroid belt between the orbits of Mars and Jupiter, and most trans-Neptunian objects lie in the Kuiper belt outside the orbit of Neptune. Pluto is one of ...
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Review-Sheet-sun-solar-system-galaxies-and-cosmology-fall

... 1. What are the three layers of the sun’s interior? What part is responsible for fusion? 2. What are the three layers of the Sun’s atmosphere? Be able to describe them briefly, such as lowest layer, the visible surface, etc… 3. What is the solar wind? What happens when the solar wind gets trapped in ...
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... to increase = Glows • Fusion begins at VERY high temps. (Some of the extra gas and dust may form planets) ...
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Astro 1 Levine Homework Solar System

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some interesting facts about planets

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29.1 Models of the Solar System

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Compare the following sets of stars using the words: BRIGHTER or

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Final Exam: Review Questions

... 39. What is a subduction zone? With what type of plate boundary is it associated? 40. What evidence is there of seafloor spreading? 41. What is a difference between the theory of continental drift and the theory of plate tectonics? 42. Why is the oldest oceanic lithosphere not as old as some contine ...
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... Which of the following statements is FALSE? A. Accretion disks and bi-polar jets are features associated with both star formation and active galactic nuclei B. Hayashi tracks describe the evolution of a star on the HR diagram after it has started nuclear fusion C. New stars in the Milky Way are born ...
Chapter 27 PLANETS OF THE SOLAR SYSTEM
Chapter 27 PLANETS OF THE SOLAR SYSTEM

... Inner Planets (Mercury, Venus, Earth, Mars) Contain large %’s of heavy elements (ex: iron, nickel). Inner planets lost their dense gases because at the temperature of the gases, gravity wasn’t strong enough to hold onto them; solar radiation may have blown or boiled away gases. As densest materials ...
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... Studying these clusters allows scientists to observe stars that are similar in age, composition and distance but different in size. It also provides information that scientists would not be able to observe about one star because of the length of its life cycle. What does this information explain abo ...
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... c. Kepler: Supported the heliocentric model but discovered that the orbits of the  planets were not circular but elliptical.  d. Galileo: Worked with the refracting telescopes to discovery more about the solar  system like Jupiter and its moons.  e. Newton: His laws of motion and gravity explained h ...
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Astronomy 101 Review - Physics and Astronomy
Astronomy 101 Review - Physics and Astronomy

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Class activities Due Now: Planet Brochure Discuss MC#2

... orbiting object if gravity decreased?  Inquiry 15.1-15.4: EIS 8-11 Standard- 6-8 ES1B Earth is the third planet from the sun in a system that includes the Moon, the Sun, seven other major planets and their moons, and smaller objects such as asteroids, plutoids, and comets. These bodies differ in ma ...
Approximately 14 billion years ago, all matter and energy was
Approximately 14 billion years ago, all matter and energy was

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Star Formation
Star Formation

... - Interior heating causes differentiation; leads to layered interior - Primitive H, He atmospheres heated away ...
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Planetary habitability



Planetary habitability is the measure of a planet's or a natural satellite's potential to develop and sustain life. Life may develop directly on a planet or satellite or be transferred to it from another body, a theoretical process known as panspermia. As the existence of life beyond Earth is unknown, planetary habitability is largely an extrapolation of conditions on Earth and the characteristics of the Sun and Solar System which appear favourable to life's flourishing—in particular those factors that have sustained complex, multicellular organisms and not just simpler, unicellular creatures. Research and theory in this regard is a component of planetary science and the emerging discipline of astrobiology.An absolute requirement for life is an energy source, and the notion of planetary habitability implies that many other geophysical, geochemical, and astrophysical criteria must be met before an astronomical body can support life. In its astrobiology roadmap, NASA has defined the principal habitability criteria as ""extended regions of liquid water, conditions favourable for the assembly of complex organic molecules, and energy sources to sustain metabolism.""In determining the habitability potential of a body, studies focus on its bulk composition, orbital properties, atmosphere, and potential chemical interactions. Stellar characteristics of importance include mass and luminosity, stable variability, and high metallicity. Rocky, terrestrial-type planets and moons with the potential for Earth-like chemistry are a primary focus of astrobiological research, although more speculative habitability theories occasionally examine alternative biochemistries and other types of astronomical bodies.The idea that planets beyond Earth might host life is an ancient one, though historically it was framed by philosophy as much as physical science. The late 20th century saw two breakthroughs in the field. The observation and robotic spacecraft exploration of other planets and moons within the Solar System has provided critical information on defining habitability criteria and allowed for substantial geophysical comparisons between the Earth and other bodies. The discovery of extrasolar planets, beginning in the early 1990s and accelerating thereafter, has provided further information for the study of possible extraterrestrial life. These findings confirm that the Sun is not unique among stars in hosting planets and expands the habitability research horizon beyond the Solar System.The chemistry of life may have begun shortly after the Big Bang, 13.8 billion years ago, during a habitable epoch when the Universe was only 10–17 million years old. According to the panspermia hypothesis, microscopic life—distributed by meteoroids, asteroids and other small Solar System bodies—may exist throughout the universe. Nonetheless, Earth is the only place in the universe known to harbor life. Estimates of habitable zones around other stars, along with the discovery of hundreds of extrasolar planets and new insights into the extreme habitats here on Earth, suggest that there may be many more habitable places in the universe than considered possible until very recently. On 4 November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs within the Milky Way. 11 billion of these estimated planets may be orbiting Sun-like stars. The nearest such planet may be 12 light-years away, according to the scientists.
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