Origin and Nature of Planetary Systems
... Introduction: While there is only one Solar System (the system of the star Sol), as of early April 2015, there are 1207 known extrasolar planetary systems with 1911 known planets (called extrasolar planets or exoplanets). Of these planetary systems 480 have two or more planets. In this activity, we ...
... Introduction: While there is only one Solar System (the system of the star Sol), as of early April 2015, there are 1207 known extrasolar planetary systems with 1911 known planets (called extrasolar planets or exoplanets). Of these planetary systems 480 have two or more planets. In this activity, we ...
Slide 1
... they run out of nuclear fuel.. Typically 1,000 times the size of our solar system These Ten have names like Owl, the Cat's Eye, the Ghost of Jupiter, Ring. This glorious final phase in the life of a star lasts only about 10,000 ...
... they run out of nuclear fuel.. Typically 1,000 times the size of our solar system These Ten have names like Owl, the Cat's Eye, the Ghost of Jupiter, Ring. This glorious final phase in the life of a star lasts only about 10,000 ...
Which Objects Represent the Eight Planets in Our
... new, scientifically accepted definition of the word, “planet”. According to these scientists, a planet must have three characteristics: a) It must orbit a Star (Sun) b) It must have enough mass for its self-gravity to form it into a spherical shape c) It must have “cleared” nearby objects away from ...
... new, scientifically accepted definition of the word, “planet”. According to these scientists, a planet must have three characteristics: a) It must orbit a Star (Sun) b) It must have enough mass for its self-gravity to form it into a spherical shape c) It must have “cleared” nearby objects away from ...
AST 301 Fall 2007 Review for Exam 3 This exam covers only
... evidence that they once did exist? Explain clearly why the terrestrial and jovian planets have such different properties in terms of the theory described in this chapter. The section on the discovery of extrasolar planets is one of the most exciting and evolving areas in astronomy at this time, so I ...
... evidence that they once did exist? Explain clearly why the terrestrial and jovian planets have such different properties in terms of the theory described in this chapter. The section on the discovery of extrasolar planets is one of the most exciting and evolving areas in astronomy at this time, so I ...
The Newtonian Revolution: The discovery of natural law
... decent quantitative model of the planets’ motion • It had the Earth at the center • It placed the planets Mercury and Venus carefully to match the observed angle offsets between the sun and these planets. • Accounted for retrograde motion with epicycles. Then needed to offset the center of epicycles ...
... decent quantitative model of the planets’ motion • It had the Earth at the center • It placed the planets Mercury and Venus carefully to match the observed angle offsets between the sun and these planets. • Accounted for retrograde motion with epicycles. Then needed to offset the center of epicycles ...
Circumstellar habitable zone
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the region around a star within which planetary-mass objects with sufficient atmospheric pressure can support liquid water at their surfaces. The bounds of the CHZ are calculated using the known requirements of Earth's biosphere, its position in the Solar System and the amount of radiant energy it receives from the Sun. Due to the importance of liquid water to life as it exists on Earth, the nature of the CHZ and the objects within is believed to be instrumental in determining the scope and distribution of Earth-like extraterrestrial life and intelligence.The habitable zone is also called the Goldilocks zone, a metaphor of the children's fairy tale of Goldilocks and the Three Bears, in which a little girl chooses from sets of three items, ignoring the ones that are too extreme (large or small, hot or cold, etc.), and settling on the one in the middle, which is ""just right"".Since the concept was first presented in 1953, stars have been confirmed to possess a CHZ planet, including some systems that consist of multiple CHZ planets. Most such planets, being super-Earths or gas giants, are more massive than Earth, because such planets are easier to detect. On November 4, 2013, astronomers reported, based on Kepler 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 in the Milky Way. 11 billion of these may be orbiting Sun-like stars. The nearest such planet may be 12 light-years away, according to the scientists. The CHZ is also of particular interest to the emerging field of habitability of natural satellites, because planetary-mass moons in the CHZ might outnumber planets.In subsequent decades, the CHZ concept began to be challenged as a primary criterion for life. Since the discovery of evidence for extraterrestrial liquid water, substantial quantities of it are now believed to occur outside the circumstellar habitable zone. Sustained by other energy sources, such as tidal heating or radioactive decay or pressurized by other non-atmospheric means, the basic conditions for water-dependent life may be found even in interstellar space, on rogue planets, or their moons. In addition, other circumstellar zones, where non-water solvents favorable to hypothetical life based on alternative biochemistries could exist in liquid form at the surface, have been proposed.