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24. Life Beyond Earth: Prospects for Microbes
24. Life Beyond Earth: Prospects for Microbes

... • The Drake equation says that the number of civilizations in the Milky Way Galaxy is NHP x flife x fciv x fnow, where NHP is number of habitable planets in the galaxy, flife is the fraction of these habitable planets actually have life on them, fciv is the fraction of the lifebearing planets upon w ...
IOTA Plans for the 2017 Total Solar Eclipse
IOTA Plans for the 2017 Total Solar Eclipse

... phenomena, first visually by viewing a projected image of the Sun but since 1983 mostly by video recording the eclipse to obtain a more complete record of the phenomena. • Solar radius values determined from observations of nine eclipses were published in 1994 (Fiala, Dunham, and Sofia, Solar Physic ...
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File

... would exist and should be the source of many of the comets that we see. As a result, these objects are now known as the Kuiperbelt objects, or, less often, Trans-Neptunian Objects. ...
Tycho, Kepler, and Newton
Tycho, Kepler, and Newton

... • The Sun lies at one of the foci of the ellipse • The eccentricity of an ellipse is a measure of how 'squished' from a circle the shape is • Most planets in the Solar System are very close to a perfect circle ...
Minor Bodies of the Solar System Standardized Test Prep
Minor Bodies of the Solar System Standardized Test Prep

... Read the passage below. Then, answer questions 8–11. Kuiper Belt Objects To explain the source of short-period comets, or comets that have a relatively short orbit around the sun, the Dutch-American astronomer Gerard Kuiper proposed in 1949 that a belt of icy bodies must lie beyond the orbits of Nep ...
Formation of the Crust and Continents
Formation of the Crust and Continents

... How old is Earth? • We know that Earth must be at least as old as the oldest rocks in the crust. – The age of the oldest rocks on Earth is between 3.96 to 3.8 billion years. – Evidence of 4.1- to 4.2-billion-year-old crust exists in the mineral zircon that is contained in metamorphosed sedimentary r ...
Chaos in the Solar System
Chaos in the Solar System

... showing that a region of relatively strong instability extend over these two resonances. This result was questioned by Sussman and Wisdom (1992) which did not recover such a large variation for the secular frequencies, but reached only 2(s4 − s3 ) − 3(g4 − g3 ) = 0 instead of (??). Recently, in our ...
grade 7 natural sciences term 4 planet earth and beyond
grade 7 natural sciences term 4 planet earth and beyond

... Tides are the predictable, repeated rise and fall of the sea and ocean levels. You can see the effect of the tides in the waves on the sea. During high tide, the sea level rises and the waves bring the seawater further up the beach, or raise the sea level in the harbour. During low tide, the water l ...
ReadingsAst
ReadingsAst

... significantly closer to the sun at some times of year than at others that this effect would produce seasons, but the Earth's elliptical orbit is in fact almost perfectly circular. (For some other planets the ellipticity of the orbit is an issue, but not for the Earth.) The Celestial Sphere When disc ...
Juno Fact Sheet and Outline Script Jupiter, the third brightest object
Juno Fact Sheet and Outline Script Jupiter, the third brightest object

... formed. Understanding the amount of water will also tell scientist the conditions in which the heavy elements collapsed to help form Jupiter and how the rest of its gaseous structure formed together due to the effects if gravity. How and when Jupiter formed may hold clues to the process the reset of ...


... genes, and eventually genetic differences would increase until members of the groups can no longer interbreed. At this point, they have become separate species and the speciation is complete. Through time, these two species might give rise to new species, and so on through millennia. Another process ...
Jupiter
Jupiter

... * Jupiter has rings. They were discovered by Voyager 1 in 1979. Four rings have been observed. They are made of mostly dust. The rings are a reddish color accept the Halo Ring which is blue. ...
key questions about the early earth
key questions about the early earth

... students that the Earth is essentially a blue marble whose surface is dominated by oceans. This vision of a blue Earth has even been espoused by popular science writers such as the non-fiction work 'Pale Blue Dot' by the late Carl Sagan. For many it would be difficult to envision an Earth without it ...
meteorite - National Geographic Society
meteorite - National Geographic Society

Basic Debris Disk Model - Institute of Astronomy
Basic Debris Disk Model - Institute of Astronomy

... Must be taken into account when interpreting observations Non-axisymmetric structures explained as perturbations to this model, particularly due to planets Rare exceptions may be systems undergoing periods analogous to ...
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Document

... © 2014 Pearson Education, Inc. ...
Chapter 12 Resource: The Solar System
Chapter 12 Resource: The Solar System

... and sulfuric acid. Venus’s atmosphere is 100 times more dense than Earth’s atmosphere. From the surface of Venus up to 20 km, there appears to be a clear region of atmosphere. A thick layer of clouds extends from about 50 km to 80 km above the surface of Venus. These clouds are composed of drops of ...
The Origin of Mercury - Institute of Planetary Science
The Origin of Mercury - Institute of Planetary Science

... This scenario has the clear advantage of having its consequences calculated in enough detail to allow potentially explicit testing. However, it also suffers from a number of difficulties. For example, it is not clear whether high enough temperatures can be reached and maintained for long enough in t ...
Chapter 7
Chapter 7

... Earth’s characteristics are not set in stone and are prone to change over time. o Coral studies from 440 million years ago.  11% more tidal cycles per year.  Earth spun 11% more on its rotational axis. Not everything in earth is a cycle we can see. ...
ppt file
ppt file

... be explained by dust migrating into a planet’s resonances. They predicted planet locations/masses and orbital motion of the dust structures. Vega ...
Chapter 22
Chapter 22

... How old is Earth? • We know that Earth must be at least as old as the oldest rocks in the crust. – The age of the oldest rocks on Earth is between 3.96 to 3.8 billion years. – Evidence of 4.1- to 4.2-billion-year-old crust exists in the mineral zircon that is contained in metamorphosed sedimentary r ...
Space Bits: Outer Space Objects
Space Bits: Outer Space Objects

... vacuum. The space vacuum is more commonly referred to as outer space. It is the space between celestial bodies that is most empty of matter. Meteroids are not very big they can be as small as a speck of dust. A meteor is the visible path of a meteoroid that enters the earth’s atmosphere. Meteors occ ...
Powerpoint slides - Earth, Planetary, and Space Sciences
Powerpoint slides - Earth, Planetary, and Space Sciences

... Neptune as N moved outwards (recall the 3:2 resonance) • Charon is most likely the result of a collision. Clues: – Its orbital inclination (and Pluto’s rotation) strongly suggest an impact (c.f. Neptune) – The angular momentum of the system (see next slide) – Comparable size of two bodies also sugge ...
AP Physics Multiple Choice Practice – Gravitation 1. Each of five
AP Physics Multiple Choice Practice – Gravitation 1. Each of five

... 55. Two iron spheres separated by some distance have a minute gravitational attraction, F. If the spheres are moved to one half their original separation and allowed to rust so that the mass of each sphere increases 41%, what would be the resulting gravitational force? (A) 2F (B) 4F (C) 6F (D) 8F (E ...
Planets in the Sky
Planets in the Sky

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Late Heavy Bombardment



The Late Heavy Bombardment (abbreviated LHB and also known as the lunar cataclysm) is a hypothetical event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago, corresponding to the Neohadean and Eoarchean eras on Earth. During this interval, a disproportionately large number of asteroids apparently collided with the early terrestrial planets in the inner Solar System, including Mercury, Venus, Earth, and Mars. The LHB happened after the Earth and other rocky planets had formed and accreted most of their mass, but still quite early in Earth's history.Evidence for the LHB derives from lunar samples brought back by the Apollo astronauts. Isotopic dating of Moon rocks implies that most impact melts occurred in a rather narrow interval of time. Several hypotheses are now offered to explain the apparent spike in the flux of impactors (i.e. asteroids and comets) in the inner Solar System, but no consensus yet exists. The Nice model is popular among planetary scientists; it postulates that the gas giant planets underwent orbital migration and scattered objects in the asteroid and/or Kuiper belts into eccentric orbits, and thereby into the path of the terrestrial planets. Other researchers argue that the lunar sample data do not require a cataclysmic cratering event near 3.9 Ga, and that the apparent clustering of impact melt ages near this time is an artifact of sampling materials retrieved from a single large impact basin. They also note that the rate of impact cratering could be significantly different between the outer and inner zones of the Solar System.
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