query: what is the makeup of earth 's atmosphere

pos: Atmosphere of Earth Atmosphere of Earth The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water

pos: Atmosphere of Earth from the Deep Space Climate Observatory (DSCOVR) and show Earth as it rotates during a day. Atmosphere of Earth The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04%

neg: Atmosphere of Earth the energy Earth receives from the Sun. Earth also emits radiation back into space, but at longer wavelengths that we cannot see. Part of the incoming and emitted radiation is absorbed or reflected by the atmosphere. In May 2017, glints of light, seen as twinkling from an orbiting satellite a million miles away, were found to be reflected light from ice crystals in the atmosphere. When light passes through Earth's atmosphere, photons interact with it through "scattering". If the light does not interact with the atmosphere, it is called "direct radiation" and is what you see if you were to

neg: Experimental testing of time dilation at rest in S′, so its worldline is the ct′-axis. The upper atmosphere is at rest in S, so its worldline is the ct-axis. Upon the axes of x and x′, all events are present that are simultaneous with A in S and S′, respectively. The muon and Earth are meeting at D. As the Earth is at rest in S, its worldline (identical with the lower atmosphere) is drawn parallel to the ct-axis, until it intersects the axes of x′ and x. Time: The interval between two events present on the worldline of a single clock is called proper

neg: Impact crater effects of travel through the atmosphere, the lowest impact velocity with an object from space is equal to the gravitational escape velocity of about 11 km/s. The fastest impacts occur at about 72 km/s in the "worst case" scenario in which an object in a retrograde near-parabolic orbit hits Earth. (Because kinetic energy scales as velocity squared, Earth's gravity only contributes 1 km/s to this figure, not 11 km/s). The median impact velocity on Earth is about 20 km/s. However, the slowing effects of travel through the atmosphere rapidly decelerate any potential impactor, especially in the lowest 12 kilometres where

neg: Urban thermal plume far greater impact at higher latitudes (above 40°N and above 40°S), where the Earth-atmosphere system undergoes net "cooling" by radiation. Urban thermal plume An urban thermal plume describes rising air in the lower altitudes of the Earth's atmosphere caused by urban areas being warmer than surrounding areas. Over the past thirty years there has been increasing interest in what have been called urban heat island (UHI), but it is only since 2007 that thought has been given to the rising columns of warm air, or ‘thermal plumes’ that they produce. We are all familiar with on-shore breezes at the seaside

neg: Atmosphere of Venus The densest part of the atmosphere, the troposphere, begins at the surface and extends upwards to 65 km. At the furnace-like surface the winds are slow, but at the top of the troposphere the temperature and pressure reaches Earth-like levels and clouds pick up speed to 100 m/s. The atmospheric pressure at the surface of Venus is about 92 times that of the Earth, similar to the pressure found below the surface of the ocean. The atmosphere has a mass of 4.8 kg, about 93 times the mass of the Earth's total atmosphere. The density of the air at the

neg: Earth form an acceptable variant. Another convention capitalizes "Earth" when appearing as a name (e.g. "Earth's atmosphere") but writes it in lowercase when preceded by "the" (e.g. "the atmosphere of the earth"). It almost always appears in lowercase in colloquial expressions such as "what on earth are you doing?" The oldest material found in the Solar System is dated to (Bya). By the primordial Earth had formed. The bodies in the Solar System formed and evolved with the Sun. In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten

neg: J002E3 may return to orbit the Earth in the mid-2040s. The object's Earth orbital paths occasionally take it within the radius of the Moon's orbit, and could result in eventual entry into Earth's atmosphere, or collision with the Moon. The Apollo 12 empty S-IVB, Instrument Unit, and spacecraft adapter base, had a mass of about . This is less than one-fifth of the mass of the Skylab space station, which was constructed from a similar S-IVB and fell out of orbit on July 11, 1979. Objects with a mass of about enter Earth's atmosphere approximately 10 times a year, one of

neg: Idealized greenhouse model model, we assume the atmosphere is completely transparent to sunlight. The planetary albedo α is the fraction of the incoming solar flux that is reflected back to space (since the atmosphere is assumed totally transparent to solar radiation, it does not matter whether this albedo is imagined to be caused by reflection at the surface of the planet or at the top of the atmosphere or a mixture). The flux density of the incoming solar radiation is specified by the solar constant S. For application to planet Earth, appropriate values are S=1366 W m and α=0.30. Accounting for the fact

neg: Grey alien direction consistent with their own genetic makeup, and similar to their own physiology and general physical structure, since genetically that is what they would presumably be most familiar with. Counter to this view, the anatomy, physiology, and genetic makeup of primates and humans are extremely similar to other animals on Earth, including those with divergent non-humanoid forms such as sea urchins, sea squirts, and acorn worms. Since the history of life on Earth gives some idea of what is and is not feasible on other worlds, and there is no conclusive evidence of any past extraterrestrial genetic manipulation in our

neg: Earth analog as having similarities to Earth and many speculated about Venusian civilization. These beliefs were dispelled in the 1960s as the first space probes gathered more accurate scientific data on the planet and found that Venus is a very hot world with the surface temperature around under an acidic atmosphere 92 times thicker the Earth's. From 2004, Cassini–Huygens began to reveal Saturn's moon Titan to be one of the most Earth-like worlds outside of the habitable zone. Though having a dramatically different chemical makeup, discoveries such as the confirmation of Titanian lakes, rivers and fluvial processes in 2007, advanced comparisons to

neg: Geochemical cycle As all closed systems, it follows the law of conservation of mass which states that matter cannot be created nor destroyed, thus, the matter, although transformed and migrated, remains the same as when the Earth was formed. The Earth system contains seven different reservoirs that are separated into surface reservoirs, which include atmosphere, hydrosphere, biosphere, pedosphere, and lithosphere and the isolated reservoirs that include deep Earth and outer space. Geochemical cycles are concerned with the interactions between deep earth which consists of Earth´s mantle and core, and the lithosphere which consists of the Earth´s crust. Flux in geochemical cycles is

neg: Experimental testing of time dilation B, where the worldline of Earth intersects the x-axis, corresponds in S to the position of Earth simultaneous with the emergence of the muon. C, where the Earth's worldline intersects the x′-axis, corresponds in S′ to the position of Earth simultaneous with the emergence of the muon. Length "L=AB" in S is longer than length "L′=AC" in S′. If no time dilation exists, then those muons should decay in the upper regions of the atmosphere, however, as a consequence of time dilation they are present in considerable amount also at much lower heights. The comparison of those amounts allows for

neg: Institute for Earth System Preservation considered sum of the planet´s interacting physical, chemical, biotic and societal processes. The atmosphere, hydrosphere, and cryosphere are parts of the earth system as well as the grand natural cycles (carbon cycle, nitrogen cycle, phosphorus cycle and sulfur cycle) including the water cycle. All living organisms, including humans and their activities, are an integral part of the earth system. The growing human population, however, seriously challenges the interaction of the system´s components and dynamics. Advancing solutions to maintain the resilience of the grand living conditions on planet Earth is the main interest of IESP's members. Therefore, IESP organizes interdisciplinary, discussion-based

neg: Extraterrestrial atmosphere reaching 70 m/s or more in the upper troposphere. The stratosphere and mesosphere extend from 65 km to 95 km in height. The thermosphere and exosphere begin at around 95 kilometres, eventually reaching the limit of the atmosphere at about 220 to 250 km. The air pressure at Venus' surface is about 92 times that of the Earth. The enormous amount of CO in the atmosphere creates a strong greenhouse effect, raising the surface temperature to around 470 °C, hotter than that of any other planet in the Solar System. The Martian atmosphere is very thin and composed mainly of

neg: Reducing atmosphere had a reducing atmosphere, along with Mars and Venus. This would have proven to be a good environment for "Cyanobacteria" to evolve the first photosynthetic metabolic pathways which gradually increased the oxygen portion of the atmosphere, changing it to what is known as an oxidizing atmosphere. With increased levels of oxygen, the evolution of the more efficient aerobic respiration might have been enabled, allowing animal life to evolve and thrive. Though most scientists conceive of the early atmosphere as reducing, a 2011 article in "Nature" found that cerium oxidation in zircon—which comprises the oldest rocks on Earth at roughly 4.4

neg: Man-made structures visible from space far above sea level their hypothetical or actual observer in space is located. When just speaking of "space", an asker might mean anywhere from the edge of space (Kármán line) at an altitude of to low Earth orbit of 160–2,000 km (99-1200 mi) to Apollo 12's orbit at to the Moon, which orbits about away. The Kármán line is accepted by the World Air Sports Federation, an international standard setting and record-keeping body for aeronautics and astronautics, as the boundary between the Earth's atmosphere and outer space. However, a practical definition for the purpose of answering questions on what astronauts

neg: Free-return trajectory 2 or 1.5 years, respectively. A two-year free return means from Earth to Mars (aborted there) and then back to Earth all in 2 years. The entry corridor (range of permissible path angles) for landing on Mars is limited, and experience has shown that the path angle is hard to fix (e.g. +/- 0.5 deg). This limits entry into the atmosphere to less than 9 km/s. On this assumption, a two-year return is not possible for some years, and for some years a delta-v kick of 0.6 to 2.7 km/s at Mars may be needed to get back to Earth.

neg: Atmosphere of Jupiter NEB(N) and NEB(S). Circulation in Jupiter's atmosphere is markedly different from that in the atmosphere of Earth. The interior of Jupiter is fluid and lacks any solid surface. Therefore, convection may occur throughout the planet's outer molecular envelope. As of 2008, a comprehensive theory of the dynamics of the Jovian atmosphere has not been developed. Any such theory needs to explain the following facts: the existence of narrow stable bands and jets that are symmetric relative to Jupiter's equator, the strong prograde jet observed at the equator, the difference between zones and belts, and the origin and persistence of large

neg: Sub-orbital spaceflight 1 km/s than for one with a maximum speed of 7 or 8 km/s. We can calculate the minimum delta-v and the corresponding maximum altitude for a given range, "d", assuming a spherical earth of circumference 40 000 km and neglecting the earth's rotation and atmosphere. Let θ be half the angle that the projectile is to go around the earth, so in degrees it is 45°×"d"/10 000 km. The minimum-delta-v trajectory corresponds to an ellipse with one focus at the centre of the earth and the other at the point halfway between the launch point and the destination point

neg: History of Earth layer near the upper part of the atmosphere. The ozone layer absorbed, and still absorbs, a significant amount of the ultraviolet radiation that once had passed through the atmosphere. It allowed cells to colonize the surface of the ocean and eventually the land: without the ozone layer, ultraviolet radiation bombarding land and sea would have caused unsustainable levels of mutation in exposed cells. Photosynthesis had another major impact. Oxygen was toxic; much life on Earth probably died out as its levels rose in what is known as the "oxygen catastrophe". Resistant forms survived and thrived, and some developed the ability

neg: Seveneves "Doc" Dubois Harris calculates that the number of collisions will increase exponentially. A large number of moon fragments will begin entering Earth's atmosphere, forming a "white sky" and blanketing the earth within two years with what he calls a "Hard Rain" of bolides; this will cause the atmosphere to heat to incandescence and oceans to boil away, destroying the biosphere and rendering Earth uninhabitable for thousands of years. It is decided to evacuate as many people and resources as possible to a "Cloud Ark" in orbit, including a "swarm" of "arklet" habitats that will be able to avoid the debris

neg: Carrie Anderson research concerns the atmosphere of Saturn's moon Titan, which is, according to NASA, "a model for what the early Earth might have been like." Titan has a thick, nitrogen-dominated atmosphere and is the only world in the solar system other than Earth known to possess stable liquid on its surface." (Titan's seas are not water, however, but methane and ethane.) In 2015, Anderson reported her discovery of a chemically new, high-altitude ice cloud residing in Titan's south polar stratosphere during Titan's early southern winter season, chemically consistent with co-condensed hydrogen cyanide and benzene. During her 12-year tenure on the Cassini

neg: Composition of Mars (N) makes up 2.7 percent of the atmosphere. As far as we know, organic compounds are absent except for a trace of methane detected in the atmosphere. On 16 December 2014, NASA reported the "Curiosity" rover detected a "tenfold spike", likely localized, in the amount of methane in the Martian atmosphere. Sample measurements taken "a dozen times over 20 months" showed increases in late 2013 and early 2014, averaging "7 parts of methane per billion in the atmosphere." Before and after that, readings averaged around one-tenth that level. The elemental composition of Mars is different from Earth′s in several significant

neg: Jupiter spacecraft, or delta-v. Entering a Hohmann transfer orbit from Earth to Jupiter from low Earth orbit requires a delta-v of 6.3 km/s which is comparable to the 9.7 km/s delta-v needed to reach low Earth orbit. Gravity assists through planetary flybys can be used to reduce the energy required to reach Jupiter, albeit at the cost of a significantly longer flight duration. Beginning in 1973, several spacecraft have performed planetary flyby maneuvers that brought them within observation range of Jupiter. The Pioneer missions obtained the first close-up images of Jupiter's atmosphere and several of its moons. They discovered that the

neg: J002E3 which impacts the Earth's surface approximately once every 10 years. Eleven essentially similar empty S-IVB stages from Apollo, Skylab and Apollo-Soyuz Test Project missions have re-entered the atmosphere from 1966 to 1975. In all cases (including the Skylab station), the objects burned in the atmosphere and broke into relatively small pieces, rather than striking the Earth as a single mass. On the other hand, these objects entered from low Earth orbit or ballistic trajectory, with less energy than J002E3 might possibly have if it were to enter from Solar orbit. J002E3 J002E3 is the designation given to an object in

neg: DUT1 DUT1 The time correction DUT1 (sometimes also written DUT) is the difference between Universal Time (UT1), which is defined by Earth's rotation, and Coordinated Universal Time (UTC), which is defined by a network of precision atomic clocks. UTC is maintained via leap seconds, such that DUT1 remains within the range −0.9 s < DUT1 < +0.9 s. The reason for this correction is partly that the rate of rotation of the Earth is not constant, due to tidal braking and the redistribution of mass within the Earth, including its oceans and atmosphere, and partly because the SI second (as now

neg: UNAVCO percent of Earth's crust is unobservable using solely electromagnetic energy-based geodetic techniques. Seafloor geodesy can now expand geodetic positioning to off-shore environments. Researchers can see the effects of changes in Earth's crust far beyond what we can measure with instruments placed solely on dry land. Space geodesy utilizes electromagnetic signals propagating through the atmosphere of Earth, providing information on tropospheric temperature and water vapor and on ionospheric electron density. Thus, in the early twenty-first century, the goal of geodesy has evolved to include study of the kinematics and dynamics of both Earth’s atmosphere and the solid Earth. Geodetic research associated

neg: Atmosphere of the Moon and potassium, which are not found in the atmospheres of Earth, Mars, or Venus. At sea level on Earth, each cubic centimeter of the atmosphere contains approximately molecules; by comparison the lunar atmosphere contains fewer than molecules in the same volume. On Earth, this is considered to be a very good vacuum. In fact, the density of the atmosphere at the Moon's surface is comparable to the density of the outermost fringes of Earth's atmosphere, where the International Space Station orbits. The elements sodium and potassium have been detected in the Moon's atmosphere using Earth-based spectroscopic methods, whereas the isotopes

neg: Betelgeuse real, due to pulsations in the atmosphere. The star is also a slow rotator and the most recent velocity recorded was 5 km/s—much slower than Antares which has a rotational velocity of 20 km/s. The rotation period depends on Betelgeuse's size and orientation to Earth, but it has been calculated to take 8.4 years to turn on its axis. In 2004, astronomers using computer simulations speculated that even if Betelgeuse is not rotating it might exhibit large-scale magnetic activity in its extended atmosphere, a factor where even moderately strong fields could have a meaningful influence over the star's dust, wind

neg: Extraterrestrial atmosphere observed in 1990. However, the storms and the band pattern are less visible and active than those of Jupiter, due to the overlying ammonia hazes in Saturn's troposphere. Saturn's atmosphere has several unusual features. Its winds are among the Solar System's fastest, with Voyager data indicating peak easterly winds of 500 m/s. It is also the only planet with a warm polar vortex, and is the only planet other than Earth where eyewall clouds have been observed in hurricane-like structures. The atmosphere of Uranus is composed primarily of gas and various ices. It is about 83% hydrogen, 15% helium, 2%

neg: Exploration of Io on Io or on Earth, at the volcano Surt. Earth-based telescopes coming online over the next decade, such as the Thirty Meter Telescope at the Mauna Kea Observatory, will provide more-detailed observations of Io's volcanoes, approaching the resolution achieved by "Galileo"<nowiki>'</nowiki>s near-IR spectrometer. Hubble ultraviolet, millimeter-wave, and ground-based mid-infrared observations of Io's atmosphere have revealed strong density heterogeneities between bright, frost-covered regions along the satellite's equator and its polar regions, providing further evidence that Ionian atmosphere is supported by the sublimation of sulfur dioxide frost on Io's surface. The "New Horizons" spacecraft, en route to Pluto and the Kuiper belt,

neg: Carbon dioxide in Earth's atmosphere actual surface temperature of approximately 14 °C (57.2 °F). Carbon dioxide is believed to have played an important effect in regulating Earth's temperature throughout its 4.7 billion year history. Early in the Earth's life, scientists have found evidence of liquid water indicating a warm world even though the Sun's output is believed to have only been 70% of what it is today. It has been suggested by scientists that higher carbon dioxide concentrations in the early Earth's atmosphere might help explain this faint young sun paradox. When Earth first formed, Earth's atmosphere may have contained more greenhouse gases and concentrations

neg: Voyager 1 the rotation of Saturn (the length of a day) at 10 hours, 39 minutes, 24 seconds. "Voyager 1"'s mission included a flyby of Titan, Saturn's largest moon, which had long been known to have an atmosphere. Images taken by "Pioneer 11" in 1979 had indicated the atmosphere was substantial and complex, further increasing interest. The Titan flyby occurred as the spacecraft entered the system to avoid any possibility of damage closer to Saturn compromising observations, and approached to within , passing behind Titan as seen from Earth and the Sun. Voyager's measurement of the atmosphere's effect on sunlight and Earth-based

neg: Experimental testing of time dilation with the mean decay time of the muon in its proper frame. As the muon is at rest in S′, we have γ=1 and its proper time "T′" is measured. As it is moving in S, we have γ>1, therefore its proper time is shorter with respect to time "T". (For comparison's sake, another muon at rest on Earth can be considered, called muon-S. Therefore, its decay time in S is shorter than that of muon-S′, while it is longer in S′.) The muon emerges at the origin (A) by collision of radiation with the upper atmosphere. The muon is

neg: Kent Rominger Pallet Satellite, studied the origin and makeup of stars. In completing his second space flight, Rominger orbited the earth a record 278 times, traveled over 7 million miles and logged 17 days, 15 hours and 53 minutes in space. STS-85 in Space Shuttle "Discovery" (August 7–19, 1997) was a 12-day mission during which the crew deployed and retrieved the CRISTA-SPAS satellite, operated the Japanese Manipulator Flight Demonstration (MFD) robotic arm, studied changes in the Earth's atmosphere and tested technology destined for use on the future International Space Station. The mission was accomplished in 189 Earth orbits, traveling 4.7 million miles

neg: Atmosphere of Jupiter water cloud layer is located, to as high as 0.2–0.5 bar. Storms on Jupiter are always associated with lightning. The imaging of the night–side hemisphere of Jupiter by "Galileo" and "Cassini" spacecraft revealed regular light flashes in Jovian belts and near the locations of the westward jets, particularly at 51°N, 56°S and 14°S latitudes. On Jupiter lightning strikes are on average a few times more powerful than those on Earth. However, they are less frequent; the light power emitted from a given area is similar to that on Earth. A few flashes have been detected in polar regions, making Jupiter

neg: Atmosphere of Venus chemical compounds are present only in trace amounts. Aside from the very surface layers, the atmosphere is in a state of vigorous circulation. The upper layer of troposphere exhibits a phenomenon of super-rotation, in which the atmosphere circles the planet in just four Earth days, much faster than the planet's sidereal day of 243 days. The winds supporting super-rotation blow at a speed of 100 m/s (~360 km/h or 220 mph) or more. Winds move at up to 60 times the speed of the planet's rotation, while Earth's fastest winds are only 10% to 20% rotation speed. On the other

neg: Rare Earth hypothesis the atmosphere is not stripped over time by solar winds. A terrestrial planet of the right size is needed to retain an atmosphere, like Earth and Venus. On Earth, once the giant impact of Theia thinned Earth's atmosphere, other events were needed to make the atmosphere capable of sustaining life. The Late Heavy Bombardment reseeded Earth with water lost after the impact of Theia. The development of an ozone layer formed protection from ultraviolet (UV) sunlight. Nitrogen and carbon dioxide are needed in a correct ratio for life to form. Lightning is needed for nitrogen fixation. The carbon dioxide gas

neg: Paul Wild (Australian scientist) the frequency drifted with time. The team deduced that the type II bursts were associated with shock waves coming out through the solar atmosphere at 1000 km/s and were associated, 30 hours later, with aurora in the Earth's night sky. They had discovered the answer to a century-old riddle: what was the agency that conveyed the disturbance from the solar flare to the Earth? Type II bursts continue to be closely monitored by spectrographs on the ground and in satellites for "space weather" reporting, since their disruption of the geomagnetic field and ionosphere can cause blackouts to radio communication and

neg: Sample Collection for Investigation of Mars This Stardust mission was similar in that it returned extraterrestrial material to Earth with an unmanned robotic spacecraft. SCIM would collect air and dust samples by flying through the atmosphere of Mars without landing or orbiting. The design utilizes heritage from the successful "Stardust" and "Genesis" sample return missions. A pass through the atmosphere about above Mars' surface at a speed of 6 km/s would result in millions of particles being encountered. The particles would be collected in an aerogel and returned to Earth inside a small sealed capsule. Analysis of the dust could confirm the origin of the suspected

neg: Asteroid laser ablation in Earth atmosphere. However, had the meteor reached Earth's surface or exploded lower in the atmosphere the results could have been catastrophic. Despite NASA's efforts to detect Near Earth Objects (NEO's), the Chelyabinsk Meteor went undetected. In recent years, NASA, in partnership with the European Space Agency, have been increasing their efforts to track all NEO's with the potential to cross Earth's orbit. On their website, NASA has a public list of all known NEO's which present a potential impact risk. However, the list remains incomplete and the question of what to do in the event of an imminent impact

neg: K Puppis the star. The total amplitude is 0.015 apparent magnitude. k Puppis is a chemically peculiar star with a strong magnetic field. It is classified as a He-weak star and in addition to a deficit of helium in its spectrum, it shows an overabundance of many iron peak and rare earth elements. All of its spectral lines show variability, probably due to variations in the chemical makeup of its atmosphere as it rotates. K Puppis k Puppis (k Pup, k Puppis) is a Bayer designation given to an optical double star in the constellation Puppis, the two components being k Puppis

neg: Geochemical cycle over a long term changes of great magnitude occur, including the evolution of continents and oceans. Some may use the terms biogeochemical cycle and geochemical cycle interchangeably because both cycles deal with Earth´s reservoirs. However, a biogeochemical cycle refers to the chemical interactions in surface reservoirs such as the atmosphere, hydrosphere, lithosphere, and biosphere whereas a geochemical cycle refers to the chemical interactions that exist in crustal and sub crustal reservoirs such as the deep earth and lithosphere. The Earth, as a system, is open to radiation from the sun and space, but is practically closed with regard to matter.

neg: Spherical Earth sunrise and after sunset are observed at ground level, because the Sun is still visible from higher altitudes. Longer twilights are observed at higher latitudes (near the poles) due to a shallower angle of the Sun's apparent movement compared to the horizon. On a flat Earth, the Sun's shadow would reach the upper atmosphere very quickly, except near the closest edge of the Earth, and would always set at the same angle to the ground (which is not what is observed). The "spotlight Sun" theory is also not consistent with this observation, since the air cannot be lit without the

neg: Earth-grazing fireball Earth-grazing fireball An Earth-grazing fireball (or Earth-grazer) is a fireball, a very bright meteor that enters Earth’s atmosphere and leaves again. Some fragments may impact Earth as meteorites, if the meteor starts to break up or explodes in mid-air. These phenomena are then called Earth-grazing meteor processions and bolides. Famous examples of Earth-grazers are the 1972 Great Daylight Fireball and the Meteor Procession of July 20, 1860. As an Earth-grazer passes through the atmosphere its mass and velocity are changed, so that its orbit, as it re-enters space, will be different from its orbit as it encountered Earth's atmosphere. There

neg: Absorbing Man this by using his hammer's powers to transform the ground's molecular makeup. As Creel is acquiring additional mass from direct contact with the Earth when this happens he ends up drifting harmlessly into the atmosphere. A short time later, Loki retrieves Creel from space using Asgardian technology after he has knocked out an Asgardian warlock and sends Creel back to battle Thor. After Creel is nearly beaten due to Thor's fighting skill, Loki transports him to Asgard and reveals the true source of his "absorbing" powers. After being humbled by Loki, Creel agrees to act as his agent, and he

neg: Earth free oxygen, but the loss of reducing agents such as hydrogen is thought to have been a necessary precondition for the widespread accumulation of oxygen in the atmosphere. Hence the ability of hydrogen to escape from the atmosphere may have influenced the nature of life that developed on Earth. In the current, oxygen-rich atmosphere most hydrogen is converted into water before it has an opportunity to escape. Instead, most of the hydrogen loss comes from the destruction of methane in the upper atmosphere. The gravity of Earth is the acceleration that is imparted to objects due to the distribution of

neg: Atmosphere of Venus Atmosphere of Venus The atmosphere of Venus is the layer of gases surrounding Venus. It is composed primarily of carbon dioxide and is much denser and hotter than that of Earth. The temperature at the surface is 740 K (467 °C, 872 °F), and the pressure is 93 bar (9.3 MPa), roughly the pressure found underwater on Earth. The Venusian atmosphere supports opaque clouds made of sulfuric acid, making optical Earth-based and orbital observation of the surface impossible. Information about the topography has been obtained exclusively by radar imaging. Aside from carbon dioxide, the other main component is nitrogen. Other

neg: Atmosphere of Venus day to last 116.5 Earth days. The surface of Venus spends 58.3 days in darkness before the sun rises again behind the clouds. The troposphere on Venus contains 99% of the atmosphere by mass. Ninety percent of the atmosphere of Venus is within 28 km of the surface; by comparison, 90% of the atmosphere of Earth is within 10 km of the surface. At a height of 50 km the atmospheric pressure is approximately equal to that at the surface of Earth. On the night side of Venus clouds can still be found at 80 km above the surface. The

neg: Atmosphere of Venus Black Swift Technologies for a concept study of a Venus glider that would exploit wind shear for lift and speed. Atmosphere of Venus The atmosphere of Venus is the layer of gases surrounding Venus. It is composed primarily of carbon dioxide and is much denser and hotter than that of Earth. The temperature at the surface is 740 K (467 °C, 872 °F), and the pressure is 93 bar (9.3 MPa), roughly the pressure found underwater on Earth. The Venusian atmosphere supports opaque clouds made of sulfuric acid, making optical Earth-based and orbital observation of the surface impossible. Information about

neg: Exploration of Io April 6, 1973, respectively, on the first unmanned mission to the outer Solar System. "Pioneer 10" became the first spacecraft to reach the Jupiter system on December 3, 1973. It passed within of Io. During "Pioneer 10's" fly-by of Io, the spacecraft performed a radio occultation experiment by transmitting an S-band signal as Io passed between it and Earth. A slight attenuation of the signal before and after the occultation showed that Io had an ionosphere, suggesting the presence of a thin atmosphere with a pressure of 1.0 bar, though the composition was not determined. This was the second atmosphere

neg: Mars Exploration Program to characterize both the current and past climate of Mars, as well as factors that influence climate change on Mars. Currently what is known is that the climate is regulated by seasonal changes of Mars' ice caps, movement of dust by the atmosphere, and the exchange of water vapor between the surface and the atmosphere. To understand these climatic phenomena means helping scientists more effectively model Mars' past climate, which brings a higher degree of understanding of the dynamics of Mars. The geology of Mars is differentiable from that of Earth by, among other things, its extremely large volcanoes and

neg: History of Earth melting in basalt. Earth is often described as having had three atmospheres. The first atmosphere, captured from the solar nebula, was composed of light (atmophile) elements from the solar nebula, mostly hydrogen and helium. A combination of the solar wind and Earth's heat would have driven off this atmosphere, as a result of which the atmosphere is now depleted of these elements compared to cosmic abundances. After the impact which created the moon, the molten Earth released volatile gases; and later more gases were released by volcanoes, completing a second atmosphere rich in greenhouse gases but poor in oxygen. Finally,

neg: J. Marvin Herndon the conventional view is that it is iron–nickel alloy More recently, he has suggested "georeactor" planetocentric nuclear fission reactors as energy sources for the gas giant outer planets. as the energy source and production mechanism for the geomagnetic field and stellar ignition by nuclear fission. In 2005 Herndon postulated what he calls whole-earth decompression dynamics, which he describes as a unified theory combining elements of plate tectonics and Earth expansion. He suggests that Earth formed from a Jupiter-sized gas giant by catastrophic loss of its gaseous atmosphere with subsequent decompression and expansion of the rocky remnant planet resulting in "decompression

neg: History of geology astronomers and gave it to Lunar geologists. In recent years, geology has continued its tradition as the study of the character and origin of the Earth, its surface features and internal structure. What changed in the later 20th century is the perspective of geological study. Geology was now studied using a more integrative approach, considering the Earth in a broader context encompassing the atmosphere, biosphere and hydrosphere. Satellites located in space that take wide scope photographs of the Earth provide such a perspective. In 1972, The Landsat Program, a series of satellite missions jointly managed by NASA and the U.S.

neg: Radiant Silvergun are also hidden dogs that when shot, will give the player bonus points and unlock more game options. The story of "Radiant Silvergun" is told non-linearly through animated videos and scripted dialogue between stages. In the year 2520, scientists on Earth have unearthed a giant crystal along with a robot bearing the same serial number as another robot called "Creator" on the Tetra spaceship orbiting around Earth. After the crystal begins summoning enemies to attack Earth, fighter pilots on Tetra board their Silvergun fighters and fly down through the atmosphere to save what they can of the planet. The Silvergun

neg: Exploration of Jupiter the direct trajectory. Ion thrusters capable of a delta-v of more than 10 kilometers/s were used on the Dawn spacecraft. This is more than enough delta-v to do a Jupiter fly-by mission from a solar orbit of the same radius as that of Earth without gravity assist. A major problem in sending space probes to Jupiter is that the planet has no solid surface on which to land, as there is a smooth transition between the planet's atmosphere and its fluid interior. Any probes descending into the atmosphere are eventually crushed by the immense pressures within Jupiter. Another major issue

neg: Asteroidal water both finds (with their Earth entry and impact unobserved) and falls (meteorites from a known, recent meteor event), that water cannot be entirely terrestrial contamination. As the precision of isotopic abundance analyses grew, they confirmed that meteorite water differs from Earth water. As water at Earth (especially its atmosphere) is well-mixed, significantly different isotope levels would indicate a separate water source. Water content of the CI and CM types are often in double-digit percentages. Much telescopic observation and hypothesizing attempted to link meteorite classes to asteroid types. The Galileo and NEAR missions then established S-type asteroids as the parent bodies

neg: Messages from Earth immediately attacks and destroys most of the Ganymede base before flying off. Sheridan orders the "White Star" to attack the ship, enraging it and making it follow the "White Star". Sheridan then orders them to drive the "White Star" into the atmosphere of Jupiter, knowing the intense pressure and gravity will potentially be inescapable. Just at the point of the "White Star"s failure, Sheridan has them pull out; the Shadow ship is unable to brake and is destroyed as it falls into the gravity well. As they are about to leave the atmosphere, the "White Star" is attacked by the

neg: Aerobraking is comparable to the aerodynamic resistance of moving at 0.6 m/s (2.16 km/h) at sea level on Earth, approximately the amount experienced when walking slowly. Aerocapture is a related but more extreme method in which no initial orbit-injection burn is performed. Instead, the spacecraft plunges deeply into the atmosphere without an initial insertion burn, and emerges from this single pass in the atmosphere with an apoapsis near that of the desired orbit. Several small correction burns are then used to raise the periapsis and perform final adjustments. This method was originally planned for the Mars Odyssey orbiter, but the significant

neg: Polar circle arc in the tilt is equivalent to change of about 31 metres north or south in the positions of the polar circles on the Earth's surface). The main reason for this is that the sun rays bend in the atmosphere of planet Earth, this phenomenon is more obvious to see, at high latitudes. Polar circle A polar circle is either the Arctic Circle or the Antarctic Circle. On Earth, the Arctic Circle is located at a latitude of N, and the Antarctic Circle is located at a latitude of S. Areas inside each polar circle and its associated pole (North

neg: Ice divide it gets. This large amount of snow causes there to be a very small off-set from the ages of the ice to the air and gases trapped inside. This gives the scientists to give much more precise predictions of what the atmosphere was like in history. If the WAIS project is a success it will educate scientists around the world how the atmosphere of Earth has changed completely over 100,000 years. Ice divide An ice divide is the boundary on an ice sheet, ice cap or glacier separating opposing flow directions of ice, analogous to a water divide. Such ice

neg: Weather constantly being lost to space, creating what is essentially a very thin atmosphere throughout the Solar System. The movement of mass ejected from the Sun is known as the solar wind. On Earth, the common weather phenomena include wind, cloud, rain, snow, fog and dust storms. Less common events include natural disasters such as tornadoes, hurricanes, typhoons and ice storms. Almost all familiar weather phenomena occur in the troposphere (the lower part of the atmosphere). Weather does occur in the stratosphere and can affect weather lower down in the troposphere, but the exact mechanisms are poorly understood. Weather occurs primarily

neg: Joseph Francisco compounds that cause acid rain. It's the unusual chemistry facilitated by this molecule, however, that will attract the most attention from scientists. Somewhat like a human body metabolizing food, the Earth's atmosphere has the ability to "burn," or oxidize pollutants, especially nitric oxides emitted from sources such as factories and automobiles. What doesn't get oxidized in the atmosphere falls back to Earth in the form of acid rain. "The chemical details of how the atmosphere removes nitric acid have not been clear," Francisco says. "This gives us important insights into this process. Without that knowledge we really can't understand the

neg: Atmosphere of Venus gases, most notably sulfur dioxide. The amount of nitrogen in the atmosphere is relatively small compared to the amount of carbon dioxide, but because the atmosphere is so much thicker than that on Earth, its total nitrogen content is roughly four times higher than Earth's, even though on Earth nitrogen makes up about 78% of the atmosphere. The atmosphere contains a range of compounds in small quantities, including some based on hydrogen, such as hydrogen chloride (HCl) and hydrogen fluoride (HF). There is carbon monoxide, water vapour and atomic oxygen as well. Hydrogen is in relatively short supply in the

neg: Greenhouse effect space by the atmosphere and clouds, and 19% is absorbed by the atmosphere and clouds. Most of the remaining energy is absorbed at the surface of Earth. Because the Earth's surface is colder than the Sun, it radiates at wavelengths that are much longer than the wavelengths that were absorbed. Most of this thermal radiation is absorbed by the atmosphere and warms it. The atmosphere also gains heat by sensible and latent heat fluxes from the surface. The atmosphere radiates energy both upwards and downwards; the part radiated downwards is absorbed by the surface of Earth. This leads to a

neg: Escape velocity and the French Guiana Space Centre (latitude 5°14' N). In most situations it is impractical to achieve escape velocity almost instantly, because of the acceleration implied, and also because if there is an atmosphere, the hypersonic speeds involved (on Earth a speed of 11.2 km/s, or 40,320 km/h) would cause most objects to burn up due to aerodynamic heating or be torn apart by atmospheric drag. For an actual escape orbit, a spacecraft will accelerate steadily out of the atmosphere until it reaches the escape velocity appropriate for its altitude (which will be less than on the surface). In many

neg: Earth science Earth science Earth science or geoscience includes all fields of natural science related to the planet Earth. It is the branch of science dealing with the physical constitution of the earth and its atmosphere. Earth science is the study of our planet’s physical characteristics, from earthquakes to raindrops, and floods to fossils. Earth science can be considered to be a branch of planetary science, but with a much older history. “Earth science” encompasses four main branches of study, the lithosphere, the hydrosphere, the atmosphere, and the biosphere, each of which is further broken down into more specialized fields. There are

neg: Dragonfly (spacecraft) quadcopter with double rotors, an octocopter. Such rotor configuration would be able to tolerate the loss of at least one rotor or motor. Each rotor would be about 1 m in diameter. The aircraft would travel at about 10 m/s or 36 km/h and climbs up to 4 km altitude would be desired for best scientific value. The power required to hover a given mass on Titan is 38 times less than that required on Earth, due to Titan's denser atmosphere and lower gravity. The atmosphere is about four times as thick as Earth's, but local gravity (15 percent of

neg: Extraterrestrial atmosphere other trace elements, including compounds based on hydrogen, nitrogen, sulfur, carbon, and oxygen. The atmosphere of Venus is much hotter and denser than that of Earth, though shallower. As greenhouse gases warm a lower atmosphere, they cool the upper atmosphere, leading to compact thermospheres. By some definitions, Venus has no stratosphere. The troposphere begins at the surface and extends up to an altitude of 65 kilometres (an altitude at which the mesosphere has already been reached on Earth). At the top of the troposphere, temperature and pressure reach Earth-like levels. Winds at the surface are a few metres per second,

neg: Snowball Earth that the increase in alkalinity over the course of glaciation is sufficient to explain the thickness of cap carbonates formed in the aftermath of Snowball Earth events. Global temperature fell so low that the equator was as cold as modern-day Antarctica. This low temperature was maintained by the high albedo of the ice sheets, which reflected most incoming solar energy into space. A lack of heat-retaining clouds, caused by water vapor freezing out of the atmosphere, amplified this effect. The carbon dioxide levels necessary to unfreeze Earth have been estimated as being 350 times what they are today, about 13%

neg: Lunar and Planetary Laboratory and Planetary Laboratory has been involved in almost every interplanetary spacecraft sent. These are some of the major ones that it was or is involved: The Lunar and Planetary Laboratory is involved with Spacewatch, the program to identify near-Earth asteroids, with the Planetary Atmosphere Project to measure the content of the atmospheres of various planets, with occultations, the art of measuring the spectrography of a star when it passes behind a planet, to see what a planet's atmosphere is composed of, with studies of the planet Mercury, with the Catalina Sky Survey, related to the Spacewatch program, as well as

neg: Hydroxyl radical Earth atmosphere. It is the most widespread oxidizer in the troposphere, the lowest part of the atmosphere. Understanding OH variability is important to evaluating human impacts on the atmosphere and climate. The OH species has a lifetime in the Earth atmosphere of less than one second. Understanding the role of OH in the oxidation process of methane (CH) present in the atmosphere to first carbon monoxide (CO) and then carbon dioxide (CO) is important for assessing the residence time of this greenhouse gas, the overall carbon budget of the troposphere, and its influence on the process of global warming. The

neg: Star Blazers: Space Battleship Yamato 2199 military base on Pluto, then started planetary bombardment with modified asteroids called "planet bombs". The planet bombs hampered United Nations efforts to rebuild their space fleet and forced Earth to build underground cities to protect humanity. The planet bombs altered the atmosphere and irradiated the planetary surface, causing the complete destruction of the planet's biosphere. The Gamilas then started what is believed to be their first step in terraforming—preparing the Earth to be inhabited by themselves—by introducing plant life that was lethal to any life on Earth. With mankind facing extinction, the United Nations started planning for a small colony

neg: Shailaputri which is perfection associated with Ananda (bliss). Verily, Shailaputri is the Muladhara Shakti to be realized within Self and sought for higher depths, in the YOGA-maditation. This is an experience in the soul-searching of Immutable within human existence. Shailaputri is the physical consciousness of the Divine Mother Durga. She is truly Parvati, daughter of the King Hemavana, as described in the Shiva Purana. Shailaputri is the manifestation of this earth planet, which includes what is apparent on this earth, and within the globe. Shailaputri covers all the hills, vales, water resources, seas and oceans, including atmosphere. Therefore, Shailaputri is the

neg: Weather the amount of energy received by Neptune is only about of that received by Earth, yet the intensity of weather phenomena on Neptune is far greater than on Earth. The strongest planetary winds discovered so far are on the extrasolar planet HD 189733 b, which is thought to have easterly winds moving at more than . Weather is not limited to planetary bodies. Like all stars, the sun's corona is constantly being lost to space, creating what is essentially a very thin atmosphere throughout the Solar System. The movement of mass ejected from the Sun is known as the solar

neg: Idealized greenhouse model that the surface area of a sphere is 4 times the area of its intercept (its shadow), the average incoming radiation is S/4. For longwave radiation, the surface of the Earth is assumed to have an emissivity of 1 (i.e., the earth is a black body in the infrared, which is realistic). The surface emits a radiative flux density F according to the Stefan-Boltzmann law: where σ is the Stefan-Boltzmann constant. A key to understanding the greenhouse effect is Kirchhoff's law of thermal radiation. At any given wavelength the absorptivity of the atmosphere will be equal to the emissivity. Radiation

neg: Paleolightning of early Earth (the first billion years) was drastically different from its current state. Initially, hydrogen and helium compounds dominated the atmosphere. However, given the relatively small size of these elements and the warmer temperature of Earth compared to other planets at the time, most of these lighter compounds escaped, leaving behind an atmosphere composed mainly of methane, nitrogen, oxygen and ammonia with small concentrations of hydrogen compounds and other gases. The atmosphere was transitioning from a reduction atmosphere (an atmosphere that inhibits oxidation) to one of oxidation, similar to our current atmosphere. The origin of life on Earth has

neg: Atmosphere of Titan N is preferentially lost from the upper atmosphere under photolysis and heating. Because Titan's original N–N ratio is poorly constrained, the early atmosphere may have had more N by factors ranging from 1.5 to 100 with certainty only in the lower factor. Because N is the primary component (98%) of Titan's atmosphere, the isotopic ratio suggests that much of the atmosphere has been lost over geologic time. Nevertheless, atmospheric pressure on its surface remains nearly 1.5 times that of Earth as it began with a proportionally greater volatile budget than Earth or Mars. It is possible that most of the

neg: Equations for a falling body the absence of an atmosphere all objects fall at the same rate, as astronaut David Scott demonstrated by dropping a hammer and a feather on the surface of the Moon.) The equations also ignore the rotation of the Earth, failing to describe the Coriolis effect for example. Nevertheless, they are usually accurate enough for dense and compact objects falling over heights not exceeding the tallest man-made structures. Near the surface of the Earth, the acceleration due to gravity "g" = 9.81 m/s (meters per second squared; which might be thought of as "meters per second, per second", or 32.2 ft/s

neg: Geological history of Earth short, greenstone belts represent sutured protocontinents. The Earth's magnetic field was established 3.5 billion years ago. The solar wind flux was about 100 times the value of the modern Sun, so the presence of the magnetic field helped prevent the planet's atmosphere from being stripped away, which is what probably happened to the atmosphere of Mars. However, the field strength was lower than at present and the magnetosphere was about half the modern radius. The geologic record of the Proterozoic () is more complete than that for the preceding Archean. In contrast to the deep-water deposits of the Archean, the

neg: Earth-grazing meteoroid of 13 October 1990 did not change measurably during the flight. Jiří Borovička and Zdeněk Ceplecha from the Ondřejov Observatory in Czechoslovakia estimated that the deceleration caused by the friction of the atmosphere reached only 1.7 m/s at the fireball's perigee (closest approach to Earth), and its velocity was reduced by only 0.012 km per second (less than 0.03%). This corresponds well with computer simulations provided by D. W. Olson, R. L. Doescher and K. M. Watson at the Southwest Texas State University, who concluded that the deceleration was less than 0.5 m/s except for a few seconds near perigee. This small loss of

neg: Paleoclimatology early temperature record of Earth with the exception of one cold glacial phase about 2.4 billion years ago. In the late Archaean eon, an oxygen-containing atmosphere began to develop, apparently from photosynthesizing cyanobacteria (see Great Oxygenation Event) which have been found as stromatolite fossils from 2.7 billion years ago. The early basic carbon isotopy (isotope ratio proportions) was very much in line with what is found today, suggesting that the fundamental features of the carbon cycle were established as early as 4 billion years ago. The constant rearrangement of continents by plate tectonics influences the long-term evolution of the atmosphere

neg: Earth analog or coal), interaction with the atmosphere, volcanically or artificially. A true Earth analog therefore might need to have formed through similar processes, having possessed an atmosphere, volcanic interactions with the surface, past or present liquid water and life forms. There are several factors that can determine planetary temperatures and therefore several measures that can draw comparisons to that of the Earth in planets where atmospheric conditions are unknown. Equilibrium temperature is used for planets without atmospheres. With atmosphere, a greenhouse effect is assumed. Finally, surface temperature is used. Each of these temperatures is affected by climate, which is influenced by

neg: Neptune a mass about 1.2 times that of Earth. The pressure at the centre is 7 Mbar (700 GPa), about twice as high as that at the centre of Earth, and the temperature may be 5,400 K. At high altitudes, Neptune's atmosphere is 80% hydrogen and 19% helium. A trace amount of methane is also present. Prominent absorption bands of methane exist at wavelengths above 600 nm, in the red and infrared portion of the spectrum. As with Uranus, this absorption of red light by the atmospheric methane is part of what gives Neptune its blue hue, although Neptune's vivid azure

neg: Percival Lowell detail in mid-1896 soon after the Alvan Clark & Sons refracting telescope was installed at his new Flagstaff, Arizona observatory. Lowell observed the planet high in the daytime sky with the telescope's lens stopped down to 3 inches in diameter to reduce the effect of the turbulent daytime atmosphere. Lowell observed spoke-like surface features including a central dark spot, contrary to what was suspected then (and known now): that Venus has no surface features visible from Earth, being covered in an atmosphere that is opaque. It has been noted in a 2003 "Journal for the History of Astronomy" paper and

neg: Comparative planetary science atmosphere of Titan is considered analogous to an early, colder Earth; the atmosphere of Pluto is considered analogous to an enormous comet. The presence or absence of a magnetic field affects an upper atmosphere, and in turn the overall atmosphere. Impacts of solar wind particles create chemical reactions and ionic species, which may in turn affect magnetospheric phenomena. Earth serves as a counterexample to Venus and Mars, which have no planetary magnetospheres, and to Mercury, with a magnetosphere but negligible atmosphere. Jupiter's moon Io creates sulfur emissions, and a feature of sulfur and some sodium around that planet. Similarly, Earth's

neg: Atmospheric escape HO in oceans, greatly decreasing the atmospheric density. With liquid water running over the surface of Earth, CO can be drawn down from the atmosphere and sequestered in sedimentary rocks. Some estimates indicate that nearly all carbon on Earth is contained in sedimentary rocks, with the atmospheric portion being approximately 1/250,000 of Earth's CO reservoir. If both of the reservoirs were released to the atmosphere, Earth's atmosphere would be even denser than Venus's atmosphere. Therefore, the dominant “loss” mechanism of Earth's atmosphere is not escape to space, but sequestration. However, in 1 billion years' time, the Sun will be 10%

neg: Impact winter (this is for a stony object hitting at 20 km/s). The porous comet-like objects are made up of low-density silicates, organics, ice, and volatile, and often burn up in the upper atmosphere because of their low bulk density (≤1 g/cm). Although the asteroids and comets that impact the Earth hit with many times the explosive force of a volcano, the mechanisms of an impact winter are similar to those that occur after a mega-volcanic eruption induced volcanic winter. In this scenario massive amounts of debris injected into the atmosphere would block some of the sun's radiation for an extended period

neg: Atmosphere of Venus winds quickly decrease towards the higher latitudes, eventually reaching zero at the poles. Such strong cloud-top winds cause a phenomenon known as the super-rotation of the atmosphere. In other words, these high-speed winds circle the whole planet faster than the planet itself rotates. The super-rotation on Venus is differential, which means that the equatorial troposphere super-rotates more slowly than the troposphere at the midlatitudes. The winds also have a strong vertical gradient. They decline deep in the troposphere with the rate of 3 m/s per km. The winds near the surface of Venus are much slower than that on Earth.

neg: Terminal World maintained. One of the main characters, Ricasso, mentions that he has done calculations and that the atmosphere is "like a bucket with a leak in it". Another factor is where, toward the end of the book powerful machines which have a major part to play refer to the location as Earthgate "this ancient, once-dead world" and distinguish it from Earth itself. One character pick up partially on this, saying "What the hell is Earthgate anyway? Why doesn't she just say Earth and be done with it?" That having been said, at one point in the text, Mars is explicitly referenced

neg: Good and evil being could validly apply the word "good" to an ecosystem as a whole? Who would have the power to assess and judge an ecosystem as good or bad? By what criteria? And by what criteria would ecosystems be modified, especially larger ones such as the atmosphere (climate change) or oceans (extinction) or forests (deforestation)? "Remaining on Earth" as the most basic value. While green ethicists have been most forthright about it, and have developed theories of Gaia philosophy, biophilia, bioregionalism that reflect it, the questions are now universally recognized as central in determining value, e.g. the economic "value of Earth"

neg: Earth-grazing fireball is no agreed-upon end to the upper atmosphere, but rather incrementally thinner air from the stratosphere (~50 km), mesosphere (~85 km), and thermosphere (~690 km) up to the exosphere (~10,000) (see also thermopause). For example, a meteoroid can become a meteor at an altitude of 85–120 km above the Earth. An Earth-grazing fireball is a rarely measured kind of fireball caused by a meteoroid that collides with the Earth but survives the collision by passing through, and exiting, the atmosphere. four grazers have been scientifically observed. Earth-grazing fireball An Earth-grazing fireball (or Earth-grazer) is a fireball, a very bright meteor

neg: Space tornado from space tornadoes Much of what is understood about space tornadoes was obtained through a NASA mission called Time History of Events and Macroscale Interactions during Substorms (THEMIS), which deployed several probes to measure the strength of the electrical currents, size, and velocity of the rotating plasma. Space tornado A space tornado is solar windstorm and is exponentially larger and more powerful than conventional tornadoes on Earth. They are also thought to produce the "aurora borealis" phenomenon. Tornadoes on Earth are formed by within the atmosphere by thunderstorms, while space tornadoes are formed by plasma interacting with magnetic fields. Space

neg: Terraforming of Venus sulfur dioxide atmosphere via removal or conversion to some other form, and the addition of breathable oxygen to the atmosphere. These three changes are closely interrelated, because Venus' extreme temperature is due to the high pressure of its dense atmosphere, and the greenhouse effect. Prior to the early 1960s, the atmosphere of Venus was believed by astronomers to have an Earth-like temperature. When Venus was understood to have a thick carbon dioxide atmosphere with a consequence of a very large greenhouse effect, some scientists began to contemplate the idea of altering the atmosphere to make the surface more Earth-like. This

neg: Sulfanyl and hydrogen in the radical is 0.134 nm. HS reacts with carboxylic acids to make carbonyl sulfide (COS) and probably is the main source of this substance in the atmosphere of Earth. HS—S is called disufanyl with lengthening chains as trisulfanyl, tetrasulfanyl and pentasulfanyl HSSSSS. S* is termed sulfanidyl. HS is known as sulfanylium, and the common hydrosulfide ion HS is also known as sulfanido for a ligand or sulfanide as an anion. Further down the periodic table, HSe is known as selanyl, and HTe is termed tellanyl. Sulfanyl Sulfanyl (), also known as the mercapto radical, hydrosulfide radical, or

neg: Kepler-78b to . This temperature is high enough to have stripped the planet of any stable atmosphere, but the liquid and solid portions of the planet should be stable. According to Francesco Pepe, one of the astronomers involved with the discovery, the planet may be Earth-sized but "it can be imagined like a lava planet rather than an Earth-like planet." The acceleration of gravity on the planet surface is estimated to be ~11 m/s, slightly larger than Earth's. According to CFA astronomer Dimitar Sasselov, "this lava world is an abomination. There’s no physical way a small world, only 20 percent larger

neg: International Geosphere-Biosphere Programme cycle, sulfur cycle, water cycle and phosphorus cycle. "It delivers scientific knowledge to help human societies develop in harmony with Earth's environment." IGBP research is organised around six projects representing the Earth system - land, atmosphere, ocean and where they meet (land-atmosphere, land-ocean. atmosphere-ocean) and two further projects looking at the Earth system as a whole: Past Global Changes (PAGES) which looks at palaeoclimate, and the Analysis, Integration and Modelling of the Earth System (AIMES), which helps set the agenda for Earth system models. Plus four joint projects - carbon, water, human health and food security - with the other