vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Exploration of Mars
The MRO contains a host of scientific instruments such as the HiRISE camera , CTX camera , CRISM , and SHARAD . The HiRISE camera is used to analyze Martian landforms , whereas CRISM and SHARAD can detect water , ice , and minerals on and below the surface . Additionally , MRO is paving the way for upcoming generations of spacecraft through daily monitoring of Martian weather and surface conditions , searching for future landing sites , and testing a new telecommunications system that enable it to send and receive information at an unprecedented bitrate , compared to previous Mars spacecraft . Data transfer to and from the spacecraft occurs faster than all previous interplanetary missions combined and allows it to serve as an important relay satellite for other missions . Rosetta
H II region
As with planetary nebulae , estimates of the abundance of elements in H II regions are subject to some uncertainty . There are two different ways of determining the abundance of metals ( metals in this case are elements other than hydrogen and helium ) in nebulae , which rely on different types of spectral lines , and large discrepancies are sometimes seen between the results derived from the two methods . Some astronomers put this down to the presence of small temperature fluctuations within H II regions ; others claim that the discrepancies are too large to be explained by temperature effects , and hypothesise the existence of cold knots containing very little hydrogen to explain the observations .
Cardinal direction
Astronomy provides a method for finding direction at night . All the stars appear to lie on the imaginary Celestial sphere . Because of the rotation of the Earth , the Celestial Sphere appears to rotate around an axis passing through the North and South poles of the Earth . This axis intersects the Celestial Sphere at the North and South Celestial poles , which appear to the observer to lie directly above due North and South respectively on the horizon .
Maya calendar
The Maya counted the lunations . This cycle appears in the lunar series as two glyphs that modern scholars call the ' C ' and ' X ' glyphs . The C glyph could be prefixed with a number indicating the lunation . No prefixing number meant one , whereas the numbers two through six indicated the other lunations . There was also a part of the C glyph that indicated where this fell in a larger cycle of 18 lunations . Accompanying the C glyph was the ' X ' glyph that showed a similar pattern of 18 lunations . Lunation
Mars
Mars is approximately half the diameter of Earth with a surface area only slightly less than the total area of Earth 's dry land . Mars is less dense than Earth , having about 15 % of Earth 's volume and 11 % of Earth 's mass , resulting in about 38 % of Earth 's surface gravity . The red - orange appearance of the Martian surface is caused by iron ( III ) oxide , or rust . It can look like butterscotch ; other common surface colors include golden , brown , tan , and greenish , depending on the minerals present . Comparison
Venus
Most Venusian surface features are named after historical and mythological women . Exceptions are Maxwell Montes , named after James Clerk Maxwell , and highland regions Alpha Regio , Beta Regio , and Ovda Regio . The latter three features were named before the current system was adopted by the International Astronomical Union , the body which oversees planetary nomenclature .
Hilda group
The typical Hilda object has a retrograde perihelion motion . On average , the velocity of perihelion motion is greater when the orbital eccentricity is lesser , while the nodes move more slowly . All typical objects in aphelion would seemingly approach closely to Jupiter , which should be destabilising for them -- but the variation of the orbital elements over time prevents this , and conjunctions with Jupiter occur only near the perihelion of Hilda asteroids . Moreover , the apsidal line oscillates near the line of conjunction with different amplitude and a period of 2.5 to 3.0 centuries . A
Exploration of Mars
Mars has long been the subject of human interest . Early telescopic observations revealed color changes on the surface that were attributed to seasonal vegetation and apparent linear features were ascribed to intelligent design . Further telescopic observations found two moons , Phobos and Deimos , polar ice caps and the feature now known as Olympus Mons , the solar system 's tallest mountain . The discoveries piqued further interest in the study and exploration of the red planet . Mars is a rocky planet , like Earth , that formed around the same time , yet with only half the diameter of Earth , and a far thinner atmosphere ; it has a cold and desert - like surface .
Moon landing
Willy Ley wrote in 1957 that a rocket to the Moon `` could be built later this year if somebody can be found to sign some papers '' . On 4 October 1957 , the Soviet Union launched Sputnik 1 as the first artificial satellite to orbit the Earth and so initiated the Space Race . This unexpected event was a source of pride to the Soviets and shock to the U.S. , who could now potentially be surprise attacked by nuclear - tipped Soviet rockets in under 30 minutes . Also , the steady beeping of the radio beacon aboard Sputnik 1 as it passed overhead every 96 minutes was widely viewed on both sides as effective propaganda to Third World countries demonstrating the technological superiority of the Soviet political system compared to that of the U.S. This perception was reinforced by a string of subsequent rapid - fire Soviet space achievements . In 1959 , the R - 7 rocket was used to launch the first escape from Earth 's gravity into a solar orbit , the first crash impact onto the surface of the Moon and the first photography of the never - before - seen far side of the Moon . These were the Luna 1 , Luna 2 and Luna 3 spacecraft . A
History of the center of the Universe
The Flat Earth model is a belief that the Earth 's shape is a plane or disk covered by a firmament contain heavenly bodies . Most pre-scientific cultures have had conceptions of a Flat Earth , including Greece until the classical period , the Bronze Age and Iron Age civilizations of the Near East until the Hellenistic period , India until the Gupta period ( early centuries AD ) and China until the 17th century . It was also typically held in the aboriginal cultures of the Americas , and a flat Earth domed by the firmament in the shape of an inverted bowl is common in pre-scientific societies .
Ancient Egyptian deities
Most deities were depicted in several ways . Hathor could be a cow , cobra , lioness , or a woman with bovine horns or ears . By depicting a given deity in different ways , the Egyptians expressed different aspects of its essential nature . They are depicted in a finite number of these symbolic forms , so that deities often could be distinguished from one another by their iconographies . These forms include men and women ( anthropomorphism ) , animals ( zoomorphism ) , and , more rarely , inanimate objects . Combinations of forms , such as deities with human bodies and animal heads , are common . New forms and increasingly complex combinations arose in the course of history , with the most surreal forms often found among the demons of the underworld . Some deities can only be distinguished from others if they are labeled in writing , as with Isis and Hathor . Because of the close connection between these goddesses , they could both wear the cow - horn headdress that was originally Hathor 's alone . Statue
Mars
The rotational period and seasonal cycles of Mars are likewise similar to those of Earth , as is the tilt that produces the seasons . Mars is the site of Olympus Mons , the largest volcano and second - highest known mountain in the Solar System , and of Valles Marineris , one of the largest canyons in the Solar System . The smooth Borealis basin in the northern hemisphere covers 40 % of the planet and may be a giant impact feature . Mars has two moons , Phobos and Deimos , which are small and irregularly shaped . These may be captured asteroids , similar to 5261 Eureka , a Mars trojan .
Kuiper belt
Bright objects are rare compared with the dominant dim population , as expected from accretion models of origin , given that only some objects of a given size would have grown further . This relationship between N ( D ) ( the number of objects of diameter greater than D ) and D , referred to as brightness slope , has been confirmed by observations . The slope is inversely proportional to some power of the diameter D:
Sundial
Prismatic dials are a special case of polar dials , in which the sharp edges of a prism of a concave polygon serve as the styles and the sides of the prism receive the shadow . Examples include a three - dimensional cross or star of David on gravestones .
Sundial
As an elegant alternative , the style ( which could be created by a hole or slit in the circumference ) may be located on the circumference of a cylinder or sphere , rather than at its central axis of symmetry .
Mauna Kea
The shield - stage lavas that built the enormous main mass of the mountain are tholeiitic basalts , like those of Mauna Loa , created through the mixing of primary magma and subducted oceanic crust . They are covered by the oldest exposed rock strata on Mauna Kea , the post-shield alkali basalts of the Hāmākua Volcanics , which erupted between 250,000 and 70 -- 65,000 years ago . The most recent volcanic flows are hawaiites and mugearites : they are the post-shield Laupāhoehoe Volcanics , erupted between 65,000 and 4,000 years ago . These changes in lava composition accompanied the slow reduction of the supply of magma to the summit , which led to weaker eruptions that then gave way to isolated episodes associated with volcanic dormancy . The Laupāhoehoe lavas are more viscous and contain more volatiles than the earlier tholeiitic basalts ; their thicker flows significantly steepened Mauna Kea 's flanks . In addition , explosive eruptions have built cinder cones near the summit . These cones are the most recent eruptive centers of Mauna Kea . Its present summit is dominated by lava domes and cinder cones up to 1.5 km ( 0.9 mi ) in diameter and hundreds of meters tall . Scoria
Technological and industrial history of the United States
From those first tentative steps , to the 1969 Apollo program landing on the Moon , to today 's reusable Space Shuttle , the American space program has brought forth a breathtaking display of applied science . Communications satellites transmit computer data , telephone calls , and radio and television broadcasts . Weather satellites furnish the data necessary to provide early warnings of severe storms .
Astronomical spectroscopy
Dust and molecules in the interstellar medium not only obscures photometry , but also causes absorption lines in spectroscopy . Their spectral features are generated by transitions of component electrons between different energy levels , or by rotational or vibrational spectra . Detection usually occurs in radio , microwave , or infrared portions of the spectrum . The chemical reactions that form these molecules can happen in cold , diffuse clouds or in the hot ejecta around a white dwarf star from a nova or supernova . Polycyclic aromatic hydrocarbons such as acetylene ( C H ) generally group together to form graphites or other sooty material , but other organic molecules such as acetone ( ( CH ) CO ) and buckminsterfullerenes ( C and C ) have been discovered .
C Moon
The name `` C Moon '' was inspired by lyrics in the song `` Wooly Bully '' by Sam the Sham and the Pharaohs . McCartney said , `` There 's a line in ( Wooly Bully ) that says , ' Let 's not be L7 . ' Well , L7 , it was explained at the time , means a square -- put L and 7 together and you get a square ... So I thought of the idea of putting a C and a moon together ( a half - moon ) to get the opposite of a square . So ' C Moon ' means cool , in other words . ''
Reuleaux triangle
Similar methods can be used to enclose an arbitrary simple polygon within a curve of constant width , whose width equals the diameter of the given polygon . The resulting shape consists of circular arcs ( at most as many as sides of the polygon ) , can be constructed algorithmically in linear time , and can be drawn with compass and straightedge . Although the regular - polygon based Reuleaux polygons all have an odd number of circular - arc sides , it is possible to construct constant - width shapes based on irregular polygons that have an even number of sides .
Astronomical spectroscopy
Planets , asteroids , and comets all reflect light from their parent stars and emit their own light . For cooler objects , including solar - system planets and asteroids , most of the emission is at infrared wavelengths we can not see , but that are routinely measured with spectrometers . For objects surrounded by gas , such as comets and planets with atmospheres , further emission and absorption happens at specific wavelengths in the gas , imprinting the spectrum of the gas on that of the solid object . In the case of worlds with thick atmospheres or complete cloud cover ( such as the gas giants , Venus , and Saturn 's satellite Titan ( moon ) ) , the spectrum is mostly or completely due to the atmosphere alone .
Lunar eclipse
Eclipses only occur during an eclipse season , when the Sun is close to either the ascending or descending node of the Moon .
Magnetosphere of Jupiter
Jupiter demonstrates bright , persistent aurorae around both poles . Unlike Earth 's aurorae , which are transient and only occur at times of heightened solar activity , Jupiter 's aurorae are permanent , though their intensity varies from day to day . They consist of three main components : the main ovals , which are bright , narrow ( less than 1000 km in width ) circular features located at approximately 16 ° from the magnetic poles ; the satellites ' auroral spots , which correspond to the footprints of the magnetic field lines connecting Jupiter 's ionosphere with those of its largest moons , and transient polar emissions situated within the main ovals . Whereas the auroral emissions were detected in almost all parts of the electromagnetic spectrum from radio waves to X-rays ( up to 3 keV ) , they are brightest in the mid-infrared ( wavelength 3 -- 4 μm and 7 -- 14 μm ) and deep ultraviolet spectral regions ( wavelength 80 -- 180 nm ) .
History of chemistry
Philosophical attempts to rationalize why different substances have different properties ( color , density , smell ) , exist in different states ( gaseous , liquid , and solid ) , and react in a different manner when exposed to environments , for example to water or fire or temperature changes , led ancient philosophers to postulate the first theories on nature and chemistry . The history of such philosophical theories that relate to chemistry can probably be traced back to every single ancient civilization . The common aspect in all these theories was the attempt to identify a small number of primary classical element that make up all the various substances in nature . Substances like air , water , and soil / earth , energy forms , such as fire and light , and more abstract concepts such as ideas , aether , and heaven , were common in ancient civilizations even in absence of any cross-fertilization ; for example in Greek , Indian , Mayan , and ancient Chinese philosophies all considered air , water , earth and fire as primary elements . Ancient
Lunar distance (astronomy)
The average lunar distance is increasing , which implies that the Moon was closer in the past . There is geological evidence that the average lunar distance was about 52 R during the Precambrian Era ; 2,500 million years BP .
Lunar distance (astronomy)
Lunar distance expressed in selected units Unit Mean value Uncertainty Ref meter 7008384402000000000 ♠ 3.844 02 × 10 6997110000000000000 ♠ 1.1 mm kilometer 7005384402000000000 ♠ 384 402 6997110000000000000 ♠ 1.1 mm mile 238,856 0.043 in Earth radii 60.32 AU 1 / 388.6 = 6997256999999999999 ♠ 0.002 57 light - second 7000128200000000000 ♠ 1.282 s 6989375000000000000 ♠ 37.5 ps
Lunar distance (astronomy)
Although the instantaneous uncertainty is sub-millimeter , the measured lunar distance can change by more than 7007210000000000000 ♠ 21 000 km from the mean value throughout a typical month . These perturbations are well understood and the lunar distance can be accurately modeled over thousands of years . The
Lunar distance (astronomy)
Astronomers O'Keefe and Anderson calculated the lunar distance by observing 4 occultations from 9 locations in 1952 . They calculated a mean distance of 7008384407600000000 ♠ 384 407. 6 ± 4.7 km , however the value was refined by in 1962 by Irene Fischer , who incorporated updated geodetic data to produce a value of 7008384403700000000 ♠ 384 403. 7 ± 2 km .
Lunar distance (astronomy)
The experiment was repeated in 1958 at the Royal Radar Establishment , in England . Radar pulses lasting 6994499999999999999 ♠ 5 μs were transmitted with a peak power of 2 megawatts , at a repetition rate of 260 pulses per second . After the radio waves echoed off the surface of the Moon , the return signal was detected and the delay time measured . Multiple signals were added together to obtain a reliable signal by superimposing oscilloscope traces onto photographic film . From the measurements , the distance was calculated with an uncertainty of 7003125000000000000 ♠ 1.25 km .
Lunar distance (astronomy)
Modern cameras have now reached the resolution level capable of capturing the Moon with a precision enough to perceive and more importantly to measure this tiny variation in apparent size . The results of this experiment were calculated as LD = 7001605100000000000 ♠ 60.51 + 3.91 − 4.19 R . The accepted value for that night was 60.61 , which implied a 7000300000000000000 ♠ 3 % accuracy . The benefit of this method is that the only measuring equipment needed is a modern digital camera ( equipped with an accurate clock , and GPS receiver ) .
Lunar distance (astronomy)
These initial experiments were intended to be proof - of - concept experiments and only lasted one day . Follow - on experiments lasting one month produced a mean value of 7008384402000000000 ♠ 384 402 ± 1.2 km , which was the most accurate measurement of the lunar distance at the time .
Communications satellite
Like LEOs , these satellites do n't maintain a stationary distance from the earth . This is in contrast to the geostationary orbit , where satellites are always approximately 35,786 kilometres ( 22,236 mi ) from the earth .
Earth's location in the Universe
Feature Diameter Notes Sources Earth 12,756.2 km ( equatorial ) Measurement comprises just the solid part of the Earth ; there is no agreed upper boundary for Earth 's atmosphere . The geocorona , a layer of UV - luminescent hydrogen atoms , lies at 100,000 km . The Kármán line , defined as the boundary of space for astronautics , lies at 100 km . Orbit of the Moon 768,210 km The average diameter of the orbit of the Moon relative to the Earth . Geospace 6,363,000 -- 12,663,000 km ( 110 - 210 Earth radii ) The space dominated by Earth 's magnetic field and its magnetotail , shaped by the solar wind . Earth 's orbit 299.2 million km 2 AU The average diameter of the orbit of the Earth relative to the Sun . Encompasses the Sun , Mercury and Venus . Inner Solar System ~ 6.54 AU Encompasses the Sun , the inner planets ( Mercury , Venus , Earth , Mars ) and the asteroid belt . Cited distance is the 2 : 1 resonance with Jupiter , which marks the outer limit of the asteroid belt . Outer Solar System 60.14 AU Includes the outer planets ( Jupiter , Saturn , Uranus , Neptune ) . Cited distance is the orbital diameter of Neptune . Kuiper belt ~ 96 AU Belt of icy objects surrounding the outer Solar System . Encompasses the dwarf planets Pluto , Haumea and Makemake . Cited distance is the 2 : 1 resonance with Neptune , generally regarded as the outer edge of the main Kuiper belt . Heliosphere 160 AU Maximum extent of the solar wind and the interplanetary medium . Scattered disc 195.3 AU Region of sparsely scattered icy objects surrounding the Kuiper belt . Encompasses the dwarf planet Eris . Cited distance is derived by doubling the aphelion of Eris , the farthest known scattered disc object . As of now , Eris 's aphelion marks the farthest known point in the scattered disc . Oort cloud 100,000 -- 200,000 AU 0.613 -- 1.23 pc Spherical shell of over a trillion ( 10 ) comets . Existence is currently hypothetical , but inferred from the orbits of long - period comets .
Earth
The Hill sphere , or the sphere of gravitational influence , of the Earth is about 1.5 million km ( 930,000 mi ) in radius . This is the maximum distance at which the Earth 's gravitational influence is stronger than the more distant Sun and planets . Objects must orbit the Earth within this radius , or they can become unbound by the gravitational perturbation of the Sun .
The Shining (film)
There are fringe analyses relating this number change to rumors that Kubrick faked the first moon landing , as there are approximately 237,000 miles between Earth and Moon ( average is 238,855 miles ) and the movie is a subtle confession of his involvement . Another theory is an obsession with the number 42 and its forms in the movie and the product of the digits in 237 is 42 .
Earth
Earth orbits the Sun at an average distance of about 150 million km ( 93 million mi ) every 365.2564 mean solar days , or one sidereal year . This gives an apparent movement of the Sun eastward with respect to the stars at a rate of about 1 ° / day , which is one apparent Sun or Moon diameter every 12 hours . Due to this motion , on average it takes 24 hours -- a solar day -- for Earth to complete a full rotation about its axis so that the Sun returns to the meridian . The orbital speed of Earth averages about 29.78 km / s ( 107,200 km / h ; 66,600 mph ) , which is fast enough to travel a distance equal to Earth 's diameter , about 12,742 km ( 7,918 mi ) , in seven minutes , and the distance to the Moon , 384,000 km ( 239,000 mi ) , in about 3.5 hours .
Lunar distance (astronomy)
An experiment which measured the round - trip time of flight of laser pulses reflected directly off the surface of the Moon was performed in 1962 , by a team from Massachusetts Institute of Technology , and a Soviet team at the Crimean Astrophysical Observatory .
Lunar distance (astronomy)
An experiment was depicted in the television comedy `` The Big Bang Theory '' , which portrayed the measurement of the lunar distance using lasers. ( 1 )
Speed of light
Radar systems measure the distance to a target by the time it takes a radio - wave pulse to return to the radar antenna after being reflected by the target : the distance to the target is half the round - trip transit time multiplied by the speed of light . A Global Positioning System ( GPS ) receiver measures its distance to GPS satellites based on how long it takes for a radio signal to arrive from each satellite , and from these distances calculates the receiver 's position . Because light travels about 7005300000000000000 ♠ 300 000 kilometres ( 7008299337984000000 ♠ 186 000 mi ) in one second , these measurements of small fractions of a second must be very precise . The Lunar Laser Ranging Experiment , radar astronomy and the Deep Space Network determine distances to the Moon , planets and spacecraft , respectively , by measuring round - trip transit times .
Earth
Apart from meteors within the atmosphere and low - orbiting satellites , the main apparent motion of celestial bodies in Earth 's sky is to the west at a rate of 15 ° / h = 15 ' / min . For bodies near the celestial equator , this is equivalent to an apparent diameter of the Sun or the Moon every two minutes ; from Earth 's surface , the apparent sizes of the Sun and the Moon are approximately the same .