Humans (Homo sapiens) have inhabited the
Earth in the last 300,000 years at least,[1] and they had witnessed directly observable
astronomical and
geological phenomena. For millennia, these have arose admiration and curiosity, being admitted as of
superhuman nature and scale. Multiple imaginative interpretations were being fixed in
oral traditions of difficult dating, and incorporated into a variety of
belief systems, as
animism,
shamanism,
mythology,
religion and/or
philosophy.
Although such phenomena are not "
discoveries" per se, as they are part of the common human experience, their observation shape the knowledge and comprehension of the world around us, and about its position in the
observable universe, in which the
Sun plays a role of outmost importance for us. What today is known to be the
Solar System was regarded for generations as the contents of the "whole
universe".
The most relevant phenomena of these kind are:
Basic
gravity. Following the
trajectory of free falling objects, the
Earth is "below" us and the
sky is "above" us.
Nightly apparent movement of the
celestial sphere with its main features regarded as "
fixed":
stars, the brightest of them forming casual groupings known as
constellations, under different names and shapes in many cultures. Different constellations are viewed in different seasons and
latitudes. Along with the faint strip of the
Milky Way, they altogether conform the idea of the
firmament, which as viewed from Earth it seems to be a consistent, solid unit rotating smooth and uniformly. This leads to the intuitive idea of a
geocentric universe.
Presence of the
Moon, with its
phases.
Tides. Recognition of meteorological phenomena as sub-lunar.
Yearly apparent transit of the Sun through the constellations of the
zodiac. Recognition of the lunar cycle as a (lunar)
month, and the solar cycle as the (solar) year, the basis for
calendars.
The
Antikythera mechanism (Fragment A – front); visible is the largest gear in the mechanism, approximately 140 millimetres (5.5 in) in diameter
The Antikythera mechanism (Fragment A – back)
2nd millennium BCE – Earliest possible date for the composition of the Babylonian
Venus tablet of Ammisaduqa, a 7th-century BC copy[2] of a list of observations of the motions of the planet
Venus, and the oldest planetary table currently known.
2nd millennium BCE –
Babylonian astronomers identify the inner planets
Mercury and Venus and the outer planets
Mars,
Jupiter and
Saturn, which would remain the only known planets until the invention of the
telescope in early modern times.[3]
Late 2nd millennium BCE – Chinese established their timing cycle of 12
Earthly Branches based on the approximate number of years (11.86) it takes
Jupiter to complete a single revolution in the sky.[citation needed]
c. 750 BCE – During the reign of
Nabonassar (747–733 BC), the systematic records of ominous phenomena in
Babylonian astronomical diaries that began at this time allowed for the discovery of a repeating 18-year cycle of
lunar eclipses.[6]
776 BCE – Chinese make the earliest reliable record of a solar eclipse.[7][failed verification]
687 BCE – Chinese make earliest known record of
meteor shower. [8]
c. 560 BCE –
Anaximander is arguably the first
to conceive a mechanical model of the world, although highly inaccurate: a
cylindrical Earth[11] floats freely in space surrounded by three concentric wheels turning at different distances: the closest for the stars and planets, the second for the Moon and the farthest for the Sun, all conceived not as bodies but as "fire seen thru holes" in every wheel.[12] But he starts to feed the idea of
celestial mechanics as different of the notion of planets being heavenly
deities, leaving
mythology aside.
c. 475 BCE –
Parmenides is credited to be the first Greek who declared that the Earth is spherical and is situated in the centre of the universe, believed to have been the first to detect the identity of
Hesperus, the evening-star, and
Phosphorus, the morning-star (Venus),[13] and by some, the first to claim that moonlight is a reflection of sunlight.[14]
c. 450 BCE –
Anaxagoras shows that the
Moon shines by reflected sunlight: the phases of the Moon are caused by the illumination of its sphere by the Sun in different angles along the lunar month. He was also the first to give a correct explanation of eclipses, by asserting that the Moon is
rocky, thus
opaque, and closer to the Earth than the Sun.[15]
c. 400 BCE –
Philolaus and other
Pythagoreans propose
a model in which the Earth and the Sun revolve around an invisible "Central Fire" (not the Sun), and the Moon and the planets orbit the Earth.[16] Due to philosophical concerns
about the number 10, they also added a tenth "hidden body" or
Counter-Earth (Antichthon), always in the opposite side of the invisible Central Fire and therefore also invisible from Earth.[17]
c. 360 BCE –
Plato claims in his Timaeus that
circles and spheres are the preferred shape of the universe and that the Earth is at the centre. These circles are the orbits of the heavenly bodies, varying in size for every of them. He arranged these celestial orbs, in increasing order from the Earth: Moon, Sun, Venus, Mercury, Mars, Jupiter, Saturn, and the
fixed stars located on the
celestial sphere forming the outermost shell.[18]
c. 330 BCE –
Heraclides Ponticus is said to be the first Greek who proposes that the
Earth rotates on its axis, from west to east, once every 24 hours, contradicting Aristotle's teachings.
Simplicius says that Heraclides proposed that the irregular movements of the planets can be explained if the Earth moves while the Sun stays still,[23] but these statements are disputed.[24]
c. 280 BCE –
Aristarchus of Samos offers the
first definite discussion of the possibility of a
heliocentric cosmos,[25] and uses the size of the Earth's
shadow on the
Moon to estimate the Moon's orbital radius at 60 Earth radii, and its physical radius as one-third that of the Earth. He also makes an inaccurate attempt to measure the distance to the Sun.[26]
c. 250 BCE – Following the heliocentric ideas of Aristarcus,
Archimedes in his work The Sand Reckoner computes the diameter of the universe centered around the Sun to be about 1014stadia (in modern units, about 2
light years, 18.93×1012km, 11.76×1012mi).[27]
c. 200 BCE –
Eratosthenes determines that the radius of the Earth is roughly 6,400 km (4,000 mi).[29]
c. 150 BCE – According to
Strabo (1.1.9),
Seleucus of Seleucia is the first to state that the
tides are due to the attraction of the Moon, and that the height of the tides depends on the Moon's position relative to the Sun.[30]
c. 150 BCE –
Hipparchus uses
parallax to determine that the distance to the Moon is roughly 380,000 km (236,100 mi).[31]
c. 87 BCE – The
Antikythera mechanism, the earliest known computer, is built. It is an extremely complex astronomical computer designed to predict solar and lunar eclipses accurately and track the movements of the planets and the Sun. It could also calculate the differences in the apsidial and axial precession of heavenly bodies with extreme degree of accuracy.[33]
28 BCE – Chinese history book Book of Han makes earliest known dated record of
sunspot.[34]
c. 150 CE –
Claudius Ptolemy completes his work Almagest, that codifies the astronomical knowledge of his time and cements the geocentric model in the West, and it remained the most authoritative text on
astronomy for more than 1,500 years. The Almagest put forward extremely complex and accurate methods to determine the position and structure of planets,
stars (including some objects as nebulae,
supernovas and galaxies then regarded as stars also) and heavenly bodies. It includes a catalogue of 1,022 stars (largely based on a previous one by Hipparchus of about 850 entries) and a large amount of
constellations,
comets and other astronomical phenomena.[35] Following a long astrological tradition, he arranged the heavenly spheres ordering them (from Earth outward): Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn and fixed stars.
Middle Ages
c. 420 –
Martianus Capella describes a modified geocentric model, in which the Earth is at rest in the center of the universe and circled by the Moon, the Sun, three planets and the stars, while Mercury and Venus circle the Sun.[36]
c. 500 – Indian mathematician-astronomer
Aryabhata accurately computes the solar and lunar eclipses, and the length of Earth's revolution around the Sun.
c. 500 – Aryabhata discovers the oblique motion of the apsidial precession of the Sun and notes that it is changing with respect to the motion of stars and Earth.
c. 500 – Aryabhata discovers the rotation of the Earth by conducting
experiments and giving
empirical examples for his theories. He also explains the cause of day and night through the
diurnal rotation of the Earth. He also developed highly accurate models for the orbital motion of the Moon, Mercury and Mars. He also developed a geocentric model of the universe.[37][38][39]
c. 620 – Indian mathematician-astronomer
Brahmagupta describe gravity as a attractive force by the term guruvatkarshan.[40]
628 – Brahmagupta gives methods for calculations of the motions and places of various planets, their rising and setting, conjunctions, and calculations of the
solar and
lunar eclipses.[41][42]
850 –
Al-Farghani (Alfraganus) translated and wrote commentary on
Ptolemy'sAlmagest and gave values for the motion of the ecliptic, and the
precessional movement of the
heavenly bodies based on the values given by Ptolemy and Hipparchus.[45]
1019 –
Al-Biruni observes and describes the
lunar eclipse on September 17 in detail and gives the exact latitudes of the stars during it.[46]
c. 1030 – In his major astronomical work, the Mas'ud Canon, Al-Biruni observed that, contrary to Ptolemy, the Sun's
apogee (highest point in the heavens) was mobile, not fixed.[47]
1031 – Chinese astronomer and scientist
Shen Kuo calculates the distance between the Earth and the Sun in his mathematical treatises.[48][failed verification]
c. 1060 –
Andalusi astronomer
Al-Zarqali corrects geographical data from
Ptolemy and
Al-Khwarizmi, specifically by correcting Ptolemy's estimate of the longitude of the
Mediterranean Sea from 62 degrees to the correct value of 42 degrees.[50] He was the first to demonstrate the motion of the
solar apogee relative to the fixed background of the stars, measuring its rate of motion as 12.9 seconds per year, which is remarkably close to the modern calculation of 11.77 seconds.[51] Al-Zarqālī also contributed to the famous Tables of Toledo.
1180s (decade) –
Robert Grosseteste described the birth of the Universe in an explosion and the crystallisation of matter. He also put forward several new ideas such as rotation of the Earth around its
axis and the cause of day and night. His treatise De Luce is the first attempt to describe the heavens and Earth using a single set of physical laws.[53]
c. 1200 –
Fakhr al-Din al-Razi, in dealing with his conception of physics and
the physical world, rejected the
Aristotelian and
Avicennian view of a single world, but instead proposed that there are "a thousand thousand worlds (alfa alfi 'awalim) beyond this world such that each one of those worlds be bigger and more massive than this world as well as having the like of what this world has."[54]
c. 1300 –
Jewish astronomer
Levi ben Gershon (Gersonides) recognized that the stars are much larger than the planets. Gersonides appears to be among the few astronomers before modern times, along Aristarcus, to have surmized that the fixed stars are much further away than the planets. While all other astronomers put the fixed stars on a rotating sphere just beyond the outer planets, Gersonides estimated the distance to the fixed stars to be no less than 159,651,513,380,944 Earth radii, or about 100,000 light-years in modern units.[57][58]
c. 1350 –
Nicole Oresme put forward several revolutionary theories like
mean speed theorem, which he used in calculating the position and shape of the planetary orbits, measuring the apsidial and
axial precession of the
lunar and solar
orbits, measuring the angles and distance between ecliptics and calculating stellar and
planetary distances. In his Livre du Ciel et du Monde, Oresme discussed a range of evidence for the daily rotation of the
Earth on its
axis.[61][62]
1440 –
Nicholas of Cusa proposes that the Earth rotates on its axis in his book, On Learned Ignorance.[63] Like Oresme, he also wrote about the possibility of the plurality of worlds.[64]
1577 – Tycho Brahe records the position of the
Great Comet of that year as viewed from Uraniborg (in the island
Hven, near
Copenhagen) and compares it with that observed by
Thadaeus Hagecius from
Prague at the same time, giving deliberate consideration to the movement of the Moon. It was discovered that, while the comet was in approximately the same place for both of them, the Moon was not, and this meant that the comet was much further out, contrary to what was previously conceived as an atmospheric phenomenon.[72]
1582 – Pope
Gregory XIII introduces the
Gregorian calendar, an enhanced solar calendar more accurate than the previous Roman
Julian calendar.[73] The principal change was to space
leap years differently so as to make the average calendar year 365.2425 days long, more closely approximating the 365.2422-day
'tropical' or 'solar' year that is determined by the Earth's revolution around the Sun. The reform advanced the date by 10 days: Thursday 4 October 1582 was followed by Friday 15 October 1582. The Gregoran calendar is still in use today.
1584 –
Giordano Bruno published two important philosophical dialogues (La Cena de le Ceneri and De l'infinito universo et mondi) in which he argued against the planetary spheres and affirmed the Copernican principle. Bruno's infinite universe was filled with a substance—a "pure air",
aether, or spiritus—that offered no resistance to the heavenly bodies which, in Bruno's view, rather than being fixed, moved under their own
impetus (momentum). Most dramatically, he completely abandoned the idea of a hierarchical universe. Bruno's cosmology distinguishes between "suns" which produce their own light and heat, and have other bodies moving around them; and "earths" which move around suns and receive light and heat from them. Bruno suggested that some, if not all, of the objects classically known as
fixed stars are in fact suns,[74] so he was arguably the first person to grasp that "stars are other suns with their own planets." Bruno wrote that other worlds "have no less virtue nor a nature different from that of our Earth" and, like Earth, "contain animals and inhabitants".[75]
1588 – Tycho Brahe publishes his own
Tychonic system, a blend between Ptolemy's classical geocentric model and Copernicus' heliocentric model, in which the Sun and the Moon revolve around the Earth, in the center of universe, and all other planets revolve around the Sun.[76]
1604 –
Galileo Galilei correctly hypothesized that the distance of a falling object is proportional to the
square of the time elapsed.[78]
1609 –
Johannes Kepler states his first two empirical
laws of planetary motion, stating that the orbits of the planets around the Sun are elliptical rather than circular, and thus resolving many ancient problems with planetary models, without the need of any epicycle.[79]
1609 – Galileo Galilei starts to make
telescopes with about 3x up to 30x magnification, based only on descriptions of the first practical telescope which
Hans Lippershey tried to patent in the
Netherlands in 1608.[80] With a
Galilean telescope, the observer could see magnified, upright images on the Earth—what is commonly known as a spyglass—but also it can be used to observe the sky, a key tool for further astronomical discoveries.
1609 – Galileo Galilei aimed his telescope at the
Moon. While not being the first person to observe the Moon through a telescope (English mathematician
Thomas Harriot had done it four months before but only saw a "strange spottednesse"),[81] Galileo was the first to deduce the cause of the uneven waning as light occlusion from lunar mountains and
craters. He also estimated the heights of that mountains. The Moon was not what was long thought to have been a translucent and perfect sphere, as
Aristotle claimed, and hardly the first "planet".
1648 –
Blaise Pascal, aided by his brother-in-law Florin Périer at mount
Puy de Dôme, shows that air pressure on a high mountain is less than at a lower altitude, proving his idea that, as air has a finite weight, Earth's atmosphere must have a maximum height.[92]
1659 – Huygens estimated a value of about 24,000 Earth radii for the
distance Earth-Sun, remarkably close to modern values but he was based on many unproven (and incorrect) assumptions; the accuracy of his value seems to be based more on luck than good measurement, with his various errors cancelling each other out.[95]
1665 – Cassini determines the rotational speeds of Jupiter, Mars, and Venus.[96]
1729 –
James Bradley determines the cause of the
aberration of starlight, providing the first direct evidence of the Earth's motion, and a more accurate method to compute the speed of light.[107]
1758 –
Johann Palitzsch observes the return of the comet that Edmond Halley had anticipated in 1705.[115] The gravitational attraction of Jupiter had slowed the return by 618 days. Parisian astronomer
La Caille suggests it should be named "Halley's Comet".[116]
1775 –
Charles Hutton, based on his analysis of the
Schiehallion experiment, shows the Earth has a density of at least 4,500 kg·m−3 and suggests that it has a
planetary core made of metal. (In comparison with the modern accepted figure of 5,515 kg·m−3, the density of the Earth had been computed with an error of less than 20%.)[120]
1781 –
William Herschel discovers a seventh planet,
Uranus, during a telescopic survey of the Northern sky.[121]
1801 –
Giuseppe Piazzi discovers
Ceres, a body that filled a gap between Mars and Jupiter following the
Titius-Bode rule. At first, it was regarded as a new planet.[127]
1802 –
Heinrich Wilhelm Olbers discovers
Pallas, at roughly the same distance to the Sun than Ceres.[128] He proposed that the two objects were the remnants of a
destroyed planet,[129] and predicted that more of these pieces would be found.
1802 – Due their star-like apparience, William Herschel suggested Ceres and Pallas, and similar objects if found, be placed into a separate category, named
asteroids, although they were still counted among the planets for some decades.[130]
1845 –
John Adams predicts the existence and location of an eighth planet from irregularities in the orbit of Uranus.[138]
1845 –
Karl Ludwig Hencke discovers a fifth body between Mars and Jupiter,
Astraea[139] and, shortly thereafter, new objects were found there at an accelerating rate. Counting them among the planets became increasingly cumbersome. Eventually, they were dropped from the planet list (as first suggested by
Alexander von Humboldt in the early 1850s) and Herschel's coinage, "asteroids", gradually came into common use.[140] Since then, the region they occupy between Mars and Jupiter is known as the
asteroid belt.
1846 –
Urbain Le Verrier predicts the existence and location of an eighth planet from irregularities in the orbit of Uranus.[138]
1849 –
Édouard Roche finds the limiting radius of
tidal destruction and tidal creation for a body held together only by its own gravity, called the
Roche limit, and uses it to explain why Saturn's rings do not condense into a satellite.[144]
1849 –
Annibale de Gasparis discovers the asteroid
Hygiea, the fourth largest asteroid in the Solar System by both volume and mass.[145]
1856 –
James Clerk Maxwell demonstrates that a solid ring around Saturn would be torn apart by gravitational forces and argues that Saturn's rings consist of a multitude of tiny satellites.[147]
1862 – By analysing the
spectroscopic signature of the Sun and comparing it to those of other stars, Father
Angelo Secchi determines that the Sun is itself a star.[149]
1866 –
Giovanni Schiaparelli realizes that
meteor streams occur when the Earth passes through the orbit of a comet that has left debris along its path.[150]
1868 –
Jules Janssen observes a bright yellow line with a wavelength of 587.49 nanometers in the spectrum of the
chromosphere of the Sun, during a total solar eclipse in Guntur, India. Later in the same year,
Norman Lockyer observed the same line in the solar spectrum, and concluded that it was caused by an element in the Sun unknown on Earth. This element is
helium, which currently comprises 23.8% of the mass in the solar
photosphere.[151]
1895 –
Percival Lowell starts publishing books about his observations of features in the surface on Mars that he claimed as artificial
Martian canals (due to a mistranslation of a previous paper by Schiaparelli on the subject), popularizing the long-held belief that these markings showed that Mars harbors
intelligent life forms.[155]
1897 –
William Thomson, 1st Baron Kelvin, based on the thermal radiation rate and the
gravitational contraction forces, argues the age of the Sun to be no more than 20 million years – unless some energy source beyond what was then known was found.[156]
1904 –
Ernest Rutherford argues, in a lecture attended by Kelvin, that
radioactive decay releases heat, providing the unknown energy source Kelvin had suggested, and ultimately leading to
radiometric dating of rocks which reveals ages of billions of years for the Solar System bodies.[158]
1920 – In the
Great Debate between
Harlow Shapley and
Heber Curtis,
galaxies are finally recognized as objects beyond the Milky Way, and the Milky Way as a galaxy proper.[166] Within it lies the Solar System.
1935 – The Explorer II balloon reached a record altitude of 22,066 m (72,395 ft), enabling its occupants to photograph the curvature of the Earth for the first time.[170]
1946 – American launch of a camera-equipped
V-2 rocket provides the first image of the Earth from space.[174]
1949 – Gerard Kuiper discovers Uranus's moon
Miranda and Neptune's moon
Nereid.[173]
1950 –
Jan Oort suggests the presence of a cometary reservoir in the outer limits of the Solar System, the
Oort cloud.[175]
1951 – Gerard Kuiper argues for an annular reservoir of comets between 40 and 100
astronomical units from the Sun having formed early in the Solar System's evolution, but he did not think that such a belt still existed today.[176] Decades later, this region was named after him, the
Kuiper belt.
1959 – Explorer 6 sends the first image of the entire Earth from space.[178]
1959 –
Luna 3 sends the first images of another celestial body, the Moon, from space, including its unseen
far side.[179]
1962 – Mariner 2 Venus flyby performs the first closeup observations of another planet.[180]
1964 – Mariner 4 spacecraft provides the first detailed images of the surface of Mars.[181]
1966 –
Luna 9 Moon lander provides the first images from the surface of another celestial body.[182]
1967 – Venera 4 provides the first information on Venus's dense atmosphere.[183]
1968 –
Apollo 8 becomes the first crewed lunar mission, providing historic images of the whole Earth.[184]
1969 –
Apollo 11 mission landed on the Moon, first humans walking upon it.[185] They return the first
lunar samples back to Earth.[186]
1970 – Venera 7 Venus lander sends back the first information successfully obtained from the surface of another planet.[187]
1971 – Mariner 9 Mars spacecraft becomes the first to successfully orbit another planet.[188] It provides the first detailed maps of the Martian surface,[189] discovering much of the planet's topography, including the volcano
Olympus Mons and the canyon system
Valles Marineris, which is named in its honor.
1971 – Mars 3 lands on Mars, and transmits the first partial image from the surface of another planet.[190]
1978 –
Peter Goldreich and
Scott Tremaine present a
Boltzmann equation model of planetary-ring dynamics for indestructible spherical ring particles that do not self-gravitate, and they find a stability requirement relation between ring optical depth and particle normal restitution coefficient.[citation needed]
1979 – Pioneer 11 flies by Saturn, providing the first ever closeup images of the planet and its rings. It discovers the planet's
F ring and determines that its moon
Titan has a thick atmosphere.[199]
1979 – Goldreich and Tremaine postulate that Saturn's F ring is maintained by
shepherd moons, a prediction that would be confirmed by observations.[200]
1979 – Voyager 2 flies by Jupiter and discovers evidence of an ocean under the surface of its moon
Europa.[202]
1980 – Voyager 1 flies by Saturn and takes the first images of Titan.[203] However, its atmosphere is opaque to visible light, so its surface remains obscured.
1982 – Venera 13 lands on Venus, sends the first photographs in color of its surface, and records atmospheric wind noises, the first sounds heard from another planet.[204]
1986 – Voyager 2 provides the first ever detailed images of
Uranus, its moons and rings.[202]
1986 – The Giotto probe, part of an international effort known as the "
Halley Armada", provides the first ever close up images of a comet, the
Halley's Comet.[205]
1988 – Martin Duncan, Thomas Quinn, and Scott Tremaine demonstrate that short-period comets come primarily from the Kuiper Belt and not the Oort cloud.[206]
1989 – Voyager 2 provides the first ever detailed images of
Neptune, its moons and rings.[202]
1993 – Asteroid
Ida is visited by the Galileo before heading to Jupiter. Mission member Ann Harch discovers its natural satellite
Dactyl in images returned by the spacecraft, the first
asteroid moon discovered.[217]
1994 –
Comet Shoemaker–Levy collides with Jupiter, providing the first direct observation of an extraterrestrial
collision of Solar System objects.[218]
1995 – The Galileo becomes the first spacecraft to orbit Jupiter. Its atmospheric entry probe provides the first data taken within the planet itself.[215]
2004 – The Cassini–Huygens spacecraft becomes the first to orbit Saturn. It discovers complex motions in the rings, several new small moons and
cryovolcanism on the moon
Enceladus, studies the
Saturn's hexagon, and provides the first images from the surface of
Titan.[228]
2005 – M. Brown, C. Trujillo, and D. Rabinowitz discover
Eris, a TNO more massive than Pluto,[229] and later, by other team led by Brown, also its moon,
Dysnomia.[230] Eris was first imaged in 2003, and is the most massive object discovered in the Solar System since Neptune's moon Triton in 1846.
2005 – M. Brown, C. Trujillo, and D. Rabinowitz discover another notable KBO,
Makemake.[231]
2005 – The Mars Exploration Rovers perform the first astronomical observations ever taken from the surface of another planet, imaging an eclipse by Mars's moon
Phobos.[232]
2005 – Hayabusa spacecraft lands on asteroid
Itokawa and collect samples. It returned the samples to Earth in 2010.[233]
2019 – Closest approach of New Horizons to
Arrokoth, a KBO farther than Pluto.[249]
2019 –
2I/Borisov, the first interstellar comet and second interstellar object, is discovered.[250]
2022 – The Double Asteroid Redirection Test (DART) spacecraft mission intentionally crashed into
Dimorphos, the
minor-planet moon of the asteroid
Didymos, deviating (slightly) the orbit of a Solar System body for the first time ever.[251] While DART hosted no scientific payload, its camera took closeup photos of the two objects, and a secondary spacecraft, the
LICIACube, also gathered related scientific data.[252]
The number of currently known, or observed, objects of the Solar System are in the hundreds of thousands. Many of them are listed in the following articles:
^A. Aaboe; J. P. Britton; J. A. Henderson;
Otto Neugebauer; A. J. Sachs (1991). "Saros Cycle Dates and Related Babylonian Astronomical Texts". Transactions of the American Philosophical Society. 81 (6).
American Philosophical Society: 1–75.
doi:
10.2307/1006543.
JSTOR1006543. One comprises what we have called "Saros Cycle Texts," which give the months of eclipse possibilities arranged in consistent cycles of 223 months (or 18 years).
^Wilkinson, Endymion (2012). Chinese History: A New Manual. Harvard-Yenching Institute Monograph Series 84. Harvard-Yenching Institute; Harvard University Asia Center. p. 612.
ISBN978-0-674-06715-8.
^"A column of stone",
Aetius reports in De Fide (III, 7, 1), or "similar to a pillar-shaped stone", pseudo-Plutarch (III, 10).
^Most of Anaximander's model of the Universe comes from pseudo-Plutarch (II, 20–28):
"[The Sun] is a circle twenty-eight times as big as the Earth, with the outline similar to that of a fire-filled chariot wheel, on which appears a mouth in certain places and through which it exposes its fire, as through the hole on a flute. [...] the Sun is equal to the Earth, but the circle on which it breathes and on which it's borne is twenty-seven times as big as the whole earth. [...] [The eclipse] is when the mouth from which comes the fire heat is closed. [...] [The Moon] is a circle nineteen times as big as the whole earth, all filled with fire, like that of the Sun".
^Thurston, Hugh (1994). Early astronomy. New York: Springer-Verlag New York. p. 111.
ISBN0-387-94107-X.
^Dreyer, John Louis Emil (1906).
History of the planetary systems from Thales to Kepler. p. 42. To complete the number ten, Philolaus created the antichthon, or counter-earth. This tenth planet is always invisible to us, because it is between us and the central fire and always keeps pace with the Earth.
^Pedersen, Olaf (1993). Early physics and astronomy. A historical introduction. Cambridge (UK): Cambridge University Press.
ISBN0-521-40340-5.
^"Eudoxus of Cnidus." Complete Dictionary of Scientific Biography. Vol. 4. Detroit: Charles Scribner's Sons, 2008. 465–467. Gale Virtual Reference Library. Web. 2 June 2014.
^Ansari, S.M.R. (March 1977). "Aryabhata I, His Life and His Contributions". Bulletin of the Astronomical Society of India. 5 (1): 10–18.
Bibcode:
1977BASI....5...10A.
hdl:
2248/502.
^Stephenson, F. Richard (24 March 2008). Historical Eclipses and Earth's Rotation. Cambridge University Press. pp. 45, 457, 491–493.
ISBN978-0-521-05633-5.
^Lewis, Neil (2021),
"Robert Grosseteste", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Fall 2021 ed.), Metaphysics Research Lab, Stanford University, retrieved 5 November 2022
^"Alfonsine tables". Enciclopedia Columbia. Columbia University Press. 2018. a revision and improvement of the Ptolemaic tables and were compiled at Toledo, Spain, by about 50 astronomers assembled for the purpose by Alfonso X of Castile
^Owen Gingerich, Gutenberg's Gift pp. 319–28 in Library and information services in astronomy V (Astron. Soc. Pacific Conference Series vol. 377, 2007).
^Swerdlow, Noel M. (31 December 1973). "The Derivation and First Draft of Copernicus's Planetary Theory: A Translation of the Commentariolus with Commentary". Proceedings of the American Philosophical Society. 117 (6): 424.
Bibcode:
1973PAPhS.117..423S.
ISSN0003-049X.
JSTOR986461.
^Abbud, Fuad (1962). "The Planetary Theory of Ibn al-Shatir: Reduction of the Geometric Models to Numerical Tables". The University of Chicago Press. 53: 492–499 – via JSTOR.
^Kirschner, Stefan (2021),
"Nicole Oresme", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Fall 2021 ed.), Metaphysics Research Lab, Stanford University, retrieved 5 November 2022
^R. Lang, Kenneth; Charles Allen Whitney (1991). Wanderers in Space. CUP Archive. p. 240.
ISBN978-0-521-42252-9.
^Dershowitz, D.; Reingold, E. M (2008). Calendrical Calculations (3rd ed.). Cambridge University Press. p. 45. The calendar in use today in most of the world is the Gregorian or new-style calendar designed by a commission assembled by Pope Gregory XIII in the sixteenth century
^Bruno, Giordano.
"Third Dialogue". On the infinite universe and worlds. Archived from
the original on 27 April 2012.
^Astronomia nova Aitiologitis, seu Physica Coelestis tradita Commentariis de Motibus stellae Martis ex observationibus G.V. Tychnonis.Prague 1609; Engl. tr. W.H. Donahue, Cambridge 1992.
^King, C. C. (2003). The History of the Telescope. Dover Publications. pp. 30–32.
ISBN978-0-486-43265-6.
^Edgerton, Samuel Y. (2009). The Mirror, the Window, and the Telescope: How Renaissance Linear Perspective Changed Our Vision of the Universe. Cornell University Press. pp. 155–159.
ISBN978-0-8014-7480-4.
^Drake, S. (1978). Galileo at Work. University of Chicago Press. p. 152.
ISBN978-0-226-16226-3.
^Cain, Fraser (3 July 2008).
"History of Saturn". Universe Today. Retrieved 5 October 2020.
^
abBergeron, Jacqueline, ed. (2013). Highlights of Astronomy: As Presented at the XXIst General Assembly of the IAU, 1991. Springer Science & Business Media. p. 521.
ISBN978-94-011-2828-5.
^Stephen Pumfrey (15 April 2009). "Harriot's maps of the Moon: new interpretations". Notes and Records of the Royal Society. 63 (2): 163–168.
doi:
10.1098/rsnr.2008.0062.
S2CID73077683.
^Cassini, Gian Domenico (Jean-Dominique) (Cassini I) (2008). Complete Dictionary of Scientific Biography. Detroit: Charles Scribner's Sons. pp. 100–104.
^Wolf, Abraham (1939). History of Science, Technology, and Philosophy in the Eighteenth Century. New York: Macmillan. p. 232.
^Woolfson, M.M. (1993). "Solar System – its origin and evolution". Q. J. R. Astron. Soc. 34: 1–20.
Bibcode:
1993QJRAS..34....1W. For details of Kant's position, see Stephen Palmquist, "Kant's Cosmogony Re-Evaluated", Studies in History and Philosophy of Science 18:3 (September 1987), pp.255–269.
^Hoffmann, Christian Gotthold (1759 January 20) "Nachricht von dem Kometen, welcher seit dem 25. December gesehen wird" (News of the comet, which has been seen since the 25th of December), Dreßdnischen Gelehrten Anzeigen, 2nd issue.
^Dreyer, J. L. E. (1912). The Scientific Papers of Sir William Herschel. Vol. 1. Royal Society and Royal Astronomical Society. p. 100.
ISBN978-1-84371-022-6.
^Cunningham, Clifford (1984). "William Herschel and the First Two Asteroids". The Minor Planet Bulletin. 11. Dance Hall Observatory, Ontario: 3.
Bibcode:
1984MPBu...11....3C.
^Lynn, W. T. (February 1907). "The discovery of Vesta". The Observatory. 30: 103–105.
Bibcode:
1907Obs....30..103L.
^Alexander, A. F. O'D. (1970). Charles Coulston Gillespie (ed.). Dictionary of Scientific Biography. Vol. 2. New York: Charles Scribner's Sons. pp. 359–360. Bouvard, Alexis
^
abcKollerstrom, N. (2001).
"A Neptune Discovery Chronology". The British Case for Co-prediction. University College London. Archived from
the original on 19 November 2005. Retrieved 23 August 2007.
^"
Kirchhoff, Gustav Robert". Encyclopædia Britannica (11th ed.). 1911. [...] to him belongs the merit of having [...] enunciated a complete account of its theory, and of thus having firmly established it as a means by which the chemical constituents of celestial bodies can be discovered through the comparison of their spectra with those of the various elements that exist on this earth.
^Pohle, J. (1913). "Angelo Secchi" . In Herbermann, Charles (ed.). Catholic Encyclopedia. New York: Robert Appleton Company. [...][his] theory of the unity of the world and of the identity of the fixed stars and the sun received most profound scientific demonstration and confirmation.
^Thomson, William (3 August 1871).
"Inaugural Address of Sir William Thomson". Nature. 4 (92): 261–278 [268].
Bibcode:
1871Natur...4..261..
doi:
10.1038/004261a0.
PMC2070380. Frankland and Lockyer find the yellow prominences to give a very decided bright line not far from D, but hitherto not identified with any terrestrial flame. It seems to indicate a new substance, which they propose to call Helium
^Barnard, E. E. (12 October 1892). "Discovery and observations of a fifth satellite to Jupiter". The Astronomical Journal. 12 (11): 81–85.
Bibcode:
1892AJ.....12...81B.
doi:
10.1086/101715.
^Kidger, Mark (2005). Astronomical Enigmas: Life on Mars, the Star of Bethlehem, and Other Milky Way Mysteries. p. 110.
ISBN0801880262.
^England, P.; Molnar, P.; Righter, F. (January 2007). "John Perry's neglected critique of Kelvin's age for the Earth: A missed opportunity in geodynamics". GSA Today. Vol. 17, no. 1. pp. 4–9.
doi:
10.1130/GSAT01701A.1.
^Braile, L. W.; Chiangl, C. S. (1986), Barazangi, Muawia; Brown, Larry (eds.), "The continental Mohorovičič Discontinuity: Results from near-vertical and wide-angle seismic reflection studies", Geodynamics Series, vol. 13, American Geophysical Union, pp. 257–272,
doi:
10.1029/gd013p0257,
ISBN978-0-87590-513-6
^Tombaugh, Clyde W. (1946). "The Search for the Ninth Planet, Pluto". Astronomical Society of the Pacific Leaflets. 5 (209): 73–80.
Bibcode:
1946ASPL....5...73T.
^Jones, Eric M., ed. (1995).
"The First Lunar Landing". Apollo 11 Lunar Surface Journal. NASA. Archived from
the original on 27 December 2016. Retrieved 13 June 2013.
^Kowal, Charles T.; Liller, William; Marsden, Brian G. (December 1978). "The discovery and orbit of /2060/ Chiron". In: Dynamics of the Solar System; Proceedings of the Symposium, Tokyo, Japan, May 23–26, 1978. 81: 245–250.
Bibcode:
1979IAUS...81..245K.
^Littmann, Mark (1990). Planets Beyond: Discovering the Outer Solar System. pp. 173–177, including the essay "A Moment of Perception" by James W. Christy.
^"Pioneer Venus 1". Solar System Exploration. NASA. Archived from
the original on 4 October 2006. Retrieved 16 August 2013.
^Richard O. Fimmel (1980). Pioneer: First to Jupiter, Saturn, and beyond. NASA (SP-446).
^
abcNational Aeronautics and Space Administration
"Voyager 2" NASA Science: Solar System Exploration. Updated January 26, 2018. Accessed December 12, 2018.
^Pablo Santos Sanz (26 September 2008).
"La historia de Ataecina vs Haumea" (in Spanish). infoastro.com.
Archived from the original on 29 September 2008. Retrieved 29 September 2008.
^Green, Jim; Stern, S. Alan (12 December 2017).
New Horizons Kuiper Belt Extended Mission(PDF). 2017 AGU Fall Meeting. Applied Physics Laboratory. pp. 12–15. Archived from
the original(PDF) on 26 December 2018. Retrieved 26 December 2018.