History of Mars observation

Source: Wikipedia, the free encyclopedia.

Hubble's sharpest view of Mars: Although the ACS “Fastie finger” intrudes, it achieved a spatial scale of 5 miles, or 8 kilometres per pixel at full resolution.

The history of Mars observation is about the recorded history of observation of the planet

astronomers developed a geocentric model to explain the planet's motions. Measurements of Mars' angular diameter can be found in ancient Greek and Indian texts. In the 16th century, Nicolaus Copernicus proposed a heliocentric model for the Solar System in which the planets follow circular orbits about the Sun. This was revised by Johannes Kepler, yielding an elliptic orbit
for Mars that more accurately fitted the observational data.

The first

opposition
to the Sun, at which points Mars made its closest approaches to the Earth. Better telescopes developed early in the 19th century allowed permanent Martian
spectroscopic signature of water in the Martian atmosphere, the idea of life on Mars became popularized among the public. Percival Lowell believed he could see a network of artificial canals on Mars.[1] These linear features later proved to be an optical illusion, and the atmosphere was found to be too thin to support an Earth-like environment
.

Yellow clouds on Mars have been observed since the 1870s, which

originated on Mars
has allowed laboratory examination of the chemical conditions on the planet.

Earliest records

At left are two concentric circles around a disk. Lines from the circles are projected on a star chart at right, demonstrating the S-shaped motion of Mars
As Earth passes Mars, the latter planet will temporarily appear to reverse its motion across the sky.

The existence of Mars as a wandering object in the night sky was recorded by ancient Egyptian astronomers. By the 2nd millennium BCE they were familiar with the apparent retrograde motion of the planet, in which it appears to move in the opposite direction across the sky from its normal progression.[2] Mars was portrayed on the ceiling of the tomb of Seti I, on the Ramesseum ceiling,[3] and in the Senenmut star map. The last is the oldest known star map, being dated to 1534 BCE based on the position of the planets.[2]

By the period of the

synodic periods, or 42 circuits of the zodiac, every 79 years. The Babylonians invented arithmetic methods for making minor corrections to the predicted positions of the planets. This technique was primarily derived from timing measurements—such as when Mars rose above the horizon, rather than from the less accurately known position of the planet on the celestial sphere.[4][5]

Chinese records of the appearances and motions of Mars appear before the founding of the Zhou dynasty (1045 BCE), and by the Qin dynasty (221 BCE) astronomers maintained close records of planetary conjunctions, including those of Mars. Occultations of Mars by Venus were noted in 368, 375, and 405 CE.[6] The period and motion of the planet's orbit was known in detail during the Tang dynasty (618 CE).[7][8][9]

The early

astronomy of ancient Greece was influenced by knowledge transmitted from the Mesopotamian culture. Thus, the Babylonians associated Mars with Nergal, their god of war and pestilence, and the Greeks connected the planet with their god of war, Ares.[10] During this period, the motions of the planets were of little interest to the Greeks; Hesiod's Works and Days (c. 650 BCE) makes no mention of the planets.[11]

Orbital models

A series of concentric circles surround a fanciful representation of the Earth at center. Latin words and astrological symbols lie around the perimeter.
Geocentric model of the Universe.

The Greeks used the word planēton to refer to the seven celestial bodies that moved with respect to the background stars and they held a

The Republic (X.616E–617B), the Greek philosopher Plato provided the oldest known statement defining the order of the planets in Greek astronomical tradition. His list, in order of the nearest to the most distant from the Earth, was as follows: the Moon, Sun, Venus, Mercury, Mars, Jupiter, Saturn, and the fixed stars. In his dialogue Timaeus, Plato proposed that the progression of these objects across the skies depended on their distance, so that the most distant object moved the slowest.[12]

Aristotle, a student of Plato, observed an occultation of Mars by the Moon on 4 May 357 BCE.[13] From this he concluded that Mars must lie further from the Earth than the Moon. He noted that other such occultations of stars and planets had been observed by the Egyptians and Babylonians.[14][15][16] Aristotle used this observational evidence to support the Greek sequencing of the planets.[17] His work De Caelo presented a model of the universe in which the Sun, Moon, and planets circle about the Earth at fixed distances. A more sophisticated version of the geocentric model was developed by the Greek astronomer Hipparchus when he proposed that Mars moved along a circular track called the epicycle that, in turn, orbited about the Earth along a larger circle called the deferent.[18][19]

In

Claudius Ptolemaeus (Ptolemy) attempted to address the problem of the orbital motion of Mars. Observations of Mars had shown that the planet appeared to move 40% faster on one side of its orbit than the other, in conflict with the Aristotelian model of uniform motion. Ptolemy modified the model of planetary motion by adding a point offset from the center of the planet's circular orbit about which the planet moves at a uniform rate of rotation. He proposed that the order of the planets, by increasing distance, was: the Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn, and the fixed stars.[20] Ptolemy's model and his collective work on astronomy was presented in the multi-volume collection Almagest, which became the authoritative treatise on Western astronomy for the next fourteen centuries.[19]

In the 5th century CE, the

arc-minutes (1/30 of a degree) and its distance to Earth as 10,433,000 km (1,296,600 yojana, where one yojana is equivalent to eight km in the Surya Siddhanta). From this the diameter of Mars is deduced to be 6,070 km (754.4 yojana), which has an error within 11% of the currently accepted value of 6,788 km. However, this estimate was based upon an inaccurate guess of the planet's angular size. The result may have been influenced by the work of Ptolemy, who listed a value of 1.57 arc-minutes. Both estimates are significantly larger than the value later obtained by telescope.[21]

Astronomia Nova
(1609)
Modern opposition computations
These charts show the direction and distance of Mars relative to the Earth at the center, with oppositions and apparent retrograde motion approximately every 2 years and closest oppositions every 15–17 years due to Mars' eccentric orbit.

In 1543, Nicolaus Copernicus published a heliocentric model in his work De revolutionibus orbium coelestium. This approach placed the Earth in an orbit around the Sun between the circular orbits of Venus and Mars. His model successfully explained why the planets Mars, Jupiter and Saturn were on the opposite side of the sky from the Sun whenever they were in the middle of their retrograde motions. Copernicus was able to sort the planets into their correct heliocentric order based solely on the period of their orbits about the Sun.[22] His theory gradually gained acceptance among European astronomers, particularly after the publication of the Prutenic Tables by the German astronomer Erasmus Reinhold in 1551, which were computed using the Copernican model.[23]

On October 13, 1590, the German astronomer Michael Maestlin observed an occultation of Mars by Venus.[24] One of his students, Johannes Kepler, quickly became an adherent to the Copernican system. After the completion of his education, Kepler became an assistant to the Danish nobleman and astronomer, Tycho Brahe. With access granted to Tycho's detailed observations of Mars, Kepler was set to work mathematically assembling a replacement to the Prutenic Tables. After repeatedly failing to fit the motion of Mars into a circular orbit as required under Copernicanism, he succeeded in matching Tycho's observations by assuming the orbit was an ellipse and the Sun was located at one of the foci. His model became the basis for Kepler's laws of planetary motion, which were published in his multi-volume work Epitome Astronomiae Copernicanae (Epitome of Copernican Astronomy) between 1615 and 1621.[25]

Early telescope observations

At its closest approach, the

naked eye to resolve. Hence, prior to the invention of the telescope, nothing was known about the planet besides its red hue and its position on the sky.[26] The Italian scientist Galileo Galilei was the first person known to use a telescope to make astronomical observations. His records indicate that he began observing Mars through a telescope in September 1610.[27] This instrument was too primitive to display any surface detail on the planet,[28] so he set the goal of seeing if Mars exhibited phases of partial darkness similar to Venus or the Moon. Although uncertain of his success, by December he did note that Mars had shrunk in angular size.[27] Polish astronomer Johannes Hevelius succeeded in observing a phase of Mars in 1645.[29]

An orange disk with a darker region at center and darker bands in the upper and lower halves. A white patch at the top is an ice cap, and fuzzy white regions at the bottom and the right side of the disk are cloud formations.
The low albedo feature Syrtis Major is visible at the disk center. NASA/HST image.

In 1644, the Italian Jesuit

oppositions of 1651, 1653 and 1655, when the planet made its closest approaches to the Earth, the Italian astronomer Giovanni Battista Riccioli and his student Francesco Maria Grimaldi noted patches of differing reflectivity on Mars.[28] The first person to draw a map of Mars that displayed terrain features was the Dutch astronomer Christiaan Huygens. On November 28, 1659, he made an illustration of Mars that showed the distinct dark region now known as Syrtis Major Planum, and possibly one of the polar ice caps.[30] The same year, he succeeded in measuring the rotation period of the planet, giving it as approximately 24 hours.[29] He made a rough estimate of the diameter of Mars, guessing that it is about 60% of the size of the Earth, which compares well with the modern value of 53%.[31] Perhaps the first definitive mention of Mars's southern polar ice cap was by the Italian astronomer Giovanni Domenico Cassini, in 1666. That same year, he used observations of the surface markings on Mars to determine a rotation period of 24h 40m. This differs from the currently-accepted value by less than three minutes. In 1672, Huygens noticed a fuzzy white cap at the north pole.[32]

After Cassini became the first director of the

perihelic opposition), which made this a particularly close approach to the Earth. Cassini and Jean Picard determined the position of Mars from Paris, while the French astronomer Jean Richer made measurements from Cayenne, South America. Although these observations were hampered by the quality of the instruments, the parallax computed by Cassini came within 10% of the correct value.[33][34] The English astronomer John Flamsteed made comparable measurement attempts and had similar results.[35]

In 1704, Italian astronomer

Jacques Philippe Maraldi "made a systematic study of the southern cap and observed that it underwent" variations as the planet rotated. This indicated that the cap was not centered on the pole. He observed that the size of the cap varied over time.[28][36] The German-born British astronomer Sir William Herschel began making observations of the planet Mars in 1777, particularly of the planet's polar caps. In 1781, he noted that the south cap appeared "extremely large", which he ascribed to that pole being in darkness for the past twelve months. By 1784, the southern cap appeared much smaller, thereby suggesting that the caps vary with the planet's seasons and thus were made of ice. In 1781, he estimated the rotation period of Mars as 24h 39m 21.67s and measured the axial tilt of the planet's poles to the orbital plane as 28.5°. He noted that Mars had a "considerable but moderate atmosphere, so that its inhabitants probably enjoy a situation in many respects similar to ours".[36][37][38][39] Between 1796 and 1809, the French astronomer Honoré Flaugergues noticed obscurations of Mars, suggesting "ochre-colored veils" covered the surface. This may be the earliest report of yellow clouds or storms on Mars.[40][41]

Geographical period

At the start of the 19th century, improvements in the size and quality of telescope optics proved a significant advance in observation capability. Most notable among these enhancements was the two-component

Johann Heinrich Mädler and Wilhelm Beer used a 95 mm (3.7 in) Fraunhofer refracting telescope to launch an extensive study of the planet. They chose a feature located 8° south of the equator as their point of reference. (This was later named the Sinus Meridiani, and it would become the zero meridian of Mars.) During their observations, they established that most of Mars' surface features were permanent, and more precisely determined the planet's rotation period. In 1840, Mädler combined ten years of observations to draw the first map of Mars. Rather than giving names to the various markings, Beer and Mädler simply designated them with letters; thus Meridian Bay (Sinus Meridiani) was feature "a".[29][43][44]

Working at the

J. Norman Lockyer in 1862, and it has been viewed by other observers.[45] During the 1862 opposition, Dutch astronomer Frederik Kaiser produced drawings of Mars. By comparing his illustrations to those of Huygens and the English natural philosopher Robert Hooke, he was able to further refine the rotation period of Mars. His value of 24h 37m 22.6s is accurate to within a tenth of a second.[43][46]

A rectangular grid overlays meandering patterns of light and dark. Selected regions are labelled with names.
A later version of Proctor's map of Mars, published in 1905
A shaded drawing of Martian albedo features is shown in a horizontal sequence of sinusoidal projections. The map is marked up with named features.
1892 atlas of Mars by the Belgian astronomer Louis Niesten

Father Secchi produced some of the first color illustrations of Mars in 1863. He used the names of famous explorers for the distinct features. In 1869, he observed two dark linear features on the surface that he referred to as canali, which is Italian for 'channels' or 'grooves'.

William R. Dawes. Proctor named the various lighter or darker features after astronomers, past and present, who had contributed to the observations of Mars. During the same decade, comparable maps and nomenclature were produced by the French astronomer Camille Flammarion and the English astronomer Nathan Green.[49]

At the

Edward W. Maunder in 1875, but would later come into question.[51] In 1882, an article appeared in Scientific American discussing snow on the polar regions of Mars and speculation on the probability of ocean currents.[52]

A particularly favorable perihelic opposition occurred in 1877. The English astronomer

arcseconds.[53] Using this result, he was able to more accurately determine the distance of the Earth from the Sun, based upon the relative size of the orbits of Mars and the Earth.[54] He noted that the edge of the disk of Mars appeared fuzzy because of its atmosphere, which limited the precision he could obtain for the planet's position.[55]

In August 1877, the American astronomer

U.S. Naval Observatory.[56] The names of the two satellites, Phobos and Deimos, were chosen by Hall based upon a suggestion by Henry Madan, a science instructor at Eton College in England.[57]

Martian canals

Main article: Martian canals
A cylindrical projection map of mars showing light and dark regions accompanied by various linear features. The major features are labelled.
Map of Mars by Giovanni Schiaparelli, compiled between 1877 and 1886, showing canali features as fine lines
Two disks show darker patches connected by linear features.
Mars sketched as observed by Lowell sometime before 1914. (South top)

During the 1877 opposition, Italian astronomer

Edward Maunder became convinced that the linear features were merely the summation of many smaller details.[60]

In his 1892 work La planète Mars et ses conditions d'habitabilité, Camille Flammarion wrote about how these channels resembled man-made canals, which an intelligent race could use to redistribute water across a dying Martian world. He advocated for the existence of such inhabitants, and suggested they may be more advanced than humans.[61]

Influenced by the observations of Schiaparelli,

Henri Joseph Perrotin and Louis Thollon using a 38 cm (15 in) refractor at the Nice Observatory in France, one of the largest telescopes of that time.[63][64]

Beginning in 1901, American astronomer

Eugène M. Antoniadi, English naturalist Alfred Russel Wallace and others as merely imagined features.[60][66] As bigger telescopes were used, fewer long, straight canali were observed. During an observation in 1909 by Flammarion with an 84 cm (33 in) telescope, irregular patterns were observed, but no canali were seen.[67]

Starting in 1909 Eugène Antoniadi was able to help disprove the theory of Martian canali by viewing through the great refractor of Meudon, the Grande Lunette (83 cm lens).[68] A trifecta of observational factors synergize; viewing through the third largest refractor in the World, Mars was at opposition, and exceptional clear weather.[68] The canali dissolved before Antoniadi's eyes into various "spots and blotches" on the surface of Mars.[68]

Refining planetary parameters

Two orange-hued disks. The one at left shows distinct darker regions along with cloudy areas near the top and bottom. In the right image, features are obscured by an orange haze. An white ice cap is visible at the bottom of both disks.
In the left image, thin Martian clouds are visible near the polar regions.[69] At right, the surface of Mars is obscured by a dust storm. NASA/HST images

Surface obscuration caused by yellow clouds had been noted in the 1870s when they were observed by Schiaparelli. Evidence for such clouds was observed during the oppositions of 1892 and 1907. In 1909, Antoniadi noted that the presence of yellow clouds was associated with the obscuration of albedo features. He discovered that Mars appeared more yellow during oppositions when the planet was closest to the Sun and was receiving more energy. He suggested windblown sand or dust as the cause of the clouds.[70][71]

In 1894, American astronomer

Walter S. Adams in 1925.[73]

Edgar W. Woolard in 1944.[75]

Using a vacuum

radiated energy measurements of Mars were made by American physicist William Coblentz and American astronomer Carl Otto Lampland. The results showed that the night time temperature on Mars dropped to −85 °C (−121 °F), indicating an "enormous diurnal fluctuation" in temperatures.[77] The temperature of Martian clouds was measured as −30 °C (−22 °F).[78] In 1926, by measuring spectral lines that were redshifted by the orbital motions of Mars and Earth, American astronomer Walter Sydney Adams was able to directly measure the amount of oxygen and water vapor in the atmosphere of Mars. He determined that "extreme desert conditions" were prevalent on Mars.[79] In 1934, Adams and American astronomer Theodore Dunham Jr. found that the amount of oxygen in the atmosphere of Mars was less than one percent of the amount over a comparable area on Earth.[80]

In 1927, Dutch graduate student Cyprianus Annius van den Bosch made a determination of the mass of Mars based upon the motions of the Martian moons, with an accuracy of 0.2%. This result was confirmed by the Dutch astronomer

inner Solar System, from the planet's gravitational perturbations of the asteroid. His estimated margin of error was 0.05%,[82] but subsequent checks suggested his result was poorly determined compared to other methods.[83]

During the 1920s, French astronomer

Seymour L. Hess determined that the formation of the thin Martian clouds would only require 4 mm (0.16 in) of water precipitation and a vapor pressure of 0.1 kPa (1.0 mbar).[78]

The first standard nomenclature for Martian albedo features was introduced by the International Astronomical Union (IAU) when in 1960 they adopted 128 names from the 1929 map of Antoniadi named La Planète Mars. The Working Group for Planetary System Nomenclature (WGPSN) was established by the IAU in 1973 to standardize the naming scheme for Mars and other bodies.[86]

Remote sensing

A rough-hewn rock with a yellowish sheen.
Photograph of the Martian meteorite ALH84001

The International Planetary Patrol Program was formed in 1969 as a consortium to continually monitor planetary changes. This worldwide group focused on observing dust storms on Mars. Their images allow Martian seasonal patterns to be studied globally, and they showed that most Martian dust storms occur when the planet is closest to the Sun.[87]

Since the 1960s, robotic

submillimeter observation of the atmospheric composition,[89][90] and radio measurements of wind velocities.[91]

The Hubble Space Telescope (HST) has been used to perform systematic studies of Mars[92] and has taken the highest resolution images of Mars ever captured from Earth.[93] This telescope can produce useful images of the planet when it is at an angular distance of at least 50° from the Sun. The HST can take images of a hemisphere, which yields views of entire weather systems. Earth-based telescopes equipped with charge-coupled devices can produce useful images of Mars, allowing for regular monitoring of the planet's weather during oppositions.[94]

X-ray emission from Mars was first observed by astronomers in 2001 using the Chandra X-ray Observatory, and in 2003 it was shown to have two components. The first component is caused by X-rays from the Sun scattering off the upper Martian atmosphere; the second comes from interactions between ions that result in an exchange of charges.[95] The emission from the latter source has been observed out to eight times the radius of Mars by the XMM-Newton orbiting observatory.[96]

In 1983, the analysis of the

originated on Mars.[97] The Allan Hills 84001 meteorite, discovered in Antarctica in 1984, is believed to have originated on Mars but it has an entirely different composition than the SNC group. In 1996, it was announced that this meteorite might contain evidence for microscopic fossils of Martian bacteria. However, this finding remains controversial.[98] Chemical analysis of the Martian meteorites found on Earth suggests that the ambient near-surface temperature of Mars has most likely been below the freezing point of water (0 °C) for much of the last four billion years.[99]

Observations

Mars during the 1999 opposition as seen by space telescope
Mars at its 2018 opposition, with its atmosphere clouded by a global dust storm that snuffed out the solar-powered Opportunity rover
The James Webb Space Telescope captured its first images and spectra of Mars on 5 September 2022. [100]

See also

References

  1. New York Times
    . Retrieved October 1, 2015.
  2. ^
    Bibcode:2008POBeo..85...19N
    .
  3. ISBN 0-87169-214-7
    .
  4. ISBN 978-0-226-59441-5
    .
  5. ISBN 0-691-01196-6
    .
  6. S2CID 124343759
    . in particular, see table 1.
  7. S2CID 124343759
    .
  8. Bibcode:1988ncsu.work...40C
    .
  9. S2CID 115908222
    .
  10. ^ Valery, Franz; Cumont, Marie (1912). Astrology and religion among the Greeks and Romans. G. P. Putnam. p. 46. {{cite book}}: |work= ignored (help)
  11. ISBN 0-19-509539-1
    .
  12. ISBN 0-88706-733-6
    .
  13. doi:10.5479/si.00810231.2-13.377
    . Retrieved 2019-12-05.
  14. ISBN 0-521-55619-8
    .
  15. ISBN 0-521-78981-8
    .
  16. ^ In China, astronomers recorded an occultation of Mars by the Moon in 69 BCE. See Price (2000:148).
  17. ISBN 978-1-4020-8322-8. {{cite book}}: |work= ignored (help
    )
  18. ISBN 0-201-48992-9
    .
  19. ^
    ISBN 0-87784-500-X
    .
  20. ISBN 0-521-82750-7
    .
  21. CiteSeerX 10.1.1.511.7416
    .
  22. ISBN 0-19-516173-4. {{cite book}}: |work= ignored (help
    )
  23. ^ Zalta, Edward N., ed. (April 18, 2005). "Nicolaus Copernicus". Stanford Encyclopedia of Philosophy. Retrieved 2010-01-09.
  24. Bibcode:1979S&T....57..220A
    .
  25. ISBN 0-521-52878-X
    .
  26. ISBN 1-55297-802-8
    .
  27. ^
    S2CID 118187803
    .
  28. ^
    ISBN 0-387-26020-X
    .
  29. ^
    Bibcode:1984JBAA...94...45M
    .
  30. ^ Sheehan, William (1996). "Chapter 2: pioneers". The Planet Mars: A History of Observation and Discovery. University of Arizona. Retrieved 2010-01-16.
  31. ISBN 0-06-053595-4
    .
  32. ISBN 0-275-98719-1
    .
  33. ISBN 0-7167-3711-6
    .
  34. S2CID 122684047
    .
  35. ISBN 0-521-54205-7. {{cite book}}: |work= ignored (help
    )
  36. ^
    Bibcode:1954IrAJ....3...37F
    .
  37. Bibcode:1919hers.book.....M
    .
  38. Bibcode:1930PA.....38..263P
    . In particular, see p. 272 for Herschel's value for the axial tilt.
  39. ISBN 978-0-387-76507-5
    .
  40. Bibcode:1971LowOB...7..211C
    .
  41. ^ Sheehan, William (1996). "Chapter 3: a situation similar to ours". The Planet Mars: A History of Observation and Discovery. University of Arizona. Archived from the original on 2010-06-25. Retrieved 2010-01-16.
  42. ISBN 0-262-10084-3. {{cite book}}: |work= ignored (help
    )
  43. ^ a b c Sheehan, William (1996). "Chapter 4: Areographers". The planet Mars: a history of observation and discovery. University of Arizona. Retrieved 2010-05-03.
  44. ISBN 0-312-42261-X
    .
  45. Bibcode:1990JALPO..34...62P
    .
  46. doi:10.1093/mnras/33.9.552
    .
  47. ISBN 0-521-63280-3
    .
  48. Bibcode:1960ASPL....8..135A
    .
  49. ^
    ISBN 978-0-521-03373-2
    .
  50. ISBN 0-486-65994-1. {{cite book}}: |work= ignored (help
    )
  51. ISBN 0-387-26020-X
    .
  52. ^ Scientific American. Munn & Company. 1882-01-14. p. 22.
  53. ISBN 0-412-06951-2
    .
  54. Bibcode:1943MNSSA...2...85.
  55. ISBN 1-85233-106-2
    .
  56. S2CID 125660605
    .
  57. doi:10.1039/CT9028100625
    .
  58. ISBN 978-0-387-73154-4
    .
  59. ISBN 0-394-50294-9
    .
  60. ^
    Bibcode:1913PA.....21..416A
    .
  61. ISBN 0-521-81306-9
    .
  62. ISBN 0-19-517181-0
    .
  63. S2CID 33079760
    .
  64. S2CID 128159166
    .
  65. doi:10.1086/123058
    .
  66. ^ Wallace, Alfred Russel (1907). Is Mars habitable?: a critical examination of Professor Percival Lowell's book "Mars and its canals," with an alternative explanation. Macmillan. pp. 102–110.
  67. S2CID 22725986
    .
  68. ^
    ISBN 9788847028296
    .
  69. ^ "Hubble captures best view of Mars ever obtained from Earth". NASA. June 26, 2001. Archived from the original on July 24, 2011. Retrieved 2010-01-28.
  70. Bibcode:1996JBAA..106..185M
    .
  71. Bibcode:1993JBAA..103..219M
    .
  72. S2CID 30423117
    .
  73. Bibcode:1977QJRAS..18...37D
    .
  74. doi:10.1002/asna.18951381402
    .
  75. doi:10.1086/105793
    .
  76. JSTOR 40693334
    . Note: there is an error in table II where the temperatures are listed in °C but are clearly intended to be in kelvins.
  77. doi:10.1086/142965
    .
  78. ^
    doi:10.1086/126074
    .
  79. doi:10.1086/142958
    .
  80. doi:10.1086/143538
    .
  81. Bibcode:1965IAUS...21..139K
    .
  82. doi:10.1086/106364
    .
  83. doi:10.1086/110351
    .
  84. Bibcode:1929PhDT.........9L.
    An English translation is available as NASA TT F-187: Research on the polarization of light from planets and from some terrestrial substances at the NASA Technical Reports
    site.
  85. ^ Horowitz, Norman H. (March 1986). "Mars: myth & reality" (PDF). Engineering & Science. Caltech University. Retrieved 2010-01-22.
  86. ISBN 0-412-06951-2
    .
  87. ISBN 0-521-35962-7. {{cite book}}: |work= ignored (help
    )
  88. Bibcode:1988BAAS...20R.848B
    .
  89. S2CID 5547396
    .
  90. S2CID 122387978
    .
  91. doi:10.1086/170797
    .
  92. Bibcode:1997DPS....29.0410C
    .
  93. ^ Bell, J.; et al. (July 5, 2001). "Hubble captures best view of mars ever obtained From Earth". HubbleSite. NASA. Retrieved 2010-02-27.
  94. Bibcode:1993DPS....25.1105J
    .
  95. S2CID 119507734
    .
  96. doi:10.1051/0004-6361:20054253
    .
  97. doi:10.1016/S0032-0633(00)00105-7
    .
  98. doi:10.1016/j.gca.2009.05.064
    .
  99. S2CID 26314661
    .
  100. ^ "Mars Is Mighty in First Webb Observations of Red Planet". October 20, 2023.

External links

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