Venus

planet second-closest to the Sun in the Solar System
For the Roman goddess, see Venus (mythology).

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It has no natural satellite. It is named after the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows. Because Venus is an inferior planet from Earth, it never appears to venture far from the Sun: its elongation reaches a maximum of 47.8°.

Venus is earth’s “evil twin”. It’s about the same size as earth, but with deadly heat and pressure, an unbreathable atmosphere, and highly acid rain. ~ Stephen P. Maran
CONTENT : A - F , G - L , M - R , S - Z , See also , External links

Quotes

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A - F

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Thou fair-hair’d angel of the evening. ~ William Blake
  • [In 1958] some astronomers thought that Venus might have a rotation period near the 24-hour mark, as Earth and Mars do. In that case, the microwave emission might be quite copious even from the dark side, since that would have been exposed to the Sun a few hours before. In that case, microwave emission might indicate a roughly Earthlike temperature, since the fact that Venus is closer to the Sun might be balanced by the fact that its cloud layer reflects most of the sunlight it receives.
    Well, [Cornell] Mayer did detect the microwave radiation from Venus and he did not get either expected alternative. He did not get a very low temperature of a dark side that never sees the Sun, nor did he get an Earthlike temperature, nor, for that matter, anything between.
    Instead, he got a flood of microwave radiation that indicated a temperature of at least 300° C, some two hundred degrees above the boiling point of water. It was a thunderbolt. No one had expected such a hot Venus.
    • Isaac Asimov, The Secret of the Universe (Doubleday, 1991), pt. 1, ch. 2
  • Thou fair-hair’d angel of the evening,
    Now, whilst the sun rests on the mountains, light
    Thy bright torch of love; thy radiant crown
    Put on, and smile upon our evening bed!

G - L

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M - R

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Venus, unlike the Earth, has a hellish temperature. Venus is farther from the Sun than Mercury but is even hotter. The high temperature is due to an extreme greenhouse effect, the process by which the atmospheric gases raise the temperature by absorbing outward flowing heat. Earth’s atmosphere may once have contained large amounts of carbon dioxide, the way Venus’s atmosphere does now. But on earth, the oceans absorbed much of carbon dioxide, so that gas could not trap as much heat in the atmosphere as it does on Venus.
  • Venus, unlike the Earth, has a hellish temperature. Venus is farther from the Sun than Mercury but is even hotter. The high temperature is due to an extreme greenhouse effect, the process by which the atmospheric gases raise the temperature by absorbing outward flowing heat. Earth’s atmosphere may once have contained large amounts of carbon dioxide, the way Venus’s atmosphere does now. But on earth, the oceans absorbed much of carbon dioxide, so that gas could not trap as much heat in the atmosphere as it does on Venus. ... Venus is earth’s “evil twin”. It’s about the same size as earth, but with deadly heat and pressure, an unbreathable atmosphere, and highly acid rain.
  • Erstwhile the star of dawn thy light on living men was shed;
    But now in death an evening star, thou’rt light among the dead.
    • Pseudo-Plato, in A.P., vii, 670; translated by G. B. Grundy, Ancient Gems in Modern Settings (Oxford: B. H. Blackwell, 1913), p. 42

S - Z

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Some scientists believe that until about 500 million years ago the Venus surface was almost entirely devoid of landforms. Streams and oceans of molten rock were relentlessly pouring out of the interior filling in and covering over any relief that had managed to form. ~ Carl Sagan and Ann Druyan
 
The Venus transit is not a spectacle the way a total solar eclipse is a spectacle. ~ Neil deGrasse Tyson.
  • Some scientists believe that until about 500 million years ago the Venus surface was almost entirely devoid of landforms. Streams and oceans of molten rock were relentlessly pouring out of the interior filling in and covering over any relief that had managed to form.
  • Venus has about 90 times more air than Earth. It isn't mainly oxygen and nitrogen as here — it's carbon dioxide. But carbon dioxide doesn't absorb visible light either. What would the sky look like from the surface of Venus if Venus had no clouds? With so much atmosphere in the way, not only are violet and blue waves scattered, but all other colours as well — green, yellow, orange, red. The air is so thick, though, that hardly any blue light makes it to the ground; it’s scattered back to space by successive bounces higher up. Thus the light that does reach the ground should be strongly reddened — like an Earth sunset all over the sky. Further sulfur in the high clouds will strain the sky yellow. Pictures taken by the Soviet Venera landers confirm that the skies of Venus are a kind of yellow-orange.
    • Carl Sagan and Ann Druyan, Pale Blue Dot (2011 [1994]), p. 155
  • Those who are skeptical about carbon dioxide greenhouse warming might profitably note the massive greenhouse effect on Venus. No one proposes that Venus's greenhouse effect derives from imprudent Venusians who burned too much coal, drove fuel-inefficient autos, and cut down their forests.
    • Carl Sagan and Ann Druyan, Pale Blue Dot (2011 [1994]), p. 205
  • Thou, Hesper, bringest homeward all
       That radiant dawn sped far and wide:
    The sheep to fold, the goat to stall,
       The children to their mother’s side.
    • Sappho, fragment quoted in Demetrius, On Style 141 (L.P. 104a); translated by Rennell Rodd, Love, Worship and Death (London: E. Arnold, 1916), p. 5
  • For a breeze of morning moves,
       And the planet of Love is on high,
    Beginning to faint in the light that she loves
       On a bed of daffodil sky,
    To faint in the light of the sun she loves,
       To faint in his light, and to die.
  • There are certain calculations I should like to make with you,
    To be sure that your deductions will be logical and true;
    And remember, 'Patience, Patience,' is the watchword of a sage,
    Not to-day nor yet to-morrow can complete a perfect age.
    I have sown, like Tycho Brahé, that a greater man may reap;
    But if none should do my reaping, 'twill disturb me in my sleep
    So be careful and be faithful, though, like me, you leave no name;
    See, my boy, that nothing turn you to the mere pursuit of fame.
    I must say Good-bye, my pupil, for I cannot longer speak;
    Draw the curtain back for Venus, ere my vision grows too weak:
    It is strange the pearly planet should look red as fiery Mars,—
    God will mercifully guide me on my way amongst the stars.
  • What strong allurement draws, what spirit guides,
    Thee, Vesper! brightening still, as if the nearer
    Thou com'st to man's abode the spot grew dearer
    Night after night?
    • William Wordsworth, "To the Planet Venus, / Upon its approximation (as an Evening Star) to the Earth, January, 1838". Poems, Chiefly of Early and Late Years (London: Edward Moxon, 1842), p. 236

Venus Revealed (1998)

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David Harry Grinspoon, Venus Revealed: A New Look Below the Clouds of Our Mysterious Twin Planet (Basic Books, 1998)
 
For me Venus holds special fascination because of it many close connections to Earth, and the important role it has played in our changing ideas about the universe and our place in it...
 
... A knowledge of close coincidence between the cycles of Venus and human pregnancy may have contributed to the persistent, but nonexclusive of female characteristic to Venus. Western attributes The Venus de Milo and Botticelli's birth of Venus (popularly known as Venus on the Half Shell) are icons of this imagery in Western culture.
 
Maya felt that we owed our existence to Venus who they called Kukulcan and their astronomer-priests repaid the debt with the blood of human sacrifice.
 
...The planet is completely shrouded in clouds that reflect nearly 80 percent of the Sun’s light back into space, making Venus the brightest of worlds.
  • For me Venus holds special fascination because of it many close connections to Earth, and the important role it has played in our changing ideas about the universe and our place in it. It is brightest thing in our night sky, after the full moon, and has long attracted human worship, fear, and calculation. A slightly twin to our planet in size and weight, Venus (as we have learnt recently) is also currently active planet with a churning interior, young surface and continually recycling atmosphere. It is in many ways the most Earth like of other planets and a natural laboratory for studying some of the most crucial environmental tests facing us.
    • p. xiii
  • As Venus moves up and down through our twilight skies, the farthest it gets from the Sun is an angle of about 47 degrees. (This is "maximum elongation")
    • p. 9
  • You can feel when you are locked in resonance in a circle of drummers playing parts complimentary to yours. Venus and Earth have been locked in this same way, beating five against eight, for billions of years. There is no accepted physical explanation for the Venus-Earth five/eight polyrhythm. Some regard it as merely a coincidence, noting that the correspondence is not exact (it is actually off by two days of 2,820). But I suspect that this close rhythmic connection between the orbits of Venus and Earth goes back to the time when the planets were being formed from collisions between smaller “planetesimals”.
    • p. 11, on the noted aspect of music in planetary orbits
  • The great beauty and striking presence of Venus led to an association by the Greeks with Aphrodite, goddess of beauty and love. Inanna, Ishtar, Astarte and Venus are other names given to variations of this goddess in Western history, all associated with the planet. A knowledge of close coincidence between the cycles of Venus and human pregnancy may have contributed to the persistent, but nonexclusive of female characteristic to Venus. Western attributes The Venus de Milo and Botticelli's Birth of Venus (popularly known as Venus on the Half Shell) are icons of this imagery in Western culture.
    • p. 19
  • Maya felt that we owed our existence to Venus who they called Kukulcan and their astronomer-priests repaid the debt with the blood of human sacrifice. Unfortunately, almost everything we know about the Maya’s sophisticated and complex system of Venus observations/ computations/prediction/worship comes from only four books that escaped the book-burning frenzy of the invading Christians. Included in this meticulously painted bark paper books is an abundance of astronomical information, including table of solar and lunar motions and table of Venus ephemeris, or table of motions, which is accurate for over a hundred years. The entire Mayan calendar, as were those of all Mesoamerican civilizations, was based on the 260-days Venus appearance interval. The 260-day Mayan calendar is still in use today in many areas of Guatemala. The 260-day Venus interval and the 365-day year come into phase every 18,980 days, or 53 years.
    • p. 19
  • [L]et's trace the origin and history of the popular vision of Venus as Earth's soggy twin. The striking brilliance that makes Venus such a noticeable presence in our sky results paradoxically from the same feature that long kept her cloaked in mystery. The planet is completely shrouded in clouds that reflect nearly 80 percent of the Sun’s light back into space, making Venus the brightest of worlds.
    • p. 32
  • Venus, all you need to do is identify some feature or mark and note the time it takes to reappear, as it rotates around the globe. Beginning in 1666, Cassini made the first attempt to do this. He found a rotation period of 23 hours and 21 minutes. In 1789, Schroder refined this estimate to 23 hours, 21 minutes, and 19 seconds.
    • p. 45
  • For Venus is (as was well known by early telescopic observers) literally right next door. The closest planet to Earth, at every inferior conjunction she swings to within one hundred times the Moon's distance.
    • p. 50
  • In 1956, passive radio observations had allowed a startling discovery that led to the first serious challenge to the fantasies of a warm, wet Venus. Mysteriously, the planet was emitting very large amounts of microwave radiation. Further observations in the 1960s confirmed its brightness when viewed with microwave eyes.
    • p. 63
  • As long as Venus remained an object of distant observation in our sky, there was no way to be sure, and science fiction writers were free to populate Venus with ocean-dwelling beasts and evil dictators (news of the problematical microwaves was first published the same year that Zsa Zsa was thrilling audiences with her Venusian antics). We had to go there to demand some answers. This is where the rockets enter the story... the cold-war “space race” was on, science was along for the ride, onward to the planets.
    • p. 63
  • Venus was the target for the first spacecraft sent from Earth to another planet, Mariner 2 was launched on August 27, 1962.
    • p. 64
 
On Earth, only dust and pebbles get snuffed (making "shooting stars"), but on Venus you don't get any craters smaller than about two miles across. We expected this. In fact, the small size cutoff of craters conforms so closely to pre-Magellan predictions that it was a confidence booster for our models of the passage of small bodies through planetary atmospheres.
 
Artist's depiction of Magellan at Venus. - We are just starting to think about how similar feed backs between the surface and atmosphere may be affecting the climate on Venus. Although the Magellan mission was mostly about the surface, it has caused us to rethink much of what we thought we knew about the atmosphere.
  • [T]hroughout the 60s, 70s, and 80s our understanding of Venus slowly increased in depth and sophistication. But still the clouds did not clear, and major mysteries remained. The early Soviet efforts produced a string of failures...Venera 3 — actually reached Venus only to crash into the planet on March 1, 1966...the first successful mission Venera 4, reached Venus in October 1967 — first planetary probe to enter the atmosphere of another planet, do direct experiments and radio home the results...During its brief (ninety-four –minute) decent by parachute, the spacecraft measured conditions in and below the clouds, confirming that the atmosphere of Venus is mostly carbon dioxide and recording increasing temperature and pressure...at an altitude of more than sixteen miles.
    • p. 75
  • On Earth, only dust and pebbles get snuffed (making "shooting stars"), but on Venus you don't get any craters smaller than about two miles across. We expected this. In fact, the small size cutoff of craters conforms so closely to pre-Magellan predictions that it was a confidence booster for our models of the passage of small bodies through planetary atmospheres.
    • p. 254
  • But on Venus you can't tell, so the hypothesis is consistent with the way all the craters sit atop the "paint job" of planet wide lava flows. Unfortunately, this scenario is only slightly more plausible than crater-worshiping.
    • p. 258
  • Venus should have a similar overall heat production, and it has to be losing this heat somehow. It can't be holding it inside because the whole planet would just be molten. It is not enough to simply pronounce that Venus looks different from Earth so it does not have plate tectonics. We have to find some cooling mechanism.
    • p. 264
  • We are just starting to think about how similar feed backs between the surface and atmosphere may be affecting the climate on Venus. Although the Magellan mission was mostly about the surface, it has caused us to rethink much of what we thought we knew about the atmosphere.
    • p. 281
  • Mars is the most Earthlike of the other planets in its surface conditions, but Venus may be the most Earthlike in its activity. All three planets started out young and restless, with warm, churning interiors and water flowing on their surfaces. But they have gone their separate ways. Mars cooled off...Venus, too, lost its ocean, but it retains an active churning interior and a surface that has been reworked many times by processes that are apparently still ongoing.
    • p. 314

See also

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