solar eclipse--- From fear to fascination

Zeus, father of the Olympians,
made night from mid-day,
hiding the light of the shining Sun,
and sore fear came upon men.
Archilochus ― Greek poet
(Refers to the eclipse of April 6, 647 B.C. )

SUPERSTITION…SCIENCE…FASCINATION…
For centuries people feared it, made sacrifices to it, wailed over it. Today we run to greet it - a total eclipse of the sun.
Eclipses of the Sun and Moon have always left a deep impression on their viewers. The loss of the Sun, the bringer of life for ancient people, was considered a bad omen. Many ancient people―including those in the Caribbean and the islands of the Pacific― believed that during an eclipse a monster or dragon was eating the Sun. The time of an eclipse was one of prayers, sacrifices, and noise as they attempted to make the dragon drop its prey―and the dragon always did!

October 22, 2134 B.C. ― Hi and Ho, The Royal Astronomers
Predicting an eclipse was a duty of ancient Chinese astronomers. The earliest written record of a total solar eclipse comes from China. In 2134 B.C. two royal astronomers, Hi and Ho, knew that an eclipse was due. According to legend, on the day of the eclipse they were too drunk to perform the rites of chanting, beating drums and shooting arrows at the dragon that was devouring the Sun. When the eclipse took place the emperor ― also known as the 'Son of the Sky'― was caught unprepared. Advance notice was required to dispatch the archers to frighten the dragon consuming the sun. The emperor ordered Hi and Ho beheaded for their sins.
"Here lie the bodies of Ho and Hi,
Whose fate, though sad, is risible;
Being slain because they could not spy
Th' eclipse which was invisible."
(Author unknown)

1900 B.C. Stonehenge ― An Ancient Computer?
In Southern England stands an awesome arrangement of prehistoric ruins and stones that have been the subject of countless studies, poems and legends. Speculation on the study of Stonehenge have continued unabated from the time that it was first mentioned in the literature shortly after the Norman Conquest (1066). Evidence indicates that Stonehenge, built during the same era as the Great Pyramid of Egypt, was a brilliantly conceived astronomical observatory. Certain holes were apparently used as an eclipse predictor.

June 15, 763 B.C.―A Biblical Eclipse
"And on that day," says the Lord God, "I will make the Sun go down at noon, and darken the Earth in broad daylight." This eclipse is confirmed by an Assyrian historical record known as the Eponym Canon. (Amos Chapter 8, Verse 9 - Old Testament)

May 28, 585 B.C.―An Eclipse Ends a War
The most famous solar eclipse of classical times occurred in the midst of a battle between the Medes and the Lydians. The two armies were locked in battle when "the day was turned into night." (This eclipse had been predicted by Thales, the Greek astronomer and philosopher, but the prediction was probably not known to the warring nations.) According to the Greek historian Herodotus, both sides regarded the eclipse as an omen and immediately ceased hostilities, thereby ending a six year war. They signed a peace treaty and cemented the bond between their nations with a double marriage.

April 10, 628 A.D.― Death To the Empress
The death of Empress Suiko of Japan was attributed to the total eclipse of April 10, 628 A.D.

May 1, 664 A.D. ―Death To the King
"In this year the Sun was eclipsed … and Earcenbryht, the King of the Kentish people died and his son Ecgbryht succeeded to the Kingdom" (The Anglo Saxon Chronicles)

May 5, 840 A.D.― An Eclipse Ends a Life
The appearance of an eclipse was often thought to be supernatural and a sign of impending calamity.
Emperor Louis of Bavaria, son of Charlemagne, and head of a vast empire supposedly died of fright during the 5 minutes of eclipse totality he witnessed in 840 A.D. His three sons immediately fought over succession to his throne - a battle which ended three years later with the historic Treaty of Verdun and the division of the empire into what is today France, Germany and Italy.

August 9, 975 A.D. ―A Japanese Amnesty
"The Sun was eclipsed… It was the colour of ink. All the birds flew about in confusion and the various stars were all visible… There was a general amnesty on account of the eclipse."

February 29, 1504 ― Columbus and the Moon's Eclipse
In 1503 Christopher Columbus found himself marooned in the small bay of Santa Gloria, Jamaica. When the Indians refused to supply food, in exchange for trinkets, Columbus devised a plan to trick them. He had aboard the Capitana a copy of Johannes Muller's Calendarium published around 1474 which contained predictions of lunar eclipses ― one of which was scheduled for February 29, 1504. He arranged an evening meeting with the natives to coincide with the beginning of the eclipse and announced that God would show his displeasure towards them by taking away their moon. Right on cue a dark shadow began to pass over the face of the moon. When the frightened Indians pleaded for its restoration Columbus retired to 'confer' with God - probably his hourglass to check out when the total phase was due. The moon ― and the food supply were promptly restored.

1560 ―An Eclipse Postponed
In The announcement of a forthcoming eclipse in France caused many Frenchmen to panic.
They fought one another to be first in line for the confessional. One beleaguered parish priest tried to calm the populace by announcing that since there were so many waiting to confess a decision had been made to postpone the eclipse for two weeks!

1600's―Flaming Arrows
The Chippewa Indians of North America thought the sun's flame was being extinguished during an eclipse, so they fired flaming arrows into the sky to re-ignite it.

April 1, 1764 ―Eclipse, The Racehorse
One of the most famous racehorses was named "Eclipse" because it was born at the time of the annular eclipse of 1764. The Eclipse Awards, named after that horse, are given in the U.S to thoroughbred champions.

October 27, 1780―The Harvard Expedition
During the Revolutionary War the first American eclipse expedition was organized by Harvard and led by Samuel Williams, professor of mathematics and natural philosophy. Alas, the site of the projected scientific expedition lay in enemy territory. The western portion of Penobscot Bay was the only place in the path of the eclipse accessible by a ship large enough to carry the group's heavy scientific equipment.
John Hancock, the speaker of the House, pleaded with the British commander at Penobscot Bay to make the American expedition possible. Addressing the commander as a "Friend of Science," Hancock wrote: "Though we are political enemies, yet with regard to Science it is presumable we shall not dissent from the practice of all civilized people in promoting it…" A special immunity agreement was negotiated with the British so that the scientists could work unharmed.
The Harvard expedition, after all their efforts didn't see the eclipse because they chose a site outside the path of totality!
In 1980 a group of Harvard students and professors traveled to Maine to reenact William's experiment. They used identical instruments and maps used by the original expedition in 1780 ― instruments which performed flawlessly and maps which were amazingly accurate. Williams had erred in his calculations of latitude. He had set up his instruments thirty miles farther south than astronomical tables indicated he should. The expedition that had managed to make a war step aside for the sake of science missed witnessing totality because of a mathematical miscalculation.

The Eclipse Of The Sun, 1820 ― An Eclipse in Literature
High on her speculative tower
Stood Science waiting for the hour
When Sol was destined to endure
That darkening of his radiant face
Which Superstition strove to chase,
Erewhile, with rites impure…
William Wordsworth

1851―The Corona Photographed
During totality the first successful photograph was taken of the solar corona. Early eclipse observers were able to see the sun's extensive, pearly-white corona surrounding the obscuring disk of the moon. The daguerreotype proved that prominences were in fact part of the sun rather than of the moon ― as early observers had tended to believe.
Sept 7, 1858― Olmos Peru
The midday disappearance of the sun brought the citizens of Olmos to their knees. Church bells rang - intending to drive away the evil spirits from the area. The resemblance of the corona was so similar to the halos which encircle the heads of the Savior and Madonna ― they perceived the eclipse to be a manifestation of the divine presence.

1868―Helium Discovered During Eclipse
Traces of a previously unknown element, helium, were detected on the sun during this eclipse. The two English discoverers recommended the new element be named helium, after the Greek helios, meaning the sun. In 1895, 27 years after it was discovered on the sun, helium, the second most abundant element, was recognized on the earth itself..

1878 ―The Eclipse and Thomas Edison
In 1878 Thomas Edison traveled to Wyoming to view a total eclipse. He set up his scientific instruments in a chicken coop but as the Sun dimmed the chickens came in to roost.
The Inventor spent so much time fighting chickens that he had only a few seconds of the more than three minutes of totality to make his observations.

1887 ―Volcano Eclipses the Eclipse
A United States eclipse expedition set up their elaborate instruments in Yokohama, Japan under perfectly clear skies. An hour before the eclipse was to occur a nearby volcano erupted belching forth large volumes of smoke and steam which obscured the sun until the eclipse was over.

1889 ―Mark Twain's Fictional Eclipse of June 21, 528
The hero of Mark Twain's novel "A Connecticut Yankee in King Arthur's Court" used the ignorance of eclipses to save his life. The Connecticut Yankee, Hank Morgan, is struck unconscious in a quarrel and wakes up in King Arthur's England of 528 A.D. He escapes being burned at the stake by "predicting" a solar eclipse. Morgan, claiming magical powers over the sun, bargains for his life in exchange for restoring daylight. King Arthur accepts - and the sun is restored.

1890 ― "Wild beasts and Savages"
A U.S. scientific eclipse expedition departed from New York's Navy Yard to the West Coast of Africa to bring back much needed information. They unloaded their provisions and set up their instruments on the beach― some of which were so heavy they required thirty to forty sailors to lift and carry them. A voluntary group of marines had been enlisted to guard the camp from "wild beasts and savages" until the eclipse was over and the scientists returned safely to their vessel.

May 29, 1919―The Eclipse and Einstein's Theory
This eclipse of the sun was used to dramatically confirm Einstein's Theory of Relativity. The experiment sought to test his prediction that the speed of light would be slowed slightly by powerful gravity.

January 24, 1925―A Typical Day in Manhattan
One of the most memorable eclipses for the northern United States, occurred at 9:11a.m. on January 24, 1925. It was calculated that totality would sweep across Manhattan. Many were disappointed, however, since New Yorkers above 80th Street witnessed totality while those below 80th Street saw a partial eclipse.

1948―Korea … An Election Postponed
National elections scheduled in May in Korea were postponed because a total eclipse was to occur on the date originally set for the balloting.

1966―Hindu Pilgrims, Gemini 12 Astronauts and An Eclipse…
In a study of contrasts, in 1966 the first picture of a total eclipse from outside the Earth’s atmosphere was taken by the crew of astronauts aboard Gemini 12. Meanwhile, in India, Hindu pilgrims by the thousands plunged themselves in sacred bathing tanks, hoping for protection from demons.

March 7, 1970―Eclipse, Virginia ― "Not In Our Backyard… "
The town fathers of Eclipse, Virginia said 'no, thank you' to Ted Pedas and Phil and Marcy Sigler who planned to stage an Eclipse'70 Festival in Eclipse, Va. ― a town which fell within the 80-mile wide eclipse path.
Eclipse frolicking on the banks of the Chukatuck river? "Not so fast," said the locals, who demanded a security check at the drawbridge of all incoming 'heliophiles'. Contract negotiations broke down over the provision that Pedas-Sigler would not admit into Eclipse, Virginia persons who advocated the "overthrow of the federal government," were "disrespectful to the flag" or had long hair.
The path of totality for the 1970 eclipse moved northward from Mexico and at Norfolk it jutted out to sea passing over Nantucket. Efforts to stage the eclipse festival on the Massachusetts island met with strong opposition. An influx of 'Woodstock-type' hippies" paying homage to the eclipse, and their organizers, were persona non grata . While retreating from Nantucket, via ferry, the Pedas-Sigler entrepreneurs had an idea. Why not charter the ferry on which they were sailing ― or a ship ― and sail it into the path of an eclipse?
The idea of intercepting totality at sea was born. The cosmic-thinkers put in a wake up call for the eclipse of July 10, 1972.

1972―World's First Eclipse Cruise is Launched; Destination ―Totality!
In 1972 the world's first eclipse cruise Olympia's Voyage to Darkness '72 set sail from New York with 834 passengers (and one cat, Penny Nicol) to achieve a spectacular rendezvous with eclipse totality 900 miles in the North Atlantic. The ship had positioned itself under a 'hole' in the sky avoiding the inclement weather which clouded out land based eclipse observers. The advantage of the Pedas-Sigler eclipse cruise was "maneuverability" and the utilization of weather satellite data to position the ship under clear skies.

Popularizing the 1972 eclipse ― Carly Simon ― You're So Vain
There was an explosion of publicity surrounding the launching of Eclipse'72, the world's first shipborne eclipse adventure. The notion of basking in the moon's shadow was featured in the press with trendy headlines such as Moon Game for Jet Set, A Cruise Is Where the Eclipse Is At, and Attention: Everyone on Deck to View the Eclipse.
"You flew your Learjet up to Nova Scotia to see the Total Eclipse of the Sun," Carly Simon said in her 1972-73 #1 Billboard hit You're so Vain which captured the media's fascination with the solar eclipse of July 10, 1972. (By the way, the eclipse in Nova Scotia was all but clouded-out. Had Carly Simon's eclipse chaser opted for the eclipse bound Voyage to Darkness'72 he would have evaded bad weather to intercept the eclipse at sea.)
Although scientists have travelled to eclipses for over 200 years, their expeditions were for scientific observation. The hardships of travel to remote areas where eclipses normally occurred, the expense, and the risk of being 'clouded-out' discouraged the pursuit of the eclipse to all but serious astronomy buffs.
The 1972Voyage to Darkness Pedas-Sigler eclipse cruise proved to be the benchmark for conveying large numbers of enthusiasts and professional astronomers to the best vantage point to intercept eclipse totality.
The eclipse scheduled for August 11, 1999 will be the most widely observed eclipse in history. In addition to being easily accessible by land, numerous eclipse cruises are scheduled to transport thousands of viewers into its path.

1973―Canberra and Cunard Adventurer Rendezvous with Totality
On June 30, 1973 the Canberra―Voyage to Darkness'73 with 2600 people on board, rendezvoused off the African coast with the longest eclipse (7 minutes) in modern times and sailed onto the front page of The New York Times. The prolific science writer and shipboard lecturer Isaac Asimov recorded his experience in his autobiography In Joy Still Felt
To accommodate those waitlisted for the sold out Canberra the organizers chartered a second ship Cunard Adventurer―Caribbean Eclipse'73 which, with 800 passengers aboard, intercepted the June 30, 1973 eclipse 1200 miles in the mid-Atlantic.

1973―Rescue-At-Sea
A dramatic rescue at sea aboard the Canberra followed the eclipse. Passengers and students combined their skills to improvise a defibrillator for emergency treatment of a stricken seaman who was removed from a freighter in the mid-Atlantic. Walter Sullivan documented the rescue-at-sea in The New York Times. To assemble the instrument the passengers used capacitors from the ship's antenna system, plates from a television camera tripod, screwdrivers with insulated handles, diodes from the kit of a Florida skywatcher and power determinations from a passenger's pocket calculator.
(NOTE: Another rescue-at-sea occurred in the South China Sea aboard the Asian'95 Voyage to Darkness. An Indonesian fisherman had fallen off the back of his fishing boat while pulling in a heavy bucket of water for bathing. He was treading water when spotted by a quick thinking eclipse cruise passenger who tossed him a life jacket. The eclipse bound ship was maneuvered to extract him from the water. Singapore immigration was contacted but they refused to allow the fisherman to get off the ship for repatriation with Indonesia ― because he didn't have a passport.)

The Eclipse Redefines Cruising― Shipborne Astronomy;Science and Culture at Sea

In 1972 the Voyage to Darkness organizers ―a family of five educators ― astronomer Ted Pedas, historian Phil Sigler, and public school teachers George Pedas, Tom Pedas, and Marcy Pedas Sigler ― had bridged the academic world and the needs of a depressed shipping market to spawn a new industry ― educational theme cruises replete with shipboard lecturers and educational pursuits.
They proved wrong the Olympia's Captain's proclamation that "No one would ever attend a lecture on a cruise ship".
Launching an eclipse cruise was not smooth sailing. In the early '70s, travel agents politely demurred from promoting what they perceived as the ship of fools. "Sail North into the frigid Atlantic instead of the sunny Caribbean for two minutes of totality and risk being blinded by the eclipse?" they scoffed. Nor were the Planetariums quick to relinquish their sacrosanct eclipse to cosmic pied pipers seeking to make a buck off of God.
To compensate for the travel agent's lack of support the Pedas-Sigler entrepreneurs devised a plan enlisting the cooperation of Planetariums and Science Museums as 'Participating Agents'. The Director of the Fels Planetarium (Philadelphia) was first to see the merits of this unique revenue raising proposal. Rochester's Strasenburgh and Chicago's prestigious Adler quickly followed suit. New York's stodgy Hayden joined forces a year later in endorsing the deck of a ship as a viable alternative to terra firma in observing and photographing the eclipse.

The Pedas-Sigler pioneers of Astronomy Theme Cruises, in their quest for totality, had revamped the 'snooze-and-booze cruise' substituting lectures on sun spots, shadow bands and Bailey's Beads for bingo and deck quoits. And none too soon. "Earth people," states Ted Pedas, "are indeed fortunate to live on the only planet in the solar system where three celestial bodies, the sun, moon and earth align themselves to produce solar eclipses. In eons to come, future generations will not be provided with this solar phenomenon. Tidal forces of gravity will cause the moon to slowly spiral away from the earth."

EPILOGUE
Solar eclipse of April 6, 647 B.C.
"Zeus, father of the Olympians, made night from mid-day,
hiding the light of the shining Sun, and sore fear came upon men." ― Archilochus
The Sun God, Helios, proved much friendlier to the Pedas-Sigler modern day Hellenes (the Pedas family is of Greek descent) than to their predecessor, Icarus, who dared to sail too close to the sun.
The wrath of Olympus, when day turns into unearthly night, had been appeased. Archilochus would be pleased.
by

Ted Pedas and Marcy Pedas Sigler
(excerpts from Voyage to Darkness Pedas/Sigler eclipse cruise brochures 1972-2002)

solar eclipse highlights

Every time the solar eclipse take places, the occurrence and its observation mean a great thing for the astronomy. Recently, Professor Jay M. Pasachoff has surveyed Jinshan near Shanghai，Mogan Mountain and the reservoir of Tianhuangpin Pumped Storage Power Plant and Hangzhou City in order to choose the best location in the world to observe the astronomic spectacle, accompanied by chief scientist of National Astronomical Observatory Dr. Yan Yihua and Curator of Beijing Astronomical Observatory Dr. Zhujin.

The solar eclipse will take place on July 22, 2009 and it happens once every three hundred years. It will be a total eclipse of the sun that will only be visible from a narrow corridor through central China, including Chengdu, Chongqing, Wuhan, Suzhou, Hangzhou and Shanghai Cities, which means most parts of central China locate within the best area of observation. The solar eclipse is the longest total solar eclipse that will occur in the twenty-first century. Totality visible in Shanghai will last for up to 5 minutes. The last solar eclipse visible in Shanghai took place on May 10, 1575 during the Ming Dynasty (1368-1644) and it won’t happen again in Shanghai until June 9, 2309. There is no exaggeration to say the total solar eclipse is a rare chance once in centuries and many people are expecting its coming.

When the moon is directly between the sun and the earth, and the moon's shadow is cast upon the earth, it seems that to the people on the earth that the sun is not full and even disappearing. This is the solar eclipse. Actually this is one of the astronomical phenomenons when the sun is covered by the moon. Since the full solar eclipse belt is so narrow on earth that venues can observe this magic astronomical phenomenon is quite limited.

Now the hotel rooms are difficult to book for July 22nd 2009 in Anji Tianhuangping of Zhejiang province and Tongling in Anhui province, which were considered to be the best observation venue for the full eclipse in 2009. It is said that an isle locating on the solar eclipse belt had already been occupied by a travel agency for organizing astronomic amateurs to witness this eclipse. Those eclipse chasers are already get prepared for 2009’s eclipse. According to Shanghai Astronomical Observatory, observers’ number may create new world record next year. The full solar eclipse may influence natural environment, such as wind, temperature, animals and so on. Thus, when full solar eclipse takes place, temperature and humidity may fall sharply, wind direction may change, wind speed goes faster and it may darken suddenly during the daytime… lot of amateurs upload data and pictures from NASA to BBS to discuss the best observation venues. Since sun altitude of 2009’s eclipse is 55, residents living on high apartment in Shanghai may even witness at their home with the windows open.
After careful calculation, Prof. Jay M. Pasachoff, chairman of the Working Group on Solar Eclipse of the International Astronomical Union (IAU) finally released the information that the reservoir of Tianhuangpin Pumped Storage Power Plant, located at 119°35′east and 30°27′north and standing at 758 meters, would provide the best observing site. This information was released by after he went to Anji and made a practical survey of the place.

Transit of Phobos from Mars

A transit of Phobos across the Sun as seen from Mars takes place when Phobos passes directly between the Sun and a point on the surface of Mars, obscuring a large part of the Sun's disc for an observer on Mars. During a transit, Phobos can be seen from Mars as a large black disc rapidly moving across the face of the Sun. At the same time, the shadow of Phobos moves across the Martian surface.

The event could also be referred to as a partial occultation (or, popularly but inaccurately, a partial eclipse) of the Sun by Phobos.


Transit

A transit of Phobos from Mars usually lasts only thirty seconds or so, due to the moon's very rapid orbital period of about 7.6 hours.

Because Phobos orbits close to Mars and in line with its equator, transits of Phobos occur somewhere on Mars on most days of the Martian year. Its orbital inclination is 1.08°, so the latitude of its shadow projected onto the Martian surface shows a seasonal variation, moving from 70.4°S to 70.4°N and back again over the course of a Martian year. Phobos is so close to Mars that it is not visible south of 70.4°S or north of 70.4°N; for some days in the year, its shadow misses the surface entirely and falls north or south of Mars.

At any given geographical location on the surface of Mars, there are two intervals in a Martian year when the shadows of Phobos or Deimos is passing through its latitude. During each such interval, about half a dozen transits of Phobos can be seen by observers at that geographical location (compared to zero or one transits of Deimos). Transits of Phobos in the northern hemisphere happen during Martian autumn and winter; close to the equator they happen around the autumnal equinox and the vernal equinox; farther from the equator they happen closer to the winter solstice.

Observers at high latitudes less than 70.4° will see a noticeably smaller angular diameter for Phobos because they are considerably farther away from it than observers at Mars's equator. As a result, transits of Phobos for such observers will cover less of the Sun's disk. Because it orbits so close to Mars, Phobos cannot be seen north of 70.4°N or south of 70.4°S; such latitudes will obviously not see transits either.

Mars Rover Opportunity photographed transits of Phobos on March 7, 2004 and March 10, 2004 and March 12, 2004. In the captions below, the first row shows Earth time UTC and the second row shows Martian local solar time.

Solar eclipses on Pluto

Eclipses of the Sun on Pluto are caused when one of its three natural satellites – Charon, Nix and Hydra – passes in front of the Sun, blocking its light.

An eclipse can occur only when one of the satellites' orbital nodes, the points where their orbits cross Pluto's ecliptic, is lined up with the apparent position of the Sun as seen from Pluto. Since all three of its satellites orbit in the same plane, the times at which this is possible are the same for all three. There are only two points in Pluto's orbit where this can happen.

Charon typically presents an angular diameter of between 3 and 4 degrees of arc as seen from the surface of Pluto. The Sun appears much smaller, only 40 arcseconds to 1 arcminute. This means that during solar eclipses by Charon, a large proportion of Pluto's surface can experience a total eclipse.

There are large uncertainties in the diameters of Nix and Hydra, Pluto's two smaller moons, and as a result their apparent diameters (as seen from Pluto) are also uncertain. However, it is known that Nix's angular diameter is 3-9 minutes, while Hydra's is 2-7 minutes. These are much larger than the Sun's angular diameter, so total solar eclipses are possible with these moons.

The period when eclipses were observed on Pluto was between February 1985 and October 1990.As seen from Earth, Charon also transited Pluto every orbit during this period. By measuring the change in brightness during these transit events, astronomers were able to measure the radius of both Pluto and Charon. Nowadays, telescopes, such as the Hubble Space Telescope have high enough resolution that the radius can be measured directly.

The next period of time when solar eclipses can occur on Pluto will begin October 2103, peak in 2110, and end January 2117. During this period, solar eclipses will occur at some point on Pluto every orbit of Charon. The maximum duration of any solar eclipse by Charon as seen from Pluto during this period is about 90 minutes.

Solar eclipses on Jupiter

Solar eclipses on Jupiter occur when any of the natural satellites of Jupiter pass in front of the Sun as seen from the planet Jupiter. For bodies which appear smaller in angular diameter than the Sun, the proper term would be a transit. For bodies which are larger than the apparent size of the Sun, the proper term would be an occultation.

There are 5 satellites capable of completely occulting the Sun; Amalthea, Io, Europa, Ganymede and Callisto. All of the others are too small or too distant to be able to completely occult the Sun, so can only transit the Sun. Most of the more distant satellites also have orbits that are strongly inclined to the plane of Jupiter's orbit, and would rarely be seen to transit.

When the four largest satellites of Jupiter, the Galilean satellites, occult the Sun, a shadow transit can be seen on the surface of Jupiter which can be observed from Earth in telescopes.

Eclipses of the Sun from Jupiter are not particularly rare, since Jupiter is very large and its axial tilt (which is related to the plane of the orbits of its satellites) is relatively small - indeed, the vast majority of the orbits of all 5 of the objects capable of occulting the Sun will result in a solar occultation visible from somewhere on Jupiter's surface.

The related phenomenon of satellite eclipses in the shadow of Jupiter has been observed since the time of Giovanni Cassini and Ole Roemer in the mid Seventeenth Century. It was soon noticed that predicted times differed from observed times in a regular way, varying from up to ten minutes early to up to ten minutes late. Roemer used these errors to make the first accurate determination of the speed of light, correctly realizing the variations were caused by the varying distance between Earth and Jupiter as the two planets moved in their orbits around the Sun.

The website skytonight.comcarries links to predictions for eclipses of Jovian moons and their shadow transits.

Meteorological measurements

A marked drop of the intensity of the solar radiation occurs during solar eclipse. It influences the actions in the atmosphere. The variations of the atmospheric actions display in changes of standard meteorological and physical quantities. We can notice it by a measurement of the air temperature and other meteorological quantities (e.g.: air humidity, soil temperature, colour of the solar radiation).

The progressions of the quantities are usually detected by special weather stations because of a short duration of a total (annular) solar eclipse. The properties of the devices usually are: high speed of measurement, high resolution and sensitivity. Acquired results show very interesting variations in progressions of meteorological and physical quantities (e.g.: colour of the light).[47]

Artificial satellites

Artificial satellites can also pass in front of, or transit, the Sun as seen from Earth, but none are large enough to cause an eclipse. At the altitude of the International Space Station, for example, an object would need to be about 3.35 km across to blot the Sun out entirely. These transits are difficult to watch, because the zone of visibility is very small. The satellite passes over the face of the Sun in about a second, typically. As with a transit of a planet, it will not get dark.[44]

Artificial satellites do play an important role in documenting solar eclipses. Images of the umbra on the Earth's surface taken from Mir and the International Space Station are among the most spectacular eclipse images in history.[45] Observations of eclipses from satellites orbiting above the Earth's atmosphere are of course not subject to weather conditions.

The direct observation of a total solar eclipse from space is rather rare. The only documented case is Gemini 12 in 1966. The partial phase of the 2006 total eclipse was visible from the International Space Station. At first, it looked as though an orbit correction in the middle of March would bring the ISS in the path of totality, but this correction was postponed.[46]