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HISTORY

                                                                From our small world we have gazed upon the cosmic ocean for untold thousands of years. Ancient astronomers observed points of light that appeared to move among the stars. They called these objects planets, meaning wanderers, and named them after Roman deities --Jupiter, king of the gods; Mars, the god of war; Mercury, messenger of the gods; Venus, the god of love and beauty, and Saturn, father of Jupiter and god of agriculture. The stargazers also observed comets with sparkling tails, and meteors or shooting stars apparently falling from the sky.
Science flourished during the European Renaissance. Fundamental physical laws governing planetary motion were discovered, and the orbits of the planets around the Sun were calculated. In the 17th century, astronomers pointed a new device called the telescope at the heavens and made startling discoveries.
But the years since 1959 have amounted to a golden age of solar system exploration. Advancements in rocketry after World War II enabled our machines to break the grip of Earth's gravity and travel to the Moon and to other planets.
The United States has sent automated spacecraft, then human-crewed expeditions, to explore the Moon. Our automated machines have orbited and landed on Venus and Mars, explored the Sun's environment, observed comets, and asteroids, and made close-range surveys while flying past Mercury, Jupiter, Saturn, Uranus and Neptune.
These travelers brought a quantum leap in our knowledge and understanding of the solar system. Through the electronic sight and other "senses" of our automated spacecraft, color and complexion have been given to worlds that for centuries appeared to Earth-bound eyes as fuzzy disks or indistinct points of light. And dozens of previously unknown objects have been discovered.
Future historians will likely view these pioneering flights through the solar system as some of the most remarkable achievements of the 20th century.

Second Moon

In 1846, Frederic Petit, director of the observatory of Toulouse, stated that a second moon of the Earth had been discovered. It had been seen by two observers, Lebon and Dassier, at Toulouse and by a third, Lariviere, at Artenac, during the early evening of March 21, 1846. Petit found that the orbit was elliptical, with:

• a period of 2 hours, 44 minutes, 59 seconds;
• an apogee of 3,570 kilometers (2,218 miles); and,
• a perigee of just 11.4 kilometers (7 miles).

Le Verrier, who was in the audience when Petit made the announcement, grumbled that one needed to take air resistance into account, something nobody could do at that time. Petit became obsessed with this idea of a second moon, and 15 years later announced that he had made calculations about a small moon of Earth which caused some then-unexplained peculiarities in the motion of our main Moon. Astronomers generally ignored this, and the idea would have been forgotten if a young French writer, Jules Verne, had not read an abstract. In Verne's novel From the Earth to the Moon, Verne lets a small object pass close to the traveller's space capsule, causing it to travel around the Moon instead of smashing into it:

"It is," said Barbicane, "a simple meteorite but an enormous one, retained as a satellite by the attraction of the Earth.""Is that possible," exclaimed Michel Ardan, "the earth has two moons?"
"Yes, my friend, it has two moons, although it is usually believed to have only one. But this second moon is so small and its velocity is so great that the inhabitants of Earth cannot see it. It was by noticing disturbances that a French astronomer, Monsieur Petit, could determine the existence of this second moon and calculated its orbit. According to him a complete revolution around the Earth takes three hours and twenty minutes. . . . "
"Do all astronomers admit the the existence of this satellite?" asked Nicholl.
"No," replied Barbicane, "but if, like us, they had met it they could no longer doubt it. . . . But this gives us a means of determining our position in space . . . its distance is known and we were, therefore, 7,480 kilometers above the surface of the globe where we met it."

Jules Verne was read by millions of people, but not until 1942 did anybody notice the discrepancies in Verne's text:

1. A satellite 7,480 kilometers (4,648 miles) above the Earth's surface would have a period of 4 hours, 48 minutes, not 3 hours, 20 minutes.
2. Since it was seen from the window from which the Moon was invisible, while both were approaching, it must be in retrogade motion, which would be worth remarking. Verne doesn't mention this.
3. In any case, the satellite would be in eclipse and thus be invisible. The projectile doesn't leave the Earth's shadow until much later.

Dr. R.S. Richardson of Mount Wilson Observatory tried in 1952 to make the figures fit by assuming an eccentric orbit of this moon: a perigee of 5,010 kilometers (3,113 miles), an apogee of 7,480 kilometers (4,648 miles), and an eccentricity of 0.1784.

Nevertheless, Jules Verne made Petit's second moon known all over the world. Amateur astronomers jumped to the conclusion that here was an opportunity for fame -- anybody discovering this second moon would have his name inscribed in the annals of science. No major observatory ever checked the problem of the Earth's second moon, or if they did they kept quiet. German amateurs were chasing what they called Kleinchen ("little bit"). Of course they never found Kleinchen.

the Moon of Venus, 1672-1892

In 1672, Giovanni Domenico Cassini, one of the prominent astronomers of the time, noticed a small companion close to Venus. Did Venus have a satellite? Cassini decided not to announce his observation, but when he saw it again 14 years later, he entered the observation in his journal. The object was estimated to have about one-quarter the diameter of Venus, and it showed the same phase as Venus.
The object was later seen by other astronomers: James Short in 1740, Andreas Mayer in 1759, and Joseph Louis Lagrange in 1761. (Lagrange announced that the orbital plane of the satellite was perpendicular to the ecliptic.) During 1761, the object was seen a total of 18 times by five observers. The observations of Scheuten on June 6, 1761 was especially interesting. He saw Venus in transit across the Sun's disk, accompanied by a smaller dark spot on one side that followed Venus in its transit. However, Samuel Dunn at Chelsea, England, who also watched that transit, did not see the additional spot. In 1764, there were 8 observations by two observers. Other observers failed to find the satellite.
Now the astronomical world was faced with a controversy. Several observers had reported seeing the satellite while several others had failed to find it in spite of determined efforts. In 1766, the director of the Vienna observatory, Father Hell, published a treatise in which he declared that all observations of the satellite were optical illusions. He believed the image of Venus is so bright that it is reflected in the eye, back into the telescope, creating a secondary image at a smaller scale.

Others published treatises declaring that the observations were real. J. H. Lambert of Germany published orbital elements of the satellite in Berliner Astronomischer Jarhbuch 1777:

• mean distance, 66.5 Venus radii;
• orbital period, 11 days, 3 hours; and,
• inclination to ecliptic, 64°.

It was hoped that the satellite could be seen during the transit of Venus in front of the Sun on June 1, 1777. In retrospect, it is clear that Lambert made a mistake in calculating these orbital elements. At 66.5 Venus radii, the distance from Venus is about the same as ourMoon's distance from the Earth. This does not fit with the orbital period of 11 days, which is about one-third of the orbital period of our Moon. (The mass of Venus is slightly smaller than the mass of the Earth.)In 1768 , Christian Horrebow made one more observation of the satellite from Copenhagen. There were also three searches, including one made by one of the greatest astronomers of all time, William Herschel. All three of them failed to find any satellite. Quite late in the game, F. Schorr from Germany tried to make a case for the satellite in a book published in 1875.
In 1884, M. Hozeau, former director of the Royal Observatory of Brussels, suggested a different hypothesis. By analysing available observations, Hozeau concluded that the moon appeared close to Venus approximately every 2.96 years. Hozeau suggested that this was a separate planet, with a 283-day orbit around the Sun that placed it in conjunction with Venus every 1,080 days. Hozeau also named the new planet Neith, after the mysterious goddess of Sais, whose veil no mortal raised.
In 1887, three years after Hozeau had revived interest in the subject, the Belgian Academy of Sciences published a long paper in which each and every reported observation was investigated in detail. Several observations of the satellite were really stars seen in the vicinity of Venus. Roedkier's observations "checked out" especially well -- he had been fooled, in succession, by Chi Orionis, M Tauri, 71 Orionis, and Nu Geminorum. James Short had really seen a star somewhat fainter than 8th magnitude. All observations by Le Verrier and Montaigne could be similarly explained. Lambert's orbital calculations were demolished. The very last observation, by Horrebow in 1768, could be ascribed to Theta Librae.
After this paper was published, only one more observation was reported, by a man who had earlier made a search for the satellite of Venus but failed to find it. On August 13, 1892, Edward Emerson Barnard recorded a 7th magnitude object near Venus. There is no star in the position recorded by Barnard, and Barnard's eyesight was notoriously excellent. We still don't know what he saw. Was it an asteroid that had not been charted? Or was it a short-lived nova that nobody else happened to see?

Mercury's Moon, 1974

Two days before the March 29, 1974, Mariner 10 flyby of Mercury, one instument began registering bright, extreme ultraviolent (UV) emissions that had "no right to be there." The next day, the emissions were gone. Three days later, they reappeared, apparently emanating from an "object" that seemingly detached itself from Mercury. The astronomers first thought they had seen a star. But, they had seen the emissions in two quite different directions, and every astronomer knew that these extreme UV wavelengths couldn't penetrate very far through the interstellar medium. This suggested that the object must be relatively close. Did Mercury have a moon?
After a hectic Friday, during which the "object" had been computed to move at 4 kilometers (2.4 miles) per second, a speed consistent with that of a moon, Jet Propulsion Laboratory (JPL) managers were called in. They turned the then-dying spacecraft over full time to the UV team, and everyone started worrying about a press conference scheduled for later that Saturday. Should the suspected moon be announced? But the press already knew. Some newspapers -- the bigger, more respectable ones -- played it straight; many others ran excited stories about Mercury's new moon.
And the "moon" itself? It headed straight on out from Mercury, and was eventually identified as a hot star, 31 Crateris. The origins of the original emissions remain a mystery. So ended the story of Mercury's moon. At the same time, a new chapter in astronomy began: extreme UV turned out not to be so completely absorbed by the interstellar medium as formerly believed. The Gum nebula has turned out to be a emitter in the extreme UV, and spreads across 140° of the night sky at 540 angstroms. Astronomers had discovered a new window through which to observe the heavens.

Hypothetical Planets

Vulcan, the intra-Mercurial planet, 1860-1916, 1971

During the 19th century, astronomers were puzzled over unexplained deviations in the motion of Mercury. The French mathematician Urbain Jean Joseph Le Verrier, who (along with John Couch Adams) had predicted the position of Neptune based on deviations in the motion ofUranus, believed similar forces were at work. During a lecture on January 2, 1860, he announced that the solution to Mercury's deviations could be explained by assuming the existence of an intra-Mercurial planet, or possibly a second asteroid belt, inside Mercury's orbit.The only possible way to observe intra-Mercurial bodies was when they transited the Sun, or during total solar eclipses. Professor Wolf at the Zurich sunspot data center found a number of suspicious "dots" on the Sun, and a second astronomer found additional ones. A total of two dozen spots seemed to fit the pattern of two intra-Mercurial orbits with periods of 26 and 38 days.

In 1859, Le Verrier received a letter from the amateur astronomer Lescarbault, who reported having seen a round black spot on the Sun on March 26, 1859. Lescrabault thought the object was a planet transiting the Sun. He had seen the spot for about 75 minutes, during which time it moved a quarter of the solar diameter. Lescarbault estimated the object had an orbital inclination of between 5.3° and 7.3°, a longitudal node of about 183°, an "enormous" eccentricity, and a transit time across the solar disk of 4 hours, 30 minutes. Le Verrier investigated this observation, and computed the following orbit:

• a period of 19 days, 7 hours;
• a mean distance from Sun of 0.1427 AU;
• an inclination of 12° 10'; and,
• an ascending node at 12° 59'.

The diameter was considerably smaller than Mercury's and its mass was estimated at one-seventeenth of Mercury's mass. This was too small to account for the deviations of Mercury's orbit. However, Le Verrier theorized that this might be the largest member of an intra-Mercurial asteroid belt. He named it Vulcan.In 1860, there was a total eclipse of the Sun. Le Verrier mobilized astronomers throughout the world to find Vulcan. No one did. Wolf's suspicious 'sunspots' now revived Le Verrier's interest, and additional 'evidence' found its way into print just before Le Verrier's death in 1877. On April 4, 1875, German astronomer H. Weber saw a round spot on the Sun. Le Verrier's orbit indicated a possible transit on April 3 that year. Wolf noticed that his 38-day orbit also could have performed a transit at about that time. That 'round dot' also was photographed by astronomers in Greenwich and Madrid.
There was one more flurry of sightings after the total solar eclipse on July 29, 1878. Two observers claimed to have seen small, illuminated disks in the vicinity of the Sun, objects which could only be small planets inside Mercury's orbit. J.C Watson, professor of astronomy at the University of Michigan, believed he had found two intra-Mercurial planets. Lewis Swift (co-discoverer of Comet Swift-Tuttle, which returned in 1992), also saw a 'star' he believed to be Vulcan. However, it was in a different position than either of Watson's two 'intra-Mercurials.' Neither Watson's nor Swift's sightings could be reconciled with Le Verrier's or Lescarbault's 'Vulcan.'
Nobody ever saw Vulcan again, in spite of several searches at different total solar eclipses. In 1916, Albert Einstein published his General Theory of Relativity, which explained the deviations in Mercury's motions without the need to invoke an unknown intra-Mercurial planet. In May 1929, Erwin Freundlich photographed the total solar eclipse in Sumatra; the plates showed a profusion of star images. Comparison plates were taken six months later. No new objects brighter than 9th magnitude were found near the Sun.
But what did these people really see? Lescarbault had no reason to lie, and even Le Verrier believed him. It is possible that Lescarbault happened to see a small asteroid passing very close to the Earth, just inside Earth's orbit. Such asteroids were unknown at that time, so Lescarbault believed that he saw an intra-Mercurial planet. Swift and Watson could, during the hurry to obtain observations during totality, have misidentified some stars as Vulcan.
"Vulcan" was briefly revived around 1970-1971, when a few researchers thought they had detected several faint objects close to the Sun during a total solar eclipse. These objects might have been faint comets. Comets have been observed to pass close enough to the Sun and eventually collide with it.

WOMAN IN SPACE

	Women in Space
Pioneering Women of Space: 1959:  Geraldine (Jerrie) Cobb was the first woman in the U.S. to undergo astronaut testing, however, NASA cancelled the women's program in July 1961. June 1963: Soviet cosmonaut Valentina Tereshkova was the First Woman in Space. She flew on the Vostok 5 mission which was launched on June 16, 1963. It orbited the Earth 48 times and the flight lasted 2.95 days. August 1982: Soviet cosmonaut Svetlana Savitskaya was the second woman in space. She flew aboard Soyuz T-7 which was launched August 19, 1982. June 1983: Sally Ride was the First American Woman in Space and third woman in space. She flew on the shuttle Challenger STS-7 mission from June 18-June 24, 1983. July 1984: Soviet cosmonaut Svetlana Savitskaya was the First Woman to Walk in Space on July 17, 1984 aboard the Soyuz T-12. Her spacewalk lasted 3.58 hours. She was also the first woman to go to space twice (in 1982 and 1984). August 1984: Judith Resnick was the Second American Woman in Space. She flew on the shuttle Discovery STS-41D mission in August 30-September 5, 1984. October 1984: Kathryn Sullivan was First American Female Spacewalker. She flew on Challenger STS-41G on October 5, 1984. January 1986: Christa McAuliffe was chosen to be first teacher in space. She died in the Space Shuttle Challenger disaster on January 28, 1986. October 1984: Helen Sharman was the first British astronaut in space when she flew aboard the Russian space craft Soyuz TM-12 on May 18, 1991. January 1992: Roberta Bondar was the First Canadian Woman in Space. She flew on the shuttle Discovery STS-42 Mission, January 22-30, 1992. September 1992: Mae Jemison was the First Black Woman in Space during shuttle Endeavor STS-47 Mission, September 12-20, 1992. She was a Mission Specialist. April 1993: Ellen Ochoa was the First Hispanic American Woman in Space. She flew as a mission specialist aboard the Space Shuttle Discovery STS-56 mission. July 1994: Chiaki Mukai was the First Japanese Woman in Space. She flew on Shuttle Columbia STS-56 mission, 8-23 July, 1994. February 1995: Eileen Collins was the First Woman Pilot of a Space Shuttle. September 1996: Shannon Lucid returns from six months aboard the Mir Space Station, setting space endurance record for women and U.S. space endurance record. May 1999: Susan Helms was the First Woman Crew Member of the International Space Station. July 1999: Eileen Collins was the First Woman to fly as a Space Shuttle Commander. October 2001: Claudie Haigneré was the First European Woman to visit the International Space Station. February 2003: Dr. Kalpana Chawla and Dr. Laurel Clark died in the Space Shuttle Columbia disaster on February 1, 2003.