Voyager missions

Figure 10.3 Voyager I IRIS spectrum of the northern limb of Titan. (Reproduced by permission of Voyager Missions, JPL NASA)...

Figure 6. The He mass fraction Y in the atmospheres of the four giant planets. The Jovian value is from the interferometer on the Galileo probe, while all others (including a less precise earlier Jovian value) are from the Voyager missions (Table...

Voyager mission photopolarimeter experiment. Space Science Review, 21,159-81. Limaye, S. S. (1986). Jupiter new estimates of the mean zonal flow at the cloud level. 

The voyager mission consisted of two satellites launched in 1977 that reached Jupiter in 1979, Saturn in 1981 and Voyager 2 reached Uranus in 1986 and Neptune in 1989. 

When Thomas Jefferson sent Lewis and Clark into the West, he patterned their mission on the methods of Enlightenment science to observe, collect, document, and classify. Such strategies were already in place for the epic voyages made by explorers like Cook and Van-(5) couver. Like their contemporaries, Lewis and Clark were more than representatives of European rationalism. They also represented a rising American empire, one built on aggressive territorial expansion and commercial gain. 

Supermolecular absorption determines significant features of the atmospheres of the planets and their large moons, such as the vertical temperature profile and the high-altitude haze distribution, and offers opportunities for the determination of abundance ratios of helium and hydrogen, ortho- and para-H2, etc. [390, 396]. In certain spectral bands the spectra may sometimes be obtained by Earth-based observations. More commonly, the spectra will be obtained in space missions, such as IRIS of Voyager I and II future missions (Infrared Space Observatory) will doubtlessly enhance the available information significantly. 

Voyager Interstellar Mission. NASA Web site. Available online. URL http //voyager.jpl.nasa.gov/spacecraft/goldenrec.html. 

This survey of the current state of knowledge of satellite geochemistry also uncovers the many areas where there are unsolved problems and major issues still to be addressed by future observations and theoretical work. On the observational side, most of the chemical information we now have for objects beyond the Galilean satellites comes from bulk density and global telescopic spectral data. The Cassini/Huygens mission, which arrives at Saturn in July of 2004, will allow more detailed study of all the satellites of this major system. In particular. Titan is now known primarily through detailed study of its upper atmosphere from Voyager and Earth-based... 

The two Voyager spacecraft completed their planetary missions in late 1989, 12 years after they left Earth s surface. Even though their primary missions had ended, they did not lose their value to astronomers. They continued in flight beyond the orbit of Neptune, into the outermost reaches of the solar system. Scientists expect... 

The general appearance of Io s surface also appears to have changed rather dramatically between the Voyager 2 and Galileo missions. Scientists have determined that one reason for these changes... 

Apart from its most general features, the physical and chemical characteristics of Uranus were largely unknown to astronomers prior to the Voyager 2 flyby in 1981. That mission, however, provided a host of new data about the planet, its ring system, and its moons. For example, Voyager reported that the temperature of the planet at both poles is approximately the same, about 58 K (—215°C), in spite of the fact that one pole always points toward the Sun and the other pole... 

Before the invention of the telescope, Saturn was the most distant planet that anyone could see. It marked the end of the solar system. Naturally, it came to represent limits. Today, it remains the most distant planet that s easily visible with the naked eye, so that meaning still applies. But its image has improved. Thanks to the telescope and the Voyager space missions, everyone knows what Saturn looks like. Even people who have never looked through a telescope have seen pictures of its dazzling ring structure. And they know that it s the most beautiful planet in the solar system. 

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