Near-ultraviolet and visible spectrophotometry of comet Halley from Vega 2

Moreels, G.; Gogoshev, M. M.; Krasnopolsky, V. A.; Clairemidi, J.; Vincent, Michel; Parisot, J. P.; Bertaux, Jean-Loup; Blamont, J. É.; Festou, M. C.; Gogosheva, Ts.; Sargoichev, S.; Palasov, K.; Мороз, В. І.; Krysko, A. A.; Vanysek, V.

doi:10.1038/321271a0

Cited by 23 publications

(3 citation statements)

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“…(3) Among the most prominent emissions in the near ultraviolet and visible spectrum of Halley were those of the CN radical (Moreels et al, 1986;LevasseurRegourd et al, 1986). Ground-based studies of Halley showed the presence also of HCN (Schloerb et aL, 1988).…”

Section: Hydrogen Cyanide Polymers In the Solar Systemmentioning

confidence: 99%

Dark matter in the solar system: Hydrogen cyanide polymers

Matthews

1991

Origins Life Evol Biosphere

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Abstract. In the presence of a base such as ammonia liquid HCN (bp 25 °C) polymerizes readily to a black solid from which a yellow-brown powder can be extracted by water and further hydrolyzed to yield c~-amino acids. These macromolecules could be major components of the dark matter observed on many bodies in the outer solar system. The non-volatile black crust of comet Halley, for example, may consist largely of such polymers, since the original presence on cometary nuclei of frozen volatiles such as methane, ammonia, and water makes them possible sites for the formation and condensedphase polymerization of hydrogen cyanide. It seems likely, too, that HCN polymers are among the dark --C=N bearing solids identified spectroscopically by Cruikshank et aL in the dust of some other comets, on the surfaces of several asteroids of spectral class D, within the rings of Uranus, and covering the dark hemisphere of Saturn's satellite Iapetus. HCN polymerization could account also for the yelloworange-brown coloration of Jupiter and Saturn, as well as for the orange haze high in Titan's atmosphere. Implications for prebiotic chemistry are profound. Primitive Earth may have been covered by HCN polymers through cometary bombardment or terrestrial synthesis, producing a proteinaceous matrix that promoted the molecular interactions leading to the emergence of life.

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Section: Hydrogen Cyanide Polymers In the Solar Systemmentioning

confidence: 99%

Dark matter in the solar system: Hydrogen cyanide polymers

Matthews

1991

Origins Life Evol Biosphere

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“…The TKS experiment was a combination of three spectrometers : ultraviolet (120 -290 nm), near-ultraviolet and visible (275-715 nm) and infrared (950-1 900 nm).The Vega 1 instrument has been unsuccessful and the Vega 2 ultraviolet channel did not function. Nevertheless, hundreds of near ultraviolet spectra were recorded in the inner coma on 9 march 1986, with a spatial resolution never achieved before (Krasnopolsky et al, 1986;Moreels et al, 1985Moreels et al, , 1986.…”

Section: In-situ Observations Of Halleymentioning

confidence: 99%

“…Fig. 9 -Typical spectra of Halley obtained by Moreels et al (1986) on 9 march 1986' from Vega space probe. Spectrum a was recorded at r = 405 600 km from the nucleus, with an impact parameter p of 15 600 km ; spectrum b was obtained for r = 152 600 km.…”

Section: In-situ Observations Of Halleymentioning

confidence: 99%

Halley's Comet : From Remote Ultraviolet Spectroscopy to in-Situ Studies

Levasseur-Regourd

1988

J. Phys. Colloques

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Vega Project

Sagdeev

2003

Encyclopedia of Space Science and Technology

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Vega was the last successful deep space mission of the Soviet space program. It was built on the legacy of the Venera‐9 to Venera‐16 series of spacecraft launched, starting in 1975, to study Venus. In its last encounter (1986), Halley's comet's perihelion was much closer to Venus than to Earth. That created a unique opportunity to launch Vega during the astronomical window for Venus (December 1984) and to use that planet's gravity assist for redirecting the craft to the comet. Using such a choice of spacecraft trajectory, it was decided to combine a scenario to explore Venus with a Halley's comet encounter by employing a two‐element space vehicle: a planetary reentry module, carrying the Venus Lander and balloon, and a Halley flyby probe. The integrated mission was called Vega, a contraction of the Russian words “Venera” (Venus) and “Gallei” (Halley) and was conducted by the Soviet Union and a number of other countries within the framework of an Intercosmos program. The Vega mission comprised two identical spacecraft, Vega 1 and Vega 2. This was a standard approach in the Soviet Union, aimed primarily at increasing the overall reliability of the mission. In addition, if both flybys were successful, there would be a significant increase in the scientific return, which was particularly valuable considering the expected variability of the comet's activity. The Vega project was truly international. The spacecraft production and launch operation were controlled by the Soviet aerospace agency (at that time called the Ministry of General Machine Building), but the scientific program and its payload were coordinated by the International Science and Technical Committee (ISTC), representing scientific institutions and space agencies from nine countries. The ISTC designed the Vega mission program to optimize international efforts related to the Halley's comet campaign, which included the European Giotto and the Japanese Suisei and Sakigake space missions. This article discusses the launch of the two spacecraft and these encounters with Halley's comet: The mission was scientifically highly successful.

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Near-ultraviolet and visible spectrophotometry of comet Halley from Vega 2

Cited by 23 publications

References 3 publications

Dark matter in the solar system: Hydrogen cyanide polymers

Dark matter in the solar system: Hydrogen cyanide polymers

Halley's Comet : From Remote Ultraviolet Spectroscopy to in-Situ Studies

Vega Project

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