Ultraviolet Spectrometer Observations of Neptune and Triton

  title={Ultraviolet Spectrometer Observations of Neptune and Triton},
  author={A. Lyle Broadfoot and Sushil K. Atreya and J L Bertaux and Jacques E. Blamont and Alexander J. Dessler and Thomas M. Donahue and William T. Forrester and Doyle T. Hall and Floyd Leigh Herbert and Jay B. Holberg and David Hunter and Vladimir A. Krasnopolsky and Susan H. Linick and Jonathan I. Lunine and John C. McConnell and H. Warren Moos and B. R. Sandel and Nicholas M. Schneider and Donald E. Shemansky and G. R. Smith and Darrell F. Strobel and Roger V. Yelle},
  pages={1459 - 1466}
Results from the occultation of the sun by Neptune imply a temperature of 750 � 150 kelvins in the upper levels of the atmosphere (composed mostly of atomic and molecular hydrogen) and define the distributions of methane, acetylene, and ethane at lower levels. The ultraviolet spectrum of the sunlit atmosphere of Neptune resembles the spectra of the Jupiter, Saturn, and Uranus atmospheres in that it is dominated by the emissions of H Lyman α (340 � 20 rayleighs) and molecular hydrogen. The… 

On the thermal structure of Triton's thermosphere

The analysis of the Voyager 2 Ultraviolet Spectrometer (UVS) solar occultation data obtained at Triton is consistent with a spherically symmetric, isothermal thermosphere above 400 km at T∞. = 96 K.

Origin of Aurora and Airglow on the Night Side of Neptune

We have examined the latitude-longitude distribution of emissions detected by the Voyager ultraviolet spectrometer on the dark hemisphere of Neptune, The emissions have two significant geographic

Study of planetary atmospheres by absorptive occultations

As a spacecraft observes the setting or rising of the Sun or a star behind the limb of a planet, the absorption spectrum of the upper atmosphere can be observed as a function of height. This powerful

Infrared Observations of the Neptunian System

Comparison of winds derived from images with the vertical wind shear calculated from the temperature field indicates a general decay of wind speed with height, a phenomenon also observed on the other three giant planets.

The atmosphere of Neptune: Results of radio occultation measurements with the Voyager 2 spacecraft

Radio tracking data acquired during Voyager 2's occultation by Neptune have been used to study the thermal structure and composition of Neptune's troposphere and stratosphere. The occultation began

The upper atmospheres of Uranus and Neptune

  • H. Melin
  • Physics, Geology
    Philosophical Transactions of the Royal Society A
  • 2020
The current understanding of the upper atmospheres of Uranus and Neptune is reviewed, and the upcoming opportunities available to study these exciting planets are explored.

Detection of CO in Triton's atmosphere and the nature of surface-atmosphere interactions

Context. Triton possesses a thin atmosphere, primarily composed of nitrogen, sustained by the sublimation of surface ices. Aims. We aim at determining the composition of Triton’s atmosphere to

The photochemistry of methane in the atmosphere of Triton

The photochemistry of methane in Triton's atmosphere is driven by approximately equal contributions of solar and local Interstellar medium (LISM) Lyα and in combination with weak vertical mixing, K ∼



Ultraviolet Spectrometer Observations of Uranus

The high temperature of the atmosphere, the small size of Uranus, and the number density of hydrogen atoms in the thermosphere imply an extensive thermal hydrogen corona that reduces the orbital lifetime of ring particles and biases the size distribution toward larger particles.

Extreme Ultraviolet Observations from the Voyager 2 Encounter with Saturn

Combined analysis of helium (584 angstroms) airglow and the atmospheric occultations of the star δ Scorpii imply a vertical mixing parameter in Saturn's upper atmosphere of K (eddy diffusion

The upper atmosphere of Uranus: EUV occultations observed by Voyager 2

Occultation observations of the upper atmosphere of Uranus by the Voyager 2 ultraviolet spectrometer are analyzed. The measurements extend from 0.5 mbar to about 10−6 µbar using the EUV wavelengths

Overview of the Voyager ultraviolet spectrometry results through Jupiter encounter

The Voyager ultraviolet spectrometers (UVS) have been making almost continuous observations, in the 500-A to 1700-A wavelength range, of sources in the solar system and galaxy since launch in 1977.

Infrared Observations of the Neptunian System

Comparison of winds derived from images with the vertical wind shear calculated from the temperature field indicates a general decay of wind speed with height, a phenomenon also observed on the other three giant planets.

Iue observations of Neptune for H Lyman‐α emission

Neptune has been observed on seven occasions with the International Ultraviolet Explorer Observatory (IUE, Boggess et al. 1978) in an attempt to detect planetary H Ly-α line emission. The observing

The helium abundance of Saturn from Voyager measurements

Voyager radio-occultation and IR spectroscopy measurements are combined to infer an He mole fraction in the upper troposphere of Uranus of 0.152 + or - 0.033; the corresponding mass fraction is Y =

Voyager 2 at Neptune: Imaging Science Results

Voyager 2 images of Neptune reveal a windy planet characterized by bright clouds of methane ice suspended in an exceptionally clear atmosphere above a lower deck of hydrogen sulfide or ammonia ices.

Analysis of Raman scattered LY‐α emissions from the atmosphere of Uranus

A line at 1280 A, due to Raman scattering of solar Lyman alpha (Ly-α) in the atmosphere of Uranus, has been detected by the Voyager Ultraviolet Spectrometer. The measured intensity of 40 ± 20 R