Volcanically emitted sodium chloride as a source for Io's neutral clouds and plasma torus.

The atmosphere of Jupiter's satellite Io is extremely tenuous, time variable and spatially heterogeneous. Only a few molecules--SO2, SO and S2--have previously been identified as constituents of this atmosphere, and possible sources include frost sublimation, surface sputtering and active volcanism. Io has been known for almost 30 years to be surrounded by a cloud of Na, which requires an as yet unidentified atmospheric source of sodium.

Evolution of the outgassing of comet Hale-Bopp (C/1995 O1) from radio observations.

Spectra obtained from ground-based radio telescopes show the progressive release of CO, CH3OH, HCN, H2O (from OH), H2S, CS, H2CO, CH3CN, and HNC as comet Hale-Bopp (C/1995 01) approached the sun from 6.9 to 1.4 astronomical units (AU).

Substantial outgassing of CO from comet Hale-Bopp at large heliocentric distance.

When comet C/1995 O1 (Hale-Boop) was discovered, at a distance of seven astronomical units from the sun, it was more than one hundred times brighter than comet Halley at the same distance. A comet's brightness is derived from the reflection of sunlight from dust grains driven away from the nucleus by the sublimation of volatile ices. Near the sun, sublimation of water ice (a main constituent of comet nuclei) is the source of cometary activity; but at its current heliocentric distance, Hale-Boop is too cold for this process to operate.

Chemical and thermal response of Jupiter's atmosphere following the impact of comet Shoemaker-Levy 9.

In July 1994, the collisions of the fragments of comet Shoemaker-Levy 9 with Jupiter resulted in dramatic changes in the planet's atmosphere. Observations of the events suggest that the composition and thermal properties of the atmosphere were considerably modified at the impact sites, with the changes persisting for times lasting from minutes to weeks (see, for example, refs 1-4). Here we report observations of the impact sites at millimetre wave-lengths, which reveal strong emission lines associated with carbon monoxide, carbonyl sulphide and carbon monosulphide.

The polymerase-associated protein (M1) and the matrix protein (M2) from a virulent and an avirulent strain of viral hemorrhagic septicemia virus (VHSV), a fish rhabdovirus.

We have cloned and sequenced the M1 and M2 genes of both a European (virulent) and a North American (avirulent) strains of viral hemorrhagic septicemia virus, an important fish pathogen. We also compared the transcription of the two genes following infection of cells and determined the phosphorylation status and detergent solubility of the two proteins. Despite a total lack of homology with any available rhabdoviral sequence, the two VHSV proteins share comparable structural features with their respective VSV and RV equivalents.