Prometheus (volcano)

Galileo color mosaic of the volcano Prometheus and its eruption plumes. Prometheus Patera is the kidney-shaped dark region at upper right; the magma source vent is situated in the narrow "neck" directly below it. From the latter, the western flow field stretches to the left, with most of the SO₂ plumes being erupted from the flow margins at the left end.^[1]

Prometheus is an active volcano on Jupiter's moon Io. It is located on Io's hemisphere facing away from Jupiter at 1°31′S 153°56′W / 1.52°S 153.94°WCoordinates: 1°31′S 153°56′W / 1.52°S 153.94°W.^[2] Prometheus consists of a 28-kilometer (17 mi)-wide volcanic pit named Prometheus Patera and a 100-kilometer (62 mi)-long compound lava flow, all surrounded by reddish sulfur and circular, bright sulfur dioxide volcanic plume deposits.^[3] The volcano was first observed in images acquired by the Voyager 1 spacecraft in March 1979.^[4] Later that year, the International Astronomical Union named this feature after a Greek fire god, Prometheus.

Prometheus is the site of a volcanic eruption that has been ongoing since at least the Voyager 1 encounter in 1979. Between the Voyager encounters and the first observations by Galileo, a 6,700-square-kilometer (2,600 sq mi) flow field was emplaced.^[5] Later Galileo observations of this flow field revealed numerous small breakouts, particularly on the western end of the flow field.^[6]

Prometheus is the site of two volcanic eruption plumes: a small, sulfur-rich plume erupting from the magma-source vent at the eastern end of the flow field and a 75-to-100-kilometer (47 to 62 mi)-tall, SO
2-rich dust plume erupting from the active flow front at the other end.^[3] The former forms a diffuse, red deposit to the east of the Prometheus flow field. The latter forms a bright, circular deposit surrounding the entire volcano and lava flow. The SO
2-rich plume is generated as lava at the western end of the flow field covers sulfur dioxide frost, heating and vaporizing it.^[7] This is accomplished at multiple breakouts, generating gas and dust for the visible dust plume.^[8] Prometheus' plume has been observed by both Voyager spacecraft, Galileo, and New Horizons, at every appropriate imaging opportunity.

References

1. Leone, G.; Gerard Davies, A.; Wilson, L.; Williams, D. A.; Keszthelyi, L. P.; Jaeger, W. L.; Turtle, E. P. (2009). "Volcanic history, geologic analysis and map of the Prometheus Patera region on Io". Journal of Volcanology and Geothermal Research 187: 93. Bibcode:2009JVGR..187...93L. doi:10.1016/j.jvolgeores.2009.07.019.
2. Blue, Jennifer (October 1, 2008). "Io Nomenclature: Eruptive center". USGS. Retrieved 2008-10-01.
3. Davies, A. (2007). "Prometheus and Amirani: effusive activity and insulated flows". Volcanism on Io: A Comparison with Earth. Cambridge University Press. pp. 208–216. ISBN 0-521-85003-7.
4. Smith, B. A.; et al. (1979). "The Jupiter system through the eyes of Voyager 1". Science 204 (4396): 951–972. Bibcode:1979Sci...204..951S. doi:10.1126/science.204.4396.951. PMID 17800430.
5. McEwen, A. S.; et al. (1998). "Active Volcanism on Io as Seen by Galileo SSI". Icarus 135: 181–219. Bibcode:1998Icar..135..181M. doi:10.1006/icar.1998.5972.
6. Keszthelyi, L.; et al. (2001). "Imaging of volcanic activity on Jupiter's moon Io by Galileo during the Galileo Europa Mission and the Galileo Millennium Mission". J. Geophys. Res. 106: 33025–33052. Bibcode:2001JGR...10633025K. doi:10.1029/2000JE001383.
7. Kieffer, S.W.; et al. (2000). "Prometheus: Io's Wandering Plume". Science 288 (5469): 1204–1208. Bibcode:2000Science.288.1204. doi:10.1126/science.288.5469.1204.
8. Milazzo, M. P.; et al. (2001). "Observations and initial modeling of lava-SO
   2 interactions at Prometheus, Io". J. Geophys. Res. 106: 33121–33128. Bibcode:2001JGR...10633121M. doi:10.1029/2000JE001410.