AAO image reference MISC 7. « Previous || Next »
Image and text © 1991-2002, Australian Astronomical Observatory, Photograph by David Malin.
On June 15, 1991, after weeks of rumbling and venting steam and poisonous gas, Mt Pinatubo exploded on the island of Luzon, in the Phillipines. This was the largest volcanic eruption for nearly a century. The eruption killed over 700 people and ejected several cubic kilometers of dust and gas over 35km high into the stratosphere.
The effects were felt around the world and included a temporary global cooling and a thinning of the ozone layer as well as other changes in the global weather pattern. However, the most obvious effect for many people was a milkiness in the daytime sky due to scattering by high altitude aerosols, and corresponding anomalous sunsets and twilights that were noticable for years.
This picture was made 9 months or so after the eruption, in early 1992. The exposure was started two hours after sunset, when it is usually completely dark. However, high altitude dust in the stratosphere reflected sunset colours strongly enough for them to be seen (in the sky, at right) and to be reflected again, by the AAT dome. The red reflection was captured in this six-hour exposure. Here the camera is pointing directly at the south celestial pole. However, the position of the pole is hidden by the AAT dome. The appearance of the twilight sky immediately after sunset is seen here.
More star-trail images
AAT 5. Star trails southwest of the AAT dome
AAT 6. Star trails around the south celestial pole
MISC 8. Aurora Australis from Siding Spring
MISC 11. Orion star colours, step-focus technique
MISC 12. Orion's belt rising over the lights of Coonabarabran
MISC 13. North celestial pole star trails
MISC 14. South celestial pole star trails
MISC 15. North and South celestial poles star trails
MISC 16. Southern Cross and Pointers, star colours - step-focus technique, long trails
MISC 17. Pinatubo dust colours the twilight
MISC 18. The view to the north from Siding Spring
MISC 19. Sunset 'star' trail, the track of the setting sun
MISC 22 The AAT dome from the Director's Cottage.
MISC 23 Southern Cross and Pointers, star colours - step-focus technique, short trails