Control Panel
Select a collection:
Choose image type to download: Resolution: dpi Scale: %

Star trails and Pinatubo dust, centred the AAT dome

Tags: dust, AAT, reflection

On June 15, 1991, after weeks of rumbling and venting steam laden with toxic gas, Mt Pinatubo exploded on the island of Luzon, in the Phillipines. This was the largest volcanic eruption anywhere for nearly a century. The power of the eruption ejected several cubic kilometers of dust and gas over 35 km high into the stratosphere, and 700 people lost their lives.

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 world's weather pattern. However, the most obvious effect for many people was a milkiness in the daytime sky due to scattering by high altitude aerosols. This material also produced prolonged and colourful twilights that were noticeable for years after the explosion, especially by astronomers.

This picture was made nine months or so after the eruption, in January 1992. The exposure was started two hours after sunset, when it is usually completely dark. High altitude dust in the stratosphere scattered the light from over-the-horizon sunsets strongly enough for them to be seen (in the sky, at right) and to be reflected again, by the AAT dome. The red reflection and dusty glow in the sky was captured in this six-hour exposure. Here the camera is pointing directly at the south celestial pole, hidden by the AAT dome. 

Credit: David Malin

© Australian Astronomical Observatory