On September 23, Sydney woke up to a surreal scene that looked more like Mars than Australia. The entire city had turned red due to an enormous dust storm. Our readers in Sydney sent us their eerie photos of this event as it was happening. NASA's Terra satellite also captured the incredible event in these images with a spectroradiometer.

Above, the wall of dust blown from inland stretches along the populated coast around Sydney on the morning of September 23. The outline of the continent is faintly traced in the image for reference. Individual point sources for the dust can be discerned. And, according to NASA and the Australian Broadcasting Corporation, some of them were identified as rectangular agricultural plots that have been dried out by several years of drought in Australia. A high-resolution image is available from NASA.

Below, the Terra satellite imaged the dust beneath storm clouds the next morning, September 24, as it blew south across the Tasman Sea toward New Zealand, which is in the bottom right corner of the image. The picture covers 1,450 miles from north to south with a resolution of 155 miles per pixel. At this point, the plume had stretched 2,700 miles, roughly the width of the continental United States. A high-resolution image is available from NASA.

Images: NASA

See Also:

Follow us on Twitter @betsymason and @wiredscience, and on Facebook.