That white speck is a weather Balloon. The balloons are released at 8.30 a.m. every morning at the Giles Weather Station near Warakurna. I was there to see one released at Eucla in 2008 and now this one at Giles. The balloons carry instruments that record atmospheric, or barometric pressure, temperature, humidity, and wind speed. The data is sent back to the weather station and forms part of the weather data system across Australia for the Bureau of Meteorology Simple and effificient.
Atmospheric pressure indicates types of weather. Low atmospheric pressure indicates cloudiness, wind, and rain