High-resolution visible and thermal infrared images captured by a joint NASA-Japanese satellite sensor have provided the first clear glimpse of the Icelandic volcano Eyjafjallajökull that began erupting last week.

The images, taken by NASA's Earth-orbiting Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) instrument, show that although the volcano's infamous ash plume is receding, its internal temperature is rising.

Eyjafjallajökull appears on the left side of the images as a bright spot with a cloud emanating from it. More images are available here.

(Photo Credit: Michael Ramsey)

ASTER usually centers on the north Pacific region, but the satellite was redirected to Iceland to help scientists at the Iceland GeoSurvey (ÍSOR) who cannot safely approach the volcano.

Unlike standard weather-satellite images, the high-resolution pictures from ASTER can help scientists determine the plume's chemical composition and thickness, the location of lava flows, and the volcano's internal temperature.

The data can also help better monitor the volcano's activity, particularly its worrisome effect on the nearby and much larger volcano Katla, which in the ASTER images is seen as a large off-color area to the right of Eyjafjallajökull. In the past, Katla has erupted every time Eyjafjallajökull has, though the ASTER images so far show no signs of an imminent explosion.

(Photo Credit: Michael Ramsey)