Hera’s Thermal Infrared Imager (TIRI) instrument captured this image of Earth and the Moon from a distance of approximately 1.4 million kilometres. Earth is in the centre of the image and oriented with north pointing upwards, showing the East coast of the USA and the Atlantic Ocean. The Moon is visible in the top right of the image.
TIRI will image the Dimorphos asteroid in the mid-infrared spectral region to chart the temperature on the asteroid’s surface. By charting the ‘thermal inertia’ of surface regions – or how rapidly their temperature changes – physical properties such as roughness, particle size distribution and porosity can be deduced. TIRI was supplied by the Japan Aerospace Exploration Agency, JAXA, manufactured by Meisei Electric Co. Ltd. and inherited from the instrument onboard the agency’s Hayabusa2 asteroid mission, with contributions from The Belgian Science Policy Office (BELSPO).