To the Sun and back

This sequence of images shows the progress of the ESA/NASA Solar Orbiter spacecraft as it heads inwards towards the Sun and through its closest approach on 26 March 2022. The sequence begins on 30 January and completes on 4 April, by which time the spacecraft is moving away from the Sun again.

The sequence was taken by the Extreme Ultraviolet Imager (EUI) using the Full Sun Imager (FSI) telescope, and shows the Sun at a wavelength of 30 nanometers. This wavelength is emitted by a form of helium gas that is found mainly in a region of the Sun’s atmosphere called the transition region. This is the interface between the lower and upper layers of the solar atmosphere. It is only 100 km in height, yet the temperature here increases by a factor of 50 to reach the one million degrees displayed by the corona. Solar Orbiter is investigating why there is this huge increase.

The colour on this image has been artificially added because the original wavelength detected by the instrument is invisible to the human eye. Occasionally the image appears to jump. This happens on the days that EUI was not returning data to Earth. The coloured bar at the top of the image shows the impressive amount of data collected in this period, together with these brief gaps in the data coverage.