The Moon is the most likely source of the neutral sodium, making this the first detection of the lunar sodium tail out to a distance of hundreds of lunar radii. The Na emission feature is marked with an arrow in both images. The general glow throughout the two images is due to the mesospheric sodium layer near 90 km altitude.
North is upwards and East is towards the left.
The 'V'-shaped Hyades cluster is visible to the left of the sodium spot in the November panels. Click to get back to the SPA GRL Homepage.