宇宙から見た日食

About this image

On 12 August 2026, about nine hours before the total solar eclipse seen from Earth, the Moon passed in front of the Sun as seen from ESA's Proba-3, about 58,000 km above the Earth. Proba-3 is two spacecraft flying in formation: one blocks the Sun so that the other's coronagraph, ASPIICS, can image the corona in an artificial eclipse. The Moon covered the Sun while it was observing, which ESA called a "double eclipse". This is one moment of it, 08:40 UTC, joined with SOHO/LASCO (from the L1 point between the Sun and the Earth) and NASA's PUNCH (low Earth orbit), which recorded the outer corona within about half an hour: the corona from the Moon's edge out to Venus, 46° from the Sun. The ecliptic runs horizontally; Venus and Regulus are on the left (east), Jupiter and Mercury on the right (west).

How it was made

• Proba-3/ASPIICS, from the Moon's edge to about 3 solar radii: calibrated Level-2 frames; each set of 0.1, 1 and 10 s exposures merged into one high-dynamic-range image, and two sets 17 s apart averaged
• SOHO/LASCO C2 and C3, to about 25 solar radii: divided by a background built from about a month of frames (F corona, stray light); the median of the 3 frames nearest the moment, of 7 (about an hour) where the field is faint
• PUNCH, beyond: Level-3 low-noise mosaic (F corona and stars removed by the PUNCH pipeline)
• Each instrument's brightness is taken relative to its average at each distance from the Sun and matched to its neighbours where they overlap; the fade with distance is kept, strongly compressed
• Distance from the Sun is at true scale near the Sun and compressed logarithmically far out, so the eclipse and Venus fit in one frame: directions are true, distances are not to scale

Notes

• The colour is a display choice: the data are monochrome and the corona's true colour is white. Colour codes distance from the Sun: gold near the Sun, white in the middle corona (about 5–25 solar radii, LASCO's field), turning blue beyond (PUNCH's field).
• No instrument sees the north-west sector between about 3 and 21 solar radii at this moment: the arms holding LASCO C2's and C3's occulters both shade it. That sector (12.7% of the 2.5–40 solar-radii ring) is filled with a smooth surface that meets the corona on every side, and shows as a softer wedge.
• The stars are drawn from the HYG catalogue v3.8 (30,148 stars; 80% of the stars PUNCH recorded in these minutes match one). Their colours come from the B−V index, shown 1.5 times as strong as true. Mercury, Venus and Jupiter saturate PUNCH, so they are drawn at their computed positions, brightness and colour. The glow around bright points is a display effect.
• Noise is smoothed in LASCO and PUNCH, more far out and mostly along the radius. PUNCH's star residuals are cleaned; the planets, bright stars and their bleed trails, and the Moon as PUNCH saw it are masked; soft patches beyond 40 solar radii are flattened. Proba-3's occulter shading was measured on the image and divided out, and the last few pixels at the Moon's edge interpolated. The Moon's disc is shown black (inside it the instrument records its own stray light, not the Moon).
• Nothing was cloned or generated with AI, and nothing was added to the corona. For illustration, not photometry.
• Software, data and a data-only version of this view (stars and planets as recorded, nothing filled, cleaned or smoothed): doi:10.5281/zenodo.23392795