Here are the first test images of the Sun’s Corona taken by the ESA Proba-3 mission.
The images (one in visible light, the other in light emitted by iron atoms w/o half their electrons) were taken by the twin Proba-3 spacecraft, flying 150 m apart to create artificial total solar eclipses using the 1.4 m disc on the Occulter spacecraft.
Still in commissioning phase, Proba-3 requires ground control for precision flying.
Next: Autonomous flying and 6 hour eclipses!
The ESA Proba-3 mission, launched on Dec 5, 2024, consists of 2 spacecraft - the Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC), which will fly together in a 19.7 hour orbit. The OSC's 1.4m disk will eclipse the Sun, while the CSC, 150m away, will observe the Sun’s corona for 6h per orbit.
The 2 spacecraft will autonomously maneuver themselves using thrusters and align to within 1 mm accuracy, using radio links, cameras, lasers and other sensors.
Eclipses seen from Earth are used to study the Sun, but only for a few minutes every few years.
With Proba-3, artificial eclipses can be created lasting 6 hours every 19.6 hours!
Other spacecraft carry occulters and coronagraphs, e.g, the ESA/NASA Solar and Heliospheric Observatory (SOHO). It uses a occulter 0.7 m away that covers 2x the diameter of the Sun, to deal with stray light caused by diffraction.
Proba-3's disk, 150 m away, allows study within 1.1x radii.
This fascinating composite image uses data from observations made on 23 May 2025 by 3 different missions:
1. The Sun’s disc (artificially coloured in yellow), captured by the extreme-UV telescope (SWAP) aboard Proba-2
2. The outer corona (in red) imaged by the LASCO C2 coronagraph aboard SOHO, covering the area ~3x radii away from the Sun
3. The inner corona (in green), imaged by Proba-3’s ASPIICS coronagraph, covering the region from ~1.2 to 3 solar radii.
AkaSci 🛰️
Eric Jennings