A satellite of the European Space Agency (ESA) was hit by a space particle, damaging the instrument's solar panel.

ESA's Copernicus Sentinel-1A satellite was doing its routine operation on Aug. 23 when a tiny piece of space debris or micrometeoroid hit the observation instrument and punched a hole in the solar wing. On-board cameras showed that the hole was about 40 centimeters in diameter. So far, the blow did not affect the satellite's routine operations.

"Such hits, caused by particles of millimeter size, are not unexpected," Holger Krag, head of Space Debris Office at ESA's headquarters in Darmstadt, Germany, said in a press release.

"These very small objects are not trackable from the ground, because only objects greater than about 5 cm can usually be tracked and, thus, avoided by maneuvering the satellites."

The blow caused a sudden slight power reduction in the solar array of the satellite, which was orbiting at 700 km altitude. The incident also caused slight changes in the orientation and the orbit of the satellite. A video published in Space shows an overview of the incident.

Following the power loss, scientists conducted a detailed analysis of the satellite's status. The engineers also activated the board cameras to capture images of the solar array. The on-board cameras were originally carried to monitor the deployment of the solar wings.

According to ESA officials, the power loss was relatively small compared to the overall power generated by the solar wing, which remains higher than what is normally required by the satellite during routine operations.

"Analysis continues to obtain indications on whether the origin of the object was natural or man-made. The pictures of the affected area show a diameter of roughly 40 cm created on the solar array structure, confirming an impact from the back side, as suggested by the satellite's attitude rate readings," Krag added.

The Sentinel-1 satellites are part of the European Union's Copernicus Program and operated by ESA.