Viewed from La Palma's highest point where enormous telescopes dot the rocky landscape, the Cumbre Vieja volcano looks like a distant puff of smoke breaking through a blanket of white cloud to create a sense of serene isolation.
But dust from the eruption, which has been wreaking havoc on the Spanish Canary island for more than 40 days, can clog up machinery, scratch lenses and cause electrical interference at the state-of-the-art observatory, hampering scientific work.
Most of the instruments are encased within huge domes that shut when there is risk of ashfall, but two so-called MAGIC telescopes, designed to detect gamma-ray bursts in distant galaxies via glittering mirror panels, have no such protection.
"We had to improvise a little," said Victor Acciari, the centre's technical coordinator, gesturing to a screen of black bin bags taped over the mechanisms that can spin the 60 tonne structure to focus on any part of the cosmos in 20 seconds.
"We had to cover the most delicate parts, especially the gearboxes and the parts covered in grease," said the 46-year-old astrophysicist and electrical engineer.
Minimal light pollution around La Palma, the westernmost of the Canaries and among the least populated, makes it an ideal site for astronomical observation.
Situated around 16 kilometres (10 miles) from the eruption site and 1,300 metres higher up, the observatory has found other ways to remain useful on nights when the ash cloud prevents the telescopes from operating.
"There are a number of instruments that can be helpful in monitoring the eruption," said the observatory's administrator, Juan Carlos Perez Arencibia.
Besides a fixed camera trained on the plume of ash emanating from the crater that helps Spanish authorities model the cloud's behaviour, the centre recently adapted its fibre-optic network to measure seismic activity.
"It is a new situation for all of us living on the island," Perez said.
"We are trying, even with our scientific work, to provide information to our international friends and colleagues on how they can help."
Experts say it is impossible to predict how long the eruption, which has forced thousands to evacuate and destroyed over 2,000 homes, will last.
"Some telescopes will need repairs to their domes...but it's relatively simple maintenance. Operations will restart quickly," Perez said.
