Material that allows safe viewing of the Sun by blocking nearly all of its light. Proper filters should completely cover the front aperture of a telescope and should never be attached to the eyepiece; they range from glass used by welders to special plastic film. White-light filters will show sunspots, while hydrogen-alpha (Hα) filters let certain red light through that reveals the Sun’s streaming hot gases.
Hera mission plans Mars flyby en route to asteroid study
Hera mission plans Mars flyby en route to asteroid study by Erica Marchand Paris, France (SPX) Apr 26, 2024 ESA's...
