From the October 2011 issue

To avoid dew, do professional observatories heat the mirrors and lenses like we amateurs do?

Luciano Puperi Muller, Guaporé, Rio Grande do Sul, Brazil
By | Published: October 24, 2011 | Last updated on May 18, 2023

Due to the mass of the mirror surfaces, the amount of heat required to avoid the condensation of water would distort the incoming light and ruin the desired quality of the data. Most professionals avoid dew by closing the observatory well before a dew event is imminent.