SATURDAY, SEPTEMBER 5, 2026 at 5.30 p.m. at the Astronomical Centre of Arson
VENUS AT THE TELESCOPE: DISCOVERING EARTH'S INFERNAL TWIN - Paolo D’Incà - (Rheticus)
“Pearl star in the veil of twilight, cloak of clouds hiding hell: the purest light of the serene sky guarding a fire of love and eternity. Turn the dial of the cold eyepiece: within the circle of lens the eye rests. And here yousuddenly see it tremble, an elegant crescent that soars into the dark...”
Visible like a bright star at dusk and dawn, Venus continues to represent one of the most fascinating and complex subjects for amateur and scientific astronomical observation. Often referred to as Earth's "twin" due to similar size and mass, the second planet of the Solar System actually hides a radically different and extreme environment from that of Earth.
What characterizes Venus is its intense atmospheric activity dominated by a thick veil of carbon dioxide, responsible for an uncontrolled greenhouse effect that keeps surface temperatures consistently above 450 °C. This dense cloud cover reflects most of the sunlight, making the planet the brightest object in the night sky after the Moon, while completely concealing its rocky surface from visible light observation.
For astronomers and astronomy enthusiasts, observing Venus through the telescope provides insights of great historical and scientific interest. The main feature is the cycle of phases (similar to those of the Moon), whose discovery by Galileo Galilei was crucial in demonstrating the heliocentric model. Venus transitions from a small, nearly full disc when far from the Sun to a large, thin crescent when approaching Earth.
This afternoon observation of Venus with the various telescopes of the Centre will allow us to discover how, quoting Galileo, the Mother of loves, Venus, imitates the figures of Cynthia, the Moon and will be followed by a conference, conducted by Paolo D’Incà from the Rheticus board, supported by spectacular images and videos of the planet.
