Thomas Widemann (OPSPM) Title: Category 5 Hurricane, acid rains and 96.5 % CO2 on our second closest neighbor ! Abstract: Venus is *not* an extrasolar planet! Like each of our Solar System neighbors, our sister planet (in size) boasts various challenging, unanswered astronomical questions that shed additional light on the problems facing the Earth. Brightest and closest object beyond our Moon, its surface is astonishingly new, probably 800 millions years old, with only 935 impact craters on record. Its highest peak, Maxwell Montes, is 10800 m high (35400 ft), slightly above Mauna Kea above its base (10,203 km / 33,476 ft). Its towering atmosphere crushes the surface under a pressure 93 times our Earth's, at a temperature of 460 ¡C (860 F) with thick layers of bright, opaque acid clouds between 45 and 70 km (148,000-230,000 ft). Venus' ultra-slow spin period (243 Earth's days) exceeds its orbital period (224.7 days), so the day on Venus lasts longer than a year. It has no natural satellite. The entire atmosphere (96.5% CO2 and 3.5% N2) rotates in a 4 days period, 60 times faster than the planet itself, with a maximum wind speed of100 ms-1 (225 mph) at 65 km altitude. The decrease of this huge atmospheric motion with altitude can only be measured with visible spectroscopy (70-78 km) and sub-millimeter wavelength observations (90-115 km). After this short introduction on Venus and our ESPaDOnS program, we will briefly discuss another research we conduct on distant, icy bodies of the solar system using predictions and observations of stellar occultations, a program which has benefited from WIRCAM observations in 2008.