6 juin 2012
Astronomers around the world looked to the sky last night and this
morning to observe Venus as it passed across the face of the Sun
for the last time this century. ESAs Sun-watching space missions
also tuned in for the solar spectacular.
ESAs microsatellite Proba-2, situated in low-Earth orbit,
tracked Venus as it moved across the solar disc over a period of
nearly seven hours. Venus appears to wobble thanks to the slight
up-down motion of Proba-2 and the large distance between the satellite
and the Sun.
Transit of Venus as seen from Svalbard
Of particular interest was the moment of first contact when
Venus first appeared to touch the limb of the solar disc
resulting in a tiny dip in solar brightness. The dip associated
with Venus thick atmosphere, even before Venus had fully entered
the solar disc, will help exoplanet scientists study the atmospheres
of rocky Earth-sized planets outside of our Solar System.
Another phenomenon observed during the transit included the black
drop effect the small black teardrop shape that appears
to connect Venus to the limb of the Sun just after it has fully
entered the solar disc and again later, when it begins to leave
Voir la vidéo ci-dessous