Abstract
In this chapter we examine how our knowledge of present day Venus can
inform terrestrial exoplanetary science and how exoplanetary science can
inform our study of Venus. In a superficial way the contrasts in
knowledge appear stark. We have been looking at Venus for millennia and
studying it via telescopic observations for centuries. Spacecraft
observations began with Mariner 2 in 1962 when we confirmed that Venus
was a hothouse planet, rather than the tropical paradise science fiction
pictured. As long as our level of exploration and understanding of Venus
remains far below that of Mars, major questions will endure. On the
other hand, exoplanetary science has grown leaps and bounds since the
discovery of Pegasus 51b in 1995, not too long after the golden years of
Venus spacecraft missions came to an end with the Magellan Mission in
1994. Multi-million to billion dollar/euro exoplanet focused spacecraft
missions such as JWST, ARIEL and their successors will be flown in the
coming decades. At the same time, excitement about Venus exploration is
blooming again with a number of confirmed and proposed missions in the
coming decades from India, Russia, Japan, the European Space Agency
(ESA) and the National Aeronautics and Space Administration (NASA). In
this chapter, we review what is known and what we may discover tomorrow
in complementary studies of Venus and its exoplanetary cousins.