When the DAVINCI+ and VERITAS missions to Venus were given the green light by NASA last week, the scientific community was stunned. Most had expected that NASA, which hadn’t launched a dedicated mission to Venus in 30 years, would be sending at least one mission to the second planet from the sun by the end of the decade. Two missions, however, blew everyone’s mind.
Maybe NASA anticipated something we’re only just wrapping our heads around: DAVINCI+ and VERITAS will have a tremendous impact not just when it comes to Venus and solar system exploration, but also when it comes to our understanding of habitable, life-bearing worlds outside our solar system itself.
As our exoplanet discoveries continue to pile up (and we've spotted over 11,000 possible exoplanets so far) we need to learn whether an Earth-sized planet is more likely to look like Earth, or more likely to look like Venus. “We don't know which of those outcomes is the expected or likely one,” says Paul Byrne, a planetary scientist at North Carolina State University. And to find that out we need to understand Venus a lot better.
With surface temperatures of 471 °C and surface pressures 89 times worse than Earth’s, it seems impossible that water might have once existed on Venus. But Venus and Earth are about the same size, same ages, and our best guess is they are made of comparable materials and were born with very similar starting conditions. Venus is 30% closer to the sun than Earth, which is significant, but not overwhelmingly so. And yet after 4.5 billion years, these two planets have fared very differently.