NASA is finally going to Venus. And the missions—two missions, actually—could shine a light on a planet that, despite being Earth’s closest neighbor, has been cloaked in clouds and mystery for a generation.
The space agency on Wednesday announced not one but two missions to Venus, the second planet from the Sun and, at no more than 150 million miles distant, the closest planet to Earth. Mars, the fourth rock from the sun, is 212 million miles from Earth at its closest.
“We know a lot about Mars and even Jupiter and Saturn,” John Logsdon, a former NASA adviser and ex-director of the Space Policy Institute at George Washington University, told The Daily Beast. “Venus is our nearest neighbor and is largely unexplored.”
NASA last went to Venus in 1990. That’s when the Magellan probe arrived over Mars for a four-year stay loosely mapping the volcanic planet. Spacecraft from foreign space agencies have visited since then—the European Space Agency sent a probe in 2006; the Japanese space agency visited in 2010—but NASA, despite its much greater resources, has sat it out, instead preferring to spend its time and money on missions to the moon and Mars.
But Venus is special. It’s not as close by, and it’s ripe for mining, as the moon is. It’s not as benign as Mars is, meaning it’s less welcoming to human explorers. But its poisonous sulfuric clouds and potentially volcanic surface could harbor important secrets that, if and when we crack them, could tell us as much about Earth as Venus.
Because Venus experienced its own global warming eons ago, the planet might hold clues about Earth’s future. And if there’s life, or evidence of extinct life, on its now-inhospitable surface, Venus might have something to tell us about our own planet’s distant past. We won’t know for sure until we get there.
“Venus is a near-twin to the Earth in many respects, so close and nearly identical in size, and for all we know the two planets were quite similar when young,” David Grinspoon, an astrobiologist with the Arizona-based Planetary Science Institute, told The Daily Beast. “But they’ve evolved down very different pathways. Venus has much to tell us about how Earth-like planets evolve, how their climates can change, how they can lose the surface conditions we depend upon for life and how the Earth may end up in the far future.”
“It’s a first-rate tragedy,” Seth Shostak, an astronomer who works for the California-based SETI Institute, told The Daily Beast. “Four billion years ago, Venus and Earth really were sister planets—oceans on both, atmospheres on both, et cetera. But like Jeffrey Dahmer, Venus went bad. Carbon dioxide built up in its atmosphere, fostering global warming at industrial scales.”
“Today, the daytime temperature on this planet is about 800 degrees,” Shostak added. “The oceans would have boiled away a long time ago, the atmospheric water vapor’s gone too. It’s become hell on Earth, except that it’s on Venus. Exactly how that happened, exactly how Venus chose Dante’s Inferno, is still being debated. But the whole story—like many tragedies—is interesting, and possibly relevant to our own…