James Webb may soon search for planets in the Venus Zone – Here's why

Some scientists believe that Venus may have once been habitable before it became the fiery planet — known as Earth's evil twin — that it is today.

In fact, the researchers behind the new James Webb proposal believe that the detection of gases such as methane or nitrous oxide in Venus-like exoplanets could indicate that life exists on those planets.

"Detecting those molecules on an exoVenus would show that habitable worlds can exist in the Venus Zone and strengthen the possibility of a temperate period in Venus’ past," Colby Ostberg, a UCR Ph.D. student, explained in a press statement.

Ostberg led a study aimed at identifying five Venus-like planets from a list of 300 that would be ideal candidates for future James Webb observations. Their search highlighted criteria including size, mass, and orbital paths. The researchers, who published their findings in The Astronomical Journal, also looked for planets orbiting bright stars so as to give Webb the best light conditions for observing the planets.

James Webb to shed new light on planetary evolution

Those future observations could help to answer a very interesting question. As Kane put it, "Is Earth weird, or is Venus the weird one?"

“It could be that one or the other evolved in an unusual way, but it’s hard to answer that when we only have two planets to analyze in our solar system, Venus and Earth," he explained. "The exoplanet explorations will give us the statistical power to explain the differences we see."

If James Webb data shows us that most planets in the Venus Zone exhibit a similar fiery evolution to our planetary neighbor, that could actually be a cause for concern.

"That would be a warning for us here on Earth because the danger is real," Kane said. "We need to understand what happened there to make sure it doesn’t happen here."