Venus is hot right now.
Sorry; I don't want to sidetrack you into thinking about the planet's hellish surface, which is blistering enough to melt lead, nor evoke comparisons to the love goddess that shares its name.
Here's what's happening. Scientists are becoming increasingly eager to sort out a key question: Is Venus a sanctuary for microbial life?
Multiple research teams are developing missions designed to address the planet's potential as an abode for alien life — life that could be swirling high above the scorched surface within the relatively balmy Venusian clouds.
"Newer, nimbler, faster." That's the call stemming from a recently issued report led by a Massachusetts Institute of Technology (MIT)-led group that details a suite of privately funded missions to hunt for life on Venus.
The Venus Life Finder (VLF) missions are a series of three atmospheric probes designed to assess the habitability of the Venusian clouds and to search for signs of life there.
According to the report, the VLF missions would be a focused, optimal set of relatively low-cost efforts that can be launched quickly. The mission concepts come out of an 18-month study (opens in new tab) by an MIT-led worldwide consortium. The study was partially funded by the nonprofit Breakthrough Initiatives.
Ultimately, the appraisal concludes, scientists need to return to Earth a pristine sample of the Venusian cloud environment if they hope to address the Venus-life question with any robustness.
Dubbed the "fast" mission, the first VLF probe is designed to launch on a Rocket Lab Electron rocket, perhaps as early as 2023.
A cruise spacecraft would drop into the Venusian atmosphere a small entry craft that carries an instrument package. The fast mission's science goal is to measure various chemical abundances at different altitudes, including confirming the presence of phosphine gas — a potential sign of life that's a topic of considerable debate in the scientific community.
"We hope this is the start of a new paradigm where you go cheaply, more often, and in a more focused way," Sara Seager of MIT's Department of Earth, Atmospheric and Planetary Sciences, the principal investigator of the planned VLF missions, said in a statement late last year (opens in new tab).
"There are these lingering mysteries on Venus that we can't really solve unless we go back there directly," Seager added, saying that chemical anomalies leave room for the chance of life on that cloud-veiled world.
Seager was part of a team that reported in 2020 a detection of phosphine gas in Venus' atmosphere. On Earth, that gas is produced only by biological and industrial processes.
Since that claim, the phosphine discovery has been challenged. Still, Seager says the controversial finding has sparked positive momentum for the Venus missions. "The whole phosphine controversy made people more interested in Venus. It allowed people to take Venus more seriously," she said.
David Grinspoon, senior scientist for the Planetary Science Institute, which is headquartered in Tucson, Arizona, has been arguing for decades that Venus needs more exploration. He was a member of the MIT VLF study group and flags several recent shifts that have pushed Venus into the limelight.
One is the rise of exoplanet research and discoveries.
"Exoplanet scientists started to realize that if we don't understand Earth-Venus differences in our own solar system, how are we going to be able to determine what we are starting to see in classes of planets elsewhere? That was a shot in the arm for the Venus community," Grinspoon told Space.com. "It's sort of ‘ground truth' that we can get from our own solar system."
Another impetus of "why Venus now?" stems from new simulations known as general circulation models (GCMs), which suggest surprising, unexpected results — namely, that Venus may have been habitable to Earth-like life for long stretches in the past thanks to long-lasting surface water oceans.
"The implications are really startling," Grinspoon said. "There's a lot about this picture that needs to be confirmed. Indeed, that's one of the new motivations to go there. If true, it makes the history of Venus much more interesting than anyone ever thought. It gives us incentive to want to find out if it is true. Venus could have been habitable for a long time. The mystery has deepened and is now more enticing."
There is therefore new respectability for the idea that there could be a habitable zone in the clouds of Venus, even today, Grinspoon said. "It's a line that I have been pushing in the wilderness for decades."
Stirrings of momentum
In June 2021, three new missions to Venus were announced, two by NASA and one by the European Space Agency (ESA).
NASA's VERITAS, or Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy, will be the first NASA spacecraft to explore Venus since the 1990s. VERITAS will launch no earlier than December 2027 and will orbit Venus.
The NASA DAVINCI mission will launch in the late 2020s. After exploring the top of Venus' atmosphere, DAVINCI will drop a probe toward the planet's surface. On its hour-long descent, the probe will take thousands of measurements and snap up-close images of the surface.
ESA's EnVision will make detailed observations of Venus. As a key partner in the mission, NASA is providing the synthetic aperture radar instrument that will make high-resolution measurements of the planet's surface features.
Given the Venus Life Finder missions, the NASA and ESA projects and projected missions from India and Russia, "I see the stirrings of momentum," Grinspoon said. "There's so much that we don't know and so much data that we need."
Ready for action
Heartened by all the attention Venus is now receiving is Darby Dyar of Mount Holyoke College in Massachusetts. She chairs the Venus Exploration Analysis Group (VEXAG), NASA's community-based forum.
"I liken it to where we were for Mars in the mid-1990s. Back then, we didn't have a good map of Mars. We didn't know what the Martian geology was like and we didn't have the topography. We were just at the beginning of Mars exploration. Then all the missions followed, and we quickly checked all those boxes," Dyar said. "We're just at the infancy of Venus exploration, the early stages of a Venus program. Venus has a lot of catching up to do."
Dyar said the next thing that should happen in Venus exploration is working on landers. "Start with a small lander, then go to bigger and bigger landers. I'm hoping that's the direction we go."
Is the community of Venus researchers prepared to swing into action?
"You bet we are," Dyar said. "We are poised and ready to use modern data."
Leonard David is author of "Moon Rush: The New Space Race" (National Geographic, 2019). A longtime writer for Space.com, David has been reporting on the space industry for more than five decades. Follow us on Twitter @Spacedotcom (opens in new tab) or on Facebook (opens in new tab).