NASA’s sudden interest in Venus is all about climate change

Recently, NASA Administrator Bill Nelson announced that the space agency will send not one but two robotic probes to Venus under the Discovery program. The probes are DAVINCI+ and VERITAS. The two probes, which are due to be launched by the end of the 2020s, will be the first dedicated NASA missions to the second planet from the sun in decades. Why Venus and why now?

After all, a great many planetary probes, orbiters, landers and rovers have gone to Mars. Probes from three nations, the United States, China and the UAE, arrived at the Red Planet in 2021. Mars is getting all of the attention because some day humans from the planet Earth are going to pay it a visit. SpaceX’s Elon Musk wants to take settlers to the Red Planet to live there.

Also, by choosing two missions to Venus, NASA has decided not to fund missions to Io, a volcanic moon of Jupiter, or Triton, a moon of Neptune. Either undertaking would have been at least as scientifically interesting as Venus.

Nobody is anxious to visit the surface of Venus anytime soon. Venus is a hell world with an atmosphere composed of carbon dioxide and clouds of sulfuric acid. The average surface temperature is roughly 900 degrees Fahrenheit. The atmospheric pressure on the surface of Venus is 90 times that of the Earth’s surface. Robotic probes that have landed on Venus, such as the Soviet Venera, have lasted hours before being crushed and cooked by the extreme conditions.

The reason for NASA’s sudden decision to send probes to Venus has to do with the Biden administration’s new priority of studying and doing something about climate change. NASA scientists have concluded that for the first 2 billion years of its existence, Venus was remarkably like Earth, with oceans and perhaps life of some sort. However, a runaway greenhouse effect occurred that eventually created the planet that Venus is today.

Live Science suggests that, while the scientific community holds to a growing consensus that current climate change on Earth is driven by human action, mainly by carbon dioxide emitted by power plants and automobiles, natural processes can also cause the phenomenon. The sun’s output and changes in the Earth’s axial tilt can affect climate. How much climate change is caused by human activity and how much is caused by natural processes will inform public policy responses to the phenomenon.

Venus provides a model of how climate change can occur entirely due to natural processes. No one thinks that ancient Venusians caused the phenomenon with SUVs and fossil fuel plants. Hence, NASA is sending two robotic probes that will delve into the mechanisms that changed Venus from an Earth-like world to the uninhabitable mess that it is today. The space agency describes what the two probes will do.

DAVINCI+ will “measure the composition of Venus’ atmosphere to understand how it formed and evolved, as well as determine whether the planet ever had an ocean. The mission consists of a descent sphere that will plunge through the planet’s thick atmosphere, making precise measurements of noble gases and other elements to understand why Venus’ atmosphere is a runaway hothouse compared the Earth’s.” The probe will also “return the first high-resolution pictures of the unique geological features on Venus known as ‘tesserae,’ which may be comparable to Earth’s continents, suggesting that Venus has plate tectonics.”

VERITAS will “map Venus’ surface to determine the planet’s geologic history and understand why it developed so differently from Earth. Orbiting Venus with a synthetic aperture radar, VERITAS will chart surface elevations over nearly the entire planet to create 3D reconstructions of topography and confirm whether processes such as plate tectonics and volcanism are still active on Venus.” The probe will also “map infrared emissions from Venus’ surface to map its rock type, which is largely unknown, and determine whether active volcanoes are releasing water vapor into the atmosphere.”

Climate scientists, like all scientists, are hungry for more data. Venus provides another opportunity to understand what causes climate to change besides studying the process on Earth. With more data at hand, public policy decision makers will be better able to enact laws and regulations that will moderate climate change on Earth without tanking the economy. “Follow the science” is often used as a political slogan. But it is a sound practice so long as the science is backed up by data.

Mark Whittington, who writes frequently about space and politics, has published a political study of space exploration entitled Why is It So Hard to Go Back to the Moon? as well as “The Moon, Mars and Beyond,” and, most recently, “Why is America going back to the Moon.” He blogs at Curmudgeons Corner. He is published in the Wall Street Journal, Forbes, The Hill, USA Today, the LA Times and the Washington Post, among other venues.