NASA is going back to Venus after 30 years for an apocalyptic reason

After more than 30 years away, NASA is going back to a place its administrator describes as a “hot, hellish, unforgiving” world.

NASA Administrator and former astronaut Senator Bill Nelson announced today that the agency would be sending two missions to Venus. The two missions, called DAVINCI+ and VERITAS, will respectively study the planet’s atmosphere and geological history.

“These two sister missions both aim to understand how Venus became an inferno-like world capable of melting lead at the surface,” Nelson said during his State of NASA address. “They will offer the entire science community the chance to investigate a planet we haven’t been to in more than 30 years.”

These two new projects have been awarded $500 million in funding each, and are expected to launch between 2028 and 2030. They were selected from a batch of four possible missions selected by NASA’s Discovery Program in 2020.

Why is NASA going back to Venus?

The last time NASA launched a mission to study Venus was in 1989, with a satellite named Magellan. The orbiter was equipped with a radar system that allowed a view past Venus’ thick clouds and forms much of what we know today about the planet.

We don’t have an immense amount of information about the second planet from the Sun, but in 2016 NASA computer models of Venus suggested it might have had a habitable surface temperature and shallow water-filled oceans for up to 2 billion years.

But how that landscape turned into the uninhabitable hellscape Venus appears to be today is unknown. VERITAS and DAVINCI+ could help reconstruct what happened on Venus that led to a runaway greenhouse effect.

Understanding this process of Venusian climate change could be crucial to understanding how our own planet’s climate is changing, NASA said in a press release announcing the projects’ approval.

So while the colonization of Mars might be the future for humans as an interplanetary species, Venus could help us understand how to make sure our home planet stays habitable.

“Using cutting-edge technologies that NASA has developed and refined over many years of missions and technology programs, we’re ushering in a new decade of Venus to understand how an Earth-like planet can become a hothouse,” said Thomas Zurbuchen, NASA’s associate administrator for science, in a press statement.

Temperatures on our sister planet reach near 900 degrees Fahrenheit and the atmosphere is a slurry of toxic chemicals like carbon dioxide and sulfuric acid.

A team from NASA’s Goddard Institute for Space Studies put forth a theory on what might have taken place:

• Since Venus is closer to the Sun and spins on its axis much slower than Earth, solar radiation slowly baked the moisture off the surface into a thick layer of clouds.
• From there, radiation slowly broke water vapor apart, and allowed hydrogen to escape Venus’ atmosphere.
• With less water to form vapor clouds and shield the surface from the Sun’s rays, carbon dioxide built up in the planet’s atmosphere, giving rise to a runaway greenhouse effect.

What are the VERITAS and DAVINCI+ missions’ goals?

The DAVINCI+ mission has been pitched as a spacecraft that will drop a spherical probe into the planet’s atmosphere, measuring the chemical makeup of each layer. After the probe is dropped, the spacecraft will orbit the planet for a Venus year, or 225 Earth days, collecting ultraviolet and infrared images.

The mission name is short for “Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus.”

• The probe would contain its own chemistry lab, including a similar mass spectrometer and laser spectrometer to the Curiosity rover instruments on Mars.
• It would specifically be looking for noble gases like krypton, argon, neon, and xenon, which would help draw parallels between Venus and Earth’s atmospheres.

However, this lab will have to be able to take measurements amid the extreme heat and pressure of Venus’ atmosphere.

The plus sign appended to the end of the DAVINCI+ mission name denotes an added bonus of dropping equipment onto Venus: The ability to snap pictures. A “descent imaging system” will take high-res images and 3D topographic data, which will be transmitted back to Earth for analysis.

The other mission, VERITAS, is also an acronym that stands for “Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy.” While DAVINCI+ will focus on the chemical makeup of the atmosphere, VERITAS will map the geological features of Venus.

The spacecraft will orbit Venus, using radar to create 3D topographic maps of the surface and measuring the planet’s gravitational pull, according to a blog post on the mission from July 2020.

This data will help determine whether Venus has tectonic plates similar to Earth’s, as well as give insight into Venutian structures called tessera. Tessera are enormous structures similar to plateaus, NASA writes, which could have been similar to Earth’s continents if Venus was once covered in water.

VERITAS will also study infrared emissions from the planet to determine whether Venus has volcanic activity by analyzing rocks to see how recently they were formed.

The VERITAS mission is an international effort, with German, Italian, and French space agencies all contributing radar systems and other hardware to the mission.

Together, the two missions will paint a nearly complete picture of modern Venus, and offer data to help decode its past.

“It is astounding how little we know about Venus, but the combined results of these missions will tell us about the planet from the clouds in its sky through the volcanoes on its surface all the way down to its very core,” Tom Wagner, NASA’s Discovery Program scientist, said in a press statement. “It will be as if we have rediscovered the planet.”