Artist’s illustration of NASA’s VERITAS spacecraft in orbit around Venus. (Credit: NASA/JPL-Caltech)
In a win for planetary scientists, and planetary geologists in particular, it was announced at the recent 55th Lunar and Planetary Science Conference (LPSC) in Texas earlier this month that NASA’s VERITAS mission to the planet Venus has been reinstated into NASA’s Fiscal Year 2025 (FY25) budget with a scheduled launch date of 2031, with the unofficial announcement coming on the first day of the conference, March 11, 2024, and being officially announced just a few days later. This comes after VERITAS experienced a “soft cancellation” in March of last year when NASA revealed its FY24 budget, providing VERITAS only $1.5 million, which was preceded by the launch of VERITAS being delayed a minimum of three years due to findings from an independent review board in November 2022.
Artist's illustration of Quetzalpetlatl Corona on Venus displaying both active volcanism and a subduction zone. (Credit: NASA/JPL-Caltech/Peter Rubin)
While Earth and Venus are approximately the same size and both lose heat at about the same rate, the internal mechanisms that drive Earth’s geologic processes differ from its neighbor. It is these Venusian geologic processes that a team of researchers led by NASA’s Jet Propulsion Laboratory (JPL) and the California Institute of Technology hope to learn more about as they discuss both the cooling mechanisms of Venus and the potential processes behind it.
The search for life on Venus has a fascinating history. Carl Sagan famously and sarcastically said there were obviously dinosaurs there since a thick haze we couldn’t see through covered the surface. More recently, evidence has pointed to a more nuanced idea of how life might exist on our sister planet. A recent announcement of phosphine in the Venusian atmosphere caused quite a stir in the research community and numerous denials from other research groups. But science moves on, and now some of the researchers involved in the phosphine finding have come up with a series of small missions that will help settle the question more thoroughly – by directly sampling Venus’ atmosphere for the first time in almost 40 years.
Planets move in mysterious ways. Or at least their surfaces do. Earth famously has a system of tectonic plates that drives the movement of its crust. Those plate tectonics are ultimately driven by the flow of material in the mantle – the layer directly below the crust. Now, scientists have found a slightly different deformation mechanic on our nearest sister planet – Venus.
Venus' surface features are revealed in an image based on data from NASA's Magellan spacecraft and Pioneer Venus Orbiter. (NASA / JPL-Caltech)
NASA’s planetary science program is making a big bet on Venus, after decades of putting its chips on Mars in the search for hints of past or present life out there in the solar system.
The bet comes in the form of a double dose of development funding for Discovery Program missions, amounting to as much as $1 billion. Both DAVINCI+ and VERITAS were selected from a field of four finalists in a competitive process — leaving behind missions aimed at studying Jupiter’s moon Io and Neptune’s moon Triton.
“These two sister missions are both aimed to understand how Venus became an inferno-like world capable of melting lead at the surface,” NASA Administrator Bill Nelson said June 2 in his first “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.”
Lessons from Venus, which underwent a runaway greenhouse effect early in its existence, could improve scientists’ understanding of our own planet’s changing climate. The missions could also address one of the biggest questions about the second rock from the Sun: whether life could exist in the upper reaches of its cloud layer.
The planet Venus, as imaged by the Magellan mission. Credit: NASA/JPL
The discovery of phosphine in the upper clouds in Venus’ atmosphere has generated a lot of excitement. On Earth, phosphine is produced biologically, so it’s a sign of life. If it’s not produced by life, it takes an enormous amount of energy to be created abiologically.
On other planets like Jupiter, there’s enough energy to produce phosphine, so finding it there isn’t surprising. But on a small rocky world like Venus, where there’s no powerful source of energy, its existence is surprising.
A radar image of Maat Mons on Venus, from the Magellan spacecraft. Image Credit: NASA/JPL
Venus’ surface is no stranger to volcanoes. Radar images show more than 1,000 volcanic structures on the planet. But for the most part, they appear to be ancient and inactive.
Now a new study says that Venus is still volcanically active, and has identified 37 volcanic structures that were recently active. If true, there’s more going on inside Venus than thought.
Artist's concept of the VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) spacecraft, a proposed mission for NASA's Discovery Program that would launch by the end of 2021. Credit: NASA/JPL-Caltech
In February of 2014, NASA’s Discovery Program asked for proposals for the their 13th mission. Last week, five semifinalist were selected from the original 27 submissions for further investigation and refinement. Of the possible missions that could be going up, two involve sending a robotic spacecraft to a planet that NASA has not been to in decades: Venus!
The first is the DAVINCI spacecraft, which would study the chemical composition of Venus’ atmosphere. Meanwhile, the proposed VERITAS mission – or The Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy spacecraft – would investigate the planet’s surface to determine just how much it has in common with Earth, and whether or not it was ever habitable.
In many respects, this mission would pick up where Magellan left off in the early 1990s. Having reached Venus in 1990, the Magellan spacecraft (otherwise known as the Venus Radar Mapper) mapped nearly the entire surface with an S-band Synthetic Aperture Radar (SAR) and microwave radiometer. From the data obtained, NASA scientists were able to make radar altimeter measurements of the planet’s topography.
Deployment of the Magellan spacecraft with the Inertial Upper Stage (IUS) booster during the STS 30 Atlantis flight. Credit: NASA
These measurements revolutionized our understanding of Venus’ geology and the geophysical processes that have shaped the planet’s surface. In addition to revealing a young surface with few impact craters, Magellan also showed evidence of volcanic activity and signs of plate tectonics.
However, the lack of finer resolution imagery and topography of the surface hampered efforts to answer definitively what role these forces have played in the formation and evolution of the surface. As a result, scientists have remained unclear as to what extent certain forces have shaped (and continue to shape) the surface of Venus.
With a suite of modern instruments, the VERITAS spacecraft would produce global, high-resolution topography and imaging of Venus’ surface and produce the first maps of deformation and global surface composition. These include an X-band radar configured as a single pass radar interferometer (known as VISAR) which would be coupled with a multispectral NIR emissivity mapping capability.
Three-dimensional simulation of Gula Mons captured by the Magellan Synthetic Aperture Radar (SAR) combined with radar altimetry. Credit: NASA/JPL
Using these, the VERITAS probe will be able to see through Venus’ thick clouds, map the surface at higher resolution than Magellan, and attempt to accomplish three major scientific goals: get a better understanding of Venus’ geologic evolution; determine what geologic processes are currently operating on Venus (including whether or not active volcanoes still exist); and find evidence for past or present water.
Suzanne Smrekar of NASA’s Jet Propulsion Laboratory (JPL) is the mission’s principal investigator, while the JPL would be responsible for managing the project. As she explained to Universe Today via email:
“VERITAS’ objectives are to reveal Venus’ geologic history, determine how active it is, and search for the fingerprints of past and present water. The overarching question is ‘How Earthlike is Venus?’ As more and more exoplanets are discovered, this information is essential to predicting whether Earth-sized planets are more likely to resemble Earth or Venus.”
Venus, as imaged by the Magellan spacecraft using Synthetic Aperture Radar (SAR). Credit: NASA/JPL
In many ways, VERITAS and DAVINCI represent a vindication for Venus scientists in the United States, who have not sent a probe to the planet since the Magellan orbiter mission ended in 1994. Since that time, efforts have been largely focused on Mars, where orbiters and landers have been looking for evidence of past and present water, and trying to piece together what Mars’ atmosphere used to look like.
But with Discovery Mission 13 and its five semi-finalists, the focus has now shifted onto Venus, near-Earth objects, and a variety of asteroids. As John Grunsfeld, astronaut and associate administrator for NASA’s Science Mission Directorate in Washington, explained:
“The selected investigations have the potential to reveal much about the formation of our solar system and its dynamic processes. Dynamic and exciting missions like these hold promise to unravel the mysteries of our solar system and inspire future generations of explorers. It’s an incredible time for science, and NASA is leading the way.”
Each investigation team will receive $3 million to conduct concept design studies and analyses. After a detailed review and evaluation of the concept studies, NASA will make the final selections by September 2016 for continued development. This final mission (or missions) that are selected will launcd by 2020 at the earliest.
