NASA's Curious Universe - Journey to Venus

Episode Date: August 23, 2021

Let’s go to Venus! This year, two NASA missions were chosen to explore Earth’s “twin” planet, Venus. But with extreme temperatures and toxic clouds, these missions have to prepare for a difficult journey. Join Venus experts Jim Garvin, Sue Smrekar, and Giada Arney on a tour of Earth’s “twisted sister”.

We live on Earth, right? The ocean world, trees, you know, condominiums. The closest planet next door is the planet known as Venus, the morning star very often in literature. We can see her. She's the second brightest thing in the sky other than the moon. It gives you a sense that we're not alone in our little solar system. So what is Venus?

Venus ought to be a lot like us. She's in just the right neighborhood. And yet she isn't. So something changed. Understanding that is important understanding our own destiny because as we look beyond our solar system and start to see worlds that we hope are like us, they may be more like Venus. And so that may tell us about how planets change their life histories. So we need Venus as a clue to our destiny and to read the records beyond our solar system. This is NASA's curious universe.

Our universe is a wild and wonderful place. I'm Patty Boyd, and in this world. podcast, NASA is your tour guide. Venus is the second planet from the sun in our solar system. It's sometimes called Earth's twin because it's similar in size and density. But it's currently far too hot on its surface to support life as we know it or liquid water. In fact, Venus is the hottest planet in our solar system with a thick, toxic atmosphere. And while those characteristics, Statistics mean it's an unlikely candidate for life now, scientists think Venus might have been a lot more like Earth

many, many years ago. In an exhilarating announcement earlier this year, two NASA missions were selected to fly to Venus in the next decade, called Da Vinci and Veritas. These missions will allow scientists to learn more about what this strange and inhospitable planet is like now. And if it was similar to Earth in the past, which could tell us more about our future. So let's go to Venus.

We'll be following Jim Garvin, principal investigator of the Da Vinci Mission, as he takes us through the atmosphere and to the surface of our sibling planet. So Venus is a rocky planet, so it has a solid surface. It's about the size of Earth, 10% less. In size, it has 450 million square kilometers. of landscape, but it also has a massive atmosphere. And the Venus atmosphere is like no other in the solar system because it's dense, massive, super hot near the surface, like hotter than your oven.

The surface temperature, 9.50 Fahrenheit in most places, maybe 900 at the top of the biggest mountains. Big clouds, billowing clouds, extend for miles. At one point, the clouds will get a little nasty. They'll be made of stuff we would not want to breathe. sulfuric acid and other caustic chemicals that we use to clean things on Earth while they're in the clouds of Venus. We'll come out of the clouds into the hazes and below us will be the landscapes of Venus. Rolling plains we'd have in the oceans.

Presence of mountains as tall as Mount Everest, valleys, ridges, volcanoes, things we've never seen before. New landscape types we do not have on Earth. If you were able to breathe in the atmosphere of Venus, it might smell like rotten eggs. Yuck. Of course, you'd have to withstand the intense heat, pressure, and toxic fumes in order to get a good whiff. And as we're descending, the surface, pressure, and temperature is going to be getting extreme, like being half a mile deep in the ocean, but we're in a gas. But that gas is behaving more like water than like a regular gas.

So it slashes around. The carbon dioxide in the deepest part of Venus's atmosphere is what's known as a supercritical fluid. It's a state between a gas and a liquid. Not only would that CO2 be difficult to walk around in, it's also a key ingredient of why Venus is so hot. Heat from the sun gets trapped in the planet's dense atmosphere, a condition known as the greenhouse effect.

And so that's the Venus we see. She's telling us a story, but her books are a little harder to read. Venus is this incredible cosmic accident. No two bodies are more similar in our solar system than Venus and Earth. This gives us a great opportunity to try out any theory of how things work. We can take those theories and apply them to Venus. and we learn something. Now that we've traveled through the atmosphere,

the next stop on our grand tour of Venus is the rocky surface of the planet. My name is Seuss Mercar. I'm the principal investigator for the Veritas mission. I'm a Venus planetary geophysicist. Venus is just an incredibly complicated planet, which has so many similarities to Earth. You know, one really big and perhaps under-

appreciated similarity is the age of its surface. If we look at the surface of Mercury or Mars, they're covered with impact craters. That means those surfaces have been around for billions of years. So Venus, it only has about a thousand impact craters. If you account for the surface air, the ocean, Earth has about the same number. That makes it a place where we expect geologic processes to still be active. It really gives us. us a great laboratory to study active geology. The lack of craters on Venus and on Earth shows us they are both planets with relatively young surfaces.

This means there are active processes on Venus, like quakes and volcanism, reshaping the surface. And this is a process scientists are eager to learn more about. Most of the planet's surface is covered in volcanic features. many of which look like those we find here in Earth. But there are also crazy features. For example, channels, which we think are formed by lava flow eroding the surface. But those channels go for literally a thousand miles and are only like a mile wide.

Venus is one of our closest neighbors in the universe. So it makes sense that we would want to learn more. There have already been several missions to Venus, but because of the harsh nature of its atmosphere, they could only tell us so much. In the dawn of the space age, Venus was the it planet. There was just spacecraft after spacecraft heading to Venus. Some made it, some failed. But it was the planet that we thought had swamps and dense vegetation and exciting aliens. as captured in sci-fi. It was actually the place

where the first robotic spacecraft flew by another planet. Those missions, the United States mission Pioneer Venus, and the Soviet missions, Venera and Vega, they visited the atmosphere and surface with technologies largely from the 1970s. And just think back to the 70s.

Did we have cell phones? Nope. Did we have personal computers? NIP! Electric cars? Nope. Those technologies show. So does the Venus we see today. A limited picture of a masterpiece unfinished, because Venus is hard. The last U.S. mission to Venus was the Magellan Mission, which reached Venus orbit in 1990 and

operated until 1994. Jim and his team proposed going back to Venus with the Da Vinci mission four times before it was selected in 2021 alongside the Veritas mission. So after many years, actually a decade or so of trying, we are so privileged to have been selected to fly a mission name for Leonardo da Vinci, the Great Renaissance. Heron, who was able to stitch science, technology, engineering, and dreams and curiosity altogether. We would ideally launch in 2029 and fly by Venus twice in 2030 before we take the plunge in June of 2013.

And our plunge will take an hour through the entire atmosphere and then, And if we're fortunate and lucky in Venus cooperates, we may get a little data as we sit on the surface. I'm Jada Arnie, and I'm one of the deputy PIs of the Da Vinci mission to Venus. Jada, alongside Jim, is part of the team conceptualizing, preparing, and eventually launching the probe to Venus. It will consist of two parts. Both will collect new and exciting information that will help us better understand this mysterious planet. It's a really exciting concept. There's a spacecraft and the spacecraft is attached to a descent probe.

This spacecraft will do two flybys of Venus on the way there. During those flybys, the spacecraft is going to study Venus in ultraviolet light and also near infrared light. These are colors of light that our eyes can't see, but they provide information about the clouds of Venus and also the surface of Venus. Two years after launch, we're going to drop a descent probe into Venus's atmosphere that'll be released from the spacecraft. Our descent sphere is a titanium sphere. It's about the size of maybe a small bean bag chair or a large beach ball, so not enormous, but not super tiny either. The descent probe will take about an hour to fall through Venus's thick atmosphere. Following its descent, it's going to make thousands of measurements of the atmospheric composition.

And we really want to understand the composition of Venus's atmosphere better because we want to look for information about what Venus might have been like in the past. The name Da Vinci is an acronym, and the N stands for noble gases. Studying the noble gases of Venus's atmosphere in particular will help give scientists a peek at the history of how Venus became what it is today. Noble gases are unreactive gases because they don't react with things, they kind of stick around and they could record a long history of processes that could have occurred on Venus. So from those and other gases we want to learn things like the volcanic history of Venus, how

Venus got its water, how much water Venus may have had, how it may have lost that water, etc., etc. All these interesting questions about Venus's origin and evolution. Da Vinci's descent probe will make a harrowing journey through Venus's thick, cloudy atmosphere and down to the surface. It will be outfitted with state-of-the-art protective materials to keep it as safe as possible. But scientists don't have expectations that it will be able to survive the harsh conditions very long. Once we clear the bottom of the clouds, which will happen at about 38 kilometers in altitude,

will actually be able to have a crystal clear view of the surface. Then we have a camera at the bottom of our descent sphere, and that camera's going to peer downward through a sapphire window, and it's going to look at the surface from above, get a bird's-eye view of the terrain. Once it hits the surface, we don't know if it'll survive. It is not required to survive. If it does, we might be able to collect a few more minutes of data,

but that will be a bonus, and we're not expecting or planning for that at the moment. While Da Vinci will mostly focus on studying the atmosphere, the other Venus mission, Veritas, will orbit the planet, taking data to study the surface and geology. Evidence suggests that long ago, Venus hosted large, shallow oceans with a stable climate for at least a couple billion years. Measuring features of both the atmosphere and the surface can tell scientists whether or not water you used to be present on Venus, and how much it influenced its topography and climate.

Scientists like Sue are excited to see how much Earth and Venus have in common, especially when it comes to questions of planet formation, geological activity, and the presence of water. Veritas will investigate the global geologic evolution of Venus and answer some of the key questions that we need to understand about geologic evolution to get at this question of how planets become habitable, how they lose their habitability. We have an orbiter and it has really just two instruments, but those instruments take a variety of different datasets. Venus has this intense cloud layer.

We chose our instruments to be able to see through that cloud layer. Veritas will stay above Venus's atmosphere, orbiting the planet and collecting important information from above. We have a radar, which gives us a global global topographic map. So we're going to take radar data at one time and then come around about eight months later and take another radar image. And we can tell if those surfaces captured have deformed.

And then the other thing that we're going to do for the very first time is provide global maps of rock type. Veritas is very much focused on acquiring the global data sets. And DaVinci is focused on atmospheric chemistry and so they're kind of getting the vertical dimension, if you will, whereas we're getting the horizontal dimension. But these two data sets will be just incredibly complementary. Scientists are looking at Venus to answer questions about Earth's future. Venus is currently experiencing what planetary and climate scientists call a runaway greenhouse effect. This is when heat gets trapped within the atmosphere.

without any means to cool the planet down. Earth's oceans are a key ingredient for cooling our planet down. So if Venus used to have oceans, what happened to them? And what can we learn about the future of our planet as it heats up from global climate change? So the Venus we see now is a puzzle piece. In the 2020s we have the glimmers of what might have been, an oceanic world that lost its oceans.

Perhaps after billions of years of oceanic, beautiful, habitable world environments, something went awry, something changed it to be the world of today. Those things and those questions are important because they tell us what can go wrong. How climates and atmosphere climate systems change will be relevant to backcasting the climate history of Earth and forecasting the eventual climate issue. What happens if the oceans of Earth were to super evaporate away? What would that look like? What would that do to our atmosphere?

How would that evolve? Exploring and learning more about Venus doesn't just tell us more about the second planet from the Sun. It can also help us learn what Earth may be like far in the future, or even what we might find on an exoplanet orbiting a star thousands of light years away. For planetary scientists, it's almost a once-in-a-lifetime chance to have a mission you propose be accepted to fly out of our atmosphere into space and then on to another world. For Sue, Jim, and Jada,

the day they were given the green light for the projects they've poured so much work into is certainly one to remember. Well, I was standing in my kitchen. My cell phone coverage did not very good, so I wanted to get really close to my modem, my Wi-Fi signal. And the call was supposed to come in

between 5 and 6 a.m. here on the West Coast. Of course, I had woken up at 3 o'clock because I couldn't sleep. So, you know, I've been doing a lot of pacing and contemplating. I had a big pot of coffee going. I was texting a few team members

that I knew were also up. Just waiting for the news, hoping that this time our lucky number would come up. So we got a warning from NASA Head, quarters, the bosses that we work for, you may be getting a call about decisions from the head of all science at NASA is the associate administrator in the Science Mission Director at Dr. Zerbukin. And so we thought, okay, well, there's four brilliant missions.

They're all perfectly wonderful and should be selected. I was sitting at home, my dog underfoot, my dog's name is Glenda, sitting there. I told my wife, I'm nervous, told my kids, and they said, okay, we'll leave you along, Dad. And so at 8.05, the phone rings, and it's the big boss, Dr. Zerbuken. And he said, well, Jim, I have news for you. You're going to Venus. And like I had a huge sigh of relief. I thought it was bad news.

So I heard about the selection for Da Vinci the morning of the announcements that the NASA administrator made. And I was sworn to secrecy. So, you know, it was exciting, but it was also like sitting on pins and needles waiting for the announcement to remain to the whole world. so that we could actually celebrate as a team. It's pretty wild to think about the fact that I've got this mission to work on, and it's going to be something that I'm going to be working on for about the next decade. So it's a little bit scary, but it's also exciting to think about that. I haven't worked on a spaceflight mission before,

so it's hard to know for me as someone who's new to this, what my job is going to look like and how it's going to evolve as the mission continues to evolve and mature, as the years go by, but it will be exciting to find out what that looks like. Sending these missions to Venus isn't just exciting for the Da Vinci and Veritas teams, but for scientists across the world who will be able to learn and discover new exciting things about our solar system with brand new data. Veritas is a dream come true for me, and for 100 other people,

perhaps hundreds of other people that have helped make it come to fruition over the last decade. We have our current team that has worked super hard in the last four years, but there have been people on teams in the earlier versions that also made huge contributions. And we have international partners. You know, we're not doing this alone. We're going with the Italian Space Agency, the German Space Agency, the French Space Agency. It's an international endeavor,

and there have just been so many people who have worked literally night and day to make this happen. So we're going to bring the best of the tools that women and men on Earth have perfected over the last 40 years to fly by Venus and then take the plunge into our atmosphere

to read her record books, which are mystical, unknown, tantalizing, but incomplete. We're going to complete them. So all the young women and men are interested in Venus will have a foundation, a legacy so they can build the next models, the next questions, the next hypotheses. And they will be cool.

Trust me. This is NASA's Curious Universe. This episode was written and produced by Christina Dana and Kate Steiner. Our executive producer is Katie Atkinson. The Curious Universe team includes Maddie Arnold and Michaela Sosby. with support from Emma Edmund and Priya Mittal.

Our theme song was composed by Matt Russo and Andrew Santaguita of System Sounds. Special thanks to Nancy Neil Jones, Ian O'Neill and the Planetary Communications Team. If you liked this episode, please let us know by leaving us a review. Tweeting about the show at NASA and sharing NASA's curious universe with a friend. Learn more about Venus and our upcoming news. missions by visiting solar system.nasa.gov. Still curious about NASA? You can send us questions about this episode or a previous one, and we'll try to track down the answers. You can email a voice recording or send a written note to

NASA-curiousuniverse at mail.nasa.gov. Go to nassah.gov slash curiousuniverse for more information. And it's also a beautiful planet. Some of the photographs we have of Venus from above with the clouds. It almost looks like an artist painted brushstrokes across Venus's surface. I've seen photographs of the unknown UV absorber. It's got these dark markings and it's like somebody dipped their paintbrush in dark paint and just brushed it across Venus. So it's a really beautiful, beautiful planet.