In Exogeology ROCKS! Episode 10, we talk with Dr. Rosaly Lopes, a planetary scientist at JPL. She tells us all about volcanoes on Io, cryovolcanism on icy moons like Enceladus, and her travels to Earth volcanoes. I liked hearing about how you should do what you love, and how as a scientist, you always have to keep learning. Her story about catching a gigantic volcanic eruption on Io during the Galileo mission is really interesting. Watch it all here:
Posts Tagged ‘moon’
In Exogeology ROCKS! Episode 7, host Zoe Bentley meets astrobiologist Dr. Britney Schmidt, who talks to us about her travels in Antarctica, why ice is fascinating, and how all of that relates to Europa. Can life survive under an ice sheet? What funny things happened in Antarctica? Find out all of this in the latest episode of Exogeology ROCKS!
Last year you met SETI planetary geologist Dr. Cynthia Phillips in Exogeology ROCKS! Episode 6. Now, we’ve got a little bonus to go along with the episode: we get to hear from her why Europa rocks, what it’s made of, and why we should go explore it. Dr. Cynthia Phillips really gets into this little world, and you’ll see why.
Tonight I made a point of looking at the sky, the moon in particular. Why? Because tonight is the night of a “super harvest moon“.
A harvest moon is the full moon closest to the fall equinox. The equinox is a day when the day and night are exactly the same length, and the first day of fall (the same thing happens in the spring). The harvest moon usually happens at least a few days before or after the equinox, but this year’s is special.
Today, there is a full moon. Today is also the equinox. It’s not often the two occur on the exact same day.
I didn’t have the best view of the super harvest moon because it was cloudy where I am. I did see the moon peeking out from behind the clouds though, which was in my opinion beautiful. I also saw a small ring around the moon. It looked a bit like a rainbow. I was amazed at how bright it was outside even with the clouds.
Whenever I try to tell anyone what my job title is, nobody understands! I got so frustrated when I went to a geology conference and everybody kept asking me what my sign was! That’s not what I do! I’m pretty sure I’m a Virgo, but I have no idea what that means! The same thing happens when I meet astronomers. They keep assuming that I know stuff like the capital of Nebraska. I am not an astrologer and not a geographer, I’m an astronomer who is also a geologist.
Sometimes people just slip up even when they do know the difference. I had a pretty funny conversation with my grandparents when I tried to explain my job. Here’s pretty much how it went:
Grandpa: “I heard you’re an astronaut now, Petra. That sounds exciting.”
Me: “No, Grandpa. I’m not an astronaut at all, I’m an exogeologist.”
Grandma: “You’re an ex-geologist? I thought you just started this job, whatever it is. What are you doing now?”
Me: “Ex-o. Ex-o-geology is the geology of other planets.”
Grandpa: “Oh, geography!”
Grandma: “Have you made many maps dear?”
Me: “No, not geography. And mapmaking is called cartography.”
Grandpa: “Cartography? I’ve always wanted to draw cartoons. Can you draw Pluto?”
Me: “Grandpa, I’m not a cartoon artist. How’d we even get on that subject? I study things like volcanoes and craters. Geology. And I haven’t tried to draw Pluto. But there’s this spacecraft that’s headed to…oh, that Pluto.”
Grandma: “Oh, geometry, with the shapes!”
Me: “That’s mathematics, Grandma. I’m an exogeologist. That’s a combination of geology and astronomy. I look at space rocks.”
Grandma: “Like the astronauts got from the moon?”
Me: “Yes! Exactly!”
Grandpa: “That sounds fun.”
Me: “Yes, it ROCKS!”
Grandma: “So when will you be going to the moon?”
I hope this helps you to tell the differences between exogeology and completely different jobs. My grandparents finally understood after that long conversation, and I can usually get people to at least say it right. People who just haven’t heard of exogeology, or even geology or astronomy, are just part of the job. I can’t blame them really, although it is annoying. For now, I’m Petra Stone signing off. Exogeology ROCKS!
As I said before, part of being an exogeologist is getting to explore! From the bright Sun and its flares, to the outermost reaches of the Oort cloud, exogeologists get to see it all! The most exciting part is discovering new things about unexplored places.
Moons are some of the most diverse objects; some are like planets with volcanoes and atmospheres, and others are like asteroids with odd shapes and cratered surfaces. Titan has a thick and hazy atmosphere, which just makes me wonder, “What’s down there?”
Exogeologists like myself decided that Titan was a good place to explore. The Cassini-Huygens mission was and is set to explore and study Saturn and Titan. The Huygens lander detached from the Cassini spacecraft and landed on Titan. It found that there is water ice on Titan, the atmosphere is made of methane and nitrogen, and there even seems to be an underground ocean of liquid water! How cool! Literally, because Titan is so cold being so far from the Sun.
Speaking of being cold and far from the Sun, exogeology is also used for studying Kuiper Belt objects, or KBOs. The most famous KBO is Pluto, the famous dwarf planet. Just let me call it a dwarf planet for the purposes of this one blog, okay? Pluto and other dwarf planets are mostly made of rock and ice, like asteroids. We don’t have many good photographs of Kuiper Belt objects, so that’s one thing that I’d like to do in the future: take pictures of KBOs.
The most mysterious places to see are exoplanets, planets orbiting other stars! There are planets of all shapes and sizes out there, and exogeologists are finding more all the time! It rocks that there are other solar systems!
No matter where you look, you just might find something new and exciting! Exogeology ROCKS!
Yes, on Earth! Even though I mainly study other planets, Earth is a great place to see all sorts of geologic formations! Let me tell you about some great things to see on Earth that I’ve seen on the planets and moons.
Wait, craters on Earth? I thought there were only craters on the Moon! No, actually there can be craters on just about anything (as long as it has a solid surface; there aren’t craters on jovian planets). Earth has relatively few though, because smaller meteors burn up in our thick atmosphere. But some of the few meteor craters there are on Earth can be quite something to see! It’s almost like you’re on the moon! Barringer Crater in Arizona is the best example. Most craters on Earth are a bit less dramatic though, after being eroded for thousands of years. It gives you a great sense of what you’re dealing with to go and see a real crater.
Canyons are usually carved out by rivers, so why would they be in a list of exogeology related formations? After all, Earth is the only planet with such a large amount of water. Well, I’ve added them for a couple reasons. The first is that there are some formations that can best be described as canyons, even though they’re not made in the same way as the canyons we’re used to seeing. Take Mars’ Valles Marineris. It’s the largest canyon in the Solar System, but it’s a rift valley (a type of fault). On the other hand, there are channels on Mars that might have been made by the flow of water, like dried up riverbeds. I’ll talk about that more in a later post.
Ice fields are the only formation on this list I have yet to see. I’m actually going to be flying to Iceland for a few days to study glaciers. Because of this, posts over the next few days will be automated while I’m gone. Ice has been found all over: in comets and asteroids, on moons (Europa in particular), and on Mars. The gas giants are theorized to have icy cores. But not all this ice is actually frozen water. Europa might have water ice, but we don’t know for sure. Comets have water ice though. Water is so important on Earth that I think everything with water is exciting! Water is necessary for life, and that’s something I’d be thrilled to find. Could you imagine? I’m a huge science fiction fan, and that inspires me to think about big new scientific discoveries like life or undiscovered planets all the time. I’m getting off topic. Let’s get back to those awesome rocks!
Sand dunes can be found wherever there is sand, wind, and a dry climate. I went to the White Sands National Monument recently, and it was beautiful! As soon as you drove into the park there were sand dunes as far as you could see. The field of dunes was comparable to some of the dunes on Mars. An even better comparison is Utah’s Coral Pink Sand Dunes State Park. The reddish sand makes it feel as if you’re really on Mars. Dusty parts of deserts are also good places to look for dust devils, a common sight on the red planet.
Yes, I know, I was supposed to tell you about formations and not minerals. But minerals are important too! You need to look at the big things and the little things. There are a whole bunch of rocks and minerals that occur on Earth and also in space. One of my favorites is hematite. That’s an iron based mineral common on Mars. It comes in a few different forms. One form of hematite is red and rocky, and another is silvery gray and metallic. Iron in rocks is what makes Mars red! Moon rocks are pretty cool too; a rock from a lunar mare is made of the same thing as lava rocks on Earth! That ROCKS! 😉
Volcanoes have been found on Mars, Venus, Mercury, and Io. And on Titan there are cryovolcanoes! There are active and inactive volcanoes all over Earth that are fascinating to see in person. I try to go to as many volcano sites as I can during field research.
Plate tectonics is the process that makes the continents move. They spread apart like at the mid Atlantic ridge, and move under each other (called subduction) in places like Japan and the Aleutian islands of Alaska. The Earth’s surface is changing! And what’s more, there used to be plate tectonics on ancient Mars, and there still are on Titan!
Strata is just another term for rock layers. There are strata everywhere! That’s because rock layers can form all sorts of ways, like an ocean depositing sand on a beach or volcanoes erupting new lava flows. Strata can show a lot about that geographical area’s past. One time I looked at the strata in the Grand Canyon to figure out what order things happened in. I could easily see that the layers on the bottom formed first, then were tilted, and then that surface was eroded flat. More layers formed, and finally the Colorado River eroded the rocks away to create the Grand Canyon! How cool is it that you can tell what was happening for millions of years just by looking at rocks? I say that ROCKS! I do the exact same sort of thing when I look at strata from anywhere.
Can you believe so many of the same things happen on Earth that happen on other planets? I think it’s amazing. Exogeology ROCKS!
Want to know just what an exogeologist does all day? Well, maybe I can show you just how cool this job is!
When I start working for the day, the first thing I do is see if I’ve received any new data. This could be from other exogeologists or from different spacecraft. I sometimes even get rock samples to analyze. If I do, I’ll take them to the lab. There I’ll test the sample to find out its composition.
There are lots of tests I can do. I can test minerals for streak, hardness, cleavage or fracture, and of course note the color and shape of the crystals. For example, let’s say I was given a mineral sample to identify. It has cube-shaped crystals, and is gold in color. I rub it on a streak plate, and the streak is greenish black. I’ll scratch it with various tools and deduce that its Mohs hardness is 6. When I break it with a hammer, the place where it breaks is conchoidal (a distinctive curved shape). All these things put together tell me that my mineral is pyrite. If I were given a rock sample, there are a lot of various tests I could do to classify a rock, like cutting a thin slice and looking at it under a microscope.
- Here’s a quick tip about classifying rocks: If it has bubbles, it’s got to be igneous. Those bubbles are called vesicles, and they’re made when gas bubbles are trapped inside a rock as it cools.
Some days I’ll go to an observatory to do research on a planet. I need to reserve the telescope ahead of time usually. When I used a telescope at the Kitt Peak observatory, I had to reserve the telescope years in advance! But it was worth it. I got some great photographs of Jupiter and a comet during my time at the telescope. I’ve used lots of different observatories, and it’s always been productive. Well, except for that one time when it rained… I had to cancel. I must have been really unlucky that time. But that’s the trouble with astronomy; sometimes you just have to wait for another clear night. At least every other time went well.
Other days I’ll get information from a spacecraft or lander! That’s my favorite part! Once, I got to help with the LCROSS mission and interpret data from the spectrometer. The goal was to find water, and we did! That ROCKS! Since Mars is my specialty, I’ve been receiving data from the Mars Odyssey orbiter, which maps the amount of chemical elements and their distribution. I loved working on that. Maybe I’ll get to interpret data from the upcoming Mars Science Laboratory (MSL). Part of the MSL’s mission will be to study the geology of Mars.
You’re probably wanting to know, just what is it that exogeologists do? What do they look at? Why? And what do they find there? Well, let me start by giving you a tour of the Solar System.
The Solar System is a big place, and there’s still a lot we don’t know about it. But we do know where to start looking. We’ve found eight planets, some dwarf planets, comets, and numerous asteroids.
In our solar system we have, in order from the Sun: Mercury, Venus, Earth, and Mars, the inner or “terrestrial” (Earth-like) planets. These are all rocky planets that have similar geology to Earth. Then there is the asteroid belt, a ring of asteroids (big chunks of rock in a ring between the inner and outer planets) orbiting the Sun. And next out there are Jupiter, Saturn, Uranus, and Neptune, the outer or “jovian” (Jupiter-like, the gas giants) planets. And much further out, there is the Kuiper belt, a ring of asteroids and dwarf planets like Pluto and Eris. There also comets, which have orbits that take them very far from the Sun for years, and then for a short time bring them into the inner solar system. Comets are made of ice and rock, and are sometimes called “dirty snowballs” because of their composition.
And what about the Moon? Well, exogeologists also study Earth’s moon, as well as other planets’ moons. The Moon is covered in craters, made by meteorites (asteroids and other space rocks that hit another object). There are dark areas on the moon that don’t have many craters though, and those are called maria. A mare is a place where a large meteor hit and molten lava seeped up through cracks made by the impact, which then cooled to become one of the dark maria we see on the moon today.
Some of the other planets have moons too, in fact, Jupiter has 63 and Saturn has over 200! Moons can be very different from each other. Some have atmospheres (like Saturn’s Titan), and some are just asteroids and are strange shapes and have lots of craters (Like Mars’ two moons, Phobos and Deimos).
There are lots of planets to explore, and that’s what I do! I like finding out new information about everything in the solar system!