Posts Tagged ‘Mars’

Why is Olympus Mons so big?

Posted by admin on 19th October 2015 in Exogeology, Main Page

Here is a quick 2:30 video of me explaining the difference between Earth volcanoes and Mars volcanoes.

MAVEN Launch

Posted by Zoe on 18th November 2013 in Exogeology, Main Page

Today at 1:28 EST at Cape Canaveral, MAVEN successfully launched, and it’s now on its way to Mars.

MAVEN is a NASA mission to study the upper atmosphere of Mars. Its name stands for Mars Atmosphere and Volatile EvolutioN. The “volatile” part refers to compounds like CO2 (carbon dioxide), N2 (nitrogen), and H2O (water). MAVEN plans to gather clues about how those were lost over time. Once the MAVEN spacecraft reaches Mars, it will orbit the planet and use many different sensors to learn more about its atmosphere, and how it interacts with the sun and solar wind.

Learn more about MAVEN on the NASA website and the University of Colorado website (check out the science page).

One Year on Mars for Curiosity

Posted by Zoe on 5th August 2013 in Exogeology, Main Page, Petra's Blog

One year ago, the Curiosity rover landed on Mars.

Curiosity, also known as the Mars Science Laboratory (MSL), descended to the surface of Mars at 10:32 p.m. PDT on August 5, 2012 using the science fiction-sounding “sky crane” to land precisely, and thankfully, successfully.

Since that day, Curiosity has had an exciting year. In no particular order, here are a few of the rover’s major events, efforts, and discoveries:

  • Landing safely, of course.
  • Sending home her first pictures. There’s nothing like seeing an alien vista for the first time. We had seen this area of Mars from above, but when Curiosity snapped her first few photos and sent them back to Earth, we were at ground level, close up. We saw Gale crater in a way we never had before.
  • Curiosity's first image taken from the surface of Mars. (Image credit: NASA)

  • Finding rounded rocks in a riverbed. Apart from all the alliteration, this discovery is notable because it pertains to water in Mars’ past. These rocks tumbled around as they were pushed downstream by the current. They knocked into each other and became smaller and smoother and more worn down the farther they went. This happens here on Earth, which you might have noticed, and it’s why river rocks and smooth and rounded.

Rounded river rocks on Mars (left) and Earth (right). Image credit NASA/JPL-Caltech/MSSS and PSI

  • An anomaly with one of her computers’ memory and a switch to the second computer.
  • Starting to use her fancy science tools. Curiosity really is a Mars Science Laboratory. She has several cameras for navigation and taking pictures of the scenery which give you an idea of what the various sights like rock outcroppings, sand, river rocks, and everything else look like. She has a drill for taking samples. She has a scoop for…taking samples. Those last two, along with some other instruments, are on Curiosity’s robotic arm. She has spectrometers to identify materials using the light spectrum. She has a laser. With all these awesome tools and more, it’s pretty exciting that Curiosity has been using these tools throughout the past year.

Holes from Curiosity's drill (large hole) and laser ChemCam (small holes) in a rock called Cumberland. Image credit NASA/JPL-Caltech/MSSS

  • Trying to discover whether Mars has ever had a habitable environment. This one isn’t over, it’s ongoing. In fact, it’s one of Curiosity’s primary goals. An event relating to this goal is the time Curiosity found a rock sample that shows Mars may once have been habitable for microbes. There was also the time when she found evidence of water in a place called Yellowknife Bay.  Or course, I can’t wait to see what other evidence Curiosity might find.

But, Curiosity’s not done yet. The rover is on her way Mount Sharp. She’s finally driving, and even though it’s hard to leave behind the rocks nearer to the landing site, Mount Sharp promises to be even more intriguing. Why are we looking forward to investigating Mount Sharp? Well, it’s made up of layers. The layers in Mount Sharp might show us more about what Mars’ climate was like long ago and all the changes it has been through. How cool is that?

If you ask me, everything Curiosity has done in her first one year on Mars has been very cool.

-Petra Stone

Exogeology ROCKS! Episode 6

Posted by Zoe on 17th October 2012 in Main Page

Woo-hoo! I’ve just finished the sixth installment in the Exogeology ROCKS! video series. The first five can be seen here.

In Exogeology ROCKS! Episode 6, we meet Dr. Cynthia Phillips, a planetary geologist for the SETI Institute. She tells us about some interesting worlds in our solar system including Europa, Io, and Mars, how to use images to study them, and much more. I particularly like her stories about her funniest and most exciting experiences as a planetary geologist.

Congratulations, Curiosity!

Posted by Zoe on 6th August 2012 in Exogeology, Main Page, Petra's Blog

Tonight, Curiosity reached its destination: Gale Crater, Mars.

Curiosity's first image taken from the surface of Mars. Woo-hoo! (Image credit: NASA)

Curiosity, also known as the Mars Science Laboratory (MSL), traveled for about 352 million miles (567 million km) from a cleanroom at JPL on Earth to a place called Mount Sharp in Gale Crater on Mars. It’s hard to imagine traveling so far.

Curiosity's cleanroom, way back in 2010.

Mount Sharp, the area on Mars Curiosity will explore. (Image credit: NASA)

Tonight, August 5, Curiosity’s team worked through the “Seven Minutes of Terror” while everyone else, including myself, just hoped and wished for the best.

Can you even imagine how hard it would be to land a rover? Can you imagine just how nervous you’d be that all the work put into Curiosity would either have the chance to succeed amazingly or just fail terribly? I can’t, but that’s what Curiosity’s team must have felt.

Landing Curiosity had several stages. (Image credit: NASA)

Finally, can you imagine the relief and excitement as Curiosity landed safely on solid ground? I can, but not even half as much as Curiosity’s team, I’m sure.

I’m so, so glad Curiosity made the landing safely. Congratulations, Curiosity! You ROCK!

Speech on Why Exogeology ROCKS!

Posted by Zoe on 28th July 2012 in Main Page

You’ve heard that exogeology rocks, but just what is exogeology? Why does it rock?

I recently gave a speech on just that: Why Exogeology ROCKS!

Curiosity Launches Today

Posted by Petra on 26th November 2011 in Main Page, Petra's Blog

Hello, Petra Stone here with news about the Mars Science Laboratory, better known as Curiosity or the MSL. Today, this new rover finally launches on its journey to Mars.

Image from NASA

It’s been over eight years now since the last Mars rover launch, Opportunity’s in 2003. Now, Curiosity will set off on a mission to determine if life could have ever arisen on Mars, characterize the climate of Mars, characterize the geology of Mars, and prepare for human exploration. Those are the four main goals, but this newest and largest rover has eight more specific scientific objectives. There’s a lot in store for the MSL!

JPL cleanroom where Curiosity was built. Image credit Zoe Bentley.

Curiosity’s equipment ROCKS! It’s taking a drill, several cameras for steering and gathering data, a robotic arm, and even a tool called SAM with a laser in it which vaporizes rocks. No, I’m not kidding. The MSL is also powered by plutonium. This means dust buildups won’t keep Curiosity from getting the energy to explore. Even the way it lands is pretty cool. I can’t wait until Curiosity reaches Gale Crater in August next year.

Curiosity is scheduled to launch today at 10:02 EST from Cape Canaveral on board an Atlas V rocket. I can’t wait for this ROCKIN’ rover to get on its way!

Check out these webpages to learn more about Curiosity:
The Mars Science Laboratory’s website
NASA’s MSL Mission Page
Watch Curiosity Launch Live!

Mars Rover Landing Site

Posted by Petra on 29th July 2011 in Exogeology, Petra's Blog

The newest Mars rover, Curiosity (also known as the Mars Science Laboratory) has a landing site picked out: Gale crater, measuring about 150 kilometers across (93 miles) and at least 3.5 billion years old. The crater was chosen out of a hundred locations on Mars, which were gradually narrowed down, and the final choice was announced on July 22. Imagine how hard it would be to choose just one place out of one hundred to explore!

So, what is Gale crater like? There is a mountain made of layers of debris in the middle of the crater, probably made of sediment from the bottom of a lakebed or dust and volcanic ash blown by the wind. Erosion in the crater gives the rover access to the different layers. When Curiosity gets there, we’ll find out a whole lot more.

Are you curious to know when Curiosity will get to Mars? It’s currently scheduled to launch this November or December and land on the red planet in August of next year.

I can’t wait to see what Curiosity finds. You know how excited I get about exploring Mars. The Mars Science Laboratory ROCKS!

Here’s more information on Gale and Curiosity.

-Petra Stone

Iceland Volcano Erupts!

Posted by Petra on 15th April 2010 in Petra's Blog

Wow! An eruption; that ROCKS! Only, it doesn’t at all. All flights to and from Iceland were postponed, including mine. It turns out I’ll have to wait a few more days before going home. The Icelandic volcano Fimmvorduhals near Eyjafjallajoekull glacier erupted just recently on March 21. It was a small, relatively harmless eruption. There was ash,  flights were canceled, and there were evacuations, but there wasn’t much damage done considering what could have happened. Yesterday it erupted again–and I was there. Well, not there precisely, but in Iceland, so I was affected by the eruption (just a canceled flight).

Don’t ask me how to pronounce the name of the glacier; I have no idea, even though I’ve been hearing it on all the television and radio channels (I’m not a linguist). The volcano is just as difficult to pronounce. Somehow I manage to get the locals to understand me when I’m pronouncing local cities and words. It helps to know that “j” is pronounced like “y”…

I wish I’d been nearer to the volcano, but on the other hand, I was far enough to be out of harm’s way. Even still, I would have loved to see it erupt (from the sky)! Not only was there lava, but this time there was flooding due to the fact that the volcano was under a glacier! The March eruption wasn’t directly under the glacier, so there wasn’t any flooding. But yesterday’s eruption was in the main crater, which was underneath the icecap. I should figure out what would happen if a volcano erupted under the north Martian ice cap…

There might even be another eruption. There’s another volcano, Katla, which is more destructive and has an easier name. It could affect a larger area than Fimmvorduhals, even causing global damage! Fimmvorduhals, which was the one that erupted yesterday, had ash that spread all the way to the UK and stopped flights to and from there. A colleague of mine in Ireland told me that her flights were canceled due to ash there (the ash can cause a lot of damage to airplane motors)! Wow, ash can go a long ways! The lava itself seems to be less of a problem than the ash and flooding. I hope I get to see something from above when I fly home.

I guess I’ll have a bit more time to look around as a tourist before I go, and time to do more research, too, of course. Isn’t it awesome that geology can be so exciting? It’s not all just looking at rocks. Exogeology is pretty exciting, too. I mean, Io has more volcanic activity than any other body in the Solar System. And ice on Mars is being studied for traces of water ice, which is part of what I’m doing right now! Exogeology most certainly ROCKS!

To find out more about the recent Iceland eruption, read these articles:

The last link has a great photo; it really shows the scale of the eruption.

About Me

Posted by Petra on 11th April 2010 in Petra's Blog

If you’ve been reading this blog, you’ll already know me a bit. But I want to give you a better idea of what I’m like. For starters, I’m Petra Stone, an exogeologist. I love geology and astronomy, but I also love writing and traveling. The following are some questions that I’m often asked by people:

What are you currently working on?

  • I’m currently in Iceland working and studying glacial formations. This is research for the Mars mission I’m working on which is going to Mars’ north pole.

What is your favorite planet?

  • My favorite planet is Mars, because I think the geology is fascinating.

What is your favorite color?

  • Purple, of course! That’s why the planet on this website is purple! :)

What is the best project you have worked on?

  • My favorite projects to work on have included: identifying Martian rocks, using relative dating on alien formations, and traveling to far-off locations around Earth. I’ve never been off of Earth, but I’m sure it would an amazing experience. I’ve worked with several astronauts here at NASA who have been off-world and they’ve told me some fantastic stories.

What things do you like to do (what are your hobbies)?

  • Other than my job, some of my hobbies are reading, jewelry making (I bead memory wire bracelets usually), rock collecting (I have a huge collection with geodes, and jasper, and malachite, oh my!), stargazing and learning the myths behind the constellations, and of course, writing this blog! I like finding unique arts and crafts projects too, that can be really fun. I also love hiking. I love getting a great view of the area, and it gives me a chance to look at the rocks. :)
  • Another interest of mine is photography. I can never get my regular camera to take great objects like the moon, but it’s fun to get photographs of other things. I’ve taken photos of places I’ve been, things I’ve seen, and whatever I want to keep a record of or I just think looks cool. It can come in handy to be a fairly good photographer when you’re classifying rock samples (I use several special cameras for my job), but what really ROCKS is when I have the opportunity to take photographs through a telescope. Telescopes at observatories have great cameras for visible and non-visible light! I could never get photographs like those with my own camera. To see some samples of these, be sure to check out the NASA image gallery!

What is your favorite movie and/or television show?

  • I like science fiction movies and TV shows best, but I also like mystery shows. I like non-fiction TV shows too, but I often find long documentaries too long–I prefer shows to have a fictional storyline if they’re going to be really long.  The exception to this is The Elegant Universe. If you’ve ever been interested in physics, that show will get you even more interested! Seeing that for the first time really piqued my interest in string theory and m-theory.
  • My favorite TV shows are The Universe, Doctor Who, and, of course, Star Trek (all series, but Voyager is my favorite).

What are your favorite books?

  • Books I like are usually fantasy, not science fiction. I really enjoyed the Harry Potter series, the Percy Jackson series, the Magyk series,  and similar types of novels. I also really enjoy reading non-fiction science, especially if it has to do with time travel! I read magazines, technical periodicals, as well as the latest papers that my colleagues publish.

Do you enjoy writing?

  • I absolutely love writing! I spend most of my time writing papers about geology and exogeology (since those are the topics I know best and they are what I spend most of my time researching), but every once in a while I’ll take an interest in other topics and feel like I just have to share my findings with the world!
  • I occasionally even write haiku! Here are two examples:

Twinkling balls of light
So many lightyears away
Estrellas lindas

Rocky Mars landscape
Red mesa towers above
Like Arizona

As you can see, there’s a lot more going in my life than just my job. However, exogeology just happens to be what I like most, and a lot of the things I like are somehow related (ultimately everything seems to be related if you think about it enough). That’s just what I like!  It’s why I became an exogeologist.

Sometimes Being Stuck is a GOOD Thing!

Posted by Petra on 10th April 2010 in Petra's Blog

The Mars Exploration Rover Spirit, as  you may or may not have heard, is STUCK. Rover operators have tried all sorts of maneuvers to get Spirit out of the sand, but nothing has worked. I’m amazed at how persistent the rover team is on trying to free the rover. They’ve tried going backwards, and using the robotic arm to move the sand around Spirit. Still no good. Two of the wheels aren’t working now either. I can’t believe Spirit is in such a bad position. Of course this means it can’t go anywhere or see anything new, but…

Even if the rover doesn’t get out it can still be useful in such a way that it was never intended to be! The rover team has become very inventive in what they’ve thought to do with Spirit. Mars wobbles, or “precesses“, as it rotates on its axis. A stationary probe (like the stuck Spirit) would be very useful in measuring how Mars spins. The rover team has thought of a plan of how to measure this.  This is how looking past your problems and working with what you have, rather than what you wished you had, can be a really important skill!

Why exactly would we care about Mars’ wobble? Because how a planet precesses is slightly different depending on whether it has a solid or molten core. Earth has a molten core, but if its core were solid then our own planet’s wobble would be different. Wouldn’t that be weird? Not to mention Earth wouldn’t have a magnetic field. Exogeologists (myself included) want to know what Mars’ core is like, so measuring precession would give very good information on the interior structure of Mars. I’d find out so much more about the planets if I knew this. It would help a lot in understanding the way they all work.

There’s only one problem. Martian winter is coming soon! This means decreased sunlight for the solar powered rover. I’m not an expert on robotics, but I do know that if Spirit runs out of power (its “spirit”), it’ll go into hibernation and use the little sunlight it receives for solely charging its battery. When it’s in hibernation, a rover can’t communicate with Earth. That could be a big problem, I think, for the team of rover operators and for myself. I get lots of good data from that rover! What’s more, the rover has survived three winters before this by tilting its solar panels northward in order to get the best angle to the sun. But doing this isn’t possible in Spirit‘s current predicament. I sure hope this can be fixed before the season changes!

I hope you thought this was as interesting as I did, and I’d like to officially wish the Spirit rover team good luck!

I’m Petra Stone, and Exogeology ROCKS!

My Travels

Posted by Petra on 9th April 2010 in Petra's Blog

I love to travel! I’ve been to many different countries, and nearly every U.S. state. I love going to different places and seeing the world! Some of my favorite vacations were combined with fieldwork, often unintentionally. An example of this is when I went to White Sands, New Mexico. I went there to study the dunes, and I went sledding on the sand. Alamogordo, the closest town to where White Sands is located, is a town devoted to astronomy! This is where the New Mexico Museum of Space History is located (and I highly recommend it for all ages). I also went to the solar observatory nearby in Sunspot, NM. You can’t tell from their websites just how different the observatories I’ve been to are, but they really are distinct!

Here are photographs I took of the gypsum dunes at White Sands:

Another one of my favorite trips was to the Arkansas Crater of Diamonds. It’s pretty much what it sounds like: a crater with diamonds in Arkansas. The Crater of Diamonds is the only place in the world open to the public to find diamonds. It’s not an impact crater, it’s a diatreme. That’s  volcanic crater formed by an explosion from a buildup of gas. The explosion helped to bring diamonds to the surface. I identified the rocks in the crater as lamproite, and I found some beautiful butterscotch colored jasper. I also found some quartz fragments, and volcanic tuff. I expect the moon looks a bit similar to the crater, with the gray volcanic rocks and tuff. I didn’t find any diamonds, unfortunately. The area around the crater was a very pretty and humid forest environment though, so only the crater itself is at all like something found somewhere other than Earth.

Here are a couple of photographs from when I went rock collecting there:

I went to Sunset Crater Volcano National Monument just recently. I needed to see a volcano in order to compare and contrast with Io and Martian volcanoes like Olympus Mons. Most of my work is with Mars, but I’ve been doing research for some probes like Cassini and New Horizons, too. Some of the things I found showed me that Sunset Crater is not like Olympus Mons, since Sunset Crater is a cinder cone and Olympus Mons is a shield volcano. I climbed to the top of Lenox Crater, a cinder cone right next to Sunset Crater (which you’re not allowed to climb). It was a bit tricky, especially since rocks kept getting in my shoes. It seemed a bit strange to me that there are volcanoes in Arizona, but I figured out the answer. It’s a hot spot! There are no tectonic boundaries in AZ, but mantle plumes can happen anywhere. That’s something I study with other planets, too: I find something which seems strange and I figure out what caused it. It’s like a mystery! Exogeology ROCKS!

Here are a couple of photographs I took at Sunset Crater:

I just plain like traveling, and pretty much anywhere I go I can find something that ROCKS! I take little trips around the state, like to Sunset Crater, all the time. I enjoy visiting (and using) observatories, seeing geologic formations, and going to places that are completely non-exogeology related. Be sure to look at the Telescopes and Observatories page written by Zoë to see some of the telescopes I’ve used. I want to see all the most varied and interesting places I can! But I always go back to Arizona. I love it here. Besides, what better place could there be for doing what I love? Geology and astronomy both seem to lead me all over the globe, but the best place is back home in Arizona. It works out well for me!

Thinking About Martian Sunrises

Posted by Petra on 7th April 2010 in Petra's Blog

Yellow in the clouds
Pink and purple everywhere
Blue and bright orange sky

Cholla sunrise

I stayed up late last night working on a project that’s due really soon, and I stayed up so late that I saw the sunrise before I went to bed. It was beautiful! The sky got slowly lighter, and in the East the sky just above the horizon was peach and red. The sky above that turned slowly bluer.

I couldn’t help thinking of what the sunrise on Mars would be like. The Martian sky is red because of all the dust (with iron) in the air, but it can refract light in a similar way to Earth’s atmosphere. So, if I were on Mars right then, the colors would be reversed. The sky would be turning a brighter shade of red, with the sky in the horizon looking a bit blue or green. It would be amazing! Someday Martian colonists will get to see those sunsets and sunrises. I’m not sure I could get used to that though. I love my Arizona sunrises and sunsets!

Exploring the Red Planet, Part Two, Mapping

Posted by Petra on 5th April 2010 in Petra's Blog

Photograph by NASA, found at

An important part of exogeology is exploring! Rovers on the surface and orbiters up above the surface both tell us a lot about the surface of Mars.

The Mariner spacecraft were the first to provide closeup photos of another planet. That’s really impressive. There were a lot of flybys and orbiters since then, and now NASA has an amazingly good photograph of how Mars looks from space.

The other part of mapping Mars is actually going down and looking at everything close up. Rovers and landers like Viking and the Mars Exploration rovers worked hard to do that. The Viking missions were the first successful Mars landers, and there’s a picture Viking 2 took in the photo gallery.

The Mars Exploration rovers, Spirit and Opportunity, have been exploring Mars for a lot longer than was expected, and I’m still receiving data! Someday there will even be astronauts going to Mars! Exogeology ROCKS!

Exogeology on Earth

Posted by Petra on 4th April 2010 in Petra's Blog

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!

A Day in the Life of an Exogeologist

Posted by Petra on 3rd April 2010 in Petra's Blog

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.

Exogeology ROCKS!

Exploring the Red Planet, Part One, Water

Posted by Petra on 2nd April 2010 in Petra's Blog

Photograph by NASA, found at

I’ve been getting  some data from my favorite planet–Mars!

Mars being researched right now by people looking for water; traces of it in the past, and water today.

Water leaves traces in a bunch of ways. There are minerals that can only form when there’s water around, and there are geologic formations that water can form. I look for both kinds of evidence for water.

Some of the minerals I’ve found that require water are hematite and carbonates. Hematite can form without water, as it has all over Mars. But what I found that shows there must have been water are called hematite spherules. These are tiny spheres of hematite, embedded in a martian rock. They’re more commonly called “blueberries”. They could have formed as concretions, which only form when there’s liquid water, but the blueberries still don’t definitively prove the existence of water on Mars. There are other ways they could have formed, like as martian tektites.

There are other minerals that can only form with water, such as carbonate minerals like calcite and limestone. The Spirit rover has found evidence of carbonates in the Gusev Crater. You know what this means? Water! Rovers rock!

Channels on Mars were discovered a long time ago, yet exogeologists are still debating how they were made. One theory says that the channels are riverbeds, so they would have been made by water. But another says that the channels were made by lava. I’m still trying to decipher the history of the channels. But I’m hopeful that water had something to do with it.

The Phoenix rover took part in the search for water. It looked for water as part of its mission, and actually found some! I’ll say it again, rovers ROCK!

I’ve found lots of evidence for water on Mars, but I need more proof before I can say for sure that any large amounts of it existed on Mars. I think that “follow the water” is a great goal for the Mars program. I’ll have to keep searching!

How I became an Exogeologist

Posted by Petra on 31st March 2010 in Petra's Blog

Well, I’ve always been an exogeologist really, it just wasn’t my job title until now.

I’ve always been interested in geology. When I was little some of my favorite books were about volcanoes, and I started a rock collection. As I got older I learned to recognize a lot of different minerals and rocks. I just loved learning about different kinds of lava and eruptions, and about which rocks were quartz and which were pyrite. As I got older I got more books, and my rock collection grew. I read about geology as much as I could. I had a lot of other interests along the way, and I’d focus on that for a while, but geology was always an interest of mine, even if it wasn’t the focus of my life.

I also watched a lot of episodes of NOVA and The Universe. I’ve also always liked space, but never as much as rocks. I mean, lots of kids want to be an astronaut at some point, or an astronomer, or something like that. Space is just too cool not to! Or at least that’s my opinion. I lived in a great place for both geology and astronomy (Tucson AZ), and just for fun my family visited places like the Kitt Peak and Whipple observatories.

At age 13,  I started taking college classes at the local community college. By then I knew all about how geology could be used for things like analyzing moon rocks, and finding volcanoes on other planets. I thought it was really cool that Earth wasn’t the only planet to have geology! And of course, I wanted to learn more. I first took a geology class, because geology was my passion. The very last part of that class was about exogeology. And it was by far the best part. I got to see a picture of a hypothetical planet; I figured out what caused different landforms and how to use relative dating. I also got to look at craters on Earth. I later took an astronomy class, because I wanted to learn more about exogeology, but I didn’t know as much about the astronomy aspect. I knew that this was what I wanted to do. I was hooked, I wanted to be an exogeologist.

I then took more exogeology-related classes, which were mostly just geology or astronomy, one or the other, but they were all really interesting and I learned a lot. A few years ago I started working for NASA as an exogeologist. I’ve done all kinds of neat things since then, but my favorite is figuring out just what caused different formations (especially on Mars, that’s my specialty), like the Valles Marineris, or just rock strata. I love my job! I hope you’ll have just as much fun exploring exogeology as I do!

Exogeology ROCKS!