Posts Tagged ‘minerals’

Exogeology ROCKS! Episode 11

Posted by Zoe on 2nd July 2014 in Exogeology, Main Page

In this episode of Exogeology ROCKS! I get to answer a few viewer questions:
How are planets made?
Are there gemstones on other planets?
Where is the closest black hole?

Good questions! Here are my best answers.

New Photo Gallery!

Posted by Zoe on 13th April 2010 in Main Page

Hello out there! It’s Zoë again with great news! I now have a working Photo Gallery up. Petra posted new blogs recently too, about a post per day, so keep checking up on her on Exogeology ROCKS!

The photo gallery is over on the sidebar underneath the “Games and Puzzles” category. I’ve made 5 different sets of photographs: Mineral and Rock Samples, Geologic Formations, Astronomy Pictures, Spacecraft and Landers, and Telescopes and Observatories. Check them all out! Each photo has a great description of whatever it has in it, and the pictures ROCK!

Until next time, I’m Zoë Bentley 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!

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!