Archive for the ‘Exogeology’ Category

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.

More like Earth than Ever: Kepler-452b

Posted by Zoe on 2nd August 2015 in Exogeology, Main Page

Are there any other Earths out there? Is there another planet like ours, maybe one where we could live? One goal in the search for exoplanets, planets orbiting stars other than our own sun, is to find Earth-like planets. NASA’s Kepler mission just found the closest match yet!

This planet is called Kepler-452b. It’s not exactly a catchy name, but it’s informative: the name tells us the planet was found by the Kepler mission, and gives a number to the star system and a letter to each object. This planet got the letter “b” because it’s the second object found in the system, after the star.

What does it mean to say Kepler-452b is the closest match found to Earth? It’s fairly close in size to Earth, its sun is a similar star to ours, and it’s in what we call the habitable zone.

Artist's concept of newly-discovered exoplanet Kepler-452b. Image Credits: NASA Ames/JPL-Caltech/T. Pyle

Artist’s concept of newly-discovered exoplanet Kepler-452b. Image Credits: NASA Ames/JPL-Caltech/T. Pyle

A planet in its star’s habitable zone? We’ve found a few, but that’s still pretty cool—or rather, just the right amount cool for liquid water to potentially exist on the planet. This is the definition of the habitable zone. Without liquid water, we wouldn’t find a planet habitable, and in order to have liquid water, a planet would need to be warm enough for water not to freeze and cold enough for water not to boil. The temperature on the surface of a planet depends largely on its distance from its sun. The closer they are, the warmer the planet is. However, being not too close to and not too far from its star doesn’t tell you everything about a planet. It could be large or small, and made of all sorts of different materials. It could be dense and rocky like Earth or Mercury, or it could be fluffy and gaseous like Jupiter or Neptune.

So, being in the habitable zone isn’t enough to make a planet habitable. It would be hard to live on a planet without a surface you could stand on, so if you’re looking for a new planet to inhabit, pick out a rockier one. The size of the planet would also make a difference. The smaller a planet is, or even a moon for that matter, the harder it is to hold on to an atmosphere. Less mass means less gravity, which means less pull on the gases which make up an atmosphere. Gas particles can fly away over time until there are hardly any left. More mass means more pull, so it’s harder for particles to escape. So, more massive planets are more likely to have a thick atmosphere.

What about Kepler-452b? Where does this recent discovery fit in? It’s 60% larger than Earth in diameter, which is actually pretty close in size. For comparison, Kepler-452b is about 1.6 times the diameter of Earth, and Earth is about 1.9 times the diameter of Mars. Kepler-452b is considered a super-Earth in size. That’s what we call planets near in size to Earth, but on the large side.

While we know all this about Kepler-452b, there is also a lot we don’t know. We don’t know exactly what it looks like. We don’t know how close it is to actually being habitable. We certainly don’t know its whole story—yet. As technology improves, telescopes get better, and we think up cleverer ways to learn more about far-off places, we keep finding out more and more about distant worlds like this one.

Hang On, Philae!

Posted by Zoe on 12th November 2014 in Exogeology, Main Page

Could you land on a comet? Normally, the force of gravity holds a lander to the surface of a larger body, like a planet or a moon. The less mass an object has, the less gravity pulls you toward it. Comets are small. Gravity won’t do you a lot of good, so you would need to hang on tight.

That’s what Philae is doing. The European Space Agency (ESA) sent a spacecraft named Rosetta to Comet 67P/Churyumov–Gerasimenko, and Rosetta carried a dishwasher-sized probe called Philae, which was to land on the comet. The comet is about the size of a mountain, which may seem big, but think how small a mountain is in comparison to a planet! The Philae lander had to come equipped with screws in its feet and harpoons to grasp the surface.

Philae detached from Rosetta early this morning (09:03 GMT, 02:03 Arizona time) and began its descent. Curiosity had seven minutes of terror landing on Mars, but Philae took seven hours from separation to landing. At 16:03 GMT, ESA heard from the little lander. Philae had successfully touched down! But remember those harpoons? They didn’t work. Philae is clinging on by the screws in its feet, but it’s there.

Philae's view of the comet. Courtesy ESA.

Philae’s view of the comet. Courtesy ESA.

Philae will photograph and analyze the comet for the next two and a half days. If it gets enough sunlight for power, it can keep going for an “extended phase” lasting until March 2015—four whole months of comet science! After that, the comet will be closer to the sun and Philae will probably be too hot to work. Comet 67P/Churyumov-Gerasimenko will also heat up as it gets closer to the sun, so we might be able to see it active, with ices sublimating (turning from solid to gas) and creating the tails of gas and dust comets are famous for. Maybe the most exciting reasons to study a comet up close are that we get to see way, way back in history, and we get to learn about the far, far off outer solar system. Here’s wishing Philae just the right amount of sun.

Is landing on a comet even possible? Yes, but it’s tricky. Hang on tight, Philae!

More information:

Rosetta main website

Rosetta blog

Comet 67P/Churyumov-Gerasimenko

Timeline, instruments, and and landing details from Emily Lakdawalla

Bad Astronomy’s coverage, part one and part two

NPR story

ESA’s photographs


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.

321Science Presents: Asteroids Fact vs. Fiction

Posted by Zoe on 12th December 2013 in Exogeology, Main Page

Awesome news: the countdown for the OSIRIS-REx asteroid sample return mission has begun, and it’s now only 996 days until the beginning of the launch window!

Want to know more about asteroids and sort the science facts from the science fiction? The 321Science team is here to help with a video to illustrate the difference and answer a few questions about asteroids.

I’m incredibly excited about this video, which I helped to make! It was interesting seeing it go from script to numerous drawings to super-cool final product. I drew a couple of scale bars and small asteroid, placed a couple paper planets, and did a few miscellaneous other things. Also, keep your eyes peeled for a certain spaceship from a long time ago in a galaxy far, far away…

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 10

Posted by Zoe on 19th June 2013 in Exogeology, Main Page

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:

Exogeology ROCKS! Episode 7

Posted by Zoe on 22nd May 2013 in Exogeology, Main Page

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!

Bonus Track for Episode 6!

Posted by Zoe on 20th May 2013 in Exogeology, Main Page

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.

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!

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

MESSENGER Orbits Mercury

Posted by Petra on 18th March 2011 in Exogeology, Petra's Blog

MESSENGER was inserted into orbit around Mercury yesterday, March 17th. Launched on August 13th, 2004, MESSENGER has been in interplanetary flight for over six and a half years! I bet that after this long waiting, the MESSENGER team is thrilled to finally be in orbit. As for me, I think visiting Mercury ROCKS!

MESSENGER is a NASA Mercury orbiter. It’s name is an acronym for MErcury Surface, Space ENvironment, GEochemistry, and Ranging. One of its goals is to learn about the topography of Mercury’s surface, and another is to find out the composition of its atmosphere.

On its way to Mercury, MESSENGER has had one Earth flyby, two Venus flybys, and three Mercury flybys. In one of these Mercury flybys, volcanism on the surface and water in the exosphere were discovered. Also on the way to Mercury, MESSENGER took this ROCKIN’ “family portrait” of our Solar System:

There’s a lot about Mercury we’ve found because of MESSENGER. For example, could you imagine seeing a whole side of a planet which you’ve never seen before? MESSENGER gave us just that in this picture:

The instruments on board will be turned on and checked on the 23rd of March, and on the 4th of April the mission’s primary science phase begins. I look forward to seeing what new discoveries are made about our amazing innermost planet!

Exogeology ROCKS!

-Petra Stone

Life As We Don’t Know It

Posted by Petra on 3rd December 2010 in Exogeology, Petra's Blog

What if someone found a creature that wasn’t like any other, a creature which wasn’t made of the same chemicals as anything else on Earth? Wouldn’t it ROCK to find something so different? That’s exactly what geomicrobiologist Felisa Wolfe-Simon discovered in California’s Mono Lake.

Extremophiles are organisms which can survive in extreme environments, such as intense heat or lack of light. An extremophile bacteria was found recently in California’s salty, alkaline Mono Lake. This extremophile, known as GFAJ-1, can survive high amounts of normally poisonous arsenic.

By weight, the human body contains 65% oxygen, 18.5% carbon, 9.5% hydrogen, 3.3% nitrogen, 1% phosphorus, 0.3% sulfur, and small amounts of several other elements. Even though there is so much oxygen in the human body, most of that is in the form of water, so we say that humans are carbon based. Most life on Earth has a similar composition. While GFAJ-1 is tolerant of arsenic, it’s not exactly an arsenic based life form. However, it does replace one of the basic ingredients for life. This unusual microbe is not only tolerant of arsenic, but is able to incorporate it into its cells.

Yesterday, NASA held a press conference explaining this surprising extremophile. Among the presenters was astrobiologist Pan Conrad, interviewee in Exogeology ROCKS! Episode 3.

Science fiction and real science have often considered replacing important elements with chemically similar ones, but until now, there haven’t been any real life examples. When given no phosphorus and a lot of arsenic, GFAJ-1 replaces the phosphorus in its body with arsenic and continues to grow. None of the bacteria have yet entirely gotten rid of the phosphorus originally in them, but I personally think that replacing most of it is exciting enough.

This discovery changes what we know about life. There are so many possible places a life form can survive on Earth alone. Maybe life on other worlds is more common than previously thought. I sure hope so.

Trick-or-Treat, Here’s a Treat For You!

Posted by Zoe on 31st October 2010 in Exogeology, Main Page
Zoë and Mark Kelly

Zoë Bentley and astronaut Mark Kelly

Happy Halloween! Guess what’s finally finished? Exogeology ROCKS! Episode 4. It’s been a long time in the works, but I’ve completed the fourth episode of my Exogeology ROCKS! series. Exogeology ROCKS! Episode 4 features an interview with Captain Mark Kelly, mission commander of STS-134, the last scheduled space shuttle mission. For the first time ever, I’ve uploaded the full episode of Exogeology ROCKS! in one piece.

Watch Exogeology ROCKS! Episode 4 here.

Check out the other episodes here, they ROCK!

Have a ROCKIN’ Halloween!

Welcome to!

Posted by Zoe on 28th March 2010 in Exogeology, Main Page

Here on you will find information on what exogeology is, how to become an exogeologist, interviews of various scientists in the field, games and puzzles, a fictional exogeologist’s blog, a photo gallery, and much more!

I started this website as part of the NASA No Boundaries Contest, but plan to let it grow as I learn more about the topics.