The Extreme Tardigrade

Most extremophiles are bacteria, living in places like the deep-sea hydrothermal vents, sulfuric hot pools, oxygenless layers in the ocean, and other environments that are deadly to every other form of life. But there are a few extremophile animals, such as the tardigrade.

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Impressed yet? These invertebrates are some of my favorite living animals, and are a fascinating study in how evolution works. We still barely understand extremophiles of this sort, and there's a lot more research to be done. If you are interested in learning more, there are some resources below the break.

Looking for Other Worlds

The search for exoplanets has gone from being an unlikely dream 20 years ago to being a booming area of research in astronomy and planetary science. The first true exoplanet discovery, according to NASA, was in 1994. Since then, 687 have been discovered, and more are being found all the time. This video from Cosmic Journeys takes you through some of the highlights of exoplanet discovery, particularly the search for Earth-like planets.

Hat tip to Ciro Villa on Google+

Happy Sagan Day!

Carl Sagan was hugely influential in getting me interested in science and more specifically, planetary studies. His book "A Demon Haunted World" is still probably the best all around skeptical book I have read. If you haven't read it already, you really should read it. I think the book is a great introduction to critical thinking because he is able to give you the tools to think, without beating you over the head with them. There are so many wonderful quotes I could pick out of this book but here is one that I think gets to the heart of skepticism and isn't often cited.

As I've tried to stress, at the heart of science is an essential balance between two seemingly contradictory attitudes- an openness to new ideas, no matter how bizarre or counterintuitive, and the most ruthlessly skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. The collective enterprise of creative thinking and skeptical thinking, working together, keeps the field on track.

Have a great day and take some time today to look for that wonder in the world Carl was so magnificent at sharing.

 

Why Pluto Should Not be a Planet

Credit: NASA/ESA/SWRI

It was 2006 when the International Astronomical Union declared that Pluto was no longer going to be considered a planet. Ironically, this was probably one of the best followed scientific controversies of my lifetime. Even now, my chemistry teacher proclaims in class that Pluto is a planet. I just want to set the record straight on this once and for all. Pluto is not a planet and it should stay that way.

The word planet means "wanders" in ancient Greek. If you are a careful observer of the sky, there are 7 objects that "wander" against the background stars. These first 7 "planets" were Mercury, Venus, Mars, Jupiter, Saturn, the Moon, and the Sun. As time went on, we realized that the Sun is really a complete different type of object than the others. The Moon is also unique on that list because it does not directly orbit the Sun, so we put it in a different class of objects. Now, let's look at the rest of the list. Before I go any further, go look at a image of the solar system to scale. There is a good image done by the team at Space.com below the break.

So have you looked at it? Good, because then you realize that really Mercury, Venus, Earth, Mars and Jupiter, Saturn (and the later discovered Uranus and Neptune) are really 2 different types of objects. So, we break these up into the inner rocky planets and the outer gaseous planets. Then there are only a few other groups of objects. You have the moons of the solar system, some of which are bigger than Mercury. There is the asteroid belt between Mars and Jupiter. I think to most people it is clear why even the largest asteroid, Ceres, is not a planet. Like the other asteroids, Ceres has a different composition than rocky planets and its orbit crosses with the thousands of other objects that occupy that part of the solar system.

So what about Pluto? Pluto is smaller than our moon, and like Ceres, it shares an orbit. Pluto resides in what is known as the Kuiper belt. Think of the Kuiper belt as like the asteroid belt, only with icy objects instead of rocky ones and a lot farther from the sun. Pluto may not even be the largest object in the Kuiper belt. Eris was discovered in 2005 and has a diameter of 2326 kilometers known to an accuracy of 12 kilometers. Pluto is somewhere between 2300 and 2400 kilometers. Pluto's size is harder to determine because sublimating ices on its surface can give it a little temporary atmosphere. So when it comes down to it, Pluto is a different type of object than the other planets. It is not a rocky world close to the sun and its not a massive ball of gas. Pluto is something else, a icy world that is interesting in its own right, but not to be confused with anything else.

Beauty and Science: The Sagan and Feynman Series

There can be something almost magical about the universe as revealed by science. Few human beings in recent time have expressed this as well as Carl Sagan and Richard Feynman. I stumbled upon this video series the other day and was blown away. Enjoy. 

UFOs and the 2%

Being an amateur astronomer, UFOs are close to my heart. I have been asked by countless people what I think of UFOs. On the Internet, it is not hard to find claims that UFOs are evidence of a hostile alien invasion, benevolent beings here to save us from ourselves, or that there are multiple species all here competing with each other for our loyalty. It is clear people are truly seeing strange things in the sky and others report first hand encounters. So the question is 'what should believe?'

There is no denying that people see strange objects in the night sky on a regular basis. Someone recently told me a story of a object he had seen with a group of people that reportedly would move in one direction, stop, then completely change direction and continue moving along. Even I have seen a UFO. I was just starting out as an amateur astronomer.  It was twilight, and to my amazement I saw a bright object hovering over a nearby lake. The object was flashing white red and blue. I was completely taken aback and at a complete loss for an explanation.

There countless stories like the ones above. Still, I have heard even dedicated UFO proponents admit that probably 98% (or pick your own number) of sightings and encounters are hoaxes or misidentified normal phenomena. It is those 2% of sightings that we can't come up with a explanation for, that they believe represent the real encounters.

The problem with this argument is that you are moving from an unknown (hence unidentified flying object) to an answer (aliens exist) without any further evidence. Scientists work with unknowns all the time. They may have a hypothesis that they are trying to gather evidence for, but without that evidence, it remains an unknown. Law enforcement does the same thing. If a case can't be solved, they simply label it unsolved. They don't assume that aliens did it.

With that said, I want to look to see if there is any reason that this small percentage of cases might go unsolved if aliens are not visiting our planet. Some of them probably are hoaxes or hallucinations. As Randall Munroe of xkcd shows above, it doesn't take many people misunderstanding something they seen in the night sky to make a lot of UFO stories. In may other cases, we just don't have enough information to find any answer.


If you want to say aliens exist you need evidence. UFOs, even those cases that are never solved, just don't cut it. Take my story above. I see no fundamental difference between mine and many others out there, except I found out what it was. I stared at the object over the lake for hours off and on. As it slowly rose in the sky, its colors settled down into the bright familiar glow of the star Sirius. The wild colors were probably caused by a nearby fire or other air pollutants. Still if I had reported it as a UFO, without some key details, no one could have ever proven what that object was. I doubt we will ever solve all UFO cases but that doesn't bother me one bit. What gets me going is the trill of finding an answer, one I can explain and defend, and growing my understanding of how the universe really is.

Planets Wandering Alone in Deep Space

Many science fiction plots use the idea of a deserted world wandering through space completely separated from its parent star. This dramatic set is a good place for intense action, but is it realistic? Even those worlds were out there, could we find them? A NASA press release claims not only are they there, but these worlds may even outnumber stars.

A forming solar system is a violent place. As the planets form around the young star, they start gravitationally pulling on each other. These tugs can send planets careening through the solar solar system, colliding into each other, or ejected from the system entirely. It's the planets that escaped that a team of astronomers from New Zealand and Japan were looking for.

Planets are not easy to find. The biggest problem is how small they are. The Earth may not seem like a small place, but compared with the vastness of space it is nothing more than a speck of dust. Normally we look for exoplanets by seeing the planet affect the light coming from their parent star in some way. So how could astronomer find these roaming worlds separated from their parent stars?

 The team of scientists used a 5.9 foot (1.8 meter) telescope to get their data. However, I would be surprised if any telescope could see even a large planet separated from its host star, so the astronomers got some help from gravity. When light passes through a lens, the speed the light is traveling changes. That then causes the light to chage direction. When light passes by a massive object, like a star or planet, that light is bent around the object changing its direction. The bigger the object the greater the effect. This effect allows astronomers to used massive objects in space, or even clusters of them, as natural lenses. This is called microlensing. This allowed the team to watch discover these planets as they magnified the light of background stars.

I really like this study for several reasons. They found something very exciting in these wandering worlds. They gave us a starting point in trying to figure out just how many of these lonely planets there are. They also were creative in discovering them using a subtle and elegant effect. Finally, they had their results confirmed by another independent team of astronomers before publication. This is kind of science that gets me excited do research and teach each day.

Scientific Unknowns: Life on Titan?

Sunlight reflecting of one of the lakes of Titan
Image Courtesy: NASA/JPL/University of Arizona/DLR

Of all the places we look for life in the solar system, there is one that has captured my imagination more than any other. Maybe it is because of this obscure moons weirdness, or the possibly of an entirely new biology. Either way I could not discuss life in the solar system and leave it out. So what plausibly and evidence is there for life on Saturn's largest moon? The answer may surprise you.

Here on Earth all life requires water. Water makes a great solvent. This simply means a large variety of different molecules can be taken up by the water. Suspended in liquid water, those molecules can move around to do the things of life. This works great here on Earth and water may even be a good solvent for possible life on Europa. Titan however, is a balmy -290 ^oF, putting water out of the picture. Luckily Titan is covered with another liquid that may be able to fill the same role as water, liquid methane. I need be clear in saying that we have no idea if life can form in liquid methane. Maybe it forms easier in methane than it does in water. While there are some good reasons to think water may be the liquid of choice, we simply don't know. This is what make Titan such an interesting world to explore.

An infrared image of Titan showing Titan's Northern Lakes
Image Courtesy: NASA/JPL/Space Science Institute

So now we have a feel for the plausibility of life on Titan, but what about the evidence? Often in science you test a hypothesis by building a model that produces predictions. Then you test those predictions to see if the model reflects reality. In 2005 a team of astrobiologists published a paper making some suggestions about what we might expect to see if some sort of methanogenic life were enjoying the orange haze of Titan. In 2010 data from the Cassini Huygens probe matched those predictions. So what does that mean? Well it means that this model deserves strong consideration. That said, we should not be quick to accept any claim of alien life. There are a huge multitude of processes not involving life that can change the chemistry of an atmosphere. This evidence is a exciting starting point, but it is not proof.
So when it comes to Titan, even more so than Mars or Europa, I can only say we have no clue if there is any life present. Titan is a moon we have only recently gotten a good look at. Astronomy has a history of dismissing early speculations of life with future observations. Will that pattern hold true on Titan? We need more scientists and more spacecraft to find the answer. Right now I can only say that I don't know, but that I am extremely excited to see the discoveries made as we hunt down the solution.

Scientific Unknowns: Life on Europa

Europa as seen by the Galileo Spacecraft. 

Credit NASA/JPL/DLR

When we think of aliens we often think of a place similar to Earth. We think of creatures with similar body plans and similar needs. But what about the possibility of creatures that have never seen the Sun? This is the kind of life that could be hiding on Europa, Jupiter's fourth largest moon.

There are two sides to every claim, plausibility and evidence. Some claims, like many new medical drugs, start with a high plausibility but the evidence never bears them out. Others, such as quantum mechanics, start with low plausibility but the evidence becomes overwhelming until they are accepted. Right now, to my knowledge, there is no evidence of life on Europa. What makes it exciting, however, is how plausible it is that life could exist there.

Europa's entire surface is covered with ice. Located almost a half billion miles from the Sun, there is nowhere near enough heat from the sun to melt Europa's ice covered surface. Still many, if not most, scientists agree that there is likely a ocean under that ice. As Europa orbits around Jupiter, it is squeezed and stretched. This is what creates the cracks you see on the surface. This also heats Europa's core in the much the same way playing with Silly Putty will warm it up over time, creating a layer of liquid water. There is a lot of debate between scientists on how thick this ocean is. Right now, it seems likely that the ice is tens of kilometers thick with an ocean that is between 25 to 100 kilometers thick. So the question is could anything survive in the ocean?

A cutaway view showing Europa's interior. Notice the
inner rocky core surrounded by liquid water and capped
 off an outer layer of ice.
Credit: NASA/JPL

If there is any life in Europa's ocean, it have had to have formed and survive with no sunlight. The ice above this ocean is just too thick to allow in enough sunlight for any organism to use that as a source of energy. So scientists have looked to the Earth for creatures that can survive without the Sun. Probably the most similar environment to Europa here on Earth is the ocean under the Antarctic ice. When scientists have drilled into the ice there we have found life. In fact scientists have found entire colonies of organisms called black smokers that live in some of the harshest conditions on the Earth. These organisms live off of hydrothermal vents at the very bottom of the oceans where there is no light at all. Some scientists have even speculated that this is where life on Earth originated in the first place. These unique adaptations of life here on the Earth make it reasonable to think similar creatures could survive on Europa.

A hydrothermal vent on the
Mid-Atlantic Ridge. Credit NOAA

So when it comes to life on Europa we have a really good story. We have solid reasons to think the ocean is there and that life could possibly survive in that ocean. What we are missing is the evidence. A detailed study of Europa is high on NASA's priority list, but without the proper funding it could easily still be more than a decade away. At this point, we don't have the evidence to say if life exists on this icy moon or not. I hope in my lifetime a spacecraft arrives at Europa and drills through that ice. What we find in that ocean could change how we think about ourselves and the universe we live in.

A Case of Mistaken Identity

Much of the fossil record is confusing. There are tons of fossils that look a lot like normal rocks, and quite a few normal rocks that look like fossils. This makes a paleontologist's job tricky, with any fossil in any time period. However, the most challenging are microfossils. Microfossils are fossilized single-cell organisms or colonies: bacteria and algae, usually. Prior to the explosion of multicellular life in the Cambrian, microfossils are all paleontologists find. To date, the oldest bacterial fossils that have been discovered are about 3.5 billion years old.

However, microfossils are particularly controversial because they are microscopic and often lack much detail. There are several geologic processes that create structures that look a lot like these microfossils. There is also a risk of contamination: modern bacteria can slip into cracks in the rock and die there, looking for all the world like a fossil.

One of the oldest fossils discovered were 3.5 billion year old cyanobacteria in the Apex Chert of Australia. At least, that's what the research team thought they were. Other raised questions, though. In some places, the fossil had strange branching structures, that seem inconsistent with life. Analysis suggested the structures were carbon-based, which also suggests life... but graphite and organic compounds could leave similar structures without life. And that's assuming the initial analysis was correct. A more recent look, by Craig Marshall and his collegues at the University of Kansas, suggests that the "fossils" are actually just crystal-filled fractures. The original research team is planning to respond to this study, so there's certainly no solid conclusion yet. Ancient microfossils are still an active, highly debated, and very important, field of study.

Now, if you read this blog regularly, some of the things above might sound familiar. "Cyanobacteria", preserved in ancient rock, suggesting origins of life, but could easily be a case of misinterpretation... it's very similar to the debate over the alien meteorite. That's because they pose the same problems. Here on Earth, we know from other lines of evidence that cyanobacteria, or something similar, first appeared around 3.5 billion years ago. That's when free oxygen first starts to appear, and cyanobacteria are the only organisms on Earth that can produce that free oxygen. So, it's reasonable to try and find fossils of them. In space, though, we have no such evidence that cyanobacteria, or any other type of life, has developed. It's certainly possible, but it will take a lot of proof to be accepted as fact. If we can't even verify that microfossils are real microfossil on Earth, we have a long way to go before we can accept extraterrestrial microfossils.

Source: LiveScience- Most Ancient Fossils Aren't Life, Study Suggests

Updates from Space

Image credit: NASA/JPL/SSI

There has been some exciting news from space over the last week. Here are some of the highlights.

Things are looking dim for the Martian rover Spirit. We haven't heard from this hardy rover in almost a year. Sounds like they will keep trying for a few more months but things don't look good. For a rover that was designed to last 3 months, 5 years is not bad.

On a brighter note, the Messenger spacecraft has dropped into orbit around Mercury. There it can now study Mercury's strange magnetic field. Messenger will also image the 5% of Mercury's surface that has yet to be mapped.

Thought Earth was the only place in the solar system to get spring showers, think again. Scientists using the Cassini spacecraft have gathered evidence of rain showers on Titan. At almost -300 degrees Fahrenheit, Titan's rain is likely a mix of liquid methane and ethane. This weird moon never ceases amazing me.

Alien Update

I want to quickly revisit the alien meteorite from last week. Here are some good links to take a look at if you are curious.

I was wondering what NASA was going to say about this. Here is their official statement. If this research really carried some weight, I would expect NASA to be publicizing it to no end. Instead, they are distancing themselves.

This is the best review of the science in the paper I have seen so far. They also a fairly good job of reviewing the journal itself.

I know I linked to Bad Astronomy before but I am going to do it again. He does a nice job laying out the criticisms made other places in a very understandable way.

After reading all of the follow-up here and other places, my original opinion still holds. The science here is just not nearly enough to prove the claim being made.

Aliens Exist: Proof Pending

Last week I mentioned how I wanted to do some posts talking about the possibility of life in the solar system. Well, apparently that is going to be a waste of time, since this Saturday Yahoo News released an article reading in its first line "Aliens exist, and we have proof." Fox News was no better with their first line "We are not alone in the universe -- and alien life forms may have a lot more in common with life on Earth than we had previously thought." How much did we think we have in common with alien life forms before? Anyway, both articles discuss a paper done by NASA astrobiologist Dr. Richard Hoover who claim that he has found evidence for fossil alien bacteria in a meteorite. With a news story like this spreading across the Internet, I couldn't help but do some digging.

First, I went looking around my usual astronomy news sites. As of Sunday evening, I couldn't find a thing mentioning it. This is really peculiar and made me that much more skeptical. The one article I could find was on Bad Astronomy by Phil Plait. It is a good review of the paper and makes several of the same points that came to mind for me. Still, the vast under-reporting of this breakthrough in the specialized media is a point I think is worth mentioning. If you ever see something in the mainstream media, look to see what the people who deal with that subject on a regular basis have to say. While not always true, I have found that breakthroughs tend to go from the specialized media to the mainstream; nonsense tends to flow the opposite way.

With no luck in the space news, it was time to go to the paper itself. The largest problem this paper faces is in that pesky relationship between claim and evidence. If you are going to claim extraterrestrial life, you need a mountain of evidence to back you up. Dr. Hoover works hard in the paper to rule out any earth-based contamination. He is quoted in the journal press release with the following.

"What is both exciting and extraordinary is although many of the bacteria resemble and can be associated with generic species on Earth, there are others which are completely alien. Neither I nor other experts who have seen the evidence have any idea what these creatures might be."

It could be true that no one who has studied the rock has been able to identify the bacteria inside. This does not mean however, that they are necessarily alien. In the paper itself, he tries to use the specific chemistry to the meteorite and the "fossils" to rule out abiotic causes and earthly contamination. I do not have the technical knowledge to delve into these details, so it will be interesting to see what the editors of paper said when those are released.

In the end, I think this paper falls short. I want to see how the scientific community responds over the next few days and what, if anything, comes of this. That is part of what makes science so interesting. Now the paper is published and the real critique can start. For now I remain unconvinced but eagerly await to hear what story will come from this.

Scientific Unknowns: Life on Mars

The question of how much life there is in the universe is one of the most fundamental questions in astronomy, and possibly all of science. While we are just now on the brink of finding Earth-like planets around other stars, the possibility of life existing on planets very different from our own still remains. While scientists have dismissed the old notions of grand civilizations on Venus and Mars, there is tantalizing evidence of microbial life throughout the Solar System. This is a first in a series of posts I will do over the next few weeks looking at some of the top contenders.

Of all the places we look for life in our solar system, none seems to have the mystique of Mars. The search for life on Mars has deep historical roots. Percival Lowell infamously reported his evidence for a grand civilization on Mars with a grand irrigation network. This and other stories firmly set Mars as the home of extraterrestrials in science fiction. While scientists are no longer searching little green men on the surface, microbes on the red planet have become hot topic of debate. Mars surface is bathed in radiation that would likely prevent anything from living on its surface. Liquid water also can no longer exist on the surface of Mars. These both come from the fact Mars lacks the thick atmosphere and magnetic field we have on the Earth. So planetary scientists are now searching for microbes under the surface of mars. For those scientists there are three main lines of evidence.

1. Recently, there has been a growing consensus that a few billion years ago, Mars had at least a some running water on its surface. The Earth appears to have developed life fairly quickly once the oceans formed. The thinking goes that if Mars had conditions similar to that of the early Earth, it is reasonable to assume that it would have developed life in a similar way. Mars has changed so much over the last few billion years to become the dry and harsh world it is today, that it is not surprising that we don't see the abundance of life we now have on the Earth. This idea gives hope that possibly some microbial life was able to take hold on Mars during the planet's youth and maybe still be surviving under the surface.

2. If life ever existed on Mars, we could maybe find evidence of it the same way we find evidence of past life on the Earth: fossils. It is well accepted that large impacts from meteorites on the surface of Mars can lob chunks of the Red Planet into space. The Sun can then pull those into the more inner part of the solar system where they collide with the Earth. What is controversial is a claim made by a group of scientists in 1996 that one such Martian meteorite contained a fossilized bacteria. If true, this would be sure evidence of at the very least past life on Mars. After 15 years of research however, the scientific community is still far from a consensus.

In science, extraordinary claims require extraordinary evidence. Life on Mars is certainly an extraordinary claim. Unfortunately, the evidence has yet to match. Without going into extreme technical detail, the core issue is whether or not the meteorite in question, Martian meteorite ALH84001, could have plausibly formed without life. Scientists look at a multitude of characteristics, mostly based around the various minerals including their isotopes, distribution, and texture. I think it is safe to say that our current results have been inconclusive. There are scientists with strong points on either side. In the end, the evidence is just not there to make a solid decision.

3. The final hint of life on Mars is methane. This is something I touched on briefly in the past and the basic story is this. The chemistry of Mars atmosphere is such that methane breaks down over time. We have found large quantities of methane in Mars atmosphere, so we know it must be replenished by some ongoing process. At this point all we have is the observation of the methane itself, and speculation about what is causing it. The reason people get excited is because one of the ways methane is produced here on Earth is by bacteria. Scientists, however, are also quick to point out that we know of geologic processes that can produce methane in the quantities we seen on Mars. Again, this line of evidence seems tantalizing, but non-conclusive.

So, what is the final story for Mars? I have to say that, while there is good reason to continue looking for microbes under the surface, we can't say we know they will be there. Either we will see exciting geology or revolutionary biology. Regardless, Mars continues to be a place worth exploring with mysteries lurking just beneath the surface.

Our Celestial Home to Scale

Space is big. In fact, space is so big that calling it big is an understatement. Trying to get this enormous size across is one of the greatest challenges of teaching astronomy. I have seen a lot of demonstrations and images trying to get across this very concept. Recently while browsing the Internet, I found a image that blew me away. I think this brings together the relative sizes and distances in the solar system in a very clean and easy-to-understand graphic. It is simple, while still including details such as light travel times, past and future spacecraft, and some of the more recently discovered dwarf planets. It is a very long image, so click on the link to see the whole thing. It is well worth your time.

Click here to see the full post

Free Software Tools for Astronomy

I have been in the astronomy education world for about a half decade now. In that time, I have found many very cool pieces of software that are great to explore on your own and teach with. So, if you have a few extra minutes, poke around, explore, have fun, and maybe learn something along the way.

Want to know what stars and planets are going to be above your head tonight? Stellarium will tell you that and more. With it you can also see what the sky was like a thousand years ago, or in Antarctica. This program will get you acquainted with the constellations and is really easy to use. I have used Stellarium to give students a idea of what to look for in the night sky, and I use it myself on a regular basis.

NASA released a new piece of software recently that, while still in beta, I have been thoroughly impressed with. Eyes on the Solar System is a absolutely spectacular tool for exploring planets, moons, and spacecraft. I was flying around the solar system within minutes of visiting the site. Its ease of use sets it apart from many other such tools, and the graphics are well done.

Third on my list is probably the best known. Google Earth is hugely popular, but one of its best kept secrets is its ability to take you off the planet it is named for. Google Sky lets you look up at constellations and see exquisite images from telescopes. Google Moon and Mars let you explore in much the same way you explore the Earth. To get to these features, press the button with the picture of Saturn on the tool bar and select the option you desire. This is great for showing anyone the wonders of another planet. Such a thing should be made available for every planet. Enjoy your travels.

The programs above I use and love. There are others, such as World Wide Telescope  and Celestia, that I have not been able to master and effectively use. I know other people who make these programs do wonderful things so they are worth your time. If you are interested, I recommend that you give them a try. I hope you more luck than I have had.

If you found this useful, let me know and I can do more similar posts in the future.

Sagan Day

Today is Sagan Day! While many of the celebrations took place this last weekend, today would have been Carl Sagan's 76th birthday. Carl Sagan has inspired me as well as many others to love science and use the lens it gives us to explore the world. This year I celebrate by watching a few episodes his famous television series, Cosmos. All I ask of each of you is to watch this short video clip. It is in my opinion on of the best essays ever written. No matter how many times I read and listen to it, I am struck. It is humbling and uplifting. I think it exemplifies the responsibility he saw us having not only to our planet, but also to each other.

"The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explorations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe our future depends powerfully on how well we understand this Cosmos in which we float like a mote of dust in the morning sky" - Carl Sagan

On that note, Happy Sagan Day.

Have Scientists Found a Second Earth?

Ever since we stared finding exoplanets (planets orbiting a start other than our sun) back in 1992, the hunt has been on to find a Earth-like planet. Of course, the planets we found first were not the small rocky worlds like our own, but massive gaseous Jupiter-sized objects that are very close to their stars, appropriately called hot Jupiters. Over time, we got better at the techniques and have become able to find smaller and smaller planets farther and farther from their host stars. Now, have we finally found that long sought-after 'second Earth'?

So our first question is simply, what did they find? To really understand this situation, you need to understand the star this planet is orbiting. This is not a medium-large yellow star like our sun, but a much smaller red dwarf. Red dwarfs have about 1/3 of the mass of the sun and a luminosity of about 1.3% of our sun. This means a planet has to be much closer to the star then the Earth to our Sun to have any chance for life to survive.

That brings us to the planet Gliese 581g (such a creative name). Because of the method used to discover this planet, we know it has a minimum mass of about three times that of Earth, and it is unlikely that it is much larger than that. It is also the right distance away from the star to be in what's called the "habitable zone". This is the zone where a planet could potentially have liquid water on its surface. So far, so good.

Now is when things get tricky. There is still much astronomers don't know when it comes to rocky planets, and planets in general for that matter. Gliese 581g is large enough to hold on to an atmosphere, but atmospheres are tricky things to understand. Atmospheres are also hugely important for life. Mars and Venus can both be said to be in the habitable zone of our Sun, but because of Venus's overabundant atmosphere, and Mars' lack thereof, they are both devoid of life. To make things more complicated, Gliese 581g is probably tidally locked with its host star. This means that one side of the planet is in perpetual day while the other side never sees the sun.

Science rarely, if ever, gives us cut-and-dry answers. Does Gliese 581 harbor life, or would life even have a chance there? We can't be sure. What makes this discovery truly exciting, though, is the speed at which it happened. We have only been finding exoplanets for less than two decades and, of that time, our technology has only become sensitive enough to find small planets much more recently. We have really only begun to survey our neighbor stars in the galaxy and already we have found a planet that is a decent candidate to support life. If this trend continues, there could be millions of such worlds in our own galaxy alone. Think of the prospects if even just a small percentage of those worlds ever developed life.

I think it's time to kick up the planet hunt one more notch.

Was Galileo Wrong? Moden Geocentricism

So, apparently while I was busy over the summer, the world did not abandon irrationality. Too bad. But the one upside is there is still something to write about. In some ways it is fitting that as I was skimming the web I found an idea I thought died centuries ago: geocentrism. I don't think I can paraphrase what they say without someone thinking that I made this up, so here is a quote straight from the horse's mouth.

The Idea

Galileo Was Wrong  is a detailed and comprehensive treatment of the scientific evidence supporting Geocentrism, the academic belief that the Earth is immobile in the center of the universe. Garnering scientific information from physics, astrophysics, astronomy and other sciences, Galileo Was Wrong shows that the debate between Galileo and the Catholic Church was much more than a difference of opinion about the interpretation of Scripture. 

Scientific evidence available to us within the last 100 years that was not available during Galileo's confrontation shows that the Church's position on the immobility of the Earth is not only scientifically supportable, but it is the most stable model of the universe and the one which best answers all the evidence we see in the cosmos.

I am not going to waste time debunking what they say. If you need proof that the Earth goes around the sun find a Foucault pendulum or look at the many spacecraft we have sent out into the solar system. If our understanding of the solar system was this seriously flawed, the beautiful pictures we have wouldn't exist.

This is a special brand of biblical literalism, but to be fair, this is fringe even for creationists. All their material makes it sound like they are supported by the Catholic Church, but I would be shocked if this were true. The reason I think this is worth noting and discussing is because, no matter how fringe they are, the way they promote themselves is the same as the more popular pseudoscientists. The website is covered with names of "scientists" that have PhD's. I also find it amusing how they claim to use science to reject an idea that (for all intensive purposes) no scientist is questioning even in the slightest. The implication is that they have the logic and evidence that has escaped the most brilliant thinkers of the last four centuries.

I recommend you not waste too much of your life dwelling on this nonsense but remember the wonderful and exciting discoveries that are being made every day. I hope to have more time to be writing articles again (which may or may not happen). So until my next rambling, remember this stuff is still out there. Science and reason still need to be openly discussed, critical thinking taught, and sometimes, nonsense ridiculed.

This article posted in honor of Jean Bernard Léon Foucault who's 191st birthday is today.

News From the Martin Arctic

In this last week, there have been two news stories worth reporting from the North Pole of Mars.

Image credit: NASA/JPL-Caltech/University of Arizona

The Phoenix Mars Lander was a huge success. It was a small lander that was designed to find water ice at high latitudes on Mars. We originally lost contact with Phoenix in November of 2008. Phoenix was not built to survive the Martian winter, but some people were optimistic that it might have survived, possibly because of boosted optimism from the Mars rovers. Orbiters were listening as the ice receded form Mars northern latitudes. No signal was heard and now we know why.

The two pictures above show the extensive damage Phoenix took during the Martin winter. On the image from 2008 you can see both solar panels reflecting that blue color. In the image taken this year shows that one of the solar panels has completely broken off. This is probably from the buildup of dry ice (frozen carbon dioxide) until the weight of it caused the solar panel to break. So while Phoenix may have done great science, it was not able to rise from the ice.

Image Credit: NASA/JPL-Caltech/MSSS

The other story has to do with the weird shape of Mars north pole. Looking at the picture on the left you can see the large spiral pattern. In the past planetary scientists had purposed many ideas including volcanism and glacial flows. Two new papers published in the journal Nature bring a strong new idea to the table: wind.

The details of the effect are a little technical for me to dive into here, but I did want to make some points about the research. I like to point out when scientists build models that make predictions and then either confirm or dispute their hypothesis with new evidence. In this case, they came up a model of what they thought a wind carved feature would look like. When the data came in, they found it matched their models. The scientists working this research also reported their results responsibly. They published in a peer-reviewed journal and didn't make any absolute statements. Jack Holt of The University of Texas at Austin’s Institute for Geophysics said “We aren't saying they were carved by wind, rather that wind had a strong role in their formation and evolution.” I think these scientists did a great job and found a really cool result. This is science at its best.

*If you do want a more detailed breakdown of their work, I recommend Universe Today