Zeta Ophiuchi (Picture of the Day: 12/30/12)

Zeta Ophiuchi. Source

The bright star near the center of this photo is Zeta Ophiuchi. This star is exciting because it is a runaway. Moving at 24 kilometers per second, this star is plowing through the "cosmic seas", to use a quote. The bright, red area to the left of the star is a bow shock created in the interstellar medium by the solar wind from Zeta Ophiuchi. This particular image was taken in the infrared spectrum and then given false color so that we can see it.

This star, which is 20 times the mass of our sun, was likely a part of a binary star system, but was thrown free when the larger star went nova. I just find this really cool.

Lake Ellsworth (Picture of the Day: 12/28/12)

Lake Ellsworth drilling plan. Source

Some of you may have heard about lake Vostok, the subglacial lake that had been perfectly preserved for millions of years. If you haven't, don't worry about it. This lake, lake Ellsworth, is another subglacial lake, this time in Antarctica. A British team was trying to drill down to it, but have just given up because of difficulties they encountered. It's a disappointment for science, but they, or someone else, might try again. 

Invisibility and Other Science Fiction Realities

Functional invisibility cloak? Source

I've been reading an article titled 27 Science Fictions That Became Science Facts In 2012 which claims that a functional, battery-less invisibility cloak has been developed and tested. I'm having a hard time believing that this is true, but then again, anything is possible. I highly recommend reading the article, and if anyone knows more about this invisibility cloak, I'd love for you to leave a comment about it.

Curiosity at Rocknest (Picture of the Day: 12/27/12)

Curiosity's self portrait by Rocknest. Source

After a three day break in honor of the holidays, I decided to start back up my posts with some news about Curiosity, the enterprising rover exploring the alien surface of Mars.

This picture was taken by Curiosity near a place called Rocknest. To the left you can see a patch of unusually smooth soil. Curiosity took a few samples of this soil and has detected a few traces of carbon with unknown origins. It's possible that this carbon is a contaminant from Earth, but there's a chance that it originated on Mars. That's exciting. 

Orion Spacecraft

Unfinished Orion crew module. Source

"In two years, human space exploration will make its biggest leap in more than four decades." That's a quote I found from NASA and I couldn't help but get excited. To me, spaceflight is the highest calling of mankind, and I was severely disappointed when NASA's space shuttle program was forced to retire. But now it looks like companies such as SpaceX and Lockheed Martin really are picking up the torch. Moving spaceflight over to the private sector was a risky move, but it might actually be working. I can hope, at least.

The Orion Spacecraft is a part of a contract between Lockheed Martin and NASA. NASA isn't done with space, obviously, but they will no longer be running manned spaceflights alone.

EFT-1 flight plan. Source

The Orion Spacecraft is still under construction, but it will soon be ready for launch. In 2014, the plan is to send the craft into space on a United Launch Alliance Delta IV Heavy launch vehicle. This flight, dubbed Exploration Flight Test 1 (EFT-1), will be unmanned for the purposes of testing. The Orion Multi-Purpose Crew Vehicle (Orion MPCV) will orbit the Earth twice, reaching a maximum distance of 3,600 miles from the surface of the planet, 15 times farther than the International Space Station. When the orbits are done, Orion will reenter at upwards of 20,000 mph and splash down in the ocean. The purpose of this test flight is to test the the heat shielding on the crew capsule and other performance related things. If everything goes successfully this spacecraft could take humans farther into space than we have been in over four decades. I'm excited.

Orion parachute test. Source

NASA and Lockheed Martin are taking the Orion Spacecraft seriously. Currently parachute tests are underway to ensure that the crew capsule will be able to land safely. Three days ago a parachute test showed that the capsule could land safely even if one of the two drogue parachutes malfunctioned. The next test will see what happens when one of the main parachutes malfunctions. Like all space related things, the Orion Spacecraft has backups upon backups. The crew module alone has numerous backup parachutes, even though the chances of even one parachute malfunctioning are incredibly low.

What the Orion Spacecraft will look like. Source

Ultimately, if all the tests of the Orion Spacecraft go according to plan, we will once again have manned deep space missions. Orion could even take us back to the Moon, or to Mars, or even farther. I am optimistic about where we'll go with this new spacecraft. It'll be years before we make it back out into the solar system again, but I do believe that it will happen eventually.

Orion Crew Cabin (Picture of the Day: 12/23/12)

Incomplete Orion crew cabin. Source. Credit: Ken Kremer

This picture is of the Orion crew cabin. It is currently incomplete, but by 2014 it will not only be completed, it will also be attached to a Delta IV Heavy launch vehicle and blasted up to space. The 2014 launch will be a test of the Orion spacecraft and will return important data concerning life support systems, reentry effectiveness, and many other things.

Near Miss (Picture of the Day: 12/22/12)

Flight path of 2011 AG5. Source

Astronomers at NASA have determined that an asteroid, designated 2011 AG5, won't hit the Earth in 2040 after all. The 140 meter diameter rock orbits the sun along a path similar to the path Earth takes, so scientists were previously unsure of whether the asteroid would hit us or not. New observations show that we are safe from a potential extinction-level impact with this rock, and I for one am happy about that.

Extreme Climate Solutions (Picture of the Day: 12/21/12)

Seeing as how the world didn't end today, I thought I'd share this video that offers up some ways we can prevent the world from ending in the future. This video details three extreme ways that we could reduce global warming and save the planet. I don't know if any of them would work, but I do believe that we are going to have to do something on a large scale if we want to have any hope of survival.

Yummy Mealworms (Picture of the Day: 12/20/12)

Mealworms make good food. Source. Credit: Ed Oudenaarden/AFP/Getty Images

This picture may look disgusting once you realize that these edible morsels are filled with mealworms, but some people actually eat things like this. A recent study has been done that shows that replacing conventional meat production with insect production (specifically mealworms, in this case) for the purpose of human consumption significantly reduces land use and carbon dioxide production. Not only that, insects are also extremely nutritious and tasty, at least that's what I've heard. It may be a long time before Americans can get over the stigma of eating bugs, but I for one would be willing to try a few grasshoppers for lunch, assuming they were prepared well. 

If you want to learn more, I recommend reading this article.

NGC 5189 (Picture of the Day: 12/19/12)

NGC 5189. Source

This planetary nebula is very strange. Usually, nebulae like this are created by the expelled matter of a star, making them spherical. This nebula certainly isn't a sphere, however. Why is this? One hypothesis is that the star throwing off this matter is a part of a binary system. 

Sun Pillar (Picture of the Day: 12/18/12)

A sun pillar. Source

In the background, a beam of sunlight is clearly visible shooting up from the horizon. This effect is called a "sun pillar". As ice crystals order during their fall through the atmosphere they can bend light in all sorts of unique ways. One way they bend light is to make a pillar of sunlight like the one shown here. This effect is fairly uncommon, but very beautiful. This particular picture was taken in Östersund, Sweden.

Foxfire

Late at night, trekking through the woods, travelers will often see a mysterious, blue-green glow seemingly coming from the forest itself. This mysterious phenomenon has spawned many myths, earning the glow the name "fairy fire".

Foxfire. Source

Despite people's previous, mistaken belief that this unearthly glow was caused by some form of magic, it has since been realized that foxfire is the result of bioluminescence coming from fungus growing in decayed wood. Most of the time, these fungi emit a bluish green light that tends to be very dim, though it can become bright enough to read by. The light itself comes from the oxidizing reaction between luciferase and luciferin. The purpose of this light is unknown, but it likely attracts insects that will disperse the fungus' spores, or it is meant to ward off animals by indicating that the fungus is poisonous. There are many different species of foxfire fungus, but the most common one seems to be armillaria mellea.

More foxfire. Source

Historically, foxfire has been used for many purposes. These fungi produce a bright light and are very durable. Benjamin Franklin recommended that it be used as lighting in an old version of a submarine and there are reports of it being used as a natural lantern. Not to mention all the references to it, and uses put forth, in literature.

Foxfire is a fairly mysterious phenomenon, but that only serves to make it more interesting. I wish there were more I could say, but for now I recommend trying to find some this summer. I won't recommend you touch it.

Supercooled Water (Picture (or Video) of the Day: 12/17/12)

I think this video pretty much speaks for itself. I know that I say this all the time, but this is one of the coolest physical phenomena that I have come across to date. Supercooled water is really interesting.

The Red Square Nebula (Picture of the Day: 12/16/12)

MWC 922: The Red Square Nebula. Source

The square-like appearance of this nebula is no artifact of a camera. The nebula is actually shaped like this. We are not quite sure how this nebula managed to pull of this shape, but some have hypothesized that the star imbedded in the center threw off cones of material that achieved almost perfect right angles and we are viewing these cones from the side. It seems like a good explanation to me, but who knows what's actually going on?

Europa

My favorite moon, other than the one orbiting the Earth, has got to be Europa. Jupiter's sixth moon is special in one incredible way that makes it stand out among all the other moons in the solar system.

Europa. Source

You may have noticed that this moon looks a bit odd. Most of the rocky bodies in our solar system are barren hunks of rock floating dead in space, pitted and scarred with impact craters from numerous run-ins with space debris. You'd never expect to find long, unbroken lines marring the surface of any of these objects, yet Europa abounds with long, river-like markings. But it is not the appearance of Europa that makes it special, it is the reason for this appearance that sets it apart. The entire surface of the moon is water ice. That's right, Europa has water, a lot of it.

The surface of Europa even looks like it's made of ice. Source

The lines on the surface of Europa are cracks in the surface of the ice. Tidal flexing, caused by the moon's rotation and the gravity of Jupiter, cause these cracks, creating a process similar to plate tectonics on Earth. This tidal flexing could also be doing something much more interesting than cracking ice. It is likely that this tidal flexing is creating heat in the moon's core, and thus could be causing the water ice below the surface to melt. If there is liquid water, protected from space by the shell of ice, on Europa, then it is entirely possible that there is also life on the large moon.

Europa likely has an abundance of liquid water. Source

I think it's time for some boring facts before getting back to the question of life. Europa is slightly smaller than Earth's Moon, making it one of the largest moons in the entire solar system. The interior of the moon is likely silicate rock surrounding a small iron core. Beyond the rocky center of the planet should be a fairly thick sheet of liquid water. It is important to note that water has the special property of expanding when it freezes. This is important because it means that a large amount of water could be kept liquid at fairly low temperatures and gravity because the icy sheath of the moon could act as a sort of pressure chamber. All that would be needed would be some extra heat from the moon's core which, as I've mentioned, could be supplied by tidal flexing. Beyond the icy surface of Europa, there is extremely little atmosphere. Just a little bit of oxygen floating around. 

Europa orbits once of every two rotations. Source

Back to the question of life on Europa. Before I start making any claims, let me first state that there is no evidence of life on Europa. This is all speculation.

As the ice surrounding Europa cracks, water spews forth to close up the cracks. Because of this upwelling, we know that water exists, the question is how much and at what temperature. In Earth's oceans there are entire ecosystems living around geothermal vents that don't require light from the sun. These ecosystems survive off of bacterial that are capable of living off of the heat and reactive chemicals coming from these vents. It is possible, even likely, that similar vents exist on Europa. If these vents do exist it is entirely likely that bacteria and other simple organisms could live on Europa. If these bacteria do exist then it's possible that other, larger organisms could live off of them. The problem with this, however, is that the larger organisms that survive around geothermal vents on Earth also rely on oxygen, something that likely doesn't exist in the oceans of Europa. It is possible that life on the large moon could find some other way of life independent of oxygen, but Richard Greenberg posits that they might not have to. He claims that cosmic rays that hit the surface of Europa could convert some of the water ice into oxygen which could then be absorbed into the subsurface oceans through the cracks that form in the ice. This would be a slow process, but eventually it could put enough oxygen into the oceans for large, aerobic organisms to survive. 

I don't know what's down below the ice on this moon, but whatever we find, it won't be an ecosystem as large or diversified as the one on Earth. Our planet is just too conducive to life for Europa to ever match.

Geminid Meteors (Picture of the Day: 12/15/12)

Geminid meteor shower. Source

This beautiful compilation of photographs expertly highlights the Geminid meteor shower that occurred this week. The pictures that went into making this photograph were taken from the Chilean Atacama Desert by ESO's Paranal Observatory. This meteor shower is likely still happening, but it should die down very soon. 

Umbra World (Picture of the Day: 12/13/12)

Umbra World. Source(1) Source(2)

This clever picture was taken during the last total solar eclipse. The photographer took 8 pictures of the scenery around him at the moment of totality then digitally stitched them together to make this crazy looking planet. The things we can do with modern technology are just crazy. 

Night Sky Over Africa (Picture of the Day: 12/12/12)

Milky Way over a quiver tree forest. Source

This picture is a composite of 16 different exposures taken in southern Namibia. In the background you can see the central band of the Milky Way Galaxy and a spot of bright light that actually comes from the small town of Keetmanshoop. These trees are known as "quiver trees" and are really just overgrown aloe plants.

Catching a Satellite (Picture of the Day: 12/11/12)

Dale Gardner captures a satellite. Source

I think this shows the heights of what any man can do. This rather simple mission strikes me as one of the coolest things that I have ever seen. This picture is of Dale A. Gardner catching a satellite. He floated over to it in free flight, grabbed on and attached a control device to Westar 6 (the satellite seen here) before piloting it into the cargo hold of the space shuttle. Not much fanfare to it, but it's still amazing to think that this happened. If you want to read more about it, click here.

Titan

Scientists are currently very interested in a "little" moon by the name of Titan. This moon, the largest orbiting Saturn, has lakes of liquid methane on its surface and a dense atmosphere, spurring speculation that life may be possible there. Maybe.

Titan, the largest moon of Saturn. Source

Not only is Titan the largest moon orbiting Saturn, it is also the second largest moon in the entire solar system, second only to Jupiter's moon, Ganymede. The specialness of Titan doesn't stop there. This moon is also the only known satellite to have a dense atmosphere and the only object besides Earth known to have standing bodies of liquid. 

Titan's surface temperature hovers around a chilly 94K (-179 C), so the fluid on its surface certainly isn't water. What is it? Methane. Not only that, but Titan's density indicates that it is composed of about 50% water ice and 50% rocky material. This is far from anything that we'd be familiar with on our water-rich and iron heavy Earth, but Titan has been compared to the Earth in many ways. One cool way that Titan is like Earth is with its liquid cycle. On Earth, water evaporates, forms clouds, and later condenses and becomes rain. This process is known as the water cycle. On Titan, something very similar happens. Methane and ethane will evaporate, float into the atmosphere to form clouds and then condense back out again in the form of rain. It does this in a way so similar to Earth that you could imagine the "spring methane rains" on Titan to look a lot like rain on Earth.

Artist's impression of rain on Titan. Source

Even though Titan can support liquid methane and other hydrocarbons, it is still a fairly "dry" place compared to Earth. Its atmosphere is mostly nitrogen, and the methane oceans are just a few standing lakes dispersed mostly around the poles. However, there is strong evidence of cryovolcanism on the moon's surface. Water ice deep inside the moon is likely heated and melted by the residual heat from the core, melting it into liquid water "magma". Just like on Earth, this "magma" can build up pressure and explode violently to the surface, spewing forth water "lava" in much the same way that volcanoes act here at home. I find this really cool.

A panoramic view of Titan's surface. Source

Then only picture ever taken from the surface of Titan. Source

And as for life on the surface of Titan, it's highly unlikely, but there's nothing to say that it isn't possible. Earth life could not exist on Titan, but that doesn't meant that life can't exist in an entirely different way than anything we've experienced. Titan has a solvent, liquid methane, which is extremely useful, if not entirely necessary, for life. Methane isn't as good a solvent as water, but this also means that more complex organic molecules can exist without being torn apart by a strong solvent. There is a high surface pressure, another plus for life. And there is an abundance of hydrocarbons that could potentially replace the molecules necessary for Earth life. The real problem for life on Titan is the temperature. 94K is extremely cold. Every other factor may be sufficient for some form of life to develop, but the temperature throws a wrench into everything. While there are more things in this universe than any of us can predict, I'm going to go out on a limb and say that Titan probably doesn't have any form of life on its surface. I could be wrong, I would even like to be wrong in this case, but I won't hold my breath.

3 Physics Experiments that Changed the World (Video of the Day: 12/9/12)

From SciShow. Watch it, it's cool.

I'm not sure if I would think of these as the top three physics experiments of history or not, but they certainly did change the world. Proving gravity exists, that light has wave-like properties, and that the atom has a dense, solid center? You can't go wrong with that.

Moonrise (Picture of the Day: 12/8/12)

Moonrise over Baku, Azerbaijan. Source

This detailed picture was taken at 2 minute intervals over Baku, Azerbaijan. We can really see the progression of the moon as it rises. I think it's pretty cool. If you look closely you can see the bright dot of Jupiter mirroring the rise of the moon for a little way.

Mars Space Suit (Picture (or video) of the Day: 12/7/12)

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I just thought this was cool. Mars isn't a very hospitable place for humans, but it will be possible for us to live there. With the proper utilization of sealed environments and suits like this, mankind might one day be able to set up a colony on the red planet.

The Giant Sequoia

The world's largest tree by volume is sequoiadendron giganteum, otherwise known as the giant sequoia. Perhaps you've heard of them.

The President, Source

These redwood trees occur naturally only on the western slopes of the Sierra Nevada mountains in California. This highly exclusive environment means that there aren't very many of these trees and that they are uniquely susceptible to climate change. They are, however, amazing creatures. They usually grow between 50 to 85 meters tall (160 to 279 ft) and 6 to 8 meters (20 to 26 ft) in diameter. Some have even been measured up to 94.8 meters (311 ft) tall and 17 meters (56 ft) in diameter. That's huge. These trees are truly staggering, it is hard to conceptualize just how monumentally large they really are.

These trees are huge. Source

Being an evergreen, this tree lives in a very cold climate. Even though it is snow laden most of the year, the leaves of a giant sequoia will never lose their green color. These trees keep their seeds in cones, just as you might expect, but these cones are unique. A giant sequoia can keep its cones closed for up to 20 years or more. The only way for these cones to release their seeds is if they become dried out. This drying usually occurs during low-intensity forest fires where convection currents take heated air up into the canopies of the trees and dry out the cones. For a while, however, giant sequoias weren't reproducing very often. As it turns out, human forest fire prevention and livestock grazing significantly reduced the frequency of low-intensity forest fires. To make matters worse, the lack of fires allowed for white firs to begin to grow which could act as a ladder for high-intensity forest fires, allowing them to reach the vulnerable canopy of the giant sequoias. And the sequoias don't just depend on forest fires to open their seed cones, they also need these fires to clear away undergrowth to allow their seeds to grow. In response to the lack-of-fire crisis, the National Park Service began to set controlled fires back in 1970. So far they have been fairly successful.

Giant sequoias have thick bark to protect them from fires. Source

There used to be a logging problem with these huge trees. Giant sequoias are few in number and take a long time to grow, so logging was seriously damaging their population. As it turned out, however, the wood of these trees was fibrous and brittle, making it of little marketable value. When the public saw that these majestic trees were being cut down and made into toothpicks there was a strong movement to protect them. Now these trees aren't logged, but the mammoth stumps of old logged trees are still a tourist attraction.

The Mark Twain tree. Source

The Gegenschein (Picture of the Day: 12/6/12)

Gegenschein over Chile. Source

The night is not darkest when the sun is directly beneath your feet. The strange, dim light seen here will appear when the sun is in such a location, making the night bright (well, not very bright at all, but still). This effect is known as the gegenschein. This picture is of the gegenschein over Chile. It turns out that the sun's light will reflect off of interplanetary dust particles to create this effect. The gegenschein is extremely dim, so this picture is particularly rare. 

Besse Cooper Dies (Picture of the Day: 12/5/12)

Besse Cooper and grandson Paul Cooper. Source

This "Picture of the Day" is a bit sadder than the rest. A distinguished person has died. 116-year-old retired school teacher, Besse Cooper, passed away yesterday. She was the previous record holder for the worlds oldest person, but now that title falls to 115-year-old Dina Manfredini. What was Besse's secret to a long life? She said it was staying out of others' business and abstaining from junk food.

Here's to you, Besse, and your inspiring refusal to let time get you down!

Water on Mercury

On November 29th of this year, 2012, NASA announced something pretty amazing. There is evidence that water ice exists on the planet Mercury. Remember, Mercury is the closest planet to the sun, and its surface temperature can reach up to 700K (that is 427 C) if not higher. Scientists from NASA aren't making any bold claims yet, but some other sources that I've heard from are. It is difficult to tell what is true about this topic and what isn't, but I'll do my best to work it all out.

Mercury. Source

NASA went through some pretty complicated steps to find the evidence for water. The bare bones essence of what they did is this: they fired a radio wave at the poles of Mercury and measured what bounced back. The results were astonishing. There found pockets of highly reflective "stuff" at the bottom of what appeared to be craters on either pole. This significant because water ice is highly reflective in the radio wave spectrum. Not only that, but radio waves bounced off of water ice tend to be depolarized, and that's what happened to these radio waves. They came back depolarized.

Mariner 10, the last spacecraft to visit Mercury. Source

If Mercury is so hot, then how is it possible that there can be water ice? The answer to this is actually pretty clever. Mercury has a 3:2 orbital resonance around the sun, which, in English, means that it has a day of 176 Earth days. Every part of Mercury gets blasted by the sun eventually, so it stands to reason that any water on its surface would evaporate away into space (given Mercury's low mass). And while it's true that any water on Mercury should get blasted away it is also true that Mercury has a lot of impact craters. The poles of Mercury never get close to facing the sun, so there are regions in some of the deeper craters on the poles where light never shines. And because Mercury doesn't have an atmosphere, there is no hot air to heat the insides of these craters. It is therefore possible to have water on Mercury.

Locations of water on Mercury. Source

NASA's official claims don't exceed much more than what I have already said, but unofficially, there are some fascinating things related to their findings. It has been estimated that there might be as much as 1 trillion tons of water ice on Mercury. That is a lot of water. But what's even more fascinating is that there is evidence of water existing on slightly warmer parts of Mercury, surviving due to an insulative layer of... something. This "something" that keeps this water from melting could very well be organic matter. I'm not just talking about stray carbon atoms. It has been speculated that this insulating layer is composed of complex organic molecules indicative of either early life or the beginnings of life.

Life on Mercury? Could it be true? I don't know the answer to these questions, but it would be amazing to think that there could be something alive, or something that was once alive, on the hellish surface of this barren planet.

Giant Sequoias: The President (Picture of the Day: 12/4/12)

The President. Source

This giant sequoia, affectionately named the President, has helped us come to some ground breaking discoveries about these great trees. In this picture (actually several pictures, giant sequoias are huge) we see Steve Stillett and his team climbing around to do some research. They have been measuring different parts of this tree and taking numerous samples over the years in order to document the growth, age, and effect of climate change on these massive plants. Surprisingly, it has become apparent that older sequoias grow faster than young ones. This 3,200 year old tree has already reached a height of 247 feet, and will continue to grow as it ages. 

Lunar Halo Over Spain (Picture of the Day: 12/3/12)

A quadruple lunar halo over Spain. Source

This image is actually quite rare and fantastic. What we are seeing here is a quadruple lunar halo over Madrid, Spain. Falling ice crystals can, on occasion, create a lensing effect in the sky. This lensing effect can create halos around the sun or Moon. These halos are rare by themselves, but here we are seeing four of these rare halos. I was blown away by this picture and just had to share it.

Star Formation Regions

This topic is very relevant to me personally. For the last week or so I have been working on a project for my Astronomy class. My group and I chose to map out the star formation regions in the distant galaxy M33. Our pictures and analyses were certainly not professional, but I learned a lot about how stars form and how to identify star formation regions.

M33 through a hydrogen alpha filter. Not as good as the pictures I took... Source

Star formation regions are just dense nebulae, clouds of dust and gas floating around in outer space. Because most star formation regions are composed primarily of molecular hydrogen (H2) they are commonly called "molecular clouds". At a certain point these molecular clouds become dense and small enough due to gravitational processes and they begin to collapse. Once they collapse in on themselves they will divide into thousands of chunks that collapse further into protostars where they begin to heat up and burn before they become full fledged stars. It really is a fascinating process, and it's no wonder that many people call these star formation regions "stellar nurseries". They are the birthplaces of baby stars.

Orion nebula. A stellar nursery. Source

Maybe you're wondering how people identify star formation regions. Maybe you aren't wondering that, but I'm going to tell you anyway. Star formation regions tend to be large, cold areas of 70% hydrogen gas. Because their temperatures can hover around 10K they don't emit much light in the visible spectrum, but that doesn't mean that they don't still emit light. These hydrogen molecules are constantly moving around and exchanging electrons, which throws off photons at very specific wavelengths. Observers can locate star formation regions by searching for regions emitting large amounts of hydrogen light. This is done with a device known as a hydrogen filter. There are several kinds of hydrogen filters, but the most common is the hydrogen alpha filter. These filters work by filtering out all light except for light of the same wavelength as the hydrogen emission spectrum.

Hydrogen alpha filter. Source

Horsehead nebula through a hydrogen alpha filter. Source

Looking for hydrogen emission signatures isn't the only way to detect star formation regions, and it might not even be the best. An observer can also look for emissions around 24 microns, that's infrared light. The reason that this works is that protostars emit heavily at around 24 microns. Where there are protostars, there is a star formation region.

Sadly my hydrogen alpha images were not nearly as high quality as most of these images, but they were sufficient for my purposes. Mapping out star formation regions is way more fun that it should be.

M33 (Picture of the Day: 12/2/12)

M33 galaxy through a hydrogen alpha filter. Source

Recently I've been working on a project for my Astronomy class at the University of Iowa. We were given free reign to choose what we wanted to study and my group and I chose to map out the star formation regions of the M33 galaxy. This picture here is of said galaxy through a hydrogen alpha filter. The Ha filter filters out all light that isn't of the same wavelength as the light emitted by hot hydrogen. The benefit of this is that it allows a viewer to identify star formation regions because these regions emit heavily in the hydrogen spectrum, but not very well in any other wavelengths.

Titan (Picture of the Day: 11/18/12)

Titan supercomputer. Source

The Oak Ridge National Laboratory has done it again. This picture is of Titan, the worlds newest and fastest supercomputer. Running at 17.5 petaflops (that's 17.5 million billion operations per second), this computer beat out Sequoia, the previous champion. With this new computer, the U.S. now has two computers above Japan's  K computer, a previous first-place super computer. I recommend reading more about it in this article.

I only wish I had a computer this fast, but then again, I suppose I'm not running the amazingly complex research programs that Titan will be running.

Layers of the Atmosphere

When most people think of "atmosphere" they think of a single envelope of gases surrounding the Earth. What's very interesting, however, is that this "envelope" isn't just a uniform region of gas. It's actually divided up into several different layers. Now, it's important to note that the boundaries between these layers aren't hard lines like the layers in a cake, they blend together.

The atmosphere becomes more transparent as it gets thinner. Source

The first layer, closest to the surface of Earth, is known as the troposphere. It extends about 17 km from the ground on average, but can extend higher closer to the equator, or lower around the poles. This region contains about 80 percent of the atmosphere's mass and 99 percent of its water vapor.

Troposphere. Source

After the troposphere is the stratosphere, but in between is the tropopause. The tropopause is the boundary between the troposphere and the stratosphere. It is a region of nearly uniform temperature and complete dryness. It also marks a change of a different, and more interesting, kind. If anybody has ever climbed a mountain, they're sure to have noticed that the air becomes colder the higher they get. This is an aspect of the troposphere that seems intuitive. However, temperatures don't behave this way in the stratosphere. Instead of cooling as the altitude increases, the stratosphere actually warms up. This is because it contains most of the atmosphere's ozone (O3) which absorbs ultraviolet radiation from the sun, converting it to heat. This layer can begin at as low as 10 km and go to around 50 km. These boundaries, like all atmospheric layers, are subject to change with season, storms and other effects, however.

Atmospheric boundaries. Source

Another look at atmospheric boundaries. Source

Next we have the mesosphere. By this point the air is really thin and the temperature is really low. However, the mesosphere goes back to the more intuitive "cooling with increased height" temperature scheme. There's not much to say about the mesosphere. It begins at around 50 km and ends somewhere around 100 km, but again, this is subject to change depending on the season.

Above the mesosphere and before the next layer is another boundary layer. This boundary, known as the mesopause, is unique because it can reach the coldest temperatures found naturally anywhere on Earth. It can get as low as 130 K, that's -143 C or -225 F. That's really, really cold.

The next layer is the thermosphere. This layer is unique in that it is not chemically mixed. Every layer previous was a more-or-less uniform mixture of various gases, but the thermosphere is so sparse and cold that it doesn't mix well. This layer of the atmosphere is separated out by the weight of the molecules that form it, with the heaviest molecules on bottom and the lightest on top. This layer is also similar to the stratosphere in that its temperature increases as altitude increases. This happens because the particles here absorb high energy solar radiation.

The thermosphere is the outermost layer of the atmosphere we all think of. Source

There is one final layer to the atmosphere. In any normal conversation about the atmosphere, most people would stop at the thermosphere, seeing as how it's the outer layer of any atmosphere that we would be able to feel, but I'm not going to stop there. The final layer is known as the exosphere. Here the "air" is so thin that particle collisions are very rare. This portion of the atmosphere mixes with space, so it has no defined ending point. One peculiar consequence of this, however, is that gas can leak out into space from here. This is known as the "slow leak" phenomenon. Most of us think of Earth's atmosphere as a solid shell around the planet, but it is actually leaking away. The loss of gas particles is incredibly slow, but given enough time (a very, very long time) our atmosphere could float away entirely. Now isn't that a scary thought.