Pluto

I just can't help writing about our solar system. It's such an interesting place! The most recent news about Pluto was its fall from planethood. What was once the 9th planet in our solar system has been reclassified to a dwarf-planet, much to the chagrin of Pluto lovers everywhere. But let's be fair, Pluto isn't even the most massive dwarf-planet in our solar system, it's beaten by Eris. I'm not going to say that Pluto isn't cool enough to be a planet, but its reclassification was correct.

Pluto

Pluto is small, only slightly more than 1/5 the mass of Earth. It is so small, in fact, that the barycenter (the point at which two masses orbit each other) between it and its largest moon, Charon, isn't even inside Pluto. This has led to some people thinking of Pluto as actually being a binary planetary system with Charon as the other "planet". Even the moons of other planets are larger than Pluto. The seven largest moons in the solar system, Ganymede, Titan, Callisto, Io, Earth's moon, Europa and Triton are all more massive than pluto.

Pluto compared to Earth

Pluto does have four moons, or satellites, of its own that we can see. The three most massive of these are Charon, Nix, and Hydra, with S/2011 P1 being the smallest. Charon is more than half the mass of Pluto while Nix and Hydra are only 50 or 60 kilometers in diameter. Of all the space that Pluto has gravitational control over, these moons are in the closest 3%. This system is therefore very compact. It is possible that Pluto may have other bits of debris or rings orbiting in the rest of that space, but we have not yet observed it.

Pluto and satellites

Pluto is very far away and very small, so it is hard for us to image it. The best pictures that we can get of it's surface are pixelated and blurry, but they do offer us a good idea of what may be down there. The surface of the planet is very interesting, with a great deal of contrast between different surface colorations and features. This would suggest that it has a very interesting topography. The surface is also fairly colorful with a mix of white, grey, black, and orange. Spectroscopic analysis of Pluto shows us that the surface is nearly 98% nitrogen ice. Pluto does have an atmosphere, but it is very thin, mostly composed of methane and dissolved nitrogen. The atmospheric pressure on the planet can change as its orbit brings it closer or farther from the sun because gas will vaporize from the surface or freeze out of the atmosphere. The core of the planet is composed of rock and ice, in fact, it may be as much as 50% ice. Through heating from radioactive decay, it is likely that this ice has separated from the rocky part of the core to form a mantle, meaning that the center of the planet would be rock surrounded by ice.

Graphical rendering of Pluto's surface

Pluto as seen from Hubble

Surface of Pluto

Pluto, like Uranus, has a tilted axis of rotation. Its rotation is offset at almost 120 degrees from the other planets, but what is really interesting is its orbital path. Unlike most of the other planets that orbit on the same plane, Pluto's orbit is tilted almost 17 degrees. Another artifact of its orbit means that it will periodically come closer to the sun than Neptune. This has obviously brought up the question as to whether or not Pluto will ever collide with Neptune. As far as we can tell, the answer to this question is no. One reason is that Pluto's orbit is tilted, making it unlikely that it will hit Neptune. Another reason is that their orbital resonances are off (3:2). Neptune will orbit the sun 3 times for every 2 times Pluto orbits the sun. The whole system works like clock work, meaning that the two bodies should never hit each other.

Planetary orbits seen from the top

Planetary orbits with Pluto's tilt shown

What is a Science Blog?

A science blog, by definition, is most definitely NOT what I've been doing. Blogging is supposed to be a personal medium, however, I like to keep my posts rather impersonal. Science is supposed to be free of personal prejudice, but that doesn't necessarily mean that one cannot express their opinions or hopes for the future. There is a whole professional realm of futurists that make predictions concerning science and what will be possible. For example, Ray Kurzweil, a 63 year old futurist is currently on an extreme diet because he believes that technology will advance far enough in his life time that he will never have to die. I do not share his view, but I do believe that it is possible that we might beat death one day.

My blog will be a of mix facts and opinion. I can teach with one post and share my views with another. I honestly do think that the future is bright. The current political situation of the world is not conducive to scientific progress, but it will continue nonetheless. I have heard it said that science has the possibility to destroy, but I do not agree in the slightest. Science does not cause harm, politicians cause harm. TNT was not invented for war, it was invented for mining. It is ultimately politicians and governments that corrupt the advances of science. Even with its use in war, science has still saved far more lives than it could ever hope to destroy. In the last couple centuries, the human population has skyrocketed entirely due to advances in medical technology and farming techniques. Casualties due to human conflicts are nearly insignificant when faced with the life giving light of science.

The Role of Science and Technology

It is a sad fact that most history text books don't mention scientists or their contribution to society. Weapons, transportation, and electricity are only ever mentioned in respect to historical events and not their individual impacts to society. It is rare in history classrooms for students to learn about the polio vaccine or about influential scientists like Madame Curie or Maxwell.

Science has a big impact on war through the creation of weapons, manufacturing techniques and transportation, all of which can basically decide the outcome of combat. In history textbooks, you will often hear that one side may have had a technological advantage that lead to their victory, but these technologies are rarely ever specifically mentioned. And aside from war, technology and science are almost never mentioned at all. In the U.S. Civil War, there were between 600,000 to 700,000 casualties, pretty significant, right? On a human scale, this is hardly even a blip. Sciences, medical sciences specifically, have saved countless billions of lives throughout all of human existence. The polio vaccine alone probably saved several million lives. These creations and the scientists involved overshadow any war without a doubt, but they are almost never mentioned in history classrooms.

Line for the polio vaccine

International politics is another major focus of history textbooks, and an undoubtedly important one too. The communication between nations, treaties and wars are all very pivotal to our existence and our continued "peace" with each other. What is almost never considered in these situations is the role of science in these interactions. The earliest and most important advancement to effect international politics was the telegraph. With this new technology, nations could communicate with each other almost instantaneously, making life much easier.

One version of the telegraph machine

One of the biggest events that history books tend to overlook was the creation of the atomic bomb. Historians do focus vehemently on the impact of the bomb and how it has shaped our world since its creation, but they rarely seem to think how it was made or that they should teach people about those who made it. This is a product purely brought about by science, and it has shaped our world more than any other one thing, but historians don't care. Science is the driving force behind our societies, but nobody cares enough to learn about it.

Mushroom cloud from the detonation of an atomic bomb

Ultimately, the humanities are rarely concerned with science because it is not exciting to the average person. People are enchanted by bloody fields of war and clashes between titanic personalities. We have to come to terms with the fact that a complete understanding of the world and ourselves will not be all that exciting at first glance. We cannot continue to romanticize society, we must understand how it is created and how it can be advanced. As I have already said, science is the driving force behind society, and even humanity itself.

Eta Carinae

The hypergiant star, Eta Carinae, is probably the most amazing star that astronomers have ever studied. The stellar system in the constellation Carina is believed to be binary, with its central, and most massive, star being more than 100 times more massive than the sun. Eta Carinae is between 7,500 and 8,000 light years from earth and could be the only hypergiant in our galaxy. So far, it is the only hypergiant that we are able to study in great detail because it is relatively close.

Carina nebula, Eta Carinae is the dense white ball centered to the left (1/5 of the way from left)

Super massive stars, like Eta Carinae, are extremely bright. This star happens to be about 4,000,000 times brighter than the sun. The reason for this is that hypergiants burn much brighter due to their great mass. Our sun can only burn so fast because it is only so massive, but Eta Carinae is so much larger. It is able to burn extremely fast and extremely bright. The brightness of this star does tend to fluctuate however. In 1843, it was observed that Eta Carinae had experienced a supernova impostor event. Over several years, the star had emitted as much light as a supernova without actually going supernova. Eta Carinae survived the explosion which was most likely caused by the tenuous struggle between gravity and the fusion reaction. The star hasn't fully recovered from this massive explosion, even though it has been over 150 years.

Eta Carinae created these lobes and center disc after its supernova impostor event

Three structures have been created around Eta Carinae by the incredibly powerful solar winds that come from the star. The central regions of these structures can be as hot as 60 MK (Megakelvin, or million Kelvin) while the outer horse-shoe region is 3 MK.

Eta Carinae has created superheated structures with solar emissions

The more massive a star is, the faster it burns itself out. Our sun will live for another 5 billion years, but Eta Carinae could go hypernova within the next million years, if not sooner. Stars like Eta Carinae are so massive that they go beyond supernovae when they die, creating something called a hypernova, probably the largest explosion possible in our universe. Once Eta Carinae goes hypernova, it will most likely collapse into a massive black hole, ejecting tight beams of gamma radiation, called gamma ray bursts, from its rotational poles. If this burst were to hit earth, it would be equivalent to one kiloton of TNT being detonated over every square kilometer over the entire hemisphere hit. The chances of this are very small however, the poles of the star are not currently pointed at us, and these tight beams have the entirety of the universe, so the chances of them hitting such a small target are incredibly slim. We will most likely be fine when the radiation from the hypernova reaches us, but the death of Eta Carinae will be spectacular. It is very possible that the light given off from the explosion will be enough to read by at night. Eta Carinae is the blazing king of the stars, reigning superior, but its life shall be short. It is very possible that it has already met its end. Being so far away, Eta Carinae could go hypernova today, and we wouldn't know for 7,500 years. One thing is for sure though, when Eta Carinae finally does die, it will die with glory.

Depiction of high energy laser beams being emitted from Eta Carinae

Wind

We all think of wind as a cool breeze that blows away the oppressive summer heat, but wind means more than just planetary wind. On Earth, "wind" generally refers to the movement of gases like nitrogen, oxygen, and carbon dioxide, air basically. Outside of our planet though, there are different winds. There are, in fact, winds from our planet to outer space called planetary wind. It's basically our planet losing light particles. On the sun, there are solar winds. Solar winds are highly charged particles like hydrogen ions that can kill anything that gets in the way.

Wind is caused by differences in air temperature. If a volume of gas is heated and placed next to a volume of unheated gas, the hot gas will flow into the cold gas. The reason for this is that the heated gas particles become more energetic and thus the pressure increases for that volume. Pressure will naturally equalize thanks to entropy, the hot gas particles will fly into the cold volume faster than the cold particles will fly into the hot volume. On earth, there are two main causes of wind, surface heating and planetary rotation. The equator is exposed to the sun for much longer than the poles, and thus it is hotter, causing that air to flow else where. The rotation of the planet can determine in what direction the winds will flow because of friction. Air will eventually hit the planet, and if that planet happens to be rotating (like ours) it will impart some of that rotational energy to the air particles.

There are more localized causes of wind too. Say you live by the ocean for example. During the day, the land will heat up much faster than the water because water has a much higher specific heat. The hot land will impart energy to air particles wich will rise. This creates an area of low pressure over the land that will be filled up with colder air from over the water. At night this process will reverse because the land cools down much faster than the water. Another major factor in wind speeds and direction are mountains and hills. A mountain range, if tall enough, can block wind from getting to the other side. This becomes a problem when they are high enough to block clouds, and thus rainfall from the oceans. High enough mountains can cause deserts. If there happens to be a gap between to mountains or hills, air will be funneled through it, and those winds can be very strong.

Another interesting feature of wind is that it can erode the land near it, similar to the way that water can carve out valleys. Winds are able to pick up debris particles like sand throw them against objects that happen to be in the way. This continual sand blasting over long periods of time can create some very interesting features.

Windpower is a very useful form of alternative energy. These incredible forces are going to continue to flow around our planet whether we're there to catch them or not, so why not gain something from it? Wind turbines can pay for themselves very quickly, and an array of them on a barren hillside can fulfill the power requirements of an entire city.

Wind plays a very important role in non human related nature. Many plants rely on wind to spread their seeds, birds often need updrafts and wind currents to aid in their flight, and many insects travel with the winds. There are also negatives in nature as well. Winds aid in spreading forest fires, without them we'd never have some of these blazing infernos that we so often see. Winds can also be detrimental to animals by blowing their scents around so that they can be hunted, or eroding the soil that grows their food. Ultimately, we need wind to survive, and it seems like there is always something bad associated with every part of nature.

Uranus

Finally we come to Uranus, the last of the Jovian planets in the Solar System, and certainly the least spoken about. Uranus is the 7th planet from the sun and is an ice giant along with Neptune. Uranus has the third largest radius in the solar system, and is fourth largest by mass, essentially switching around the stats of Neptune. Uranus is unique in that it is the only planet in the solar system with a rotation that is not perpendicular, more or less, to the plane of the Solar System. Uranus is tilted 97.77 degrees, causing it to roll around the sun like a ball instead of a top, like all the other planets. Uranus's tilt makes it somewhat funny to view because its moons orbit like the hands of a clock, and its rings can make it look like a target.

Uranus seen with rings

The odd axial tilt of Uranus means that each hemisphere of the planet can be in darkness or light for 42 years. Oddly enough, the equator of the planet is still hotter than the pole of the planet facing the sun, even though the pole gets far more sunlight. We must consider, however, than Uranus is really far from the sun.

Uranus is the coldest planet in the Solar System, with its tropopause getting down to -224 degrees Celsius (49 Kelvin). The outer cloud layer on Uranus is composed largely of methane which gives it its cyan appearance. The inner most cloud layer is believed to be composed primarily of water. Like most gas giants, the atmosphere of Uranus is mostly hydrogen and helium, but because it is an ice giant, there are also large amounts of various ices, such as water and ammonia, mixed in as well. The atmospheres of Jupiter and Saturn account for a large portion of the planets mass, but the atmosphere of Uranus accounts for very little. Uranus has some pretty fast winds by earth standards, getting up to 900km/h, but they cannot compare to the winds on Neptune. These winds are fairly unremarkable by Jovian standards, they are fairly slow and they flow with the same rotation as the core.

Uranus has a fairly plane appearance

Like Neptune, the interior of Uranus is composed mostly of rock and ice. The very core of the planet is a combination of iron, nickel, and silicates, accounting for a small percentage of the planets mass. The next layer is the mantle. The mantle is composed of water, ammonia and other volatile fluids (fluids with a low boiling point). It is here that the water-ammonia ocean is formed. There may also be ionic and super ionic water present, but it's really hard to tell from the observations that we've made. The mantle accounts for most of the planets mass, about 13.4 earth masses. After the mantle there is a final layer of gas that envelopes the core. Temperatures in the core are probably around 5,000 Kelvin.

The magnetosphere of Uranus is tilted 57 degrees from the axis of rotation so that it is more like the magnetospheres of other planets. The magnetosphere is unique in that it does not originate at the planets core, but this isn't that odd for Jovian planets. It is often the case in planets like Neptune of Uranus that their magnetic fields are created by conductive materials at their cores, like the water-ammonia oceans or ionic water. In larger planets, like Saturn or Jupiter, it is the liquid hydrogen that makes these fields. Because of the orientation of Uranus, however, the magnetic field is asymmetric, about .1 gauss over the southern hemisphere to about 1.1 gauss over the northern hemisphere. The magnetic field on earth is pretty much symmetric.

Uranus has 27 moons, all of which are small. The five largest moons are called Miranda, Ariel, Umbriel, Titania, and Oberon with Titania being the largest. Most of the moons are named after characters from works of Shakespeare or Alexander Pope.

Five largest moons of Uranus

And finally, Uranus has a system of rings like all of the other Jovian planets, except, of course, for the fact that they are tilted 90 degrees. There are 13 rings in all made of ice and bits of dust. The particles in these rings are much smaller than the ones around Saturn. A curious feature of these rings is that some of them follow the orbits of some of the moons, suggesting that they got much of their materials from those orbiting bodies.

Orbital paths of moons and rings

Uranus

Neptune

Neptune is the 8th planet from the sun, and ever since Pluto was deemed to be a dwarf planet, it is also the last planet from the sun. Neptune joins the ranks of Jupiter, Saturn and Uranus as one of the four Jovian planets in our solar system. It is also distinct in being the only planet to be mathematically predicted before it was ever observed. The orbit of Uranus was off, and so a large gravitational body, like Neptune, had to be in orbit somewhere to account for this. By diameter, Neptune is the 4th largest planet in the solar system, but by mass it is the 3rd. Neptune is, in fact, 17 times as massive as the earth, and is the only other planet besides Jupiter to have a higher surface gravity than the earth. Neptune falls behind both Saturn and Jupiter in the number of moons orbiting it, with only 13. Of those 13 moons, Triton is the largest.

Neptune compared to Earth

Like most gas giants, Neptune's atmosphere is mostly composed of hydrogen and helium, about 80% and 19% respectively. Unlike Saturn and Jupiter, however, Neptune is very icy, earning it, and its relative, Uranus, the title "Ice giant". Neptune contains proportionally large quantities of "ices" like water, ammonia and methane. The outer cloud layer can be as cold as -218 degrees Celsius (that's only 55 Kelvin). It is so cold that methane precipitates in the atmosphere, contributing to the blue color of the planet by absorbing light in the red spectrum and reflecting blue light. Methane is not enough to explain Neptune's color, meaning that there must be some other as of yet unknown agent contributing to the smooth blue that we see.

Neptune

Neptune has the fastest winds in the entire solar system, speeding up to 2,100 km/h, nearly supersonic. Neptunian winds flow mostly in the opposite direction of the planet's rotation. Generally there is a prograde wind rotation at high latitudes and a retrograde rotation at low latitudes, owing mostly to the "skin effect" and not deeper atmospheric conditions. 

The interior of Neptune is mostly composed of ices and rock. The "ice" at the core isn't actually a solid, but materials like water or ammonia. Temperatures can reach up to 5,400 Kelvin at the center, much cooler than either Saturn or Jupiter. The water, ammonia, and methane at the core are compressed significantly by the great pressure on the surface of the planet until they become liquid, forming a conductive water-ammonia ocean. The farther towards the core we go, water begins to ionize until we have free floating hydrogen and oxygen. Even further down, the ionized water crystalizes, leaving free floating hydrogen ions to mingle in a lattice of crystalized oxygen. The magnetic field of Neptune is titled 47 degrees and experiences significant warping with rotation. This field is also quite strong, about 27 times that of earth. It is believed that the odd orientation of the field is due to the movement of conductive materials in the core, like the water-ammonia ocean.

Neptune's interior composition

Probably the last feature of Neptune that I have yet to speak on is its system of rings. Like Saturn and Jupiter, Neptune has rings of dust and ice orbiting it. Like Jupiter, these rings are faint and not nearly as spectacular as Saturn's. Unlike both Saturn and Jupiter, however, Neptune's rings are fragmented, broken up into various arcs. Because of their shaky pattern, these rings are likely short lived.

Neptune's rings

Many of the planets in our solar system are various shades of reds and yellows, but Neptune offers a nice relief from these "hot" colors with its cool blue clouds, earning it the name of the god of the sea.

Saturn

Saturn is the 6th planet from the sun, and like Jupiter, it too is a gas giant. Saturn is probably best known for its planetary rings, making it more popular than its much larger relative, Jupiter. Saturn is the second largest planet in the solar system. Besides the rings themselves, Saturn has 62 moons orbiting it, most popular of which is Titan.

Saturn compared to the earth

The composition of Saturn is very similar to that of Jupiter. It has a solid core made of iron, nickel, silicon and oxygen compounds, similar to the earth. The pressures are low enough that we can predict the composition of the core, however, the best we can do for now is guess because we have no way of actually obtaining a sample for analysis. Saturn has a layer of metallic hydrogen surrounding the core which is followed by liquid hydrogen and helium, smoothly transitioning into gas the farther we get from the core. The elemental composition of Saturn's atmosphere is 96.3% hydrogen and 3.25% helium with other elements and molecules in small amounts. The upper atmosphere, including the visible clouds, is comprised of ammonia crystals on the top with ammonia hydrosulfide or water beneath. The winds on the planet can reach extreme speeds, around 1,800 km/h. These winds, and polar storms are fueled by heat from the planets core which could be as hot as 15,000 K.

Saturn releases more heat into the atmosphere than it absorbs from the sun, so its incredible core temperature must be fueled by something else. Much of the planets heat comes from gravitational compression, creating heat as Saturn tries to collapse on itself. Saturn might not be able to get enough energy from this process to account for the heat that it emits however, so it has been suggested that precipitating hydrogen falling to the planets core could release heat and cause friction in the dense atmosphere. Despite the intense temperatures at the core, the surface cloud layer is extremely cold, roughly -185 degrees Celsius, warming up to -122 degrees Celsius at the poles where heat is brought up by currents from lower layers.

The poles of Saturn are very interesting in and of themselves. The south pole features a rotating, hurricane like storm with a distinct eye wall. This is unique because it is the only known planet other than the earth to feature such atmospheric structures. The north pole, however, is far more interesting, both to astronomers and the layman alike. The north pole of Saturn features the famous hexagon, one of astronomers favorite phenomena. Some people believe that this is a sign of alien intelligence or of some devine intervention, but that is almost certainly not the case. Such geometric structures have been created in fluids in labs, so there is no reason that it shouldn't be happening on Saturn. The rotation of this storm is the same as the period of radio emissions from the planet. Which is also believed that it corresponds to the rotation of the core.

North pole hexagon

Saturn has a magnetic field, but it is slightly weaker than earths, and is about 1/20 that of Jupiter. Just like Jupiter, the magnetic field is believed to be caused by the rotating metallic hydrogen. It makes sense that the magnetic field should be so much weaker on Saturn than on Jupiter because Saturn is much smaller, and would thus have lower pressure to compress hydrogen into metallic hydrogen. Despite the minuscule strength of the magnetic field, it still manages to reach the orbit of Titan where ionized particles from the moons atmosphere are taken up by the magnetic field.

The most notable feature of Saturn is it's system of rings. There are a total of 7 rings orbiting the planet, mostly composed of frozen water and some carbon. In fact, the rings are 93% water and 7% amorphous carbon with other contaminants thrown in for good measure. The rings average 20 meters thick and are made of chunks of ice and dust that can range from the size of a grain of sand to a small car. The exact age of the rings or how they were formed is uncertain, but they have been there for as long as we've been gazing at the sky, and will remain for much longer.

Picture of Saturns rings taken by the Cassini probe

Jupiter

Jupiter is the 5th planet from the sun, but it's not at all like earth. Jupiter is a gas giant, a large planet that is not primarily composed of rock. There are four gas giants in our solar system, often called Jovian planets. Jupiter is unique because it is the largest and most massive planet in our solar system. It is more massive than twice all of the other planets combined, and is theorized to be as large as a gas giant can get. Any more mass and it would begin to shrink under its own weight to the point that its radius would hardly increase at all, and might even decrease as it collapses on itself.

The center of Jupiter is believed to be "rocky" but it is hard to tell because we cannot see through the layers of cloud and gas. The composition of the rocky core is also rather dubious, the pressure is very high, high enough to make predictions difficult. Above the center of Jupiter is a layer of liquid metallic hydrogen, made possible by the massive pressure. Above the liquid hydrogen is gaseous helium and hydrogen, capped off by frozen ammonia clouds mixed with some other chemicals. Because of the nature of gases, the boundary between liquid and gaseous hydrogen is not very well defined, they smoothly transition into one another.

Jupiter is surrounded by multicolored bands of cloud. Under each band of clouds, the wind is blowing the opposite direction of the surrounding bands. These winds are very fast, and so there are vortices and massive storms at their borders. The color of these bands is determined by the altitude of the clouds, blue being lowest followed by browns then whites with reds being the highest.

Jupiter is orbited by 64 moons. The four largest of these moons, Io, Ganymede, Europa and Callisto, are called the Galilean moons because they were first seen by Galileo. He used them to show that all objects did not, in fact, circle the earth.

It was thought that Jupiter would not have rings orbiting it like Saturn, but during observation such rings did appear. The rings orbiting Saturn are largely ice, but Jupiters are dust. The magnetic field of Jupiter and the massive gravity probably slow the dust quite a bit, causing it to fall to the planet. The rings have managed to exist, however, because they are constantly being replenished by dust from impacts on the many moons orbiting the planet.

Jupiter is so massive that it's barycenter, the point at which two gravitational bodies balance each other out, with the sun lies above the surface of the sun. All other planets barycenters lie within the sun. Jupiter also has the largest magnetic field of all the planets, dwarfed only by sun spots. The rotating metallic hydrogen can conduct a huge current which is sufficient to create the largest magnetic field we've ever seen outside the sun. It almost reaches the orbit of Saturn! This field is strong enough to trap large amounts of solar radiation, making it dangerous for humans to travel within it's range.

Jupiter is almost a failed star. The composition of the planet's atmosphere is very close to that of a primordial solar nebula. Through compression Jupiter is able to radiate more heat than it absorbs from the sun, its internat temperature reaching about 36,000K, not quite high enough to create fusion. Brown dwarf stars are even measured with respect to Jupiter, using Mj, or Jupiter masses.

Of all the planets in our solar system, Jupiter dominates. Most people recognize Saturn because of its rings, but Jupiter is by far the king, standing out in almost every way possible. Its mass can rival that of stars, and its magnetic field dwarfs all other planets. Jupiter truly is the king of the planets.

Posting Schedule

I am now going to post every other day in the hopes that I can write more interesting and better researched articles. I hope this turns out to be a good move, and if anyone would like me to continue to post more often, please tell me in the comments.

Electromagnetic Pump

A very clever mechanism has been designed to pump molten metals. Due to the intense heat associated with molten metals, it is very hard to implement conventional pumps to force them along. An electromagnetic pump uses electromagnetic fields to create a force that acts on the conductive metals to move them through tubes. Two electrodes are placed along the pump and a current is directed between them, then a magnetic field is placed opposite to these electrodes and aligned perpendicularly to the current. All this creates a force on the molten metal that propels it along the tube safely.

Electromagnetic pumps are used in places such as nuclear reactors where liquid sodium is often used as a coolant.

Hypothalamus

The hypothalamus is the part of the brain that connects the endocrine system with the nervous system, and is shared by all vertebrates. The main job of the hypothalamus is to achieve homeostasis within the body, so to achieve this, it has a great ability to regulate many of the numerous systems in our body. The hypothalamus controls our sleep patterns, our sex drive, thirst, hunger, body temperature, fight or flight response, you name it. It can easily be said that the hypothalamus controls you.

The hypothalamus regulates the body through hormones, but it doesn't produce those hormones itself. The hypothalamus instead secretes various neurohormones that induce the secretion of various other hormones from the pituitary gland. The anterior pituitary gland will produce six hormones at the command of the hypothalamus, and the posterior pituitary gland will secrete two, namely oxytocin and vasopressin.

The hypothalamus is divided up into multiple nuclei, each with a specific task. One nuclei will control sweating while another might control your Circadian rhythm, however, multiple nuclei can be involved in the secretion of hormones like vasopressin. The hypothalamus has a very intricate system of detection to tell it when the body needs regulation. It is able to respond to hormones from the rest of the body, like steroids or leptin. The hypothalamus can get data from your skin and eyes about the outside light which it uses to regulate your Circadian rhythm (your sleep patterns). The hypothalamus is also capable of using your olfactory senses to detect pheromones in the air among other things. All of the data collected by the hypothalamus is used to make sure that your body is in a constant state of homeostasis which is necessary to survival.

The hypothalamus is capable of altering our metabolism which can do a great deal for keeping us alive in times of starvation. It can make our muscles more efficient, slow down the division of cells and both hair and nail growth, and can slow down our organs, all to help us beat starvation and find food. There is a good video on YouTube that explains this quite well: http://www.youtube.com/watch?v=sG9wqZ7Dtx4

Ultimately, a small, almond sized part of our brain is the only thing keeping us from overheating, being severely depressed, not being able to fall asleep, and almost anything else you can think of.

Novae

Most people are familiar with supernovae, but they aren't the only kinds of novae in existence. Novae can range from the emissions of white dwarves to the hypernovae from hyper giants, super massive stars.

The first kind of nova is, well, a nova. Novae are caused by white dwarves that are accreting hydrogen and helium from a neighboring star. Accretion is merely a term that means the gravitational collecting of gas. A white dwarfs intense gravity is capable of stealing gas from nearby stars that have surpassed their Roche lobe, the area in which matter is still gravitationally bound to a star. As the white dwarf accretes more and more hydrogen, intense pressure and heat can cause an unstable fusion reaction which can blow off the outer shell of the white dwarf. These explosions are relatively small, with only 5% of the accreted matter being fused for the explosion. A white dwarf can, and probably will, go nova multiple times within its existence. One example of this is RS Ophiuchi which we have seen go nova 6 times. Novae are bright, ranging from 50,000 to 100,000 solar brightness. Novae are even classified based on their brightness. NA novae are fast, with rapid light increase and rapid light decrease. After 100 days, the novas brightness should have decreased by 3 magnitudes, to about 1/16 the original brightness. NB novae are slow, their brightness declining by 3 magnitudes in about 150 days. NC are very slow novae, their brightness can be maintained for over a decade. The final classification is NR/RN novae which are recurring novae.

White dwarf accreting gas from neighbor

Supernovae are much more serious than novae. A supernova is a much bigger explosion, and uses up most, if not all, of the exploding star. There are several mechanisms by which a supernova can happen. A supernova can emanate from a white dwarf that has been accreting matter. The core of the white dwarf can get hot enough that it ignites with carbon fusion and explodes violently. For more massive stars, their cores can reach a certain mass, after which they collapse, sending out a shock wave and blasting off their outer shells. These kinds of supernovae can create black holes or neutron stars. Supernovae are necessary for the creation of new stars. Supernovae blast out the matter necessary for the formation of new stars, so old stars must die so that new stars can live. Supernovae are classified in several ways. Type Ia supernovae are white dwarf supernovae. Types Ib and Ic supernovae are massive stars that collapsed in on themselves. Types II-P and II-L supernovae are super massive stars that collapse in on themselves, ranging from 9 times the mass of the sun to 50 times the mass of the sun.

Type Ia supernova

The final type of nova is a hypernova. Hypernovae are created when a hyper giant star reaches the end of its life and collapses in on itself. Hyper giant stars are between 100 and 300 times the mass of the sun. Hypernovae create black holes and can shoot out concentrated streams of gamma radiation at their rotational poles. It is believed that most of the light from hypernovae is provided by the unstable isotope nickel-56. Hypernovae are understandably rare, it is theorized that they occur ever 200 million years in our galaxy.

Eta Carinae, candidate for future hypernova

Leptin

Leptin is a 16 kDa protein hormone, meaning that it weighs 16,000 Dalton, or atomic mass units. The purpose of this hormone in the body is to regulate energy intake and expenditure. Leptin regulates your appetite and metabolism through a variety of methods. Leptin is an adipose derived hormone. It is created primarily in the adipocytes in white adipose tissue (white fat), but it is also created in a variety of other places in the body. Leptin is a protein made up of 167 amino acids.

The effects of leptin were first observed in 1950 at the Jackson Laboratory. It was observed that some mice in a colony of mice were extremely obese and would eat voraciously. It turned out that they all shared a certain kind of gene mutation that either inhibited the production of leptin or inhibited leptin receptors. When the mutated mice were injected with leptin, it was observed that they began to eat less and lost weight. Leptin itself was discovered in 1994 at Rockefeller University.

The way that leptin works is very interesting. Leptin acts on the hypothalamus to inhibit appetite. It does this by counteracting the effects of feeding stimulants like neuropeptide Y or anandamine. It also promotes the production of the apetite suppressant MSH. The way that leptin does this is to bind to neurons and impede the reception of these hormones or their production.

Leptin had been studied as a treatment for obesity in humans. In studies of people with specific mutations in the production or reception of leptin, direct injections of recombinant human leptin have been shown to reduce the persons apetite and weight. In clinical trials studying the effects of leptin on obese people in general, however, the results were inconclusive. The problem was that the recombinant human leptin was not very soluble, had a short half-life in circulation, and was biologically not very potent. Another chemical has been created as a potential treatment to obesity. This other hormone is called Fc-leptin. Fc-leptin is much more soluble, has a longer half-life, and is much more potent than regular leptin. In studies on mice, Fc-leptin successfully treated obesity.

Hunger

We've all been hungry before, but exactly how does hunger work? It is obvious to most that you feel hungry when you need food. It is a simple biological mechanism to make sure that we don't unwittingly starve to death. However, this explanation still doesn't really answer the question of what mechanism controls hunger.

One way that our body can tell that we need food is if our stomach contracts. When a balloon is inflated in someones stomach, they cease to feel hungry, and when it is deflated, they may feel hungry again. This is a simple way to tell us that there is something in our stomachs, so we don't need to eat any more, but it is certainly not the only mechanism that tells us to be hungry. Another reason that we can feel hungry is because of low blood sugar levels. Our body must tell us when we need to eat for energy, and blood sugar is a very good indication of energy levels. There are various other chemicals that can influence if we're hungry, like insulin, but they aren't as powerful.

How is the feeling of hunger achieved? Through hormones, of course. Two of the main hormones that influence our feeling of hunger are leptin and ghrelin. When we eat, adipocytes (a type of fat cell) begin to release leptin. Leptin is a hormone that reduces the feeling of hunger, so the more you eat, the more leptin there is, and the less hungry you are. Leptin levels drop with time, causing us to be hungry again. Leptin is such an interesting hormone that it warrants an article all to itself. Ghrelin is like the oposite of leptin, high levels of ghrelin increase a persons appetite. Levels of ghrelin are high when you're hungry, and then fall as you eat and become satiated. Levels of ghrelin can also increase with stress, which partially explains why some people eat more when they're stressed. Both leptin and ghrelin act on the hypothalamus, the hormone control center of the brain which releases hormones that act on the liver and cause the sensation of hunger.

Hunger can feel unpleasant, especially extreme hunger, but it does much more than that. It has been observed that starving animals are much more active than satiated animals and will gain more weight when they finally do get fed. The increase of activity could help the animals to scavenge or hunt more and thus increase their chances of survival. The same goes for the increase in weight gain. When a creature reaches a point where it is starving, the body believes that there is a scarcity of food, and so stores more of the food energy in fat cells so that the creature can last longer to find more food. If we go for too long without food, we will start to experience "hunger pangs." Hunger pangs are contractions in the stomach that will start after 12 to 24 hours without food, and are quite unpleasant. These contractions will last for only about 30 seconds, but will continue to happen for around 30 to 45 minutes. These contractions will start up again after a while if you still haven't eaten, but emotional states, such as anger or happiness, can reduce hunger pangs.

Hunger and starvation are still serious problems in our world today. There are a total of 925 million people suffering from malnutrition in the world, however this doesn't need to happen. There are nearly 7 billion people on the planet right now, but the FAO estimates that the earth could sustain 12 billion people. The problem is not lack of food, but more the globalized economy. Each country should be able to feed its own people, however, other countries often buy agricultural land or food from these countries for much more than the people of these countries could pay, thus sending all of the food away from poorer nations into richer nations such as the US. Ultimately rich nations take advantage of poor nations, causing their people to starve.

Olympus Mons

Olympus Mons is a dormant volcano on Mars. As far as we've seen, this volcano has formed the largest mountain in the entire solar system, almost three times as tall as Mount Everest. Olympus Mons stands 25 km tall with an edifice 600 km wide.  For a reference point, Olympus Mons covers an area about the same size as Arizona. The summit of the mountain features six nested calderas, forming a depression 60x80 km across and up to 3.2 km deep. The edge of the volcano drops off in a sheer cliff, a feature unique in shield volcanos on Mars, of which Olympus Mons is one. Because it is a shield volcano, Olympus Mons is fairly flat, the average slope being only 5 degrees.

Olympus Mons was able to get so large because Mars doesn't have plate tectonics. On earth, plate tectonics keeps land masses moving over volcanic hotspots creating new volcanos instead of building on the same one, like around the Hawaiian islands. On Mars, the lack of plate tectonics means that the same hotspot will keep building on the same volcano for as long as its active, producing volcanic mountains like Olympus Mons.

The Mars Express orbiter has found lava flows on the peak of Olympus Mons ranging from 115 million years old to around only 2 million years old. In geological terms, 2 million years is fairly recent, so Olympus Mons might still be volcanically active, but we haven't seen any activity for quite some time.

Allergies

It's summer time, and that means that the pollen count is high again. Many people are allergic to different kinds of plant pollen, like that from ragweed. The most common allergic response to pollen is usually increased mucus production and watery eyes, but it can get much worse. Allergic responses can range anywhere from minor itchy eyes to inflammation of the lungs that can send you to the hospital.

Allergies are caused by usually harmless antigens that enter our body and cause an overactive immune response in people who are hypersensitive. The antigens that cause allergic reactions are called allergens. When an allergen enters the body, IgE (Immunoglobulin E) antibodies are created to fight of the foreign invaders. These antibodies will activate certain kinds of white blood cells called mast cells and basophils. When activated, these white blood cells will release chemicals such as histamines and serotonin that can cause constriction of smooth muscles (which can cause difficulty breathing), blood vessel dilation, and swelling. Allergies are called type 1 hypersensitivity, or immediate hypersensitivity. There are 4 kinds of hypersensitivity.

Most people get severe rashes when touching poison ivy, but this reaction is actually an allergic reaction. Poison ivy, and other plants such as poison oak, contain an oily substance called urushiol which causes the itchy and inflamed rashes that most of us get when touching poison ivy. This means that some people don't experience anything when they touch these plants because they aren't allergic, but allergic reactions can be developed, so it is never a good idea to go around touching poison ivy.

Many allergies, especially those caused by food, are responses to certain kinds of proteins. The most common food allergy is a peanut allergy. Peanut allergies can be quite severe, causing anaphylaxis which can be life threatening. Anaphylaxis can cause hives, gastrointestinal distress such as vomiting, trouble breathing, and a whole host of terrible things. Allergy causing proteins can be found in many places, from the whites of eggs to latex gloves, which makes them a common allergen.

It is true that allergies have a strong genetic factor. Twins have a 70% chance of having the same allergies, and parents with allergies are likely to have children with allergies. However, the children of allergic parents don't necessarily inherit a specific allergy, they inherit the likelihood to develop an allergy. There is allergy discrimination between genders. Overall, males have a higher risk of developing allergies than females, but females have a higher risk of developing asthma. Not all allergies are based on genetics however, your environment can have a significant impact on if you develop allergies, and what kind of allergies you do develop. Pollution, illnesses and repeated exposure can often cause a person to develop allergies even if they do not have a genetic disposition to allergies.

Allergies can be treated with anti-histamines to reduce swelling and counteract the effects of mast cells. Other treatments such as steroids are immediate responses to allergic reactions, but immunotherapies exist that can help to rid a person of their allergies altogether.

Venus

The planet Venus is the second planet from the sun and is often called Earth's "sister planet" because of their similar size and composition. It is the second brightest object in the night sky, out shined only by the moon. Because of its terrestrial properties, it was thought that Venus might harbor life under its opaque cloud cover. There have been multiple science fiction stories written about it. It has since been discovered, however, that the obscuring cloud layer is composed of sulfuric acid and that the planet is very hot, making it one of, if not the most, inhospitable planets in the solar system.

The atmosphere of Venus is uniquely interesting. Of all of the planets in the solar system, Venus's is the densest. The planets atmosphere also consists mostly of carbon dioxide, meaning that the planet has no carbon cycle or biomass to take the carbon out of the air, yet another sign that the planet is lifeless. It is thought that the planet used to have water oceans, but they evaporated as the planet heated up, and that all of the hydrogen created was whisked away into space by solar winds. Venus has no magnetic field to shield it, meaning that there is nothing to shield its atmosphere from solar winds. The pressure on the surface of the planet is roughly 90 atm, that's 90 times the pressure of earths atmosphere at sea level.

Venus could be an example of the extreme end of the greenhouse effect. With the massive amounts of carbon dioxide in the atmosphere, heat imparted by the sun cannot escape easily, which heats up the surface of the planet significantly, even hotter than the surface of mercury where it faces the sun. The fate of Venus might be an example of what could happen to the Earth if massive amounts of carbon dioxide were to be pumped into the atmosphere.

The surface of Venus has been mapped out by Project Magellan, showing us a bleak landscape shaped by years of volcanic activity. I will provide some links in the comments that show the surface of the planet. One interesting feature of Venus's geography is that its landmasses aren't moving. On earth there is constant plate tectonics which means that our continents are always moving. Venus, however, is still. There are little to no small impact craters of Venus's surface, indicating that most small meteorites burn up in the dense atmosphere, and larger ones break up, making closely clumped impact craters.

Venus reaches its maximum brightness in the early morning and evening, rightfully earning it the title of Morning Star, and Evening Star. Venus has a very slow retrograde orbit. One Venian day is equal to 243 earth days. This slow rotation could be the reason that Venus has no magnetic field.

Our sister planet holds many wonders, but none of which are life. While the planet may have captivated the minds of science fiction writers of the past, it is nothing but dead planet now.

Solar Flares

Our sun is a massive ball of burning hydrogen, a giant nuclear furnace. With the incredible heat generated by the sun, massive jets of plasma tend to shoot out from its surface, bent into enormous arches by magnetic fields. Every now and then these magnetic fields will get tangled up in each other and can become so warped that they snap, sending out masses of charged particles known as coronal mass ejections (CMEs), or solar flares.

Sometimes these CMEs will fly at the earth, but they are usually deflected by the magnetic field that surrounds the planet. If the electromagnetic charge of the flare is aligned parallel to the earths magnetic field, then the flare will be deflected, however, if the charge is aligned opposite to the earths, the fields will connect and the charged particles will be directed to the earths poles, often causing the phenomenon known as auroras.

For a while now NASA has been observing the sun using a variety of satellites, among which are the Solar Terrestrial Relations Observatory and the Solar Dynamics Observatory. The goal of these satellites is to help us understand more how the sun works and to allow us to predict when solar flares will occur. When a solar flare hits our planet, orbiting satellites must be shut down because the charged particles in a solar flare can cause surges in electrical equipment which could disable a satellite. Because of this prediction is key.

The sun is known to go through stages in solar storm activity, and some predictions say that our sun is going to become much more active soon. With an increase in the frequency and severity of solar winds, there is a concern about the effect that it could have on our civilization. If a solar flare were to make it past the planets magnetic field, it would cause massive power surges in the electrical grid and could blow out transformers, sending us into darkness. If we were to lose power, there would be a whole host of problems that we would have to deal with. Food would go bad and electrical gas pumps would stop working. Transportation would become very difficult, and starvation would be a real concern. Apart from that, if power were to be cut off to nuclear power plants, they would be in serious threat of melt down. Nuclear power plants have back up generators to keep the nuclear rods that boil water cool, but there is a significant threat that we wouldn't be able to get the power back up before those generators ran out of fuel to pump water.

There are several things that can be done to help protect us against collapse after a solar flare. One of the biggest problems is that transformers take years to manufacture, and we don't have many replacement ones laying around. Production of replacement transformers is key. Already there is a Recovery Transformer project (RecX) funded by the Homeland Security in the U.S. that is developing temporary transformers. Another step that must be taken is surge protection, so that our electronics aren't fried when a solar flare hits. The Neutral Capacitor and Bypass Device is already in existence and is designed to block massive DC currents and reroute AC currents caused by normal electrical problems. More funding still needs to go into these devices before they can protect us from solar storms, and public concern is ultimately what will drive this research.

The James Webb Space Telescope

NASA is churning out yet another telescope to once again push the limits of how far into the universe we can look. The James Webb Space Telescope is designed to peer back and catch a glimpse of the universe's first galaxies to give us a better idea of how our universe formed after the big bang. The telescope will work primarily in the infrared spectrum and will sport a 6.5 meter wide mirror along with a tennis court sized sun shield. The mirror and sun shield are so large that they will have to be folded up before they can be put inside the rocket that will send the telescope into orbit.
The telescope will orbit the earth 1.5 million kilometers away (1 million miles), and will be launched in 2018.

Parasites

The word "parasite" refers to any number of biotrophic organisms, organisms that feed off of a host without killing them, ranging from microscopic bacteria to macroscopic leeches. Parasitic creatures that eventually cause their host to die or become sterile are not parasites, they are called parasitoids and are necrotrophic. Parasites live off of a host, and keep that host alive so that they can continue to benefit. Parasitoids on the other hand generally feed off of their hosts while they're young, killing the host in the process. Parasitoids become free living in their adult stages, and no longer have a need for a host. The line between parasite and parasitoid is somewhat blurry.

There are many different types of parasites, like protelean parasites that are only parasites during their juvenile stage. Parasites classified based on if they live inside or outside the host are endoparasites and ectoparasites, endoparasites living on the inside of their hosts body, and ectoparasites living on the outside of their hosts body. Endoparasites are further classified into intercellular and intracellular parasites. Intercellular parasites live in spaces inside the host body, such as the intestines or cavities that the parasite makes for itself. Intracellular parasites live within the hosts cells themselves, this classification includes various bacteria and viruses. Other parasites called epiparasites or hyperparasites are parasites that live off of other parasites. It turns out that nothing is safe from being fed upon by a parasite.

Parasites do more than just feed off of a host. Social parasites include classifications like kleptoparasitism where the parasite steals food from another creature, or brood parasitism such as various species of birds that leave their eggs in another birds nest to be cared for by the host bird. Parasitism occurs pretty much whenever one creature exploits another for its own gain.

Some of the more interesting kinds of parasites are capable of infecting a hosts brain and influencing or even controlling its actions. One of the more widely known "mind control" parasites is the Cordyceps fungus which is known for infecting the brains of bullet ants and causing them to have an uncontrollable urge to climb. The ant will cling onto a branch as the fungus continues to grow, eventually killing the ant and growing out of the creatures exoskeleton to release its spores and infect other ants. There are several kinds of Cordyceps fungus, each one specialized to a different insect, and each more fascinating than the last.

Another mind controlling parasite is a barnacle called Sacculina that infects crabs. A female Sacculina barnacle will find a joint in a crabs armor and then molt out of its shell, injecting itself into the crab. While inside the crab, the parasite will grow tentacles through the hosts body, altering the crabs hormone levels and rendering it infertile. If a male crab is infected, its physiology will even be altered such that the crab becomes female. Once a male Sacculina comes and impregnates the female growing within the crab, the crab will care for the parasites eggs as if it were its own. The host actually cares for and nurtures more parasites.

Parasites are often disturbing creatures, but you can't help but admit that they are fascinating. They are so specifically adapted to their prey, and they are capable of amazing, and horrifying, feats.

Albedo

Albedo is an objects reflection coefficient. Albedo is measured as the amount of radiation reflected by an object divided by the amount of radiation originally hitting the object. So the higher the number, the more reflective the object is.

The way in which albedo is measured is on a scale from 0 to 1. 0 means no reflection, so absolutely black, and 1 means perfect reflection, so pure white.

In terms of astronomy, albedo is used to measure the reflectiveness of planets to give us an indication of their surface composition. The albedo of the earth is between 30 and 35%, due largely to cloud cover. In climatology, albedo is used to predict areas of high temperature and areas of low temperature based on cloud cover and the amount of sunlight reflected.

Terrestrial albedo, obviously, is the albedo of the earth. Oceans and forests tend to have low albedos while deserts and cities have fairly high albedos. Over time, humans have come to change the earth’s albedo through clear cutting forests for resources and to make ways for cities. Clearing forests generally increases albedo and would be expected to cause local climate cooling, but other repercussions of clear cutting complicates the matter.

Space Debris

The U.S. and about 50 other countries currently have satellites in orbit around the earth for various commercial and military uses ranging from communication to observation like those used by Google to take pictures of the earth. However, these satellites are constantly under threat of colliding with pieces of space debris moving at hundreds of miles per hours.

When a satellite is destroyed or a missile detonates in orbit, bits of metal and other materials are left over in orbit. Some of these pieces can be fairly large, and can move very fast. Larger bits of space debris are capable of destroying satellites, costing millions in damage. Other, smaller particles of space debris come from coolant exhaust or spent rocket fuel. These sand like particles are capable of blasting satellites over time, causing serious damage.

Sand like space debris is easily neutralized by coating a satellite in foil to vaporize the particles before they reach the satellites hull, but exposed devices, such as solar panels and optics are still left vulnerable. Larger bits of space debris are not so easily neutralized, however they are easier to detect and therefore avoid. The SSN (Space Surveillance Network) is used to track satellites and debris particles with a diameter larger than 10cm. The information from the SSN is used to alter the orbits of satellites that are in danger of being hit by space debris so that collision can be avoided.

Seing how space debris is such a serious problem, there have been several suggestions to rid the space above our planet of these harmful objects. One of the main ideas is to use giant "nets" that would collide with space debris and trap it, eventually falling back to earth and burning up upon reentry. These nets would be composed of closely intwined, thin metal threads. Another proposition has been to use ground based lasers to target debris and push it out of a harmful path or to destabilize its orbit and send it back to earth.

Whatever the solution, space debris could pose a serious threat to our space based infrastructure. If even one satellite is destroyed, it becomes space debris and could threaten other satellites and turn them into space debris, potentially causing a chain reaction that would make orbital satellites impossible. This scenario may not be very likely, but if it should happen we would lose GPS navigation, satellite TV, and any number of things to which we have grown accustomed.