Water on Earth: Asteroids!?

There has always been much speculation over how Earth has always contained water. However, there is definitely a scientific truth: During the formation of the solar system, scientists know that the space was mostly permeated by hydrogen gas. When the Sun was forming, it generated a lot of heat, and this resulted in spherical distributions of temperature ranging from extremely hot to extremely cold, as a function of radius. Because of this, scientists can define boundaries where metals, rocks, ice and water could condense out of the hydrogen gas at certain temperatures! This is why, at present day, we can see how the inner solar system is composed of solely rocky planets, and past the asteroid belt in the outer solar system, there are jovian planets which are all mostly gas.

Now that there is proper context, it makes sense that water could not have condensed in the inner solar system, simply because it was too hot and the water would have vaporized. However, there is no problem with water condensing in the outer solar system. Here lies the basis of the water-comet theory: When the solar system was still early in its age and gravitational interactions were forcing collisions between bodies, an H2O-abundant comet reached Earth and crossed its orbital path, thus colliding with it. It also could have been multiple asteroids that delivered the goods, but regardless, the result is the same and the reasoning is sound. The purpose of this post is this: recently, new evidence for asteroids carrying water in other star systems has solidified the theory's ideas. "In observations obtained at the William Herschel Telescope in the Canary Islands, the University of Warwick astronomers detected a large quantity of hydrogen and oxygen in the atmosphere of a white dwarf (known as SDSS J1242+5226). The quantities found provide the evidence that a water-rich exo-asteroid was disrupted and eventually delivered the water it contained onto the star." This is profound because it proves that other systems also have asteroids that carry high volumes of water, and it most likely isn't a single case!

For more information: http://phys.org/news/2015-05-fresh-evidence-earth-asteroid-debris.html?utm_source=menu&utm_medium=link&utm_campaign=item-menu

Book Review: In Search of Dark Matter

I have been searching for a book to read on a scientific topic recently, and one that really piqued my interest was a book discussing dark matter. It is called "In Search of Dark Matter", written by Ken Freeman and Geoff McNamara. It attempts to explain the mystery of dark matter, and why it is puzzling the modern scientific world. It also simultaneously tries to provide appropriate historical context, and reaches across a variety of disciplines to get the message across. However, the most important aspect that this book contains is that it discusses modern, up-to-date research on dark matter. Most of the book's content strikes at the heart of the problem; for example, it talks about gravitational lensing, galaxy rotation curves, WIMPs (weakly interacting massive particles), and even alternatives to the entire dark matter theory itself. This work does not rely purely on one conjecture, rather it tries to open up the discussion so that nothing is left out. I highly value that trait, and am going to enjoy completing this book sometime soon. Here is the link to the book for anyone interested: http://www.amazon.com/Search-Matter-Springer-Praxis-Exploration/dp/0387276165/ref=sr_1_1?ie=UTF8&qid=1428002097&sr=8-1&keywords=in+search+of+dark+matter

The elusive IMBH in Omega Centauri

Recently, I have had the opportunity to examine Dr. Pryor's work. Among his work with globular clusters and dwarf galaxies, there were hints that the possibilities of IMBHs (intermediate mass black holes) existed in some of the systems studied. Relating to this field, the most notable celestial phenomenon is Omega Centauri. This system has undergone many classifications: Over two thousand years ago, Ptolemy catalogued it as a single star. In 1677, Edmond Halley classified it as a nebula. In the 1830s, John Herschel recognized it as a globular cluster. Now, astronomers are not so sure that Omega Centauri is a globular cluster, but in fact a dwarf galaxy that has had its outer stars stripped. You might be tempted to ask: What is the basis for the reasoning that Omega Centauri is a dwarf galaxy and not a globular cluster? It shares all of the properties of regular globular clusters, so what's the deal? It turns out that Omega Centauri, although similar to other globular clusters, is a bit more unique in terms of its physical description. It rotates faster than the general distribution of globular clusters, it is also highly flattened and contains many generations of stars (typical clusters only have one generation of stars). Furthermore, Omega Centauri is about ten times more massive than the average globular cluster, making it nearly as massive as a dwarf galaxy! Moreover, the speeds of stars closer to the center of the system are relatively incredibly higher than expected. The stellar velocities are directly tied to the mass of the cluster itself; the findings indicated that the mass of Omega Centauri was not enough to compensate for the speeds observed. Rather, the team at the Max-Planck Institute for Extraterrestrial Physics highly suggested that in order to properly account for the speeds observed, there would have to be a black hole at the center of Omega Centauri that has approximately 40,000 solar masses! Before any justified skepticism from the viewers, there is precedent for this type of research. There was a globular cluster in Andromeda classified as "G1" that shared these properties and had an IMBH in its center. This further supports the idea that Omega Centauri has an IMBH in its center as well! It is hypothesized that past interactions with the Milky Way caused Omega Centauri to distort, and it is also suggested that this system could be a possible model for black hole formation. For anyone interested, the link is here: http://www.spacetelescope.org/news/heic0809/

Time for solar physics! A discussion on Alfvén Waves

There have always been two very serious questions in the scientific community of solar physics: 1: Why is the solar corona hotter than the surface of the Sun? and 2: Why does the solar wind gain so much speed when it leaves the Sun's atmosphere? These questions are inherently complex, since the physical phenomena are not logically intuitive. Let me frame some examples. For the case of the corona: assume I provide an operational light bulb that radiates light from its surface. As one would expect, the intensity of the light should decrease as the distance increases. As simple as this seems, the solar corona, which is located millions of kilometers above the Sun's surface, does not obey this statement. The corona, which is a plasma-filled region (plasma is hot, ionized gas that interacts with magnetic fields strongly), is immensely hotter than the surface of the Sun! The Sun's surface is measured to be about 5770 K, while the corona is measured to be about 1.7 million K! Clearly there is some hidden mechanism that is eluding scientists. For the case of the solar wind, the situation is much simpler, but there is still no clear explanation for it. There exists the solar corona, a magnetically active region that moves plasma continuously. However, from this solar corona ejects the "solar wind", which is a collective of charged particles that extends out into the Solar System. The question is: how does the solar wind leave the corona and how does it gain such high speeds? What mechanism is responsible for providing the energy for such a phenomenon? Luckily for solar physics, there was a theory proposed in 1942 by Hannes Alfvén that predicted the existence of "magnetic plasma waves", which potentially solve both of these problems! Here is the core of the theory: The magnetic field lines around the Sun fluctuate incredibly, and they serve as a good medium for waves to travel on. Since plasma permeates the space around the magnetic field lines, the plasma interacts with the field and "sticks to it". Now, the magnetic field lines are like strings tied from both ends; when they are perturbed, the matter on the string will stay still, but oscillations will produce as a result. So the plasma oscillates on the magnetic field lines continuously, and these waves carry energy which transport that energy to the corona. This can trigger a heating effect, which is what is possibly observed in the corona! On top of that, these waves, coined Alfvén waves, theoretically carry enough energy to accelerate charged particles into the Solar System at speeds of 300-600 kilometers per second! This process is a jackpot for solar physics, and if more technology is introduced to study the Sun's atmosphere, this information can be confirmed experimentally. Talk about two birds with one stone!