Twenty-two years ago, the Suizhou meteorite broke into 12 pieces and struck the ground near Hubei, China. This meteorite contained a high-pressure chromite-spinel polymorph called xieite, which was recently classified as the first new mineral with a post-spinel structure. The formation of this mineral requires temperatures between 1800 and 1950 °C, and pressures between 18 and 23 GPa. Because of the high temperatures and pressures required to form this mineral, it is believed that this meteorite suffered from a catastrophic collision.

The discovery of xieite was made by an American-Chinese team from the Guangzhou Institute of Geochemistry, Carnegie Institute of Washington, Chinese Academy of Sciences and the Geophysical Laboratory. Xieite was given official mineral status by the International Mineralogical Association’s Commission of New Minerals, Nomenclature and Classification. To be classified as a mineral, a substance must fit into five characterizations: 1) A mineral must be naturally occurring on Earth or somewhere in the Universe, not in a lab; 2) A mineral must be stable at room temperature (with the exception of ice and mercury); 3) A mineral should be inorganic, meaning it contains no C-C double bonds; 4) A mineral must be describable by a chemical formula– in xieite’s case it is Fe²⁺ Cr₂ O₄; and 5) A mineral must have an ordered atomic arrangement.

Spinels are a class of isometric minerals with the general formula XY₂O₄. These minerals are found in the Earth’s upper mantle, starting at the core mantle boundary, or Mohorovicic discontinuity, and down to depths of about 70 km. Any spinel found at greater depths contain high amounts of chromite. If found in the Earth, post-spinel chromite (which is 10% more dense than spinel-chromite) would have to have formed deep in the mantle, at depths of about 500 km.

Because of the high temperatures and pressures required for the formation of xieite, this new mineral could potentially become a useful tool for astronomers and geophysicists. If xieite is found in other asteroids, astronomers can use it to estimate the pressures and forces that have acted on the asteroid during impact. Likewise, if xieite is found in basaltic lava flows, or igneous intrusions, geophysicists can use the mineral to determine what depths in the mantle the magma originated.

So as fate would have it two days after writing my most recent blog entry, an article was published with the title “First Picture of Planet around Sun-Like Star”. In my previous blog post I mentioned how we had only indirectly observed planets around other stars and had yet to photograph one directly. Well first I must say that even before this new discovery, my statement was not entirely correct. Some people within the last year have claimed that they had photographed planets around stars. I did not mention it because the jury is still out on these pictures as to whether or not what is seen is actually an orbiting planet or perhaps just a background object.

However, even with those couple of photos floating around, this new one is slightly more interesting. Those few photos we have so far of possible planets have all been around very dim stars called red dwarfs or even dimmer brown dwarfs. This new picture is of a star that is very much like our sun. The planet observed is giant (about eight times the mass of Jupiter) and lies far out from its star (about 330 times the Earth-Sun distance). It’s large mass, or size, is one the key factors in being able to view it directly. This planet is extremely far out from its host star; for frame of reference, Neptune is our farthest planet and lies only 30 times the earth-sun distance.

The discovery was made by the Gemini North Telescope on top of Mauna Kea, which is associated with the previously mentioned Subaru Telescope. However, more studies will have to be done to prove this object is in fact orbiting the observed star, but evidence from the indirect method of detection supports the idea that this is not just a background object in the picture.

Given the distance to its star and other strange qualities such as its large mass and hot temperature (about 1500C compared to Jupiter at 110C), we may have to really start looking at our models of planet formation. Currently our theories would not predict, or allow for, such a planet to be where it is and how it is. For those who want to see the pretty picture of the planet, Google the star name 1RXS J160929.1-210524 (nice name huh?) or should be available from the Gemini observatory’s website.

Where can you find the world’s largest refrigerator, the world’s fastest racetrack, the hottest spot on Earth, and the emptiest space for thousands of light years? CERN’s Large Hadron Particle Accelerator lays claim to each of these records. Propelled by 9300 super-cooled magnets (-271.3°C), a particle will travel 26,658m at speeds of 99.99% the speed of light through a vacuum whose pressure is 10^-13 atm’s. Two colliding beams of particles will collide with energies of 14 Tev which will generate temperatures 100,000 times the temperature of the center of the sun.

The LHC will be conducing six experiments: ALICE, ATLAS, CMS, LHCb, TOTEM, and LHCf. The ALICE experiment (A Large Ion Collider Experiment) will attempt to recreate the earliest conditions predicted by the big bang. This will be achieved by colliding lead ions at speeds of 99.99% the speed of light. The collision will separate the ions into protons and neutrons, and under temperatures 100,000 times the heat of the sun, should further break down into a quark-gluon plasma, scientists hope to observe this plasma as it cools and recreates known particles.

On September 10^th at precisely 10:28 am, the first step towards experimentation and hopefully discovery was taken, as a test beam successfully traveled the nearly 27,000 m tunnel. For CERN this was a moment of triumph as they observed their marvel of engineering come to flawless life. But their 20 year journey was not without pain, as CERN even had to battle a doomsday scenario lawsuit.

On March 21, 2008 Walter Wagner, founder of Citizens Against The Large Hadron Collider, filed a lawsuit against the US Department of Energy, Fermi lab, the National Science foundation, and CERN. The goal of the lawsuit was to put a time restraint on the activation of the LHC while safety issues were evaluated. The safety issues Wagner is concerned about include miniature black holes, and strangelets. Wagner fears that if the LHC creates miniature black holes, they would fill their tremendous appetites by feasting on the Earth. Defendants of the LHC say that this is of no concern because any black hole that does form would have a lifespan of about 10^-23 seconds. Wagner also fears that if strangelets are formed they will transform the entire planet into a lump of exotic matter.

Once the experimentation has begun, and Wagner can once again sleep through the night, the LHC hopes to prove or disprove a major theory, discover new subatomic particles, search for extra dimensions, discover what causes the formation of mass, and explore the mysteries of dark matter. Whether or not all or even one the goals are achieved, one thing is for certain; the LHC will expand our knowledge and provide us with a clearer image of the universe in which we live.

As of September 2008 a total of 309 extrasolar planets have been discovered. So far only massive gas giants, like Jupiter, have been detected, although some as small as Neptune. No terrestrial, or earth like planets, have been discovered yet. This is because of the current limitations on the technology, or the method, used to detect planets. However, this will hopefully be changing soon.

Currently it is difficult to locate earth-sized planets because they are very small, and do not give off much reflected light from their stars. So far no planet has been bright enough on its own to be detected by our telescopes. We can only detect planets by the small gravitational effects these planets have on their host stars. Planets do not have much mass compared to stars but the little mass they have exerts a pull on their stars; it makes them wobble slightly. We can use the Doppler effect to measure this wobble. The Doppler effect makes it so that the light from the star is bluer when moving toward us, and redder when moving away from us. So when watching a star with a planet around it, the pull from the planet as it orbits the star causes this shift in the observed light from the star, thus we know the planet is there. However, the mass of earth-sized planets is too small to create any noticeable wobble.

However, progress is definitely being made. The Subaru Telescope, located atop mount Mauna Kea in Hawaii, has an 8.2-meter mirror and has recently started scanning nearby stars looking for planets. There are eight innovative cameras and spectrographs at Subaru optimized for various astronomical investigations in optical and near-infrared wavelengths. One of these cameras is called HiCIAO, or High Contrast Instrument for the Subaru Next Generation Adaptive Optics. It is designed to block out the harsh direct light from a star, so that nearby faint objects such as planets can be viewed. The new adaptive optics system uses 188 actuators behind a deformable mirror to remove the atmospheric distortion from its view, allowing Subaru Telescope to observe close to its theoretical performance limits. The Subaru Telescope hopes to be the first to directly observe a planet outside our solar system.

Now even though Subaru hopes to be the first to direct image a planet, it still cannot detect an earth-sized planet. NASA was planning on launching a space telescope for this purpose called the terrestrial planet finder. This would consist of two observatories planned to not only detect these types of planets but also even study their characteristics such as size, distance from star, and even atmospheric components. However, due to budget cuts at NASA the project has been postponed indefinitely. I think until this project, or a similar one is funded and launched, we will continue to be limited by our current earth-based telescopes, and earth-like planets will remain outside our view.