Now that 2009 has begun its important for all to know that 2009 has been declared the international year of astronomy. It is the 400th anniversary of when Galileo Galilee first turned his telescopes to the heavens, opening a whole new world of scientific discovery. It is an important time to remind and education the public about the world of astronomy, with astronomy budgets tightening getting the public involved is crucial to keeping support alive and well.

The history surrounding Galileo is quite fascinating and worth looking into for any science or history enthusiast. He was truly one of the first real scientists, pioneering what we know as the modern scientific method. Galileo lived an interesting life teaching mainly in Pisa Italy (where he did the famous experiment of dropping objects of different weights off the leaning tower) and then spending the majority of his life in Florence. In Florence he spent his time educating the ruling family of the time, the Medici. He did not invent the telescope as many think, as it was first invented for use as a naval navigation tool. He was the first to use it for astronomical purposes. With his telescope he discovered the moons of Jupiter and documented sunspots, the phases of Venus, and made detailed drawings of the surface of the moon. For anyone interested a terrific read on the subject is the book ‘Galileo’s Daughter’ by Dava Sobel. It is a good biography not just of his professional but also personal life and includes real transcripts of letters between him and his daughter; it gives a good view of life in Italy at the time.

Back in 2009, many events will be happening throughout the year to commiserate this occasion. For a full list check out the official website at www.astronomy2009.org. The kick off will officially be in Paris on January 15 and 16 featuring keynote speeches from Nobel laureates and video feeds from scientists all over the world. The solar physics group will be having a yearlong campaign in over 30 countries at 150 different venues. ‘The Cosmic Diary’ is a website being launched in January focusing on the daily lives of astronomers with over 50 astronomers from 35 countries participating with blogs, articles, video, and more. Another event is the ‘100 Hours of Astronomy’ taking place on April 2-5. It will feature live web casts, public viewings, and other outreach events. One interesting feature going on the month of January is the project ‘Dark Skies Awareness’, where the International Year of Astronomy organization is trying to rise awareness about light pollution and they’ve called on the public to count the number of stars that are visible in areas with differing light pollution and you can then compare with there data on the number of stars when there is no light pollution and the results are quite surprising.

I personally encourage anyone reading to get involved. There are many ways for the public to get involved in astronomy. You can head out to your local planetarium and see what they have going on. Or go to a public viewing night held by your local university or observatory. I know some university’s go out into the community and do things like Universe in the Park viewing nights, or if you have children you can sign up their class or troop to have astronomy students come do a presentation. If you already have a telescope just take it out and make sure it gets some use, and if you know how try hooking up your camera to it and enter an astronomy picture contest. Astronomy is a fascinating subject, but in difficult financial times its important to keep the public enthused involved and educated, hopefully with some of these large scale events going on people will get reminded just how fun and amazing it can be to look up to the heavens as Galileo did so many years ago.

Throughout the Earth’s history there have been several mass extinctions. Perhaps the most famous and controversial is the extinction event which killed off the dinosaurs and 70% of all other living creatures on the Earth. This mass extinction occurred about 65 million years ago, and marks the end of the cretaceous period, and is often referred to as the K-T extinction event.

It is referred to as the K-T extinction event because of a layer of sediment found around the world which marks the boundary between the cretaceous and tertiary periods. Below this layer, there are several non-avian dinosaur fossils, and above it there are no such fossils. Besides dinosaurs, several species of plants and invertebrates also disappear from this top layer of soil. The few lucky survivors of the extinction event include several mammalian and bird clades.

The leading hypothesis for this mass extinction event is called the Alvarez hypothesis, named after a team of father and son scientists, Luis and Walter Alvarez, who first suggested it in 1980. The Alvarez team found concentrations of iridium hundreds of times higher than normal in the rocks around the K-T boundary. Iridium is a high density element, which is rarely found in the Earth’s crust; because of its high-density and iron-loving characteristics, iridium is believed to be found at its highest concentrations in the Earth’s core. Because Iridium is an iron-loving element, the Alvarez team speculated that the high concentrations of iridium found around the K-T boundary, was due to a large asteroid impact.

Using the concentrations of iridium found around the K-T boundary, the Alvarez team was able to determine that these concentrations were normal in a type of asteroid known as chondrites. They were also able to calculate that the size of the asteroid would have been about 10 kilometers in diameter. The energy released during such an impact would be equivalent to 100 trillion tons of TNT—twice as powerful as the largest nuclear bomb ever tested.

An impact of this magnitude would likely have produced a dense cloud of dust, which would have engulfed the entire planet. This dust would have blocked off sunlight, which would cause a change in the climate, and temporarily prevented photosynthesis. The lack of photosynthesis could account for the extinction of several species of plant life. The loss of plant life, coupled with a cooling climate, would reverberate through the food chain, causing the extinction of many types of animals, including the dinosaurs.

The scar of such an impact is located in the Yucatan Peninsula, and is called the Chicxulub Crater. This crater was created by an asteroid impact approximately 10km in diameter, and isotope analysis dates this crater to the end of the cretaceous—about 65 million years ago. To some, this is enough to confirm Alvarez hypothesis; but Gerta Keller, a professor of geosciences at Princeton University, believes otherwise.

Professor Keller agrees that the extinction was due to a changing climate, but she disagrees with what may have caused such a change. Her research implies that the mass extinction occurred 300,000 years before the Chicxulub impact. Her team estimates the age of the impact based on spherules found in Texas and New Mexico. A layer of spherules was formed when rock was vaporized by the impact, shot into the stratosphere, and then rained down over North and Central America. This layer was used to determine that the impact happened precisely 300,000 years before the mass extinction occurred.

The layers of sediment above and below the spherules layer show exactly how life was affected by the impact. Keller’s studies show that not a single species found in the layer beneath the spherules layer disappeared from the layer above. She believes that the mass extinction that occurred 300,000 years after the Chicxulub impact was caused by a series of volcanic eruptions in the Deccan Traps.

These volcanic eruptions were periodic, and lasted from 10 to 100 years, producing a volume of lava, in cubic miles, greater than the Rockies and Sierras combined. From each eruption, toxic gas was spewed into the atmosphere and oozing lava spread 650 miles across India, forming the longest lava flows on Earth. The sulfur dioxide injected into the atmosphere would have turned to aerosols, causing global cooling, while acidizing the ocean through acid rain. The marine record shows that 50% of ocean life was killed off by the first eruptions, and the mass extinction was complete by the end of the eruption frenzy.

Everybody asks the question, “What killed the dinosaurs?” Perhaps the better question is, “why didn’t they return?” Keller states that the dinosaurs were steadily dying off before the chicxulub impact; her solution is that the volcanoes were slowly killing everything. Why then didn’t the dinosaurs, or something similar make a comeback after the volcanoes quit, and the Earth regained equilibrium? Did the volcanoes permanently alter the composition of the atmosphere? Did the Chicxulub impact hit the Earth hard enough to change its axial tilt? Was there a reduction in solar flux reaching the Earth due to an aging sun? One thing seems certain: after the demise of the Dinosaurs, there was not enough energy reaching the Earth to sustain such massive life forms. One might speculate that the conditions which led to the demise of these magnificent creatures, also created an environment suitable for the evolution of intelligent life, and eventually present day man.

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It’s no new thing to find a planet these days since we’ve detected hundreds of extrasolar planets by now. Now being able to determine the chemicals present on other planets, now that’s pretty new and exciting. Now for the first time carbon dioxide has been detected on a planet outside of our solar system.

The planet is called HD 189733b and lies about 63 light years from us. It’s a large planet, about the size of Jupiter with a very short rotation period of only 2.2 days. Astronomers have been observing the planet for a while now using both the Hubble Space Telescope and Spitzer Infrared Space Telescope. Last year they discovered water vapor and then some time later methane. But this is the first time an organic compound such as this has been found on another world. Now this planet is too hot to support life, but chemicals like this one are by products of life processes thus when we are able to start detecting earth sized planets this may be an indirect way of discovering other life forms.

It is exciting not just knowing that these other planets are there but we’re actually able to say something about them. Using the Hubble Near Infrared Camera and Multi-Object Spectrometer (NICMOS) to study the infrared light emitted by the planet. Gases in the planet’s atmosphere absorb certain wavelengths of light from the planet’s hot glowing interior. The astronomers identified not only carbon dioxide, but also carbon monoxide. The molecules leave their own unique spectral fingerprint on the radiation from the planet that reaches Earth. This is the first time a near-infrared emission spectrum has been obtained for an exoplanet. With these detection techniques we can describe the conditions, chemistry, and atmospheric composition of other planets.

This planet was a good candidate for this type of study because of the orientation of the planet to Earth’s orbit. The planet’s orbit is facing us edge on, so when it moves around its star and the star eclipses it. So astronomers are bale to subtract out the light that is due only to the star and thus are left with the spectrum coming from the planet.

Once the new James Webb Space Telescope launches things will get even more exciting. Astronomers will be able to use this technique but with the much greater sensitivity of the new telescope hopefully it will be on terrestrial, or earth like planets. Until then astronomers will be using this technique to look at other exoplanets to see what other new things they can discover.

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Three undergraduate students from the Netherlands have made a new discovery in our universe without even trying. They discovered a new extrasolar planet, which is a great discovery itself, but to top it off they discovered it using a new technique and found it orbiting a special kind of star.

Students Meta de Hoon, Remco van der Burg, and Francis Vuijsje were given the assigned to develop search algorithms. They did so well on this project that they had time to test their search algorithm on real data. So they set to work investigating light fluctuations in thousands of stars in the so far unexplored OGLE database. The brightness of one of the stars was noticed to decrease by about 1% every two and a half days. The students were then allowed to use the ESO Very Large Telescope in Chile to follow up and confirm that a planet was causing the fluctuations.

The planet was given the name OGLE2-TR-L9b, but the students like to call it ReMeFra-1 after their names. The planet is quite large, weighing in at about five times the mass of Jupiter. To make sure that it was a planet and not a small star o brown dwarf they used spectroscopy to look at the chemical make up of the orbiting body and confirmed it is not a star. The planet is orbiting very close to its star; it lies at only three percent of the Earth-Sun distance giving it an orbital period of only 2.5 days. This discovery is also special because of the type of star. The star, named OGLE-TR-L9 is now the hottest star found to have a planet orbiting it. The star itself also rotates very quickly, which would have made it hard to use the conventional method of planet detection to find this one.

So we can add another extrasolar planet to the growing list. With each new planet discovery we learn so much. We have now expanded the list of possible stars that could have planets, knowing that stars this hot and fast can have planets. This technique may prove quite useful in detecting planets around similar stars. And the part that I think is most exciting is that this was all done by undergraduate students. Undergraduates are usually lucky to get some research experience, maybe a have a paper published with their names below their professor’s, but these students did something extraordinary and they’re getting the credit. It shows that you don’t have to be a stuffy know it all professor who has been researching for many years to be able to contribute.