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October 13, 2010

National Fossil Day!

The Thermopolis Archaeopteryx
One of the most amazing fossils ever found
Today marks the first annual National Fossil Day. Sponsored by the National Park Service and the American Geological Institute, this holiday of sorts is designed to promote the scientific and educational value of fossils. There's events going on nation-wide, sharing the wonder of fossils with the public and showing how they need to be protected and preserved, so that we can continue to learn from them and so that everyone can enjoy the wonder they create.

National Fossil Day is part of Earth Science Week, October 10-16. This year, the theme of Earth Science Week is Exploring Energy, a very important topic in today's world. A huge percentage of our energy comes from fossil fuels, such as oil, coal, and natural gas. These resources, just like any other fossil, took hundreds of millions of years to form, and will take hundreds of millions more to recharge. It's a sobering issue, that certainly needs attention.

So, take a look at Earth Science Week, National Fossil Day, and the USGS Energy Information. Go learn what a trilobite, a Tully Monster, a cycad, and a Protoceratops are. Visit your local natural history museum. And enjoy National Fossil Day!

October 7, 2010

Have Scientists Found a Second Earth?

Ever since we stared finding exoplanets (planets orbiting a start other than our sun) back in 1992, the hunt has been on to find a Earth-like planet. Of course, the planets we found first were not the small rocky worlds like our own, but massive gaseous Jupiter-sized objects that are very close to their stars, appropriately called hot Jupiters. Over time, we got better at the techniques and have become able to find smaller and smaller planets farther and farther from their host stars. Now, have we finally found that long sought-after 'second Earth'?

So our first question is simply, what did they find? To really understand this situation, you need to understand the star this planet is orbiting. This is not a medium-large yellow star like our sun, but a much smaller red dwarf. Red dwarfs have about 1/3 of the mass of the sun and a luminosity of about 1.3% of our sun. This means a planet has to be much closer to the star then the Earth to our Sun to have any chance for life to survive.

That brings us to the planet Gliese 581g (such a creative name). Because of the method used to discover this planet, we know it has a minimum mass of about three times that of Earth, and it is unlikely that it is much larger than that. It is also the right distance away from the star to be in what's called the "habitable zone". This is the zone where a planet could potentially have liquid water on its surface. So far, so good.

Now is when things get tricky. There is still much astronomers don't know when it comes to rocky planets, and planets in general for that matter. Gliese 581g is large enough to hold on to an atmosphere, but atmospheres are tricky things to understand. Atmospheres are also hugely important for life. Mars and Venus can both be said to be in the habitable zone of our Sun, but because of Venus's overabundant atmosphere, and Mars' lack thereof, they are both devoid of life. To make things more complicated, Gliese 581g is probably tidally locked with its host star. This means that one side of the planet is in perpetual day while the other side never sees the sun.

Science rarely, if ever, gives us cut-and-dry answers. Does Gliese 581 harbor life, or would life even have a chance there? We can't be sure. What makes this discovery truly exciting, though, is the speed at which it happened. We have only been finding exoplanets for less than two decades and, of that time, our technology has only become sensitive enough to find small planets much more recently. We have really only begun to survey our neighbor stars in the galaxy and already we have found a planet that is a decent candidate to support life. If this trend continues, there could be millions of such worlds in our own galaxy alone. Think of the prospects if even just a small percentage of those worlds ever developed life.

I think it's time to kick up the planet hunt one more notch.

October 6, 2010

The Census of Marine Life

Around 70% of Earth's surface is covered in water. On average, this water -the ocean- is about 14,000 ft (2.65 miles, 4.267 km) deep.(source) The ocean is also one of the least well-explored places on our planet. It's practically an alien world. Recently, numerous scientists, including marine biologists, oceanographers, geologists, and others, have been working to rectify this gap in our knowledge of the planet. One exciting new step they've taken is the new Census of Marine Life.

The scale of this project was fantastic: over 2700 scientists, from more than 80 different countries, publishing 2600 papers over the course of a decade, spending countless hours on field expeditions and lab analysis. The recently published Census shows an impressive scale of oceanic diversity: 120,000 species, from plankton to whales and everything in between, were observed through the course of this project. Multiple maps were created to show where different organisms live.

Still, as impressive and large scale as this census of the oceans is, it's far from comprehensive. On the maps of organism ranges, there are places that show where the sea has yet to be explored. Dr. Ian Poiner, chair of the Census Steering Committee, claims that there are still at least 3/4 of a million species in our oceans that remain undiscovered. This is just a start to understanding our fellow creatures beneath the waves. There's a lot yet to learn. Space may be the final frontier, but the ocean holds tantilizing opportunities for exploration as well.

For more information on the Marine Life Census, and to explore the OBIS (Ocean Biogeographic Information System) database, visit the Census of Marine Life.

Source: Science Daily: First Census of Marine Life shows ocean life is richer, more connected, more altered than expected