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Are Some Exoplanets More Like Earth? – On Science

January 10, 2014

Is the king of the jungle about to get dethroned?

What creepy crawly lives in outer space?

Predators face extinction and there could be global consequences.

Strange lights in the darkest parts of the ocean? The answer could surprise you. Coming up today, On Science!

Hello and welcome to On Science, I’m Emerald Robinson

Like the fine print on a new diet product you are so hoping will work, the discovery of exoplanets usually come with a disclaimer – probably not like Earth. Super-Earths at several times larger than our own planet are thought to be covered entirely in water. However, a new study challenges that. A new model created by researchers at Northwestern University took into account the effects of seafloor pressure and the high gravity of exoplanets. On our own planet, water is moved between oceans and the Earth’s mantle. The division of this water is determined by seafloor pressure, which is relative to gravity. In their model, they found that as the size of the super-Earth increases, gravity and seafloor pressure also go up, which would expose land. They said that they could put 80 times more water on a super-Earth and still have its surface look like Earth. But they said there is two slight problems with their model—they don’t have knowledge of super-Earth’s tectonics and the amount of water Earth actually has in its mantle. Again, there’s that disclaimer.

Here’s another science assumption we might have gotten wrong. A new study in the Caribbean Sea found that bioflourescence in fish isn’t so rare after all. So we knew about the glowing corals and jellyfish and even parrots, but glowing fish really wasn’t a big one. Researchers were inspired by a green eel fluorescing off of Little Cayman Island and that got them to research more. They used specific lighting to mimic the ocean’s light and a special camera that can capture the fish’s fluorescent light. With bioflourescense, the animal absorbs light, converts it, and sends it out in a different color. The team identified over 180 species of bioflourescent fish, and these fish have yellow filter in their eyes that help them see normally invisible fluorescent displays. Not only is this glowing protein beneficial to the species for communication and protection, but it could be useful for humans in a wide variety of scientific uses!

There is one species on Earth that is about to become extinct if we don’t do something about it! The African lion is facing extinction across West Africa with numbers dropping to as low at 250. The wild cat conservation group, appropriately named Panthera, revealed how endangered the species really is. Once having flourished throughout the entire West African region, this particular lion species now only resides in five countries with one population having as few as 50 lions. Dwindling numbers are due to competition for land with humans and livestock. The West African lions have unique genetic sequences not found in any other lions and there are fewer than 35,0000 total lions in Africa to date. The king of the jungle no longer reigns in Africa.

The decline of large predators, like the lions, is having an effect on ecosystems not just in Africa but all across the globe. A researcher from Oregon State University says that we are losing large carnivores as a whole and that ironically we are learning about their important ecological effects just as they are vanishing. They identified seven endangered species with significant ecological effects which included African lions, leopards, gray wolves, and sea otters. Loss of these large predators allows the populations of grazing animals like deer and elk to thrive, which in turn disrupts local vegetation and changes the dynamics of birds and small mammals, along with other myriad effects. They say the classic notion of large predators as harmful animals that deplete fish and wildlife is outdated. Instead, “human tolerance of these species is a major issue for conservation.” Gotta love all the Earth’s creatures, people.

And to close today’s show, here’s a beautiful Hubble image of a creepy, crawly Tarantula Nebula—which doesn’t sound so beautiful after all. The Tarantula Nebula is a region of star clusters, glowing gas, and dark dust. A project called the Hubble Tarantula Treasury Project is exploring and mapping this nebula to better understand its starry anatomy. The Tarantula is located in one of our closest neighbors, the Large Magellanic Cloud. This particular image is composed of near-infrared observations from both Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys. The purple haze you see comes from a combination of infrared filters. The project will continue to scan and image many of the stars within the Tarantula, helping astronomers better understand the nebula’s structure. We look forward to more of these strangely beautiful images!

And that’s what’s up On Science. Have a great weekend On Scientists!



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