Label: Science News

January 19, 2011

Photographer Bence Máté describes the scene in today’s Cool Animal Photo of the Week: "I was photographing hummingbirds when I heard the sharp, alarming noise of the birds reacting to the presence of a predator. Sixty feet away from me this green-crowned brilliant (also known as Heliodoxa jacula, a type of hummingbird) was fearlessly attacking a small viper."

Máté took this photograph in Costa Rica, where about 50 of the 338 known species of hummingbirds, as well as tree-dwelling vipers, live in the tropical foliage.

This amazing image is a winner in Nature’s Best Photography magazine’s 2010 Best Photography contest. You can see more great nature photography on their website.

January 11, 2011

Is there a glass of milk sitting on the table as you read this over breakfast? Bet you didn’t know that the production of milk is one of the big offenders in the creation of damaging greenhouse gases.  How are dairy farmers are working to improve this situation? By reducing cow burps!

That’s right. Half of the greenhouse gas emissions associated with each gallon of milk take the form of methane gas, which is released both when cows burp and when they produce manure (that is, when they poop). And it’s not just a problem here. A British study found that methane emissions from gassy cows are responsible for 4% of the U.K.‘s total greenhouse gas emissions. A 2006 United Nations study found that cows produce a staggering 18 percent of the world’s greenhouse-gas emissions — more than planes, trains and automobiles combined.

Can burping cows really be responsible for all this? When cows digest their food, stomach bacteria produce methane, an ozone-forming gas considered 23 times worse than carbon dioxide when it comes to trapping heat in the atmosphere. "A lot of people think this gas is coming from the rear end," explains Nancy Hirshberg of Stoneyfield Farms in Highgate, Vt. "Ninety-five percent is actually from the front end, from the burps." Stoneyfield Farms is one of the many dairy producers who are working to develop new kinds of feeds that will help cows digest their food better, as well as constructing machines called methane digesters, which convert the bad methane gas to usable biogas.

Some families have one meat-free and dairy-free meal every week to help this problem of burping cows!

January 5, 2011

10-year-old Kathryn Gray of Birdton, New Brunswick, Canada has discovered a supernova, the youngest person ever to make such a finding. How would a ten-year-old have access to the equipment needed to spot a supernova, you might ask? She was working with her father, astronomer Paul Gray.

Supernovas happen when huge stars explode and die. You can see it through a telescope because an exploding star gives off a very bright light, much more brilliant than anything around it. Kathryn’s supernova happened in a distant galaxy called UGC 3378, which is about 240 million light-years away from our Milky Way Galaxy.

Kathryn was helping her father by studying “before and after” images of the same place in that galaxy, using an instrument called a blink telescope – that way you can see when something new has happened. And sure enough, she found a supernova.

If her teacher asks the class this week to write about “what I did over my winter vacation,” Kathryn Gray is certainly going to have a story to tell!

Photo Credit: David Smith/AP

January 4, 2011

OK, so I know we usually only highlight one special science or nature photo each week. But, this is such a spectacular sight, we just have to show you.

People in Europe and the Middle East were treated to a partial solar eclipse when the sun rose this morning. Because the moon was covering 85% of the sun, the sun rose as a crescent. This is not something that you see everyday!

This photo was taken by Peter Rosen in Stockholm, Sweden. There are many more amazing images at SpaceWeather.com.

January 4, 2011

Sea turtles are the last of our world’s ancient reptiles, and have been swimming the seas for more than 200 million years, since back when dinosaurs still roamed the earth. But in just the last few decades, hunting, coastal development, fishing and pollution have reduced their populations to dangerously low levels, to the point that sea turtles are now endangered. That is why many of us, including our young environmental reporter Alana G., were very worried about the fate of the sea turtles when the Deepwater Horizon oil spill happened in the Gulf last year.

The very good news is that the rescue efforts were quite successful. NOAA (the National Oceanographic and Atmospheric Administration), the Gulf states, many nonprofit partners and the Gulf fishermen teamed up to rescue more than 400 sea turtles from oiled waters and take them to aquariums and other facilities for de-oiling and rehabilitation. Marine biologists even moved more than 25,000 sea turtle eggs to Florida’s Atlantic coast, so that the hatchlings would make their way from their sandy nests to clean water. More than 96 percent of the 400 sea turtles brought into rehabilitation have survived, and most of them have already been returned to the wild. This is great news!

Unfortunately, scientists also learned something disturbing from the Gulf oil spill. Most of the dead turtles that turned up on the beaches did not have oil on their bodies and necropsies (that is what you call the autopsy of an animal) showed that they were in good health prior to their death. It appears that the majority of these 600 turtles died from drowning, after being trapped in fishing gear.

So now a new effort begins, to make fishing equipment more "turtle proof" in the Gulf, where five of the world’s seven species of marine turtles live. In order to protect this species and get them off the endangered list, NOAA is considering establishing a rule requiring fishermen to use TEDs (Turtle Excluder Devices). These escape hatches allow sea turtles to swim out of the shrimp skimmers so they don’t drown. As NOAA and the states continue to assess the natural resources damaged by the spill, we are gaining a much clearer picture of what we need to do long-term to protect these glorious, ancient creatures. 

December 21, 2010

Nothing like setting your alarm for 3:10 am, only to discover that the skies were too overcast to see last night’s full lunar eclipse. We heard this from friends right across the U.S., unfortunately.

The good news is that NASA’s  Jet Propulsion Laboratory has posted hundreds of great photos - click here if you’d like to see more (SeeMore - get it? haha). 

December 20, 2010

We have nearly reached the longest night of the year here in the northern hemisphere. Tomorrow night, December 21 (or December 22 in some years), known as the "winter solstice," is also the day we consider to be the official beginning of winter. Solstice means "the sun stands still," and the winter solstice is the day when the midday sun is at its lowest point above the horizon. It seems to hover there, never rising very high in the sky, and then sets again - hence the idea that the sun is "standing still."  This happens because Earth is tilted on its axis in such a way that the northern hemisphere is pointing farther away from the sun than at any other time of the year.

This year’s "longest night" will be an even darker night than usual during a full moon (at least for some hours), because the arrival of the winter solstice coincides with a full eclipse of the moon in the early hours of December 21 (late tonight). And this lunar eclipse is going to be a beauty - visible to everyone in Northern and Central America (if the skies are clear and the weather cooperates).

Do you know what happens during a lunar eclipse?

Think about it. We see the full moon shining brightly in the sky because it is illuminated by the sun. What we call "moonlight" is really just sunlight reflected back at us from the moon. So, what would cause the full moon to suddenly go dark?

It could only happen if the sunlight were cut off.

And what could possible block sunlight from reaching Earth’s moon? That’s right, our planet EARTH itself! A lunar eclipse happens when the Sun, Earth and the Moon are all in a straight line, so that for a little over an hour, the moon is completely in the darkness of earth’s shadow.

It will not completely disappear - instead, it becomes

a deep, deep orange color. It takes 3 to 4 hours to

see the whole event from when the first shadow starts

to creep across the moon’s surface until it is fully

obscured, and then the shadow gradually recedes,

eventually leaving the full moon glowing in the sky again.

Here are the times, if you decide to stay up (or go to bed and then get up in the middle of the night) to see it.

Happy Winter Solstice, everyone!

December 18, 2010

This tiny marine snail has a unique way of protecting itself. When it feels threatened, it lights up its plain, yellowish shell and emits a bright, neon green light. It probably makes it appear larger than it is to potential predators. In a laboratory experiment, scientists found that the snail lit up when confronted by crabs and swimming shrimp.

The snail, Hinea brasiliana, is a type of clusterwink snail that is typically found bunched up in groups along rocky shorelines. The green glow results from a phenomenon known as bioluminescence - or light made by living animals (pronounced "bio-loom-i-NESS-ens"). The most familiar example of bioluminescence is the firefly, which is actually a beetle. Fireflies use the flickering patterns of light to attract mates.

 Photo: Dimitri Deheyn / SIO / UCSD 

December 13, 2010

This weekend I spent a lot of time fooling around with Google Earth, marveling at the incredibly crisp and clear satellite photographs of my house, my street, my neighborhood…..  It is incredible (though a little spooky!) to see the kind of pictures we can capture from cameras orbiting in the exosphere (the outermost portion of Earth’s atmosphere).

Then this morning I came across this photograph of the tallest building in the world - the Burj Khalifa building in Dubai. It was taken by the GeoEye-1 satellite from an altitude of 423 miles. Look at how tiny the other buildings down on the ground look…..and then look at how big the Buri Khalifa appears. Can you think of another way to know, by looking at this photograph, that the building is very tall?

You can tell by looking at the shadows cast by all of the buildings in the photograph. The big building has a shadow that is at least 5 times longer than the shadow of any other building in this cityscape. That really tells you something about how tall this building is!

This skyscraper stands 2,717 feet high, has 160 floors, and is the tallest human-made structure ever built. When the building was opened in January of this year, it returned the location of Earth’s tallest free-standing structure to the Middle East, where the Great Pyramid of Giza held the record for almost four thousand years (up until 1311, when they built the Lincoln Cathedral in England).

When I wrote my book SKYSCRAPERS in 2005, the tallest building in the world was Taipei Financial Center in Taiwan. It rose 1,667 feet into the air, and had 101 stories. 

I wrote in that book:

Skyscrapers are super-tall buildings that seem to scrape against the sky.

When you look down from a high window, people on the streets look like tiny ants.

Clouds may drift by below your view. It feels like you’re on top of the world.

How I would love to be able to look down from the top of this new record-holder. Talk about being in the clouds!

December 10, 2010

Christmas came early this year for gorillla conservation experts. A census that counted endangered mountain gorillas in their African habitat shows that their number has grown by more than 25% since 2003. This is big news because just 30 years ago we were down to 250 mountain gorillas, and scientists believed that the species was in danger of extinction.

Scientists who did the census this spring found 480 mountain gorillas (Gorilla beringei beringei) living in 36 groups, plus 14 solitary silverback males. They live in a huge park called the Virunga Massif which spans three countries - the Democratic Republic of Congo, Rwanda and Uganda. The governments of these nations are credited with working hard alongside wildlife conservation groups to protect the gorillas by policing poachers and protecting against accidental snaring by local hunters.

"The mountain gorilla is the only one of the nine subspecies of African great apes experiencing a population increase.  While we celebrate this collective achievement, we must also increase efforts to safeguard the remaining eight subspecies of great apes," said David Greer, African Great Ape Coordinator at the World Wildlife Fund (WWF). 

 You can learn more about mountain gorillas in my book, and visit the International Gorilla Conservation Program website to learn how you can help.

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