Earthshine may help yield clues to life on other planets
A setting crescent moon amid the thin line of Earth's atmosphere.
February 29th, 2012
01:00 PM ET

Earthshine may help yield clues to life on other planets

Did you ever look up at the sky on a clear night during a crescent moon and see the faint outline of the "dark" side of the moon?

What you are actually seeing is the reflection of the Earth’s light on the surface of the moon. The part of the moon you are observing really isn’t the dark side, or you wouldn’t be able to see it. Scientists call this reflection “earthshine.” They are studying the characteristics of this faint light to see if it could someday be used to determine the atmospheric and surface compositions of Earthlike planets outside the solar system (exoplanets), and whether these distant planets could host life.

A group of scientists led by Michael Sterzik at the European Southern Observatory are using the Focal Reducer/Low-dispersion Spectrograph (FORS) mounted on the Very Large Telescope in Chile to study the characteristics of earthshine. These characteristics are being used to create theoretical models that could identify Earthlike exoplanets harboring life.

Previous techniques have used the light bouncing back from exoplanets to determine the makeup of their atmospheres. However, these observations need to be fine-tuned in order to determine whether life exists on these planets.

The new technique used by Sterzik uses a property of light called polarization. Polarization tells scientists not only how bright an object appears, but also measures the shifting rotation of electromagnetic waves. Light reflected by surfaces such as water, land, or vegetation is polarized. This polarized light can be used to determine the characteristics of a reflecting surface. In the case of the reflected light called earthshine, it tells us the properties of Earth’s atmosphere and surface, Sterzik explains.

So how will these observations be used to determine if life exists on exoplanets? That’s where biosignatures come in. A biosignature is any substance such as an element, isotope, molecule or phenomenon that provides scientific evidence of past or present life.

When scientists look through their telescopes, they do not expect to see intelligent forms of life. However, they can detect gases such as oxygen, ozone, methane and carbon dioxide. These gases can occur without the presence of life. However, an abundance of these gases existing individually alongside each other could indicate the existence of life. If life isn’t present, these gases would react and combine with one another.

Current techniques only provide a rough characterization of giant exoplanets using today’s instrumentation and telescopes. Detecting water and oxygen in exoplanets is currently out of reach, and new telescopes and sensors will be needed to directly observe the characteristics of an exoplanet’s atmosphere.

In the meantime, scientists will continue explore earthshine in order to fine-tune theoretical models that could one day be used to determine if life is present on other planets.

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Filed under: In Space
Giant fleas sucked dinosaur blood
Scientists found these fossilized fleas from the Middle Jurassic. The one on the left is female, the other male.
February 29th, 2012
01:00 PM ET

Giant fleas sucked dinosaur blood

When feathered dinosaurs roamed the Earth, so did giant fleas that sucked their blood.

Scientists have found the fossils of these fleas in China, and published a study of them in the journal Nature. They are about 165 million years old, making them the oldest fleas ever found.

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Filed under: Dinosaurs • On Earth
Inside the Mariana Trench
The Mariana Trench is deeper than Mount Everest is tall, and has had only two previous human visitors.
February 29th, 2012
09:49 AM ET
February 28th, 2012
09:28 AM ET

The Ultimate Periodic Table

Theo Grey has a remarkable collection of pure elements, which he keeps in a giant, wooden periodic table. In this video clip, he shows off some of his most interesting specimens, and talks about how his collection got started. Grey is a co-founder of Wolfram Research and the author of The Elements, a wildly popular iPad app about the periodic table. He also writes a column about dangerous science experiments for Popular Science magazine.

Theodore Grey
The Elements
Periodic Table

This video was produced by the American Chemical Society.

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Filed under: Voices
Asteroid grains help explain 'space weathering'
The asteroid 25143 Itokawa, in 2005.
February 27th, 2012
05:46 PM ET

Asteroid grains help explain 'space weathering'

Did you know that Japan has a space agency? They do, and JAXA (the Japanese Aerospace Exploration Agency) is doing some cool science with miniscule asteroid grains.

A team of Japanese scientists took a look at five tiny grains of the asteroid 25143 Itokawa and found evidence to support theories of "space weathering," that is, the changes in an asteroid's surface brought on by a continuous assault by micrometorites and solar wind.

In order for scientists to study these grains, which are merely nanometers in size, they first had to come down to Earth, and not by entering our atmosphere as meteorites. Meteorites, while material from asteroids, are assumed to have lost their surface material on entry into our planet's atmosphere. JAXA's Hayabusa spacecraft literally sent home bits of the near-Earth asteroid 25143 Itokawa for scientists to study in a capsule, which came home on June 13, 2010.

This is the first potentially space-weathered material, other than the Apollo moon rocks, available for hands-on study and observation. Previous studies of space weathering and asteroids have been conducted using spectroscopy - the study of light radiated from an object.

The five grains studied by the Japanese team indicate that space weathering isn't a single phenomenon, but should instead be understood as the effect of a combination of processes affecting the asteroid's surface.

These samples, and the study overall of space weathering, is key to understanding the formation of the solar system.

Their findings appear in the journal Proceedings of the National Academy of Sciences.

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Filed under: Discoveries • In Space
Moon, Jupiter and Venus light up the sky
Planets aligned on Saturday to give stargazers a celestial delight. Jupiter is at the top and Venus is on the bottom.
February 27th, 2012
01:58 PM ET

Moon, Jupiter and Venus light up the sky

Venus, Jupiter and the crescent moon came together in a shining triangle on Saturday and Sunday night, putting on a show for stargazers from Virginia to California.

Photographer Scott Shoup went to a lake near his home in Superior, Colorado, hoping to get a shot of the moon and planets reflecting off the water.

In Iron Mountain, Michigan, Jason Asselin heard about the alignment but snow was in the forecast, so he was expecting a cloudy sky when he went outside on Saturday night. He was "surprised and happy to find out that the clouds actually weren't there, and I was able to see Venus, Jupiter and the Moon very clearly." He grabbed his camera and tripod and shared a few shots. (Venus is the one closest to the moon.)

Matt Hartman, a photographer in Los Angeles, California, set up his tripod on the balcony and shot photos every 10 seconds from 7 to 9:30 p.m. to create this time-lapse video of the objects  disappearing from view as clouds move in.

Hartman often shoots celestial happenings and says, "It’s always a real pain to get things in space because you're moving, the things in space are moving, and space is moving."

If you enjoy counting stars and tracing comet tails, we want to hear from you at CNN iReport. All cool space and science stories are welcome!

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Filed under: In Space • iReport • News
February 24th, 2012
01:10 PM ET

Rare Challenger disaster video surfaces

They are nightmarish images that are burned into the national consciousness: the ominous twin exhaust trails of the exploding space shuttle Challenger.

More than a quarter century later, in an extremely rare discovery, Bob Karman of  Hicksville, New York,  has uncovered amateur VHS videotape of the tragedy, shot during his family's vacation on that day, January 28, 1986. The video first surfaced on  New Scientist.

Appearing on CNN Newsroom on Friday, Karman said he believes it is the only known VHS amateur videotape of the explosion. The other known tape was shot on Betamax format, Karman told CNN's Fredricka Whitfield. "The emotions do come out every time you see the tape  and the tragedy that occurred," said Karman. "It just reinforces the bravery of these astronauts going up in space."

In the video, Karman, his late wife and his then-three-year-old daughter Kim are at an Orlando, Florida, airport - about 50 miles from Kennedy Space Center.

"While we were at the airport people were returning from their vacations and I said, 'Look over there and you'll be able to see the space shuttle taking off,'" Karman recalled.

Off camera, you can hear voices in the video suggesting that they're unaware of the historic events that are taking place before their eyes.

"They're on their way," says a voice.

Of course they weren't on their way.

Challenger's seven crew members - who President Reagan famously said "slipped the surly bonds of Earth" - perished shortly after liftoff. See CNN's 25th anniversary coverage from 2011.

"I had a sense that there was something going wrong," said Karman. "But it wasn't until we got on the airplane that the pilot announced the tragedy that had occurred."

"The rest of the plane flight home was very somber."

Karman's daughter can be seen at the top of the video. She now works at New Scientist, said Karman, who stumbled across the tape again after all these years as part of a home-video digitizing project in preparation for his retirement.

"I remembered this tape, but it was a lot better than I remembered," Karman said. "So I sent a copy to my daughter at New Scientist magazine and it became an Internet sensation."

How often does an artifact like this pop up? Especially when you consider that most Americans didn't own video recorders in 1986. It makes you wonder what other historic video treasures are out there buried in closets, attics and basements.

Follow CNN Newsroom's Randi Kaye on Facebook.

Follow CNNLightYears on Twitter

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Filed under: News
Follow Friday: A Vancouver science diary
The AAAS meeting took place at the Vancouver Convention Center. Yep, that's the view. Yep, I want to go back.
February 24th, 2012
09:50 AM ET

Follow Friday: A Vancouver science diary

Editor's note: Elizabeth Landau (@lizlandau) is a writer/producer for CNN.com.

Meat from stem cells? Singing without your vocal chords? I'm still trying to mentally process all of the cool research that I learned about at the American Association for the Advancement of Science annual meeting.

Last weekend, @AAASMeetings drew about 8,000 scientists, journalists, educators, policymakers and communicators came from all over the world to idyllic Vancouver, British Columbia.

For someone who misses the knowledge-thirst-quenching aspects of college, it's pretty blissful. You choose between dozens of subjects to learn about during the day, and then you get to hang out with fascinating people in the evenings. And you're tweeting the highlights to thousands of people, some of whom will want to meet up with you later. Of course, you'd better get those tweets right, or you'll get a #FAIL.

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Filed under: FollowFriday • Voices
Scientists: New amphibian family augurs more India discoveries
An adult Chikilidae, a new family of legless amphibian known as a caecilian, is shown with eggs and hatchlings in India.
February 23rd, 2012
08:11 PM ET

Scientists: New amphibian family augurs more India discoveries

Scientists have found what they say is a new family of legless amphibians in Northeast India animals they say may have diverged from similar vertebrates in Africa when the land masses separated tens of millions of years ago.

The find, the scientists say, might foreshadow other discoveries in Northeast India and might help show the area played a more important evolutionary role than previously thought.

The creatures are part of an order of limbless, soil-dwelling amphibians called caecilians not to be confused with snakes, which are reptiles. Caecilians were previously known to consist of nine families in Asia, Africa and South America.

But different bone structures in the head distinguish this apparent 10th family, and DNA testing links the creatures not to other caecilians in India, but to caecilians that are exclusively from Africa, the scientists report this week in the Proceedings of the Royal Society of London.

FULL STORY
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Filed under: On Earth
February 23rd, 2012
01:22 PM ET

Oops! Speed of light may still be the limit

By Christopher Cottrell, CNN

It could have shaken the very cornerstones of modern physics but - oops! - it experienced some technical difficulties. An experiment suggesting that particles could travel faster than the speed of light had some potential flaws, scientists announced Thursday.

The contemporary understanding of how the universe works is based on Albert Einstein’s 1905 Special Theory of Relativity, which says the speed of light is a constant that cannot be exceeded - it's the universe's speed limit. To go beyond it would be to look back in time, the late German physicist said.

Scientists at OPERA – which stands for Oscillation Project with Emulsion-Racking Apparatus – were surprised last year to find that tiny particles called neutrinos were arriving at their destination faster than expected. They were tasked with tracking tiny particles as they soar through 730 kilometers of solid rock between a particle accelerator at CERN in Geneva and the Gran Sasso underground laboratory in Italy.

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