What’s the News: An international team of researchers, led by the National Center for Atmospheric Research, has learned that large magnetic waves are partly to blame for the Sun’s immensely hot corona. The study, published in the journal Nature, also suggests that the waves could be the driving force behind the solar wind.

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• While modeling plasma flows deep inside the sun, scientists may have found an explanation for why some sunspots cycles (like the most recent one) are weaker than others. “It’s the flow speed during the cycle before that seems to dictate the number of sunspots. Having a fast flow from the poles while a cycle is ramping up, followed by a slow flow during its decline, results in a very deep minimum.”
• Risky business: In defending President Obama’s vision for space exploration that relies upon commercial space companies, NASA administrator Charles Bolden says the country must “become unafraid of exploration. We need to become unafraid of risks.”
• Bad timing: Just as Apple unveils its new iPad—and Steve Jobs uses the opportunity to gloat about his company’s superiority in apps compared to Google’s Android system—Google had to take 21 apps off the Android Market because they were infected with malware.
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Starting this week, NASA will have a new eye in the sky to better sort out the way that greenhouse gases, air pollution, and solar activity interact to affect the climate of our planet. The Glory satellite, currently set to launch on Friday, will spy on changes both in our atmosphere and in the sun.

Its main job will be to study fine airborne particles known as aerosols. Smaller than the diameter of a human hair, these specks can move great distances across the globe and are largely responsible for hazy skies. [The New York Times]

Greenhouse gases and their contribution to climate change have been the subject of much research, of course, but aerosols remain murkier. Climate scientist James Hansen, a member of the Glory team, says researchers must use an uncertainty range for modeling aerosols that’s three to four times greater than what they use with greenhouse gases, simply because the contribution of aerosols is much less understood.

The Glory mission will, if all goes according to plan, collect data on the micro-physical, chemical and optical properties of aerosols using two instruments—an Aerosol Polarimetry Sensor (ARS) and a Total Irradiance Monitor (TIM)—that will monitor the climate system and provide new data for scientists working on the issue of climate change. The APS will collect visible and near-infrared data scattered from aerosols and clouds and the TIM, mounted on a special track that allows it move independent of the satellite, should record total electromagnetic radiation given off by the sun that hits the top of Earth’s atmosphere. [The Atlantic]

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The twin satellites have taken their positions, and now we get to see something we’ve never seen before: the whole sun, all at once.

The pair of observers that make up NASA’s Solar Terrestrial Relations Observatory (STEREO) have been traveling since 2006 to reach opposite sides of our star, and they just beamed back the first 360-degree solar images.

The satellites are in the same orbital path as Earth, more or less, and have just taken up their final positions — one is where we’ll be in three months, and the other where we were three months ago. (The first has NASA’s least imaginative name to date: STEREO A, for “ahead.” The second is called STEREO B, for…you can probably guess.) [TIME]

Seeing the far side of the sun isn’t just a scientific curiosity. It could also helps researchers figure out the sun’s violent outbursts, like the coronal mass ejections that could endanger astronauts and foul up satellites if one headed for Earth.

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Good news, solar sail enthusiasts: the NASA experimental spacecraft that was feared to be a dud sprang into life last week.

NanoSail-D was launched aboard a small satellite in December; once the satellite was in orbit the engineers back on Earth ordered the cargo door opened, and waited for NanoSail-D to pop out as planned. But the solar sail craft remained stubbornly inside the cargo bay. As weeks passed with no action, NASA’s hopes for the craft sunk.

But last Wednesday, NASA announced that NanoSail-D had spontaneously emerged.

“We knew that the door opened and it was possible that NanoSail-D could eject on its own,” Mark Boudreaux, FASTSAT project manager at the Marshall Center, said in a press release. “What a pleasant surprise this morning when our flight operations team confirmed that NanoSail-D is now a free flyer.” [CNN]

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The answers to what might be found deep inside the moon have themselves been found deep inside data that’s been collecting dust for more than 30 years.

When Apollo 11 astronauts Neil Armstrong and Buzz Aldrin stepped onto the lunar surface in 1969, they did more than make history and utter unforgettable words. They also deployed seismic sensors that would allow scientists back on Earth to monitor the activity on the moon. Crews from the 12th, 14th, 15th, and 16th iterations of Apollo also deployed sensors, the lot of which took measurements until 1977. Using recently developed techniques of analysis, two teams working independently say they have gone back into that catalog of data and sorted through the statistical noise that has confounded researchers, creating a clear picture of the moon’s core.

The new study provides the first confirmation of layering of the moon’s core and suggests that the moon, like Earth, has a solid inner core surrounded by a molten outer core, researchers said. But the moon’s interior also has another layer of partially melted material – a ring of magma – around its outer core, the study found. [MSNBC]

The moon shakes with moonquakes, but those are more scattered and weaker than the quakes we experience here on the home world, and the moon’s busted-up surface made the signals difficult for Apollo seismic monitors to read. Through a statistical technique called waveform stacking, the new teams could better identify how seismic waves move through the moon, and especially how the core affects them. That, in turn, shows the size and density of the core.

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Whales don’t wear sunscreen. And because these massive sea mammals must surface to breathe, they are being exposed to more and more ultraviolet radiation sneaking through the weakened ozone layer. According to Karina Acevedo-Whitehouse, lead author of a study in the Proceedings of the Royal Society B, some whales are getting serious sunburns at an alarming rate.

From 2007 to 2009, her team sampled fin, sperm, and blue whales in the sun-drenched Gulf of California, which is the long, skinny expanse of water between mainland Mexico and Baja California.

Nearly all of the skin samples contained “sunburn cells,” abnormal cells associated with ultraviolet-induced DNA damage. These indicators were even found in the lowest layer of skin on the whales, suggesting that those individuals were suffering from very severe sunburns. [Discovery News]

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The edge of the solar system is not some static line on a map. The boundary between the heliosphere in which we live and the vastness of interstellar space beyond is in flux, stretching and shifting more rapidly than astronomers ever knew, according to David McComas.

McComas and colleagues work with NASA’s Interstellar Boundary Explorer (IBEX), a satellite orbiting the Earth with its eye turned to the edge of the heliosphere—the bubble inflated by the solar wind that encapsulates the solar system and protects us from many of the high-energy cosmic rays zinging across interstellar space. This week in the Journal of Geophysical Research, the team published the results of IBEX’s second map of the region, and found that its makeup has changed markedly over the span of just six months. Says McComas:

“If we’ve learned anything from IBEX so far, it is that the models that we’re using for interaction of the solar wind with the galaxy were just dead wrong.” [National Geographic]

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At long last, here comes the sun (mission).

Never mind NASA’s numerous observatories; never mind the unmanned Pioneer 10 and Voyager probes careening toward the far reaches of the solar system—no craft has ever gone to the center of the solar system, the sun. This decade that will change. NASA is in the process of selecting the instruments for its Solar Probe Plus, a mission to launch by 2018 that will get closer to then sun than ever before, and hopefully find some answers to the open questions that remain about our life-giving star.

“The experiments selected for Solar Probe Plus are specifically designed to solve two key questions of solar physics: why is the Sun’s outer atmosphere so much hotter than the Sun’s visible surface, and what propels the solar wind that affects Earth and our Solar System,” said Dick Fisher, director of Nasa’s Heliophysics Division in Washington DC. [BBC News]

The probe isn’t quite setting the controls for the heart of the sun, Pink Floyd-style, but it will draw dangerously close.

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The sun is breaking the known rules of physics—so said headlines that made the rounds of the Web this week.

That claim from a release out about a new study by researchers Jere Jenkins and Ephraim Fischbach of Purdue, and Peter Sturrock of Stanford. The work suggests that the rates of radioactive decay in isotopes—thought to be a constant, and used to date archaeological objects—could vary oh-so-slightly, and interaction with neutrinos from the sun could be the cause. Neutrinos are those neutral particles that pass through matter and rarely interact with it; trillions of neutrinos are thought to pass through your body every second.

In the release itself, the researchers say that it’s a wild idea: “‘It doesn’t make sense according to conventional ideas,’ Fischbach said. Jenkins whimsically added, ‘What we’re suggesting is that something that doesn’t really interact with anything is changing something that can’t be changed.’”

Could it possibly be true? I consulted with Gregory Sullivan, professor and associate chair of physics at the University of Maryland who formerly did some of his neutrino research at the Super-Kamiokande detector in Japan, and with physicist Eric Adelberger of the University of Washington.

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When Ikaros unfurled, it unfurled like a spinning top blossoming into a pinwheel. Out in space earlier this month, the center piece of Japan’s solar sail was rotating quickly when it began to extend the arms that had been wrapped up inside. As they stretched out into a stiff X shape, like the stakes that hold a kite taut, the craft slowed to a gentler rotation (a consequence of conservation of angular momentum, like the way a figure skater’s spin slows down when she extends her arms). The JAXA scientists then could let Ikaros stretch the shining sail into a square that spanned 66 feet diagonally.

When Ikaros unfurled, it also breathed new life into a technology that has been dreamed for decades—using the the pressure of sunlight itself to cruise the solar system, and perhaps beyond.

In Brooklyn this week, solar sail enthusiasts gathered for an international symposium. Last night Osamu Mori of the Ikaros team (seen above with a mock-up) was the toast of the party, and a group of experts joined him to celebrate and look forward to a bevy of new explorations. The roster included Planetary Society current director Louis Friedman and director-to-be Bill Nye, NASA’s Les Johnson, Malcolm McDowell of the University of Strathclyde in Scotland, and Roman Kezerashvili of the host New York City College of Technology.

“I feel like they deserve a ticker-tape parade here in New York City,” Friedman said, “rather than just showing up for a scientific conference.”

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Ikaros hasn’t flown too close to the sun. It’s flown just close enough to ride the light.

Japan’s space agency JAXA confirmed on Friday that its solar sail project, Ikaros, achieved another of its goals: The sun’s photons pushed against the sail and accelerated the craft.

The effect stems from the cumulative push of light photons striking the solar sail. When measured together, it adds up to a small continuous thrust that does not require fuel use by the Ikaros craft. JAXA engineers used Doppler radar measurements of the Ikaros craft to determine that sunlight is pressing on the probe’s solar sail with a force of about 1.12 millinewtons (0.0002 pounds of force) [MSNBC].

Japan launched Ikaros in May and unfurled the sail in June. Now, JAXA scientists say, “with this confirmation, the IKAROS was proved to generate the biggest acceleration through photon during interplanetary flight in history.” Coming soon: A controlled flight in which the researchers turn the sail toward or away from the sun to control Ikaros’ velocity.

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Image: JAXA

South Korea’s attempt to jump into the space race met with disaster today. A little more than two minutes after takeoff today, the nation’s Naro rocket exploded. It had been carrying a satellite, and South Korea was vying to become the tenth country to put a satellite in orbit with rockets assembled at home.

South Korea has invested more than 500 billion won (400 million dollars) and much national pride in the 140-ton Naro-1. The liquid-fuelled first stage of the rocket was made in Russia, while the second stage was built domestically, as was the satellite [AFP].

In Japan, meanwhile, happier news: Last month its space agency, JAXA, launched a batch of new missions into space that included its solar sail project, called Ikaros. Today it unfurled the sail, seen above in the blinding light of the sun.

After separating from Akatsuki [a separate probe going on to Venus], Ikaros began unfolding four panels that, when fully unfurled, should look like a square kite measuring 66 feet (20 meters) along its diagonal. Pictures sent back by a camera mounted on the spacecraft’s hub show the extension of four booms holding the panels, plus the unfurling of sail material. This is the “primary deployment” of the sail. During the secondary stage of deployment, the sail is stretched out to its full extent [MSNBC].

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You can’t rise from the primordial ooze if that ooze is frozen. But about three billion years ago the sun was around thirty percent dimmer, meaning our planet should have been a snowball. The puzzle has haunted scientists for decades, but a study in Science has a new answer: It argues that a dense cloud of “fractal haze” enveloped the Earth.

Old Theories

This isn’t the first attempt to solve the early Earth conundrum. Carl Sagan, for one, had a few ideas. First, in 1972, he speculated that the atmosphere had ammonia which could trap heat, but later work showed that the sun’s ultraviolet radiation would have broken that ammonia down. In 1996 he tried again, saying that Earth might have had a thick haze, perhaps a nitrogen-methane mix, that blocked the ultraviolet but let in enough of the sun’s then-meager rays to warm the planet. Unfortunately, that too was a no go:

Early models assumed the haze particles were spheres, and that when individual particles collided, they globbed together to make bigger spheres. These spheres blocked visible light as well as ultraviolet light, and left the Earth’s surface even colder. “It basically led us to a dead end where we couldn’t have a warm early Earth,” said Eric Wolf, a graduate student in atmospheric sciences at the University of Colorado at Boulder and the first author of the new study. [Wired]

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Remember the sunscreen speech? The Chicago Tribune column, which became an urban legend and then a bizarre spoken word hit for Baz Luhrmann, began

Wear sunscreen.

If I could offer you only one tip for the future, sunscreen would be it. The long-term benefits of sunscreen have been proved by scientists, whereas the rest of my advice has no basis more reliable than my own meandering experience.

But is even this sage advice subject to the “it’ll cause cancer, no wait, it’ll cure cancer” back-and-forth that plagues medical studies? Reading some headlines today, you might think so. Don’t toss out your tube of Banana Boat just yet, though.

The non-profit Environmental Working Group released another of its reports on the sunscreen industry, coming down hard on the chemicals it uses and the claims it makes in its advertising. Some stories about the report drew headlines like “Sunscreen May Hurt, Not Help;” “Your Sunscreen May Give You Cancer: Study;” and “Study: Many Sunscreens May Be Accelerating Cancer.”

EWG’s report claims that a Vitamin A compound called retinyl palmitate, used in some 40 percent of sunscreens, breaks down and causes skin damage under exposure to sunlight. The report cites research done under the Food and Drug Administration. But, according to dermatologist Henry W. Lim of Henry Ford Hospital:

These claims, says Lim, are based on a study in mice, which are far more susceptible to skin cancer than humans. “It’s dangerous to apply a finding in mice to humans, and I’ve spoken with a number of my colleagues about this and we all agree that it’s very premature to even cast doubt about the safety of this chemical.” The EWG also flagged products with oxybenzone, which it calls a “hormone-disrupting” compound. This, too, is based on mice data, says Lim; the animals were fed significantly greater amounts of the chemical than what’s commonly applied in sunscreen. Other research found no significant changes in blood hormone levels in human volunteers who were told to apply sunscreens containing oxybenzone every day for two weeks [U.S. News & World Report].

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