February 22, 2013
On Wednesday, NASA released an image of a series of enormous sunspots snapped by at the Solar Dynamics Observatory, an orbiting telescope. The sunspots—the dark spots in the center of the image—are estimated to be larger in diameter than six Earths placed next to each other.
These sunspots pose no inherent danger—they’re merely temporary areas of intense magnetic activity that inhibit the sun’s normal convection currents—but, on occasion, the unstable area around a sunspot can trigger an unusually large solar flare (below), flinging streams of radiation outward from the sun. And a big enough solar flare can lead to an alteration in solar wind significant enough to set off a geomagnetic storm here on Earth, with the potential to short the circuitry on satellites and disrupt our telecommunications infrastructure worldwide.
It so happens that at least once during recorded history, a solar event of this magnitude did occur: the solar storm of 1859. On September 1 and 2 of that year, the largest geomagnetic storm in recorded history occurred, causing aurorae (the northern and southern lights) to be visible around the world. The Baltimore American and Commercial Advertiser wrote:
Those who happened to be out late on Thursday night had an opportunity of witnessing another magnificent display of the auroral lights…The light appeared to cover the whole firmament, apparently like a luminous cloud, through which the stars of the larger magnitude indistinctly shone. The light was greater than that of the moon at its full, but had an indescribable softness and delicacy that seemed to envelop everything upon which it rested.
Of course, the massive solar storm also caused damage, triggering telegraph malfunctions (even giving operators electrical shocks) and causing some telegraph pylons to suddenly spark and catch fire.
A much smaller solar storm occurred in 1989, knocking out power throughout much of Quebec for over 9 hours, disrupting communications with several satellites in orbit and interfering with the broadcast of short-wave radio in Russia. Aurorae were reportedly visible as far south as Florida and Georgia; given the ongoing Cold War and the fact that many had never seen this phenomenon before, some feared that a nuclear strike was in progress.
How did solar activity 93 million miles away lead to such destruction? These types of storms are the result of a sudden coronal mass ejection (CME)—a massive burst of solar plasma (electrons, protons, and ions) that is hurtled out into space—which often occurs alongside particularly large solar flares.
The solar wind is a continuous stream of charged particles thrown out from the sun towards earth, but a particularly large CME can lead to a big enough surge in the speed and energy of the particles to disrupt the magnetic field surrounding Earth. This, in turn, causes aurorae and the disruptions to our telecommunications equipment, which rely upon electromagnetic forces.
If a CME as large as the one that triggered the 1859 storm were to occur today, the consequences could be devastating. Given the increase in our reliance on electricity and telecommunications (even since 1989), the effects would certainly be far more significant than malfunctioning telegraph pylons.
It’s hard to appreciate just how many aspects of modern life rely on technologies that could be affected. As Daniel Baker of the University of Colorado’s Laboratory for Atmospheric and Space Physics told National Geographic in 2011, ”Every time you purchase a gallon of gas with your credit card, that’s a satellite transaction.” A giant storm could disrupt our GPS systems, communication with planes in flight and other crucial satellite-based technologies.
But the biggest concern, experts say, would be disruptions to our power grid—as a 2011 OECD report (PDF) on the impacts of solar storms points out, “Electric power is modern society’s cornerstone technology on which virtually all other infrastructures and services depend.” A surge in solar wind can blow out power transformers by melting their copper windings, and especially in highly interconnected regions (such as the East Coast), transformer failures can trigger cascading effects, spreading power outages over wide areas.
One analysis looked at a 1921 storm—which was ten times more powerful than the 1989 event—and estimated that if it occurred today, it would leave some 130 million people without power, potentially affecting water and food distribution, heating and air conditioning, sewage disposal and a host of other aspects of the infrastructure we take for granted daily. The total cost of an even larger storm, such as the 1859 event, could be enormous: an estimated $1 to $2 trillion in the first year alone, and a total recovery that could take 4 to 10 years in total.
The good news is that CMEs large enough to trigger a disruptions like the 1859 storm are rare–for the most severe damage to occur, a CME has to be directed in such away that Earth receives the brunt of the blast. Fortunately, solar activity occurs in a cycle with a duration of roughly 11 years, during which all kinds of solar activity (including the number of sunspots, the frequency of flares and the level of mass ejections) fluctuate from high to low and back to high again. However, we’re near the peak of the cycle, which NASA predicts will occur this fall.
Both NASA and the National Weather Service’s Space Weather Prediction Center monitor solar activity and issue warnings when CMEs and other alterations in the solar wind occur. The SWPC’s current 3-day forecast predicts no storms over the weekend, despite this new enormous sunspot.
If a massive CME were spotted, such 3-day forecasts give us some lead time: there are some measures electric utilities could take to protect their equipment, such as quickly disconnecting transformers. Polar flights, which travel at the highest altitudes, could be rerouted to avoid contact with damaging solar particles, and some satellites could be switched into a safe mode to minimize damage. Here on Earth, at the very least, we’d have some time to prepare for potential power blackouts and other problems.
February 12, 2013
This Friday afternoon at approximately 2:26 Eastern time, an asteroid roughly half the size of a football field (147 feet) in diameter will pass extremely close to the Earth—just 17,200 miles from our planet’s surface. That said, there’s no need to worry, as NASA scientists confirmed with certainty nearly a year ago that the asteroid will not make an impact and poses absolutely no threat.
Nevertheless, the proximity of the asteroid’s path is noteworthy: it will come within a distance 2 times the Earth’s diameter, passing us by even closer than some geosynchronous satellites that broadcast TV, weather and radio signals. As Phil Plait writes in his comprehensive post on the asteroid over at Slate, “This near miss of an asteroid is simply cool. It’s a big Universe out there, and the Earth is a teeny tiny target.”
The asteroid—likely made of rock and referred to as 2012 DA14 by scientists—was first spotted last February by astronomers at Spain’s Observatorio Astronómico de La Sagra. Asteroids, like planets, orbit the Sun, and this one passed us by on its last orbit as well, but at a much greater distance—it came within roughly 1.6 million miles last February 16. After this year’s near miss, the rock’s orbit will be altered significantly by the influence of Earth’s gravity, and scientists calculate that it won’t come near us again until the year 2046 at the soonest.
On Friday, though, it will pass by Earth between 18:00 and 21:00 UTC (1-4 p.m. Eastern time, or 10 a.m.-1 p.m. Pacific) and come closest at roughly 19:26 UTC (2:26 p.m. Eastern, 11:26 a.m. Pacific). That means that observers in Eastern Europe, Asia and Australia get to see its closest pass at nighttime, whereas those in North America, Western Europe and Africa will have to wait until after sunset, when the asteroid has already begun to move away.
For all observers, the asteroid will be too small to see with the naked eye, though it should be viewable with binoculars or a telescope. Universe Today has the technical details on where exactly to spot the asteroid in the sky. A number of observatories and organizations will also broadcast video streams of the asteroid live, including NASA.
A fly-by like the one on Friday isn’t particularly rare in terms of mere proximity. There are seven closer asteroid passes on record—in 2011, a tiny asteroid set the record for near misses by coming within 3300 miles of Earth, and in 2008, an even smaller one actually made contact with the atmosphere, burning up over Africa.
Both of those rocks, though, were less a meter across.What distinguishes this asteroid is that it’s passing close by and theoretically large enough to cause major damage if an impact were to occur. While an asteroid of this size passes this closely roughly every 40 years on average, a collision with an object this size only happens once every thousand years or so.
What kind of damage would that impact wreak? For a comparison, many are noting the Tunguska event, an explosion over a remote area Russia in 1908 that was likely caused by an asteroid of similar size burning up in the atmosphere. The explosion knocked down more than 80 million trees covering an area of some 830 square miles; scientists estimate it released more than 1,000 times as much energy as the nuclear bomb dropped on Hiroshima and triggered shock waves that would have registered a 5.0 on the Richter scale.
Of course, unlike in 1908, we now have the power to observe approaching asteroids well ahead of time—and might have the ability to prevent potential collisions. Bill Nye is among those who argue that this event should serve as a wake-up call for the importance of investing in asteroid-detecting infrastructure, such as observatories and orbiting telescopes. The B612 Foundation supports this mission, and advocates for the development of technologies that could slightly alter the path or speed of an approaching object to avoid an impact.
This time, at least, we’re lucky. But Ed Lu, a former astronaut and head of B612, says this event should not be taken lightly. ”It’s a warning shot across our bow,” he told NPR. “We are flying around the solar system in a shooting gallery.”
January 21, 2013
Over the weekend, the Sun moved into the constellation Aquarius, blocking it from view in the night sky. Although the “Age of Aquarius” of popular culture is far off, tonight some Western Hemisphere observers will get a little bit of astronomical free love as the Jupiter–the second brightest planet in the night sky (the brightest being Venus)–kisses the Moon.
To sky watchers in most of North America, the planet and the Moon will flirt: Jupiter will be less than a finger’s width from the waxing Gibbous Moon. The time of their closest approach varies by location–observers on the East coast will see it at around 11:30 p.m. Central time stargazers should look up at around 10:00 p.m., while those in Mountain time will see Jupiter’s nearest approach to the Moon at about 8:30 p.m. Pacific time observers will catch their best view early in the evening, at roughly 7:00 p.m. The close approach can be best seen with a wide-field telescope at low magnifications (40x or lower) or binoculars, but can even be viewed with the naked eye.
From much of South America, the planet will appear touch the Moon; in some regions, the Moon will completely hide Jupiter from view. This game of hide-and-go-seek, termed occultation, will cause Jupiter to disappear and reappear from the skies over much of central South America. However, when viewed from much of the east coast of Brazil and Uruguay, the Moon will set before Jupiter reemerges.
For the past few days, Jupiter has been close to the Moon at sunset, but today, careful observers may even be able to spot Jupiter in the late afternoon, before the Sun sets. “First locate the Moon medium-high in the east; then look a few Moon-widths left or lower left of the Moon for Jupiter,” explained Tony Flanders, associate editor at Sky & Telescope magazine. “It should be easy to spot with binoculars if the air is clear,” he said in a statement.
Those with telescopes can even see Jupiter’s Great Red Spot between 9:00 p.m. and 10:40 p.m. EST today. In addition, Jupiter’s moon Europa will pass in front of Jupiter between 8:13 and 10:37 p.m. EST, although the moon’s shadow–which crosses Jupiter from 10:22 p.m. to 12:46 a.m. will be easier to spot. Have fun planet-watching!
January 3, 2013
Last year, noted meteorite collector Jay Piatek traveled to Morocco and bought a single stone, less than a pound in weight, that had been discovered in the country some time earlier. When he passed it on to researchers at the University of New Mexico to perform a mineral analysis, they found something unexpected.
The meteor seemed to have originated on Mars, but the rock’s composition didn’t exactly match any of the well-studied meteorites from there found previously. When the researchers compared it to data from soil and rock samples obtained by Curiosity and other recent Martian rovers, though, they realized that rather than originating in the planet’s mantle, as the others had, it appeared to have come from the Martian crust.
Most intriguingly, when they analyzed the basaltic breccia rock even more closely, they discovered it contained a large quantity of water molecules locked in its crystalline structure. While previous studies of Martian meteorites have suggested the presence of water on the red planet, this sample’s analysis, published today in Science, revealed that it contained 10 times more water than any Martian meteorite examined before.
The discovery of the water molecules in the rock at concentrations of 6000 parts per million could indicate the presence of liquid water sometime during Mars’ history. “The high water content could mean there was an interaction of the rocks with surface water either from volcanic magma, or from fluids from impacting comets during that time,” study co-author Andrew Steele of the Carnegie Institute said in a statement.
Apart from the presence of water, the researchers say that information they’ve gleaned over the course of a year-long analysis of the meteor—the first ever linked to the Martian crust—could significantly impact our understanding of the planet’s geology as a whole. The meteorite is primarily composed of chunks of basalt cemented together, indicating that it formed from rapidly cooling lava, likely on the planet’s crust. While we’ve found meteorites from the Moon that match this composition, we haven’t seen anything like it from Mars previously.
Already, the researchers determined that the specimen is roughly 2.1 billion years-old, formed during Mars’ Amazonian epoch, a time period from which we had no previous rock samples. “It is the richest Martian meteorite geochemically,” Steele said. “Further analyses are bound to unleash more surprises.”
December 31, 2012
NASA has big plans for manned travel in deep space. Although missions haven’t been officially announced yet, experts speculate that the agency plans to establish a space station on the far side of the moon sometime in the next decade, a stepping stone towards landing on an asteroid in 2025 and potentially trying to reach Mars sometime around 2033.
Getting to Mars, though, would require astronauts to endure a round-trip (or possibly one-way) journey that could be as long as three years—which could be particularly worrisome given the results of a study on the health effects of cosmic radiation published today in PLOS ONE. Although we’ve known for some time that the radiation experienced by space travelers could pose problems over the long term, this new study is the first to establish a link with an increased chance of Alzheimer’s disease and dementia.
The researchers, a group from NASA and the University of Rochester, came to the finding by testing a specific type of cosmic radiation—high-mass, high-charged (HZE) iron particles—on mice. This kind of radiation is of particular concern, because its high speed (a result of the force of the exploding stars it’s originally expelled from, light-years away) and large mass mean that it’s tricky to protect against.
Here on Earth, we’re largely protected from it and other types of radiation by our planet’s atmosphere and magnetic field, but even a short time in deep space means much higher levels of exposure, and we haven’t yet figured out how to construct a shield that effectively blocks it. ”Because iron particles pack a bigger wallop it is extremely difficult from an engineering perspective to effectively shield against them,” M. Kerry O’Banion, the paper’s senior author, said in a statement. “One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete.”
After producing radioactive particles that generate this type of radiation using a particle accelerator at the Brookhaven National Laboratory on Long Island, the researchers exposed the mice to varying doses of the radiation, including levels comprable to what astronauts would experience on a mission to Mars. The breed of mice they used has been the subject of numerous studies on dementia and Alzheimer’s, so scientists have a relatively good understanding of how rapidly the disease and related symptoms develop over time.
But when the researchers put the mice through a series of behavioral tests—seeing if they were capable of remembering objects or specific locations—those that had been exposed to greater levels of radiation were far more likely to fail, demonstrating signs of neurological impairment far more early in life than is typical in the breed. Additionally, autopsies of these mice revealed that their brains contained higher levels of beta amyloid, the “plaque” considered a hallmark of Alzheimer’s disease.
This result doesn’t mean we have to abandon dreams of deep space travel—or even that this kind of radiation definitively leads to accelerated neurological degeneration—but it does show that cosmic radiation is going to be a graver concern the longer space missions get. Ingenious engineering has addressed many of the difficulties of space flight, but this remains a problem to be solved.
“These findings clearly suggest that exposure to radiation in space has the potential to accelerate the development of Alzheimer’s disease,” O’Banion said. “This is yet another factor that NASA, which is clearly concerned about the health risks to its astronauts, will need to take into account as it plans future missions.”