Artist's impression of cosmic rays striking Earth (Simon Swordy/University of Chicago, NASA)
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When a moderate-sized M-class flare erupted from the Sun on May 17, it sent out a barrage of high-energy solar particles that belied its initial intensity. These particles traveled at nearly the speed of light, crossing the 93 million miles between the Sun and Earth in a mere 20 minutes and impacting our atmosphere, causing cascades of neutrons to reach the ground — a rare event known as a ground level enhancement, or GLE.
The first such event since 2006, the GLE was recorded by a joint Russian/Italian spacecraft called PAMELA and is an indicator that the peak of solar maximum is on the way.
The PAMELA spacecraft — which stands for Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics — is designed to detect high-energy cosmic rays streaming in from intergalactic space. But on May 17, scientists from NASA’s Goddard Space Flight Center convinced the Russian team in charge of PAMELA to grab data from the solar event occurring much closer to home.
This graph shows the neutrons detected by a neutron detector at the University of Oulu in Finland from May 16 through May 18, 2012. (University of Oulu/NASA's Integrated Space Weather Analysis System)
The result: the first observations from space of the solar particles that trigger the neutron storms that make up a GLE. Scientists hope to use the data to learn more about how GLEs are created, and why the May 17 “moderate” solar flare ended up making one.
“Usually we would expect this kind of ground level enhancement from a giant coronal mass ejection or a big X-class flare,” said Georgia de Nolfo, a space scientist at NASA’s Goddard Space Flight Center. “So not only are we really excited that we were able to observe these particularly high energy particles from space, but we also have a scientific puzzle to solve.”
Fewer than 100 GLEs have been recorded in the last 70 years, with the most powerful having occurred on February 23, 1956. Like most energetic solar outbursts, GLEs can have disruptive effects on sensitive electronics in orbit as well as on the ground, and based on recent studies may even have adverse effects on cellular systems and development.
The M-class flare from AR 1476 on May 17, 2012 (at right) Courtesy NASA/SDO and the AIA science team.
A Digital filtergram of a prominence on the Sun, May 29, 2012. Credit: Monty Leventhal, OAM.
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This unusual prominence on the Sun looks like an exhaust-spewing smokestack. It was captured by noted Australian amateur astronomer Monty Leventhal on May 29, 2012. He used a Canon 600D camera with a Hydrogen-alpha filter and a Meade S.C. 10 inch telescope.
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his is a view of the moon transiting, or passing in front of, the Sun as seen from the STEREO-B spacecraft on Feb. 25, 2007. The Sun is in false color, and the moon appears as a black disk on the upper right. NASA's STEREO mission consists of two spacecraft launched in October, 2006 to study solar storms. Credit: NASA
With the Moon as the most prominent object in the night sky and a major source of an invisible pull that creates ocean tides, many ancient cultures thought it could also affect our health or state of mind – the word “lunacy” has its origin in this belief. Now, a powerful combination of spacecraft and computer simulations is revealing that the moon does indeed have a far-reaching, invisible influence – not on us, but on the Sun, or more specifically, the solar wind.
The solar wind is a thin stream of electrically conducting gas called plasma that’s constantly blown off the surface of the Sun in all directions at around a million miles per hour. When a particularly fast, dense or turbulent solar wind strikes Earth’s magnetic field, it can generate magnetic and radiation storms that are capable of disrupting satellites, power grids, and communication systems. The magnetic “bubble” surrounding Earth also pushes back on the solar wind, creating a bow shock tens of thousands of miles across over the day side of Earth where the solar wind slams into the magnetic field and abruptly slows from supersonic to subsonic speed.
Unlike Earth, the Moon is not surrounded by a global magnetic field. “It was thought that the solar wind crashes into the lunar surface without any warning or ‘push back’ on the solar wind,” says Dr. Andrew Poppe of the University of California, Berkeley. Recently, however, an international fleet of lunar-orbiting spacecraft has detected signs of the Moon’s presence “upstream” in the solar wind. “We’ve seen electron beams and ion fountains over the Moon’s day side,” says Dr. Jasper Halekas, also of the University of California, Berkeley.
These phenomena have been seen as far as 10,000 kilometers (6,214 miles) above the Moon and generate a kind of turbulence in the solar wind ahead of the Moon, causing subtle changes in the solar wind’s direction and density. The electron beams were first seen by NASA’s Lunar Prospector mission, while the Japanese Kaguya mission, the Chinese Chang’e mission, and the Indian Chandrayaan mission all saw ion plumes at low altitudes. NASA’s ARTEMIS mission has now also seen both the electron beams and the ion plumes, plus newly identified electromagnetic and electrostatic waves in the plasma ahead of the Moon, at much greater distances from the moon. “With ARTEMIS, we can see the plasma ring and wiggle a bit, surprisingly far away from the Moon,” says Halekas. ARTEMIS stands for “Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun”.
This is an artist's concept of the Earth's global magnetic field, with the bow shock. Earth is in the middle of the image, surrounded by its magnetic field, represented by purple lines. The bow shock is the blue crescent on the right. Many energetic particles in the solar wind, represented in gold, are deflected by Earth's magnetic "shield". Credit: Walt Feimer (HTSI)/NASA/Goddard Space Flight Center Conceptual Image Lab
“An upstream turbulent region called the ‘foreshock’ has long been known to exist ahead of the Earth’s bow shock, but the discovery of a similar turbulent layer at the moon is a surprise,” said Dr. William Farrell of NASA’s Goddard Space Flight Center in Greenbelt, Md. Farrell is lead of the NASA Lunar Science Institute’s Dynamic Response of the Environment At the Moon (DREAM) lunar science center, which contributed to the research.
Computer simulations help explain these observations by showing that a complex electric field near the lunar surface is generated by sunlight and the flow of the solar wind. The simulation reveals this electric field can generate electron beams by accelerating electrons blasted from surface material by solar ultraviolet light. Also, related simulations show that when ions in the solar wind collide with ancient, “fossil” magnetic fields in certain areas on the lunar surface, they are reflected back into space in a diffuse, fountain-shaped pattern. These ions are mostly the positively charged ions (protons) of hydrogen atoms, the most common element in the solar wind.
“It’s remarkable that electric and magnetic fields within just a few meters (yards) of the lunar surface can cause the turbulence we see thousands of kilometers away,” says Poppe. When exposed to solar winds, other moons and asteroids in the solar system should have this turbulent layer over their day sides as well, according to the team.
“Discovering more about this layer will enhance our understanding of the Moon and potentially other bodies because it allows information about conditions very near the surface to propagate to great distances, so a spacecraft will gain the ability to virtually explore close to these objects when it’s actually far away,” said Halekas.
The research is described in a series of six papers recently published by Poppe, Halekas, and their colleagues at NASA Goddard, U.C. Berkeley, U.C. Los Angeles, and the University of Colorado at Boulder in Geophysical Research Letters and the Journal of Geophysical Research. The research was funded by NASA’s Lunar Science Institute, which is managed at NASA’s Ames Research Center, Moffett Field, Calif., and oversees the DREAM lunar science center.
The University of Strathclyde's Dr. Massimiliano Vasile with a prototype of a SAM module
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The dream of clean, consistent and renewable space solar power may become a reality, thanks to new research being done at The University of Strathclyde in Glasgow, Scotland.
The concept of space solar power — gathering solar energy with satellites in low-Earth orbit and “beaming” it down to collection stations on the ground — has been around for decades, but technology restrictions and prohibitive costs have kept it in the R&D phases, with some doubting that it will ever happen at all.
Now, researcher Dr. Massimiliano Vasile, of the University of Strathclyde’s Department of Mechanical and Aerospace Engineering, has announced his team’s development of modular devices that could be used to gather solar energy in orbit, working atop an experimental “space web” structure developed by graduate students at the university’s Department of Mechanical and Aerospace Engineering.
“By using either microwaves or lasers we would be able to beam the energy back down to earth, directly to specific areas. This would provide a reliable, quality source of energy and would remove the need for storing energy coming from renewable sources on ground as it would provide a constant delivery of solar energy.”
– Dr. Massimiliano Vasile, University of Strathclyde
The web structure, part of an experiment called Suaineadh — which means “twisting” in Scottish Gaelic (and I believe it’s pronounced soo-in-ade but correct me if I’m wrong) — is made of a central hub that would go into orbit and release a square web of material that’s weighted at the corners. The whole apparatus would spin, keeping its shape via centrifugal force and providing a firm structure that other devices could build upon and attach to.
The Suaineadh experiment was successfully launched on March 19 aboard a Swedish sounding rocket and while it appears that the components worked as expected, communication was lost after ejection. As a result the central hub — with all its data — couldn’t be located after landing. A recovery mission is planned for this summer.
Meanwhile, Dr. Vasile is still confident that his team’s space solar project, called SAM, can help provide space solar power to remote locations.
A single inflatable SAM cell (M. Vasile)
“The current project, called SAM (Self-inflating Adaptable Membrane) will test the deployment of an ultra light cellular structure that can change shape once deployed,” Dr. Vasile explains. “The structure is made of cells that are self-inflating in vacuum and can change their volume independently through nanopumps.
“The independent control of the cells would allow us to morph the structure into a solar concentrator to collect the sunlight and project it on solar arrays. The same structure can be used to build large space systems by assembling thousands of small individual units.”
By collecting solar energy in space, where the constraints of day and night or weather variability are nonexistent, the satellites could ultimately beam clean energy down to otherwise off-the-grid locales.
“In areas like the Sahara desert where quality solar power can be captured, it becomes very difficult to transport this energy to areas where it can be used,” says Dr. Vasile. “However, our research is focusing on how we can remove this obstacle and use space based solar power to target difficult to reach areas.
“By using either microwaves or lasers we would be able to beam the energy back down to earth, directly to specific areas. This would provide a reliable, quality source of energy and would remove the need for storing energy coming from renewable sources on ground as it would provide a constant delivery of solar energy.”
If successful, the Suaineadh/SAM project could develop into a source of renewable energy for not only small, remote locations but also neighborhoods, towns and perhaps even entire cities.
“Initially, smaller satellites will be able to generate enough energy for a small village but we have the aim, and indeed the technology available, to one day put a large enough structure in space that could gather energy that would be capable of powering a large city,” Dr. Vasile says.
Read more on the University of Strathclyde Glasgow’s site here.
Image credits: The University of Strathclyde. The project is part of a NASA Institute for Advanced Concepts (NIAC) study.
An active region on the Sun, processed in an unusual -- and accidental -- process. Credit: NASA/Goddard Space Flight Center.
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Images and video from the Solar Dynamics Observatory have shown us that the fury of the Sun can be mesmerizingly beautiful. SDO has allowed us to see loops of plasma in various wavelengths, coils of magnetic fields that are invisible to human eyes, and so much more. And then, sometimes, happy accidents happen, creating beautiful images just for beauty’s sake. The teams at Goddard Space Flight Center’s Multimedia Center are wizards at honing SDO’s raw data into works of art, and video producer Scott Wiessinger sent a note today to say he accidentally happened across a “really neat Photoshop effect,” that while not really useful scientifically, is rather beautiful and fun to watch. “There isn’t any science behind this video, it’s just a nice ‘moment of zen,’” he said.
The video is below.
The lead image shows one of the original frames in the 171 Angstrom wavelength of extreme ultraviolet, with the additional processing. This wavelength shows plasma in the corona that is around 600,000 Kelvin. The loops represent plasma held in place by magnetic fields. They are concentrated in “active regions” where the magnetic fields are the strongest. These active regions usually appear in visible light as sunspots.
So, enjoy a little contemplative moment courtesy of the Goddard team:
The video shows about 24 hours of activity on September 25, 2011.
Thanks to Scott and the Goddard team for sharing their work! See more images with this unique processing at their website.
Mercury (top) and Jupiter by the LASCO C3 instrument on the SOHO spacecraft. Credit: NASA/SOHO
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Here’s a great shot from the Solar and Heliospheric Observatory (SOHO) spacecraft of Mercury (top planet) and Jupiter snuggling up together, along with the Pleiades cluster, all close to Sun, as seen from SOHO’s LASCO C3 instrument (Large Angle and Spectrometric Coronagraph). SOHO has been in space since 1995, and is a workhorse of solar observing, giving us insights into the workings of the Sun, comets and other bodies in the Solar System. Check out the SOHO website for more great images.
A series of images taken near Stockton, California, USA, between 16:34 PST, and 19:36 PST. 'I had to move a couple of times to keep it in view and by the time I got to the last picture, it was falling behind trees,' said photographer Jon Ballard.
We’ve added loads of images and videos to our eclipse gallery from last night annular solar eclipse, but this one stands on its own. An amazing timelapse video by Cory Poole was made from 700 photographs taken with a Coronado Solar Max 60 Double Stack telescope. Usually, the chromosphere can’t usually be seen due to the overwhelming brightness of the photosphere, and to see it requires special equipment. Thankfully, Poole has it: “The Telescope has a very narrow bandpass allowing you to see the chromosphere and not the much brighter photosphere below it,” Poole wrote on YouTube. Additionally, the special hydrogen alpha filter Poole used “only allows light that is created when hydrogen atoms go from the 2nd excited state to the 1st excited state.”
The chromosphere is the red circle around the outside of the Sun; its red coloring is caused by the abundance of hydrogen. Watch how the chromosphere appears along the outline of the Moon, too!
Previous "ring of fire" annular eclipse event (NASA)
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As the eclipse is happening, we’ll try to dig up every online source we can find. Here’s what we’ve got so far.
Can’t see tonight’s annular eclipse from your location? It’s ok, you can watch it here live in a feed provided by the U.S. Department of the Interior! The video (posted after the jump) will be broadcast from Petroglyph National Monument in Albuquerque, NM, beginning at 9:00 p.m. Eastern / 6:00 p.m. Pacific.
Petroglyph National Monument will be a prime location for the May 20 annular eclipse in the U.S. (NPS)
National Park Service photographers will be taking photos from many other locations as well, you can find out more on the USDOI site here.
(If the above feed is blank, they may have reached capacity. Visit the feed directly here.)
This great video created from images taken by the Solar and Heliospheric Observatory (SOHO) on May 13 and 14 show Jupiter as it comes close to the Sun (from our vantage point) in a solar conjunction. But what it really looks like is the old “Space Invaders” video game, with Jupiter marching across the screen. There’s even a couple of sungrazing comets “pewpew-ing” in like the laser cannon shots in the game, and a coronal mass ejection completes the scene as an explosion (which is actually more like “Asteroids.”) For more fun, the team who created this video at the Naval Research Laboratory’s Sungrazing Comets website takes the time to show all the different objects in the scene, which amazingly includes Callisto and Ganymede, two of Jupiter’s moons. All it needs is the funky video game background music. Continue reading “Watch Jupiter as a ‘Space Invader’”
Sunspots from today and from 65 years ago, with planet sizes for comparison.
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The short answer? Really big. The long answer? Really, really big.
The image above shows sunspot regions in comparison with the sizes of Earth and Jupiter, demonstrating the sheer enormity of these solar features.
Sunspots are regions where the Sun’s internal magnetic fields rise up through its surface layers, preventing convection from taking place and creating cooler, optically darker areas. They often occur in pairs or clusters, with individual spots corresponding to the opposite polar ends of magnetic lines.
(Read “What Are Sunspots?”)
The image on the left was acquired by NASA’s Solar Dynamics Observatory on May 11, 2012, showing Active Region 11476. The one on the right comes courtesy of the Carnegie Institution of Washington, and shows the largest sunspot ever captured on film, AR 14886. It was nearly the diameter of Jupiter — 88,846 miles (142,984 km)!
“The largest sunspots tend to occur after solar maximum and the larger sunspots tend to last longer as well,” writes SDO project scientist Dean Pesnell on the SDO is GO blog. “As we move through solar maximum in the northern hemisphere and look to the south to pick up the slack there should be plenty of sunspots to watch rotate by SDO.”
Sunspots are associated with solar flares and CMEs, which can send solar storms our way and negatively affect satellite operation and impact communications and sensitive electronics here on Earth. As we approach the peak of the current solar maximum cycle, it’s important to keep an eye — or a Solar Dynamics Observatory! — on the increasing activity of our home star.
(Image credit: NASA/SDO and the Carnegie Institution)
