National Aeronautics and Space Administration

This guest post by Geeked on Goddard friend, Andy Ptak, is about an exciting new X-ray astronomy mission that’s about to be launched.

What is NuSTAR?
This week NASA plans to launch its next X-ray astrophysics satellite, NuSTAR.  X-rays are where really exotic stuff in the Universe shines, like black holes, supernovae explosions (massive stars blowing themselves up) and really, really hot gas (millions of degrees or hotter).

But it is very hard to focus X-rays.  As any card-carrying astronomer would tell you, you focus X-rays in the same way you skip a rock on a lake (we risk getting our X-ray astronomer card taken away if we don’t use that analogy).  Normally an X-ray photon would go right through a mirror just like tossing a rock would splash into water.  But if it hits at a slight angle, the X-ray will bounce off.

NuSTAR will be the first satellite to focus astrophysical X-rays at highest X-ray energies, some roughly at the same energy as those used in medical X-rays.  Scientists and technicians at Goddard helped make the glass used for the NuSTAR mirrors, and several of us went up to Nevis Labs (part of Columbia University in New York) to help with the testing of the mirrors once they were completed last year.

A problem with focusing X-rays is that it means you need to keep the mirror and detector far apart, especially if you want to focus very energetic X-rays.  NuSTAR is also designed to be very inexpensive (by satellite standards) so it needs to be able to fit in a small launcher.  The solution to this is that it has a nifty extendible mast, as shown in this video.

Normally NASA engineers don’t like moving parts on satellites, because they might get stuck (the moving parts, not the engineers).  But even they would probably admit it looks cool when NuSTAR is extending its mirrors (the shiny metal-plated thingees) away from the detectors (on the main body of the spacecraft).

A technical challenge is that once extended, that mast will “flap around like a wet noodle”, as one senior NASA scientist put it. This isn’t directly because the satellite will be moving from target to target (called slewing). It’s because as NuSTAR moves in and out of the Earth’s shadow, the change in temperature of the mast will induce some motion. This motion is very slight, but enough to mess with the images that NuSTAR is taking.  To get around this a laser system is installed on NuSTAR.  The laser is attached to the mirror module and shines down near the X-ray detectors.  By tracking how the spot made by the laser moves we can track how the optics and detectors are moving relative to each other.  This might sound like a band-aid fix (because it is) but it is a lot cheaper than moving up to a larger launcher.

Waiting for Launch
Since building something like NuSTAR literally is rocket science, it is not surprising that there are occasionally launch delays.  All systems have recently passed flight readiness reviews and NuSTAR is planned for launch on June 13.  NuSTAR is going to launch from a rocket called Pegasus that is first dropped from an airplane. You can watch the launch coverage online.

Right now one of the main roles of GSFC scientists is to help test the software that will be used to analyze NuSTAR observations.  A slight silver lining to the launch delay is that it gives us more time to do this and to get more practice with simulated data.  This will put is in a better position to analyze the real data when it comes.  And with NASA satellites, once the data starts coming it really does quickly feel like drinking from a fire hose, so the more practice we have the better.

– Andy Ptak

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.

John Townsend in 2008.

John (Jack) Townsend, one of the founders of NASA’s Goddard Space Flight Center, passed away on Saturday, October 29. Among many other things, Townsend helped to develop the Vanguard satellite program, before NASA even existed. That was a long time ago, but many people are still around who worked with Townsend in those days.

Dave Schaefer is such a man. About a year ago, it was my pleasure to make the short drive to Dave’s home in the leafy outskirts of Silver Spring, Maryland. I was accompanied by NASA computer scientist James Fischer, who, like Dave, spent decades developing Goddard’s high-performance computing capabilities.

Dave Schaefer stands by the rug in his home office woven with the image of Explorer 12, a spacecraft he helped to design.

Dave was a member of the team that developed an important component of the Vanguard satellite: the telemetry system, which captured data from the satellite’s sensors, stored it temporarily, and relayed it to Earth.

Vanguard began as a program at the Naval Research Laboratory in Washington and transferred over to NASA (along with many of its personnel) after the agency was founded by the National Aeronautics and Space Act of 1958.

Vanguard was the first civilian satellite program, established for the International Geophysical year of 1957.  “Vanguard was supposed to orbit the very first artificial satellite,” Schaefer says. “It had its troubles.” Sputnik took over the honor, in October 1957, of becoming the first artificial Earth satellite.

But years before Sputnik was even a gleam in the eye of the Soviet politburo, Dave Schaefer and fellow staff scientist Robert Rochelle went to work at the Naval Research Laboratory, helping to lay the foundations for the U.S. civilian space program. That was in 1949.

Dave and Jack first met later, in 1955. It was all because of a radio broadcast heard in a car bound for Kansas. Schaefer told us the story this way:

“I was out in Kansas coming back from having taken two cousins of mine out there, on this auto trip. It was 1955, and here we had the radio on, and here there was a broadcast and it said mankind was going to do the greatest, most wonderful thing that had ever been done!” he says, raising his voice to preacher tone for dramatic emphasis.

“We were going to orbit an artificial moon. My God! And this was going to be done at a place called the Naval Research Lab. Well, I was already working at NRL on magnetic amplifiers. I had been there since March in 1949.

“Well I went to Whitney Matthews, who was my boss’s boss, whose name should show up in the annals of Vanguard, and I said to Whitney, “Why are we working on stupid magnetic amplifiers when the greatest thing that mankind has ever done is being done two buildings down?” And I slammed the door. I could have been out of a job, but I wasn’t.

“So two days later Whitney came to me, he said, “I have invited someone from the satellite project over to talk to us. His name is John Townsend. Jack is going to come over and talk to us tomorrow afternoon.”

“So he arrived and he said, ‘We need a telemetry system.’ He said if we go out commercially to get it, it will weigh 20 lbs. We need one that weighs — I think he said four pounds or something. And he didn’t say a lot more. He said to us, “You all think you can do it?”

“And of course we said yes, yes, yes! We made sure he went down to the elevator. We made sure he was on his way back to his office two buildings down. Then you know what we did? We ran to the nearest dictionary to figure out what in heaven’s name a telemetry system, was!

“He’d said I’ll be back in a week to see how you’re doing.  He was back in a week, because of our knowledge of magnetics, our group had a telemetry system operating for him.  And it only weighed 8 ounces, including the batteries. It met the specs, and in fact it used so little power we didn’t need to turn it off at all.” Schaefer says Bob Rochelle was the main person responsible for this achievement.

Dave Schaefer points to the portion of the Vanguard electronics core he helped to build in the late 1950s. This was an actual working model of the electronics package built for the Vanguard satellites.

The United States — with the help of Dave Schaefer, Bob Rochelle, Jack Townsend, and many other people — attempted 11 Vanguard launches from 1958-59. They achieved orbit three times.

The grapefruit-sized Vanguard 1, the world’s first solar-powered satellite, launched St. Patrick’s Day (March 17) 1958 weighed just 3.35 pounds. It remains the oldest artificial objects orbiting Earth to this day.  The Rochelle telemetry system flew on Vanguard 3, launched on September 18, 1959.  This satellite is slated to remain in orbit for 300 years.

That same year, 1959, Jack Townsend jumped ship to the new civilian aerospace program, NASA, and helped establish Goddard Space Flight Center, assuming the role of Assistant Director for Space Science and Satellite Applications.

The rest is history — our history at Goddard Space Flight Center, and the origins of the nation’s aerospace agency. As Schaefer wryly points out, “The Vanguard telemetry system, the results of a ‘dare’ of Jack Townsend’s, will be in space, remembering him, for 300 years.”

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.



Goddard Space Flight Center is abuzz with the impending launch of the NPP satellite. My Goddard science writer pals Aries Keck and Ellen Gray (and other Goddard folks) are encamped at Vandenberg Air Force Base in California, helping to spread the word. Here is a video feature about the mission. More video and stories and images will appear on the blog in the coming days.

Here’s the official description of the video above.

The NPP Pre-Launch Webcast looks at NASA’s upcoming NPOESS Preparatory Project (NPP) mission. NPP represents a critical first step in building the next-generation of Earth-observing satellites. The mission will test key technologies and instruments. It also will continue to gather information to continue to build on the data record from previous Earth-observing satellites. Tim Dunn and Bruce Reid of NASA’s Launch Services Program discuss preparations for the launch and NPP Project Scientist James Gleason talks about what results are expected from the spacecraft’s five unique instruments.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.

Take me to your (out of fuel) satellite!


Next week’s final launch of the space shuttle Atlantic will be bittersweet for all of us at NASA and for space fans the world over. It will be the end of something very, very big in many people’s lives, and in the life of the United States space program. Something to be proud of; something to mourn. STS-135 is an end and a beginning. I suspect there won’t be a dry eye in the house around here when she goes into orbit.

But for our part, Goddard’s going out in style. The shuttle Atlantis will deliver to the International Space Station a package of gear developed here in a fury of activity and inspiration and hard work over the past 18 months. It’s called the Robotic Refueling mission.

Tools and supporting gear bolted to the space station will, later in the year, allow astronauts operators using the Special Purpose Dexterous Manipulator (SPDM/Dextre) to explore an utterly new technology to repair or refuel satellites in orbit.

[Many thanks to NASA's Alex Janas for clarifying how the tools will be used on orbit, and by whom. Dextre, the space station's two-armed Canadian robotic "handyman," will manipulate the tools developed at Goddard. Operations will be entirely remote controlled by collaborating teams of flight controllers at Goddard Space Flight Center, Johnson Space Center, Marshall Space Flight Center,  and the Canadian Space Agency's control center in Quebec.]

The animation below says it all: NASA at its best: It seems-like-science-fiction-but-it’s-not.

On Tuesday last, gogblog tagged along on a media tour of the robotic refueling mission, led by veteran Goddard public affairs stalwart Dewayne A. Washington.

We met the brains and muscle behind the mission at the Building 7-10-15-29 complex, where many a great mission has been developed and tested. More details and photos in future posts……



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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.

Post 1: Welcome to Engineering Boot Camp
Post 2: Introducing Andy Hoffmaster & GROVER the rover



Andrew Hoffmaster and GROVER, Assateague State Park, Md.

Andrew (Andy) Hoffmaster is one of the dozens of interns working this summer in the Engineering Boot Camp at NASA’s Goddard Space Flight Center. He recently graduated from the Catholic University of America in Washington, D.C., with a degree in biomedical engineering

It’s Hoffmaster’s third year in Engineering Boot Camp. This year he has stepped up to a leadership role, supervising five different teams of interns who are working on a science robot called GROVER. In a time-honored NASA tradition, “GROVER” is a very impressive-sounding acronym: Goddard Remotely Operated Vehicle for Exploration and Research.

GROVER on the beach.

GROVER, in a nutshell, is a solar-and-wind-powered, caterpillar-tracked rover that carries a ground-penetrating radar device. It is designed to roam alone for months at a time measuring the thickness of the Central Greenland Ice Sheet, which is about the size of Texas. “The problem with sending people is that they run out of food and fuel too fast,” explains “NASA Mike” Comberiati, who runs the internship.

Someday, GROVER will crawl across frigid Greenland at up to 3 mph, 10 hours per day, for 4 months. NASA Mike and his interns are working with NASA cryosphere researchers Lora Koenig and Hans-Peter Marshall on the project. (Koenig is based at Goddard; Marshall is at Boise State University in Idaho.

GROVER being unloaded.

Hoffmaster and GROVER have spent a lot of time together, although in his first year  internship (2009), he didn’t work on GROVER at all. He designed and built the mechanical parts for a laser-scanning device on another robot, referred to as “the Mothership.” More on the Mothership in future posts, but you can take a quick look at her HERE.

GROVER 1 & 2
In his second internship season (2010), Hoffmaster started working on GROVER. He built the housing for the rover’s electronics. In January 2011, he accompanied Comberiati to McMurdo Station in Antarctica to help install and configure equipment to communicate with NOAA POES satellites.

Making tracks!

GROVER 1 (shown in the video and images in this post) weighs about 700 pounds. Its solar panels and wind turbines — the spinning blades produce power when it’s cloudy — provide ample power. It has performed admirably in testing.

But GROVER 1 is too heavy and too big, and it takes too long and too much work to unload and assemble. This summer, the interns assigned to build a better GROVER.

GROVER 2.0 will be lighter and smaller. It will sport more efficient solar panels and a lower center of gravity to resist tip-overs in gusty Greenland winds. The rover will also gain software to allow it to operate without constant human monitoring, and to uplink data via the Iridium satellite network.

Also, GROVER 2 will be fabricated in three sections to enable rapid assembly by people wearing bulky cold-weather gloves. After all, standing around in the cold in Greenland can be a health hazard!

This, and more, will require the labor of five intern teams to design, build, and test the electrical components and systems (headed by Hoffmaster) and four mechanical teams (headed by senior intern Guillermo Diaz, a student at Tec de Monterrey in Mexico). It all has to happen in about 5 weeks’ time.

Last year’s crop of interns completed construction of GROVER 1, which today sits on the front lawn of Building 25 in Goddard’s wooded east Campus. The rover will serve this year as a test bed for some of GROVER 2′s new systems.





On the beach with GROVER
It was a chilly day, April 1, 2011. Hoffmaster and three other interns drove with NASA Mike down to Assateague State Park, with GROVER on a flatbed truck. While backing GROVER down the ramps onto the beach, they paused cautiously to check the rover’s orientation.

Then something weird happened, Hoffmaster says. One of the twin caterpillar tracks switched into full reverse and tipped GROVER off the ramps and onto the sand. Thankfully, the robot was unscathed except for a piece of bent metal.

The culprit: “anomalous cold bit.” To us non-specialists, that means that because of cold temperatures, the caterpillar track’s electronic controller sent an incorrect instruction. It’s just the sort of thing that can happen during the development of new technology, and the interns will work to solve it this summer.

On the beach, GROVER proved itself, with enough traction to drag Andy across the sand. Sand, it turns out, is close enough to snow (from GROVER’s point of view) to provide a decent simulation of the rover’s performance in Greenland. They tested it until 3:30 that afternoon and headed for home.

Andy says Engineering Boot Camp gave him valuable engineering insights and skills that he will be able to apply to his new job with Aretech in Dulles, Virginia, developing physical therapy equipment for rehabilitating stroke patients. He’ll work on a device called a “body weight support gait trainer.” It’s a harness on a motorized trolley track that supports patients safely as they re-learn how to walk after brain injury. “I took what I learned at Goddard and can apply it to human kinematics.”

Post 1 of 5: Explore the sun on your desktop with Helioviewer
Post 2 of 5: Getting Started with Helioviewer.org

New interactive visualization tools developed by the NASA/European Space Agency (ESA) Helioviewer Project allow scientists and the general public to explore the growing body of high-definition images of the sun captured by solar observing spacecraft. A previous post explained the origin and aims of the Helioviewer Project. This post takes a closer look at a Web-based tool called Helioviewer.org.





When you first visit Helioviewer.org, you’ll see an orange ball. That’s the most recent image available of the sun, courtesy of NASA’s Solar Dynamics Observatory (SDO).

The Time menu
At the top left of the image window, three drop-down menus allow you to choose the time and date at which you want to observe the sun, including latest, meaning “the most recent available.”

The time is given in UTC: coordinated universal time, also known as GMT, or Greenwich Mean Time. To convert to U.S. Eastern Standard Time, subtract 5 hours from UTC (and so on).

Time-step allows you to browse solar images in steps of 1 second to 1 year.

The Images menu
When you first visit Helioviewer.org, the Images menu setting will default to the most recent SDO image available from the spacecraft’s Atmospheric Imagining Assembly (AIA) instrument at a wavelength of 304 Angstroms.

Think of it as looking at the sun through a filter that blocks out everything except the wavelengths near 304 Angstroms. The AIA has 10 such “channels. This Wikipedia article about SDO includes a helpful table showing the different channels and what temperature of solar material they correspond to.

To be more specific, the 304 Angstrom view from SDO is the energy emitted by positively charged helium atoms (He⁺) at around 60,000-80,000 degrees. In SDO images, it is commonly displayed  in a rich orange color.

Click anywhere on the title bar for AIA 304. This expands your viewing options.

The Opacity slider is a fader control, allowing you to display from zero to 100 percent of the image.

Below that, drop-down menus allow you to choose the image source by observatory/spacecraft, instrument, detector, and measurement type.

So, for example, change the measurement type from AIA 304 to AIA 171. At 171 Angstroms, you see magnetic loop structures protruding from the solar surface.

The AIA 171 captures ultraviolet light from processes on the sun occurring at more than a half-million degrees (compared to AIA 304′s 60,000 degrees).

Mixing multiple images
The real magic of Helioviewer.org starts when you click Add at the top right of the image menu area. This creates a second (or third, or fourth…) image.

You can use these menus to seamlessly overlay and combine multiple images of the same solar image captured in different wavelengths by SOHO and SDO.

To do it, call up multiple images at different wavelengths and then use the Opacity sliders to meld the images together by altering their relative brightnesses.

The really cool thing is that Helioviewer.org (and JHelioviewer) allow you to visualize a process happening on the sun in different ways (by overlaying images from different instruments). Or you can explore the relationship between different processes happening at different times.

Making time-lapse videos
Click Movie at the top right of the image window to create a time-lapse video of the sun’s surface. The default setting will create a video covering 24 hours, centered on the current observation time.

Alternatively, you can click Settings above the image window to make a video with duration of 3 hours to 1 week.

Under normal traffic conditions, it will take a minute or two to generate the video. But as more users call on this service, the wait times increase. In fact, in the days following the June 7 prominence eruption, the demand for video was so great that the Helioviewer Project had to literally erase the queue of requests as they stretched into days.

A pop up window will let you know when the video is ready. You will have the option of either downloading a copy or sharing it to YouTube.

The Recently shared window shows you a video recently uploaded by someone to YouTube,

Other sharing features
The Link and Screenshot features also allow you to share or store images or combinations of images created using Helioviewer.org.

Tomorrow: Explore solar images and video in depth with JHelioviewer.

LEARN MORE

Helioviewer.org (Web app)

A collection of video highlights from 2011 (so far) created by Helioviewer.org users.

See a Helioviewer.org video made by “citizen scientist” LudzikLegoTechnics on YouTube.

The Helioviewer Project Wiki:

JHelioviewer (downloadable software)

Read a Web feature about JHelioviewer and its capabilities

The JHelioviewer online handbook

JHelioviewer video tutorial on YouTube HD

ESA Web feature about JHelioviewer.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.


Have you heard about the NASA Earth science video contest?

We’re asking you to share with us your inspiring vision about what NASA’s exploration of Earth means to you by producing a short video. The contest runs through May 27.

When I heard about the contest, I wondered what kind of video I would make (were I not an employee of said contest sponsor). Nothing much came to mind.

Then the other night a weird association flashed into my head: Jacques-Yves Cousteau, NASA of the sea, exploring, documenting, and studying the “inner space” beneath the waves the way our nation’s aerospace agency explores, documents, and studies Earth from outer space.

I know, it sounds crazy, but stick with it for a minute.

First of all, for anyone reading this who has no clue who I am talking about when I say “Jacques-Yves Cousteau” and wonders if he is yet another combative F-bomb slinging TV chef, check out this lighthearted and trivia-packed video biography of the French film maker and adventurer on RocketBoom.com.

Now, back to the contest:

The NASA earth video contest asks the following: Produce a short video that captures what you find inspiring and important about the unique view of Earth and understanding about how our planet works that NASA science provides.

Jacques-Yves Cousteau


First, what is inspiring? I learned about that on TV.

My father was a documentary junkie, so my brothers and I grew up watching “The Undersea World of Jacques Cousteau,” which ran for eight seasons starting in 1968. None other than Rod Serling, the “Twightlight Zone” man, narrated most of the specials.

Cousteau had won early fame in film, most notably with “The Silent World,” co-directed with Louis Malle and winner of a 1956 Academy Award and the Palme d’Or award at the 1956 Cannes Film Festival.

If you watch “The Undersea World” now, it feels dated, unfamiliar. It could occasionally slip into pomposity, with wordy and somewhat high-falutin’ rhetorical flourishes in Cousteau’s distinctive French accent like “the rapture of the deep that puts to sleep the instinct of conservation.” Huh?

And there was the pretend-danger-drama stuff written into the narrative: For example, check out the scene in Cousteau’s Antarctica programs in which deck hands in motorized dinghies desperately pole-push chunks of floating ice away from the Calypso’s massive steel hull. (The thing was a converted mine sweeper!)

Of course, Jacques often breaks in to remind us we are about to see something “never before filmed in its natural environment.” Be still my 9-year-old heart!

But it was magic. Cousteau showed us the secret places still hidden under the sea, the places we had never been, and could never go. He took us along with him to visit places that remain, to most of us, utterly inaccessible. In this sense, Cousteau was the NASA of the sea — at least on TV! — revealing the wonders of the home planet and the wider universe.

NASA’s satellite fleet does most of the heavy lifting of data collection on the home planet these days, although numerous field expeditions also make important contributions. The satellites see the Planet, on the scale of oceans of water and air, pulsing with life and energy.

It is a perspective on the planet that does not quite trigger the same emotions as swimming with whales, cavorting with penguins, or stalking ravenous predatory fishes in the Amazon River.

But Cousteau and NASA have both frequently delivered the same sense of wonder about the beauty and complexity of the planet, and showed us how all its wheels-within-wheels-within-wheels of life, air, soil, and water have to turn together to keep it all functioning properly.

So make a video about Earth and NASA, and make sure to listen to your inner Cousteau. Better yet, go to YouTube and watch some of his work for inspiration. It may put you in the right frame of mind for a sense of wonder.

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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.

The website for NASA’s Solar Dynamics Observatory here at Goddard has a really cool feature called Pick of the Week. Starting on May 21 last year, shortly after SDO saw first light, the curators of Pick of the Week have chosen an image to feature, whether for its scientific interest of sheer drama or beauty. Here is a slide show of the pick-of-the-week images from SDO’s first year.

Steele Hill, SOHO/STEREO/SDO Media Specialist here at Goddard, chooses the pick-of-the-week images, researches the science, writes the captions, and posts the content online. These images are often displayed at science centers and museums across the country.





AND DON”T FORGET to pick your favorite video for the SDO First Light Anniversary Video Contest. Choose from 10 different videos released over the past year.



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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.

Here is the sun at 1.50am on 15th February 2011 using composite data of the Sun’s surface from two of SDO’s instruments. The cutout region shows (bottom right) the five rotating sunspots of the active region (AR 11158), and (top right) the bright release of light from the X class flare.



Back around February 14, you might have seen some images and movie clips from NASA about the massive “Valentine’s Day” solar flare. Today, researchers at the University of Central Lancashire are presenting new observations of that giant flare that they made using NASA’s Solar Dynamics Observatory.

Their conclusion: the flare was spawned by interactions between five rotating sunspots, according to research presented today at the Royal Astronomical Society (RAS) National Astronomy Meeting in Llandudno, Wales.

A press release from the RAS explains it this way:

“Sunspots are features where magnetic field generated in the Sun’s interior pushes through the surface and into the atmosphere,” said Dr Brown. “Twisting the Sun’s magnetic field is like twisting an elastic band. At first you store energy in the elastic, but if you twist too much the elastic band snaps, releasing the stored energy. Similarly, rotating sunspots store energy in the Sun’s atmospheric magnetic field. If they twist too much, the magnetic field breaks releasing energy in a flash of light and heat which makes up the solar flare.”




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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we’re at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.

UPDATE MARCH 4: Sadly, Glory launched this morning but did not reach orbit because the payload faring did not separate. The faring protects and encloses the satellite during launch and initial ascent. With this extra weight onboard, the launch system was unable to reach orbit and landed in the ocean. Condolences to the mission team that spent years designing and building the ill-fated Glory spacecraft.




To learn anything, you first need to know what you don't know. Let's call them the "known unknowns."

In climate science, one of the thorniest known unknowns is the impact of aerosols, microscopic particles that drift in the atmosphere absorbing and reflecting energy, and tweaking clouds. My colleague Adam Voiland — Goddard Space Flight Center's chronicler of all things aerosol — explained it this way in one of his many fine web features and press releases on the topic:

"The particles can directly influence climate by reflecting or absorbing the sun's radiation. In broad terms, this means bright-colored or translucent aerosols, such as sulfates and sea salt aerosols, tend to reflect radiation back towards space and cause cooling. In contrast, darker aerosols, such as black carbon and other types of carbonaceous particles, can absorb significant amounts of light and contribute to atmospheric warming."



The Glory mission, which is scheduled to go into orbit this week, will attempt a much better understanding of aerosols and — climatologists hope — lead to needed improvements in the computer simulations that predict where earth's climate is heading in the coming decades.

But for my part, the Glory mission actually takes me back a decade or so, to the mid-1990s when I worked for a now-defunct science magazine called Earth. The UN's Intergovernmental Panel on Climate Change (IPCC) had, in 1995, published its Second Assessment Report. Using a newfangled thingie called the World Wide Web, science reporters eagerly poured over the IPCC report's many hundreds of pages, trying to make sense of it all.

One issue that stood out was — you guessed it — the role of aerosols in global climate change. Here's what the panel authors said on page 525 of a portion of the IPCC report, Working Group I: The Science of Climate Change.

"Atmospheric aerosols (Chapter 2) also play an important role in the Earth's radiative budget. There are fairly reliable estimates of the amount of sulphur burned but these do not translate directly into number density of aerosols, for which the size, hygroscopic and optical properties, as well as their vertical, horizontal and temporal distributions, have not been well observed."



Allow me to translate: It's saying that we know how much sulfur-containing fuels we burn (coal, for example), which produces sulfate particles that have a cooling effect on climate; but that doesn't tell us how much of this aerosol is produced, how much energy it reflects, and where it is.

And on page 526, the report tells us why we should care about aerosols, from a practical point of view:

Thus, at present the uncertainty in aerosol radiative forcing is the largest source of uncertainty in the total radiative forcing of climate over the past industrial period. Since aerosols are very patchy in their distribution, they could create significant regional climate changes regardless of their effect on globally averaged forcing.



{If you have a lot of time on your hands or need something very heavy to hold doors open, download and print Working Group I: The Science of Climate Change by clicking HERE.}

So here is the punchline for this week: Glory will provide data needed to help resolve uncertainties about aerosols and climate. The hope is that computer models will be able to make better predictions of where Earth's climate is heading.

If you want to learn more, here is a series of recent videos about the Glory mission. And don't miss this and this web feature about Glory, by Adam Voiland.





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OH AND DID I MENTION? All opinions and opinionlike objects in this blog are mine alone and NOT those of NASA or Goddard Space Flight Center. And while we're at it, links to websites posted on this blog do not imply endorsement of those websites by NASA.