Helioviewer.org "is an open-source project for the visualization of solar and heliospheric data. The project is funded by ESA and NASA."
See also the Wiki and the JHelioviewer application.
Go back in time to prominent events (June 7, 2011 for example), create layers from different observatories and even create your own movies.
posted by vacapinta on Apr 11, 2012 - 6 comments

Earth Faces 12% Chance of "Catastrophic Solar Megastorm" by 2020 The last gigantic solar storm, known as the Carrington Event, occurred more than 150 years ago and was the most powerful such event in recorded history. [more inside]
posted by modernnomad on Feb 29, 2012 - 75 comments

On July 5th the SOlar and Heliospheric Observatory (SOHO) captured video of a comet, known as a sungrazer, in route to collide with our star. SOHO is equipped with an occluding coronograph that blocks direct sunlight and reveals the corona, but also prevents direct study of the terminal impact of sungrazers. But on July 6th, with the help of the Solar Dynamics Observatory (SDO), astronomers were able to observe the comet (slyt) streaking in front of the surface of the sun for the first time in history. It likely disintegrated before impact due to extreme heat and radiation.
posted by troll on Jul 8, 2011 - 18 comments

NASA has released the first STEREO images of the entire sun.
Previous. Previouser. Previousest.
posted by steambadger on Feb 9, 2011 - 17 comments

Solard Death Ray: Power of 5000 suns! [SLYT] The R5800: made from an ordinary fiberglass satellite dish, it is covered in about 5800 3/8" (~1cm) mirror tiles. When properly aligned, it can generate a spot the size of a dime with an intensity of 5000 suns! This amount of power is more than enough to melt steel, vaporize aluminum, boil concrete, turn dirt into lava, and obliterate any organic material in an instant. It stands at 5'9" and is 42" across.
posted by Fizz on Jan 30, 2011 - 59 comments

One of the most enduring mysteries in solar physics is why the Sun's outer atmosphere, or corona, is millions of degrees hotter than its surface. - Now scientists believe they have discovered a major source of hot gas that replenishes the corona
posted by The Whelk on Jan 8, 2011 - 13 comments

Solar flares may be affecting radioactive decay rates
posted by Confess, Fletch on Aug 24, 2010 - 57 comments

Year On Earth breaks it down, explaining the complicated mechanics involved in trying to determine how long a year really is, why seasons and ice ages happen, and how not all years are created equal.
posted by loquacious on Jul 5, 2010 - 22 comments

"First Light" for the Solar Dynamics Observatory - researchers unveiled "First Light" images from NASA's Solar Dynamics Observatory, a space telescope designed to study the Sun.
posted by Burhanistan on Apr 21, 2010 - 42 comments

Sungazer — discover the awesome beauty of the Sun. See images of Earth sized sunspots, towering prominences, and rivers of hot gas. Then, explore the cameras, telescopes, and accessories used in solar astro photography. (previously)
posted by netbros on Jun 10, 2009 - 9 comments

Atlantis. Hubble. And a big, yellow friend. Astrophotographer Thierry Legault managed to get amazing shots of Space Shuttle Atlantis approaching the Hubble Space Telescope during a transit of the sun. [more inside]
posted by dhartung on May 15, 2009 - 46 comments

Once every month, Jews bless the moon. Once every 28 years, they bless the sun! This custom dates back to the Talmud, but is also found in other sacred Jewish texts, such as The New York Times. Sometimes, there are misunderstandings. [pdf] Previously reserved to a pious handful of observant Jews, it's on the mainstream media radar this time around, possibly because of its environmental implications. Here's an interesting depiction of the ritual in modern American history, which explicitly deals with its connection to solar power.
posted by ericbop on Apr 8, 2009 - 16 comments

Manhattanhenge
posted by 445supermag on Jul 11, 2008 - 32 comments

Sunspot activity is closely linked to climate. Although it observes an 11 and 22 year cycle, the overall trend of activity shows much longer term variations. The so-called Maunder Minimum (1645-1715) coincided with the Little Ice Age, while the Medieval Maximum coincided with the Medieval Warm Period. Analysis of beryllium isotopes from ice cores in Greenland shows that sunspot activity is currently at a 1000 year high. Could this account, at least in part, for global warming? Recent data from Mars suggests this may be so, while others remain sceptical. Bonus pix, more here.
posted by unSane on Apr 10, 2007 - 60 comments

Have you ever wondered what a solar eclipse would look like from space? The STEREO (Solar TErrestrial RElations Observatory) has just sent back its view (awe-inspiring video included). It has also sent back some gorgeous pictures of our sun (and the McNaught Comet). For more media, check out the other galleries (including some 3D images). For more about the project, see NASA's STEREO homepage. Be sure to also stop by the Johns Hopkins University STEREO Page, where you can download a mission guide (pdf), view animations, watch a video of the launch, or even make your own papercraft STEREO model (pdf). You can also learn more in six minute segments with their series of short educational videos.
posted by wander on Mar 13, 2007 - 15 comments

The Thirteen Towers of Chankillo in Peru may be the Western Hemisphere's oldest known full-service solar observatory, showing evidence of early, sophisticated Sun cults, according to archaeoastronomy professor Clive Ruggles. The 2,300-year-old complex featured 13 towers running north to south along a ridge and spread across 980 feet to form a toothed horizon that spans the solar arc. Last year, another ancient observatory was discovered in Peru by Robert Benfer. The Temple of the Fox is 4,200 years old, making it 1,900 years older than the Chankillo site, but wasn't a complete calendar.
posted by homunculus on Mar 3, 2007 - 8 comments

solar deathray
posted by philcliff on Mar 23, 2005 - 19 comments

As a sufferer of Seasonal Affective Disorder, I was interested to discover this village's proposed solution. Were they inspired by Gustav Graves, d'you think?
posted by Specklet on Jan 21, 2005 - 11 comments

Because spaceflight, in and of itself, is just way to easy. On 08 August 2001, NASA launched Genesis. It was a spacecraft that would spend 1125 days in space, including 884 days collecting 0.4 milligrams of solar particles. At that point, it would launch a 500 lbs return vehicle that would travel 600 mph back to earth. When it enters the atmosphere, at approximately 11:55am EST on Wednesday of this week, it will be going close to twenty-five thousand mph. Oddly enough, this is the easy part of the mission.

Because then, two minutes later, NASA is going to catch it. In mid-air. With a helicopter. Really.
posted by NotMyselfRightNow on Sep 7, 2004 - 32 comments

omg we're all going to die, which means the hurricanes, the war against terrorism, high school free speech... it's all a big nothing!
posted by jcterminal on Oct 2, 2002 - 46 comments

A very well designed site on the Analemma. Don't be scared off by the math, as there are excellent diagrams and quicktime movies on this difficult to visualize phenomena. Difficult, but not impossible, to photograph (probably less than 10 photos are in existence) Ulrich Bienert came close, and has a gallery and some tips if you're so inclined.
posted by quercus on Aug 6, 2002 - 12 comments

A Green Flash from the Sun - I always thought this was a myth, but if NASA says it's true... (and I believe everything I read).
posted by kokogiak on Oct 27, 2000 - 13 comments