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Hi, I'm Joe Gurman, I'm a solar physicist in

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the heliophysics division at NASA's Goddard Space Flight Center.

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All of the eight large planets in the solar system orbit the Sun

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in a plane that lies within a few degrees of the Earth's 

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orbital plane, the so-called ecliptic. So when we observe the Sun with a coronagraph, 

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that blocks the much brighter light from the Sun itself so we can see the faint

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corona, the Sun's hot, outermost atmosphere, we get occasional

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glimpses of planets. And in this remarkable series of

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images, we actually get to see several different planets. And also in the upper-left

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of the image, you can see the Pleiades, the star cluster. The images of the

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planets come out here looking as though they have horizontal streaks,

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because they're so bright that they overwhelm the 

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electronics in the detector that's taking this image. SOHO's 

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Extreme Ultraviolet Telescope allows us to see a variety of solar activity 

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and some of the most intense activity we saw was in the fall of 2003. 

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It was a bit of a surprise because it was a couple of years after the maximum, the 11-year

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solar activity cycle. It's a beautiful clip, and it shows what SOHO's Extreme

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Ultraviolet Telescope can do. So what we're seeing here is those same

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periods of activity in the fall of 2003, only this 

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time from SOHO's coronagraph. And you can see a sequence of events,

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so-called coronal mass ejections, launching off in all directions

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as the active region rotates across the solar 

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surface. And you also see what looks like snow on the windshield

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of a car driving through a blizzard, and that's energetic particles

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accelerated by the solar activity hitting the detectors

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on the SOHO spacecraft. 

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Prominences are cooler gas that flows along magnetic fields

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in the much hotter solar corona. And this image from 1999

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you can see the eruption of a huge prominence from a fairly high latitude 

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in the Sun, and that tells us that it's associated with new cycle

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magnetic fields and with the expulsion of twists in 

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magnetic fields from the old solar cycle. 

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Each of those approximately 11-year halves of the magnetic cycle 

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displays its own cycle of first increasing and then decreasing 

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magnetic activity, and that's reflected in the intensity 

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of extreme ultraviolet emission from gas that's trapped in 

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the magnetic field. So in this image you can see a series

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of snapshots taken one a year over 

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a solar cycle. 

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Over the course of the SOHO

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mission, we've observed over 3,000 sun-grazing comets, comets that come

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so close to the Sun that you can't see them from the Earth because the Sun basically 

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blinds Earth-bound telescopes. With SOHO's coronagraphs, we're able to track

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the comets all the way into their evaporation near the Sun.

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In late 2012, astronomers discovered 

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a comet inbound, we didn't know if it would survive its passage with the Sun or not,

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and we were able to get these measurements with SOHO's C3 coronagraph. 

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of the comet as it passed 

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in towards the Sun, and then the ghostly image of the comet continued 

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past the Sun, but it was already evaporating. 

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If you're able to catch it, and if you blink you'll miss it, you see a wave

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traveling outwards from the flare in the lower solar corona

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EIT was really good at, and in fact discovered, these waves in the very 

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lowest part of the corona that corresponded to coronal mass ejections, and we literally

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hadn't known about that before. In a coronagraph, you don't know if an event

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is heading towards you or away from you, the geometry is the same. And

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with the addition of an extreme ultraviolet image,

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that shows a wave like this, then you know that the event has occurred on

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the Earthward side of the Sun, and we may very well have some space weather in store

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in one to three days. This clip shows Comet Machholz

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which SOHO observed in 2002 as it was passing near the Sun. And 

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as the clip shows, the direction of the comet's tail, which

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is made up of electrically charged particles, changes as it passes the Sun,

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that's because the Sun's solar wind, a continual emission of plasma

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from the Sun, is pushing it outwards. 

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This shows an entire solar rotation of about 28 days. 

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In 2001, as we were ascending up to solar maximum, 

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and you'll see several events in here, and the interesting

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thing about these is how they're distributed in latitude, they're not all

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just along the horizontal axis in this series of images. 

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And that's an indication that you are reaching solar maximum. 

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During solar minimum, the much smaller number of events that happen

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all seem to come off the east or west edges of the Sun. But as you get toward

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solar maximum, the active regions are distributed all over in latitude. 

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And you get this much more active appearance. 

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[spacecraft whooshes by] [beep beep, beep beep]

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[beep beep, beep beep, beep beep]

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