Category Archives: SDO

Plasma Sheet

The Sun is pretty energetic at the end of the solar cycle. This sheet of plasma above occurred on 28 July in about the same area that sunspot AR2665 is now. That sunspot, by the way, is the same one was associated with a very powerful CME on the far side of the Sun about a week ago.

There is a short video of the plasma sheet available from NASA.

NASA – A sheet of plasma blasted out into space from just behind the edge of the sun (July 28, 2017). While some material escaped into space, a portion of it was unable to break the pull of gravity and the magnetic forces nearby and can be seen falling back to the sun. The 3.5 hours of action was captured in a wavelength of extreme ultraviolet light.

Image: NASA/GSFC/Solar Dynamics Observatory

A Large Sunspot

AND a Juno update.  First take a look at this sunspot.  The spot is named AR2665 and it is huge.  Estimates are about 120,000 km / 74,560 miles from end to end and its a configuration that is not all that stable.  If this thing were to let off a flare, it could be an M-class and would be directed straight at us likely to produce vivid auroras at the least.

The image comes from the Solar Dynamics Observatory using the onboard Helioseismic and Magnetic Imager (HMI) is one of three instruments aboard the Solar Dynamics Observatory(SDO) designed to study oscillations and the magnetic field at the solar surface. HMI observes the full solar disk at 6173 Å with a resolution of 1 arc second.

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The Juno spacecraft successfully flew over the Great Red Spot of Jupiter at a distance of only 9,000 km / 5,600 miles. Images to be released on 14 July.

Image: NASA / SDO

Solar Flares Seen From SDO

We must be getting close to the bottom of the current sunspot cycle. So far in 2017 we’ve had 27 days with no sunspots and last year (2016) we had a total of 32. Hopefully this won’t be a repeat of 2009 when we had 260 spotless days – the HF ham bands were pretty quiet!

Space Weather Coming Our Way

Here comes an active region on the sun, But don’t worry, despite way you may hear on the internet, in the grand scheme of things this region is nothing to get too excited about. I’m sort of hoping this area gets busier as it rotates around to us.

Yes, I am in need, the need to see a decent aurora, it’s been too long! An no, you should not put much stock into the “doom and gloom” sites quick to predict our imminent demise. Yeah those sites might be kind of fun to listen to/read about but remember as with a lot of things these days, enjoy it all, but take everything with a grain of salt – we’ve lived with ol’ Sol for an awfully long time.

From NASA and the SDO:
Magnetic arcs of plasma that spiraled above two active regions held their shape fairly well over 18 hours (Jan. 11-12, 2017). The charged plasma is being controlled the magnetic field lines of the active regions. The field lines become clearly visible when viewed in this wavelength of extreme ultraviolet light. Often the arches bend and twist more dynamically than the relatively stable ones seen here.

Credit: Solar Dynamics Observatory, NASA.

The 2016 Time Adjustment

I wonder if when the new year rang in if the countdown included the extra second that was added to the world clocks. Probably not and while it might not seem like much,  the time change is important to our view of the world thanks to our modern technology even if we don’t realize it.

We have added 27  “leap-seconds” to the clock since the practice started in 1972. Read more about adding leap-seconds.

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From (mostly) NASA:   On Dec. 31, 2016, official clocks around the world added a leap second just before midnight Coordinated Universal Time — which corresponds to 6:59:59 p.m. EST. NASA missions also had to make the switch, including the Solar Dynamics Observatory, or SDO, which watches the sun 24/7.

Clocks do this to keep in sync with Earth’s rotation, which gradually slows down over time. When the dinosaurs roamed Earth, for example, our globe took only 23 hours to make a complete rotation. In space, millisecond accuracy is crucial to understanding how satellites orbit.

“SDO moves about 1.9 miles every second,” said Dean Pesnell, the project scientist for SDO at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “So does every other object in orbit near SDO. We all have to use the same time to make sure our collision avoidance programs are accurate. So we all add a leap second to the end of 2016, delaying 2017 by one second.”

The leap second is also key to making sure that SDO is in sync with the Coordinated Universal Time, or UTC, used to label each of its images. SDO has a clock that counts the number of seconds since the beginning of the mission. To convert that count to UTC requires knowing just how many leap seconds have been added to Earth-bound clocks since the mission started. When the spacecraft wants to provide a time in UTC, it calls a software module that takes into consideration both the mission’s second count and the number of leap seconds — and then returns a time in UTC.

Credit: NASA/SDO

Magnetic Field Modeling

sunmagfields

We have a mostly quiet Sun these days.

The sun had just a few, small active regions for several days this week and its magnetic field reflected that state of affairs (Dec. 13-16, 2016). Solar scientists using computer-generated models are able to portray the magnetic field lines of the sun over just about any length of time. Here we can see that the overall magnetic field structure is rather symmetrical, stable and untangled. If there were many active regions, we’d see a much more chaotic field. The sun here is shown in a wavelength of extreme ultraviolet light. — Solar Dynamics Observatory, NASA.

From the looks of the current visible image of the solar disk shows an almost spotless face, there is a nice little sunspot group on the right side of the image just above the solar equator:

solardisc

The (US) National Oceanic and Atmospheric Administration (NOAA) has a great page to get a variety of up-to-date data pretty quickly: The Space Weather Enthusiasts Dashboard

Images: NOAA/NASA/SDO

Here We Go Again

An almost spotless Sun and you just know 15 and 20 meter HF propagation is going down the tubes again.  Here’s hoping the bottom of the solar cycle does not last as long as the last time.

The peak of the solar cycle wasn’t much to write home about either, just my opinion.  Oh sure we had our good periods but all in all not so good.  Funny too because the “forecasts” were for the peak to be HUGE with off the chart solar storm etc.  Didn’t happen.  I know I watch closely being an Amateur Radio operator (one who LOVES 15 meter QRP CW).

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The original caption released with this SDO image:
This week the sun was hitting its lowest level of solar activity since 2011 (Nov. 14-18, 2016) as it gradually marches toward solar minimum. This activity is usually measured by sunspot count and over the past several days the sun has been almost spotless. The sun has a pendulum-like pattern of solar cycle of activity that extends over about an 11-year period. The last peak of activity was in early 2014. At this point in time, the sunspot numbers seem to be sliding downwards faster than expected, though the solar minimum level should not occur until 2021. No doubt more and larger sunspots will inevitably appear, but we’ll just have to wait and see.

Credit: SDO/NASA

 

Long Filament on the Sun

sdosolarfiliments

sSO gives us a look at pair of unusually long filaments on the Sun.

The two most noteworthy features on the sun this week were a pair of elongated filaments (Sept. 8, 2016). The central one was twisted into the shape of an elaborate arch at the center of the sun (yellow arrows). If this were straightened out, it would extend just about across the entire sun, almost a million miles (1.6 million Km). The other, smaller filament, (white arrows) if made straight, might reach about half that distance. Still, pretty impressive. Filaments are elongated strands of plasma suspended above the sun by magnetic forces. They are notoriously unstable and often break apart within a few days. The image was made by combining three images in different wavelengths of extreme ultraviolet light.

Credit: Solar Dynamics Observatory, NASA.

SDO Coming Back Online

On 02 August 2016 the SDO was witness to a lunar transit. The moon passed between the SDO and the Sun in a transit lasting nearly an hour from 11:13 UTC until 12:08 UTC (07:13 EDT to 8:08 EDT). When the transit over the SDO did not return to science mode.

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Returning to science mode wasn’t quite as simple as I thought it would be. Two of the three instruments (the Helioseismic and Magnetic Imager, or HMI, and the Extreme Ultraviolet Variability Experiment, or EVE) were returning data two days later. The A1A instrument came back online and was returning data on 06 August.

Here’s a sample from A1A:
sdoa1a

A few more issues should be cleared up starting today according to Dean Pesnell over at the SDO blog: You Never Miss Them ‘TIl They’re Gone!

Images: SDO/NASA