A Couple Quick Updates

by Stephanie Osborn
http://www.stephanie-osborn.com

SOLAR UPDATE:
The Sun has definitely awakened for the time. (Finally.) There are currently half a dozen spot groups on the solar near side; 2571 is about to rotate to the far side, but there are also 2573-7 as well, which range from a simple single spot to a multi-spot complex.

Solar Dynamics Observatory imagery
Labeling by Solarham.com

Note how the spots tend to cluster around the equatorial region. This is pretty typical for late in a solar cycle. Sunspots tend to start out at higher latitudes, closer to the poles, then drift equatorward.

Very minor C-class flares are occurring, but there is little chance for anything stronger. A filament did lift, and this may produce a small coronal mass ejection, or CME. We're waiting on LASCO (Large Angle and Spectrometric Coronagraph, an instrument on SOHO, the Solar and Heliospheric Observatory) imagery to determine if it made a CME or not. Such CMEs tend not to be as strong as those associated with large flares, so even if it is Earth-directed, expect pretty aurorae and a few high-latitude effects, but nothing of significance.

There are some coronal holes, but they aren't "geoeffective" (aimed at Earth). Geomagnetic activity is quiet.

Solar Dynamics Observatory imagery
Labeling by Solarham.com

More data as it comes in.

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PERSEID METEOR SHOWER:
Well, the night of August 11/12 was the absolute peak of the Perseids. I've just come in from spending about 20 minutes outside, having a look. (It's currently 4am local time.)

I have to say that I was underwhelmed, especially given the hype given to the predictions of "up to 200 meteors/hour." That comes out to be over 3 meteors per minute, or about one meteor every 15-20 seconds. So in 20 minutes, I should have seen around 66 meteors.

I saw about 1/10 that.

Now, granted, I'm in a subdivision and my skies are not the darkest. And we had some light patchy clouds moving through. But  I waited until after the moon had set before I went out, to have the darkest possible skies for my location. And I picked the clearest patches of sky to observe, and ensured I blocked any light sources. Keep in mind that I've observed this shower from this location numerous times before, as well, so I know what I'm looking for. And I've seen the Perseids storm, the year after the parent comet, Swift-Tuttle, came through -- both from a rural dark-sky site, and my yard, where I was tonight.

 

Bill Cooke, NASA Meteoroid Environment Office,
Huntsville, AL
August 10, 2009

I undoubtedly would have seen more meteors had I been in a dark-sky site. But ten times more? Really?

It's possible, also, that I simply picked a time when, coincidentally, we were going through a sparse patch -- I was busy writing, and lost track of time, or I'd have been out there earlier, for longer. I'll be interested to see what other observers have to say.

As for me -- I love the Perseids; they're gorgeous, bright fireball meteors. But this didn't come anywhere close to the spectacle I remember right after Swift-Tuttle came through. That was one I'll always remember. Tonight, not so much.

If you were out observing the Perseids, I'd love to hear your observations in the comments.

* * *

BOOK RECOMMENDATIONS:

For more information on solar activity, check out my ebook, The Weather Out There Is Frightful: Solar/Space Weather and What It Means for the Earth and You.










Just a quick promo for me and my fellow scientists, for those of you who are interested in such things: A new anthology will be released in September (we hope!) called Science Fiction By Scientists. Every short story in it is "hard SF" written by an actual scientist, along with a quick primer at the end of each story on the science involved. It's available for preorder now!


~Stephanie Osborn
http://www.stephanie-osborn.com

The Perseid Meteor Shower and Other Stuff

by Stephanie Osborn
http://www.stephanie-osborn.com

FYI, there's a lot of hullaballoo about the Perseid meteor shower this year. Here's a little tidbit to explain why.

http://www.sciencealert.com/guys-the-perseid-meteor-shower-is-here-and-it-s-going-to-be-twice-as-good-this-year

Meteor showers are actually the debris left behind by comets. The tails blown off by the Sun form tiny particles in the swath of the parent comet's orbit, and when the Earth passes through it, the debris we run into flashes through the atmosphere and burns up, producing meteors. Most of these bits are the size of dust and sand; occasionally one is pebble-sized, which will be very bright.

This is why meteor showers are so predictable: we encounter the same orbital path each year, and go through the thickest part on the same day. If the parent comet has been through recently, there is a fresh, dense deposit of debris, and the shower will be especially good.

The radiant of this shower is the constellation Perseus; that is to say, all the meteors of the shower appear to be emerging from Perseus, radiating out and away from it. But the meteors have nothing to do with Perseus. Instead, we are seeing a kind of optical illusion. Imagine that you are in a car at night, headlights on, driving through a snowstorm. As the snowflakes enter the headlights and you move through them, they appear to radiate from a point in front of the car, seeming to move out from that point and around the car. This is the same effect; it is produced by the Earth moving through the meteoric debris.

So it will be easier to see the meteors if we are metaphorically on the hood of our planet-car than on the trunk! So it is better to observe meteor showers after midnight, because we are now on the forward-facing side in our orbit. The best observing times are from around 2 or 3am until near dawn.

Facing the radiant is not the best way to see lots of meteors, because the trails will be short: the meteors are moving right at you, and the trails will be short and quick. If you look away from it, the meteors are passing by you, and they will have long trails and last longer. So the best way to look is to turn, so your shoulder is pointing at the radiant, or even put your back to it and watch one large region of sky. Then you will see meteors entering the atmosphere at shallower angles, and they will have longer tracks, with more chance to spot them.

FWIW, meteor showers are not hard-edged things. Yes, the shower will have already started, but it is early stages yet, and they won't be very frequent. Your best bet for seeing meteors is a few days either side of the peak, which will occur the night of August 11/12. Also you want to go out AFTER MIDNIGHT. This is because you will now be on the forward-facing hemisphere relative to our orbit.

Wear comfortable clothes, and even in summertime, make sure you have a jacket; it can get rather cool in the wee small hours of the night. You'll be there for a while, so think about a chair, a blanket on the ground, or the like. My preference is for a chaise lounge, because it holds me in a comfortable position for watching the sky. A lap throw or similar blanket might be nice, too, depending on the weather where you are. (If you're in the Southern Hemisphere, it'll be de rigueur. It IS winter down there, after all, Summer Olympics in Rio notwithstanding.)

DO NOT FACE the radiant; this almost guarantees you'll see little to nothing. That's because you're looking right into the direction we're going, so meteor tracks will appear short and swift.

On the night of the peak (and for several days fore and aft), Perseus will be in the northeast. Turn so that your shoulder, or even your back, faces northeast, and survey a large area of the sky looking any direction BUT northeast, and give yourself at least an hour to observe. You should see some nice meteors in that time, especially this year.

Now, according to predictions, the Perseids MAY double their normal rate. But I never say an astronomical event like this ABSOLUTELY WILL do a thing. Because there are no guarantees. Yes, Jupiter may tweak the orbit of the debris so we do plow through the center of it -- but the part we plow through might just be unusually sparse, so it makes no difference.

FYI, I have never heard of the meteors from showers making impact. This is because they are the debris left behind from comets, "dirty snowballs" whose ice has sublimated via solar radiation. All that's left is particulates ranging largely from dust up to grains of sand. Rarely you get something pebble-sized. It all burns up in the upper reaches of the atmosphere, and nothing much gets lower than around 60mi. (Regular meteors can get as low as 50mi. Some get as low as 40. It depends on the speed of the meteor. Perseids usually are gone by a 60mi. altitude.)

SOLAR UPDATE: Sometime between Thursday and Friday, a couple of new sunspot groups formed on the solar near side, 2571 and 2572. They began rather unimpressively, but are now rather reasonable sunspot groups. However, the more active of the two groups, 2572, will be rotating off the west edge to the far side in the next couple of days.

It's a little hard to determine what's going on with the solar far side right now; one of the twin STEREO spacecraft, STEREO Behind, has experienced a "transient hit" -- meaning that the electronics likely took a charged particle hit. Instrument recovery is in work now. The STEREO Ahead craft appears to indicate 2-3 large spot groups may be about to rotate to the near side.

The outflow from a large, oblong coronal hole has enhanced the solar wind in the last few days, resulting in an unsettled geomagnetic field. Another one will swing around into a 'geoeffective' (Earth-directed) position in a few more days, possibly producing more minor geomag storming. I'll post if it does.

ADDENDUM:
Just a quick promo for me and my fellow scientists, for those of you who are interested in such things: A new anthology will be released in September (we hope!) called Science Fiction By Scientists. Every short story in it is "hard SF" written by an actual scientist, along with a quick primer at the end of each story on the science involved. It's available for preorder now!

~Stephanie Osborn
http://www.stephanie-osborn.com

Throw-Back Thursday: Some Quick Look-Backs and Current Updates

by Stephanie Osborn
http://www.stephanie-osborn.com


Okay, folks, just a quick look into the past for those of you interested; this whole concept started off when a fellow author named Sarah Hoyt asked me to guest-blog for her about solar activity. Since then, she asked me back, so I have two posts on her blog about solar activity, one of which is only a few weeks old. Rather than re-post the whole thing here, I am simply going to link to her blog, to the particular articles in question.

So here's the first one, with lots of background info. It was first posted in May of 2015.
https://accordingtohoyt.com/2015/05/30/solar-space-and-terrestrial-weather-some-reflections-by-stephanie-osborn/

And here is the second one, which was posted in early July 2016.
https://accordingtohoyt.com/2016/07/15/here-spot-cmere-spot-by-stephanie-osborn/

I still get notifications on these from Sarah's blog, and will answer if you have questions, so feel free to post questions or comments, here or there, or in the Osborn Cosmic Weather Report group on Facebook.

For those who want even more information, I strongly recommend picking up my ebook, The Weather Out There Is Frightful: Solar/Space Weather and What It Means for the Earth and You. It's written by a professional astronomer (me) trained in spotted variable star science, for lay people with little to no science background.

CURRENT SOLAR UPDATE: As of this writing (early 4 Aug) we are currently in our fourth consecutive day of no visible sunspots on the near side. This is the fourth group of spotless days since June 1st. The total number of spotless days since that date currently totals 24 out of 64, or 37.5%. If we add in the days with only a tiny, short-lived spot group in that same time frame, we add in 9 more days, or 33 out of 64, at 51.6%.

A visible-light image of the Sun, taken by the Solar Dynamics Observatory on August 2, 2016, depicting a lack of sunspots on the solar near side.

~~~

HOUSEKEEPING NOTE: Oh, by the way, abusive comments and/or argumentative comments will be moderated on the Comet Tales blog and in the Facebook group. And I reserve the right not to answer such posts on Sarah's blog. I don't put up with trolling. I have better things to do with my time.

~Stephanie Osborn
http://www.stephanie-osborn.com

Solar/Geomagnetic Activity!

by Stephanie Osborn
http://www.stephanie-osborn.com

HEADS UP, SPACE FANS!

Earth is currently experiencing a GEOMAGNETIC STORM! These occur when a sudden influx of plasma (a gas cloud of charged particles) enters Earth's magnetic field from outside, most often from solar activity (a coronal mass ejection aka CME, or an enhanced wind stream from a coronal hole). They can be mild, strong, or severe, depending upon how dense the plasma cloud is.

Okay, for those of you just tuning in, let's work on explaining some terms.

~~~

      We are also sitting inside the atmosphere of the Sun, which is called the corona. Yes, we are, even at 93 million miles distant. It generates a wind, usually coming out from the Sun and spiraling away – yeah, the “solar wind.” Granted, the corona isn't very dense, but it's dense enough to create some effects, and we're working on using it to our benefit, like in solar sails and such, which can use the solar wind as much as light pressure (different topic) to maneuver around the Solar System like the spaceborne clipper ships of old. 

      But when the Sun gets... agitated, we'll say... the solar wind can get a lot denser. Coronal holes tend to move gradually from the poles down to lower latitudes, and the Sun's face develops an astronomical case of acne. This usually occurs around the time of solar maximum.

~The Weather Out There Is Frightful, Stephanie Osborn, ©2011

~~~

Now, a coronal hole is just a place in the magnetic field where the field lines stretch out to infinity, rather than looping back around, like the poles of a bar magnet. That means that the plasma can channel outward along those field lines, deep into the solar system.

This is an image of the inner corona of the Sun, taken by the Solar Dynamics Observatory on August 2, 2016, at a wavelength of 211 Angstroms. The dark regions are the coronal holes, which show up nicely at this spectral region.

If Earth happens to run into one of these "enhanced solar wind streams," as they're called, if it's strong enough, it slams into our magnetic field like a bow wave from a ship. This compressed the magnetic field on the sunward side, and stretches out the "tail" on the anti-sunward side. If the tail is stretched enough, it can snap off, and "magnetic reconnection" occurs, when the field lines reattach closer in. But magnetic reattachment itself generates a HUGE surge of energy, which is fed back into Earth along our own poles.

~~~

      So what are the effects of coronal hole winds and Coronal Mass Ejections (CMEs)? 

      They can actually raise the temperature of the outer layers of the Earth's atmosphere (the thermosphere, aptly named) sufficient to cause it to expand. This affects us, because that increases drag on satellites and spacecraft, and can cause the orbits of satellites to decay and re-enter well before they were intended... 

     Disruption of the Earth's magnetic field can be a problem. It can disrupt radio communication (including cell phones) rather severely. It can damage satellites that remain in orbit. It can generate “induced current” in any lengthy conductor...And it causes the aurorae. Most of you reading this have heard of the Northern Lights, properly termed the Aurora Borealis, but there are also the Southern Lights, the Aurora Australis. These are actually ovals that circle the magnetic poles of Earth (and most other planets with magnetic fields, by the way. They've been photographed on Jupiter.) They are where the charged particles that have been caught up from the solar wind or CME into the geomagnetic field follow the field lines down into the atmosphere. The gas molecules become excited into a higher energy state, then discharge that extra energy as light. This is very similar–in fact, essentially the same–as a fluorescent light bulb, only natural and not contained. The colors are determined mostly by the main gas that is fluorescing. Carbon dioxide produces white light; nitrogen, pink or red; oxygen, green or blue. (It can also generate ozone.)

~The Weather Out There Is Frightful, Stephanie Osborn, ©2011

~~~

So what we've got, space fans, is a big ol' coronal hole generating an enhanced solar wind stream, and the Earth ran smack into it. Currently the planetary K-index (a rough measure of the strength of the disturbance in the planetary mag field) is oscillating between 5 and 4, and at 5, we start geomagnetic storming. It's minor, so far, but it's there. So we are under an official NOAA GEOMAGNETIC STORM ALERT for MINOR GEOMAGNETIC STORMING.

This in turn means that there will be some heating of the upper atmosphere, and it can induce some currents in conductive materials near the poles. Communications may be affected in high latitudes, and migratory animals may briefly become confused.

But what it ALSO means is that we have an AURORA ALERT for high latitudes! Now, NOAA doesn't put out aurora alerts. But I do! My followers on Facebook know that whenever conditions are right, I issue an aurora alert, and give a heads-up to the regions who can reasonably expect to see one. This is not a guarantee that you WILL, only that the probability is GOOD. Therefore --

Residents of Canada, Greenland, extreme northern Russia, Finland, Sweden, Norway, Iceland, possibly extreme northern Scotland, Antarctica and the islands in the Antarctic oceans, Australia's state of Tasmania, the southern tip of New Zealand's south island, and the northern regions of the following USA states: Maine, Michigan, Minnesota, parts of North Dakota, and essentially all of Alaska --

Keep an eye to the skies tonight! You just might see an aurora!

~Stephanie Osborn
http://www.stephanie-osborn.com

A New Direction

by Stephanie Osborn
http://www.stephanie-osborn.com
1 August 2016

Effective today, I'm taking Comet Tales in a new direction.

Many of you know me as an author. Many know me as a scientist. Oddly, many do NOT know me as BOTH.

So I'm going to show y'all how it works! Starting today, Comet Tales is going to feature the latest information in solar weather, and space weather and news! Alongside that will be information on my latest book releases, and any titles of mine that pertain to the space news of the day!

I won't be posting on a completely regular basis; rather, I'll post on an as-needed basis to ensure you have the most up-to-date information I've got! That might be once a day, it might be once a week, depending on what's happening. It may be a longish post, detailing and explaining a solar event, or it may be a link to a detailed article, with a few comments. So keep up with the blog! Follow me, and you'll always know the latest going on in the space above our atmosphere!

Today's space news:

Asteroid Bennu

We've got a little time, but asteroid 101955 Bennu could cause problems in about 120 years:
http://news.sky.com/story/asteroid-strike-could-cause-immense-suffering-10519054

It's unlikely but not impossible.

Can we do anything about it? Yes.

Travis S. Taylor and I discussed that in our nonfiction book, A New American Space Plan. There are many possible ways to redirect an asteroid or comet, and we cover them all in our book. Check it out!

Sunspots/Solar Activity

Also we have yet another day with no visible sunspots. If the active sunspots that rotated off about 5 days ago have survived, they would seem to be the only spots on the solar surface. The most recent imagery from the STEREO website (which is NOT on the Solarham website, which has begun updating less and less frequently in recent weeks) indicates that they have indeed survived and are nearing the center of the solar farside disk.

Spot group 2570, which showed up to end the last no-spot run, dissipated on Saturday; another short-lived binary spot group showed up on Sunday but didn't even stay around long enough to be numbered, and now, officially August 2nd GMT/UTC, we are back to no spots.

If I count the "dinky" spots as being essentially no spots, then 30 out of the last 63 days have had little to no sunspots visible (47.6%). 22 out of 63 were unequivocally spotless (34.9%).

And yes, I do know a thing or two about this -- my graduate work was in spotted variable star astronomy. I have an ebook out about solar variability called The Weather Out There Is Frightful, and it talks about spots, flares, coronal mass ejections, the solar cycle, extended minima, and more. 


~Stephanie Osborn
http://www.stephanie-osborn.com