Federation Scum Is Attacking Mars!
What’s the last thing a Romulan commander sees on their tactical screen before a volley of phasers turns them into space vapor?
I’m guessing this:
That’s not a bunch of Federation symbols flying across some alien world. Well, it is an alien world, but it’s not in the distant reaches of the Alpha Quadrant: That’s Mars, and those are actually sand dunes, seen by the HiRISE camera on board the Mars Reconnaissance Orbiter.
Technically, they’re called barchan dunes. They can form when the wind blows predominantly from one direction. If there’s an obstacle, like a big rock or small hill, the wind will blow around the obstacle, the same way water flows around a rock. Sand will pile up on the leading edge and also be swept around to the backside. Eddies in the wind create circular currents on the downwind side, building up walls of sand on the sides and creating that horseshoe crab-like appearance.
Eventually, you get a long, shallow slope leading to a crest, a sharp edge, then a steeper slope downwind. The wind supports the sand from rolling back down the upwind side, but downwind the sand is free to roll down, creating a steeper slope. The long arms leading downwind are due to the eddies in the wind behind the obstacle. Once formed, these dunes can actually move as a piece; the sand rolls up the shallow slope and then down the steep one, keeping the overall shape of the dune even though the individual sand grains change. In that way, it’s very much like a traffic jam on a highway, which persists and can move even as individual cars enter and leave it.
Barchan dunes are common on Earth and on Mars. They can form long, narrow chains called seifs, too—those make for very dramatic and beautiful formations.
Time-Lapse Video: Stars That Fell As Snow
I do enjoy watching the odd time-lapse video of the sky or two, and I love sharing them with y’all as well. Many are beautiful, of course, and that’s reason enough to spread the word. They encourage people to go outside and look up, and I hope by now you know how I feel about that!
But these highly sped-up animations show us the motions of the sky we miss in our 60-seconds-to-the-minute lives. It’s only when the heavens are accelerated that some things pop out, and it’s worth noting them.
Lovely, isn’t it? You can see halos around the Moon, light pillars, and other beautiful phenomena. (I love the snow on the ground sparkling and twinkling as the flakes reflect the moving moonlight.) But that’s not what I want to bring to your attention.
At 1:31, a sequence starts showing Orion sliding past the silhouette of a house. It’s very nice, but there are two hidden secrets in it. Did you see them?
Let me help. To the left of Orion and near the top of the frame is the bright star Procyon (the brighter star Sirius is below it—at the top of this post is a picture from the video, and Procyon is the star at the top left). Restart the video at 1:31 and keep your eyes on Procyon as it moves left to right.
Did you see it that time? There is what looks like a star just below Procyon, and it suddenly appears, gets brighter, then fades. Replay it again if you need to. Did you notice anything else odd about it?
The “star” doesn’t move with the other stars! It seems to sit tight in the sky. That’s because it’s not a star, it’s a geostationary satellite. These are satellites launched into special orbits that are about 36,000 kilometers (22,000 miles) up. At that height, they orbit the Earth once every 24 hours, the same as the rotation rate of the Earth. Because of that, they appear to stay more or less glued to the sky, while the stars slide past them (from their point of view the Earth looks like it’s not spinning below, so they’re always over the same spot on our planet, making them useful for weather observations and communications).
I suspect the satellite gets brighter and fades because it’s reflecting either sunlight or moonlight off its solar panels, and as the angle changes we see that reflected light pass over us. Usually they’re pretty faint and hard to see.
I mentioned there’s a second secret: It’s a second geostationary satellite! Just before the bright one appears under Procyon, there’s another one to the left of it, at the tip of a tree branch. At first I thought it was the branch, maybe reflecting some ambient light. But after watching it a few times I’m pretty sure it’s another satellite.
Incidentally, these satellites generally have orbits that are very nearly directly over the Equator. Both of the objects in the video are in fact in the part of the sky corresponding to that position (the “celestial equator”) so that adds credence to my hypothesis.
And there you go! Like I said, in a time-lapse video there are things that can appear and make themselves known that you would otherwise be totally in the dark about. Hidden away in the sky, there’s knowledge and beauty and science and fun.
But that’s redundant, isn’t it?
Sometimes, you just need a little flash of inspiration to make your day go a bit better. Even if that flash is caused by a chunk of space rock the size of a grape slamming into Earth’s atmosphere at 50,000 miles per hour and converting its considerable kinetic energy into light and heat in mere seconds.
Like, say, this.
Astrophotographer Mark Gee was about 20 minutes outside of Wellington, New Zealand, capturing the Milky Way rising over the ocean when that bit of cosmic debris made its showy demise. Normally, this would have been a lovely shot of the center of our galaxy with Antares glowing orange and various gas clouds dotting the stream of stars. But as chance would have it our planet was in the right place at the right time to intersect that small rock, and Gee was also at the right place and the right time to capture it on his camera.
He’s taken incredible photos of the night sky before, some of which take incredible care and planning to get the stunning results seen. But this time, a happy coincidence took a good shot and made it great.
It’s actually rather amazing what you can see from orbit. Once you’re off the ground, above it, your perspective changes, and you can put things in context. Signs of civilization can shrink down to almost nothing compared with the glory of nature, making them difficult to spot.
For example, peruse this image taken by a satellite:
Can you even see any signs of human activity there on the surface?
Oh, wait a second. My apologies. I forgot to mention: That’s not the surface of Earth … it’s the surface of Mars. And the signs of humanity you see there are really just a single sign.
Can you spot that blip right in the center? That’s the Mars rover Opportunity!
It’s only about 2.3 x 1.6 meters (7.5 x 5.2 feet) in size, so it’s just a few pixels across as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. If the scientists and engineers programming the probe didn’t know exactly where Opportunity was, it would be impossible to find! But we know exactly where all our working hardware is on Mars, and we know exactly where the orbiting cameras point, making it far simpler to get pictures of the land-bound rovers.
Opportunity is seen here at what’s called Solander Point, where it found that odd rock nicknamed the “jelly doughnut.” The rock suddenly appeared next to the rover, when earlier images taken by Opportunity showed bare ground. That was quite a mystery, but it’s now pretty clear that the rock was a piece of a larger one broken off by one of the rover’s wheels. Images like this one from HiRISE are pretty useful when things like this happen; it shows no fresh craters nearby, making it unlikely the rock was ejected by a small impact.
But for those of us back home who don’t study Mars for a living (and, I’d wager, even for those who do), images like this are still a thrill. As my friend Emily Lakdawalla puts it, “Seeing a spacecraft on the surface of a planet from another spacecraft never gets old.”
She’s right. It’s a great reminder that we humans are amazing when we want to be. We can, in a short time, go from creating myths about lights in the sky to landing on them and discovering their truths for ourselves.
A Monster Star Plows Through the Galaxy? Shocking.
Correction, March 6, 2014: Well, this will take a moment to explain.
In the article below, I wrote that the star Kappa Cas is moving through the galaxy at a stunning 1,100 km/sec. This turns out to be incorrect: The speed of the stellar wind blowing off its surface is that fast, but the star itself is moving far more slowly.
I based the original number off the NASA press release, which made that assumption about the speed. However, an email by astronomer Manfred Pakull set me straight. The star is actually moving relative to the Sun at about 25 km/sec, which means it’s moving around the galaxy at around the same speed we are.
So why is there an arc of material compressed next to it instead of a more spherical shell of dust? The speed of the star is very small compared to the wind speed, so I’m guessing the dusty material the star’s wind is ramming is not evenly distributed. Note that the overall shape is more like part of a sphere as opposed to a bow wave, so this seems likely. Funny, too: When I read the press release I looked for journal papers on the star and found none (Pakull did mention one, which has some relevant numbers for the star). That’s surprising if it really is a runaway star, so now that anomaly makes more sense. Everything else I wrote below is correct, but note that the parts about it being a runaway are almost certainly incorrect. And also? It’s still gorgeous.
When you look up at the sky, you’d be forgiven to think that the stars are motionless, frozen in time, mounted on the velvet vault of the heavens.
But in fact they are in motion, orbiting the center of our galaxy much like the planets orbit the Sun. The Sun itself, for example, is moving along at roughly 200 kilometers per second (450,000 mph). Some orbit a lot faster.
Take Kappa Cassiopeiae, for example. It’s what’s called a runaway star, screaming through space at a terrifying 1,100 kilometers per second … 2.5 million miles per hour! As it happens, it’s also a blue supergiant, a massive, hot star. These kinds of stars tend to blow out a fast wind of subatomic particles, like the solar wind on steroids. As the star plows through space, its wind rams into the material around it, creating a vast shock wave like air off the nose of a supersonic fighter jet. It’s invisible to the eye, but when you point an infrared telescope like Spitzer at it, you get stunning beauty:
How about that? Kappa Cas is the blue star in the center, and you can see the material arcing around it, snowplowed by the fierce interaction of the star and its surroundings. This image is infrared, which means the colors aren’t “real”; blue is a combination of light at 3.6 and 4.5 microns (five and six times the wavelength of the reddest light the human eye can see), green is from 12 microns, and red is 24 microns. What you see as red is dust that floats between the stars, and green is from complex particles very much like soot (created by stars both when they are born and when they die). In Spitzer images, stars tend to look blue because they give off most of their light toward that end of the spectrum.
The Sun is also moving through interstellar material, but the effect is nowhere near as profound as that from Kappa Cas. But then the wind from Kappa Cas is millions of times more powerful than the Sun’s and is blowing outward several times faster. Add that to the already incredible speed of the star, and you get a bow shock that’s a mind-crushing four light years ahead of the star: 40 trillion kilometers. That’s the same distance as the nearest star from the Sun, so you can see the influence of Kappa Cas extends a long, long way.
We’ve seen other cases of this as well. Zeta Ophiuchi is one; another massive star barreling through the night. Spitzer has observed it before, and it’s so beautiful that it’s one of my favorite all time astronomical photographs. Another infrared observatory, WISE, also took a great shot of it.
This raises the question: Just why is Kappa Cas on the run? There are a few ways stars can get accelerated to such high velocities. One is if they started out life as a binary, two stars locked in a tight orbit. If the other star exploded as a supernova, the two stars lose their grip on each other, and the angular momentum can fling them both away at high speed, just like a slingshot. Another possibility is that Kappa Cas was born in a cluster of a stars, and a close encounter with a pair of stars in the cluster gave it a kick sufficient to fling it out and into interstellar space.
Kappa Cas is actually bright enough to see with the naked eye; it’s a fourth magnitude star in the W of Cassiopeia. Better take a look while you can, though; being a blue supergiant, Kappa Cas doesn’t have long to live. Even though it has something like 40 times the Sun’s mass, it burns through its nuclear fuel at a far faster rate, shortening its lifespan considerably. Someday, perhaps in the next few hundred thousand years or less, it will explode. It’s 4,000 light years away, so we’re safe, but it’ll get really bright when it goes, getting far brighter than Venus in the sky. What a sight that will be!
Planet Bonanza: The Number of Known Earth-Sized Worlds Just Topped 100
- They have confirmed an additional 700+ exoplanets orbiting 300 other stars.
- Ninety-five percent of these planets are smaller than Neptune.
- One hundred or so are roughly the size of Earth(!!!).
- Four of these new planets are in their stars’ habitable zone.
- Like our solar system, these planets orbit in roughly the same plane.
Yegads. OK, let’s go over these point by point.
First, Kepler is designed to look for planets orbiting other stars by detecting a small drop in the starlight if a planet passes directly between us and the star. This is called the transit method, and it’s been used to great success. However, there are ways these observations can look like a planet is transiting when really it’s something else; a background star changing brightness, for example.
For that reason, when Kepler sees what looks like an exoplanet, it’s called a candidate until it’s verified. There are more than 2,500 candidates in the Kepler data! This has created something of a bottleneck in the data, making it hard to confirm planets rapidly. What astronomers did then is pretty clever: Look for multiple planets orbiting a single star. Why? Because you don’t expect to see very many of them if the candidate is a “false positive”; you might see just a handful out of thousands of candidates.
What they found instead were hundreds of such planets. They were able to then eliminate the false positives from the sample, leaving a pretty big set of more than 800 planets detected! Of these, more than 700 are newly found.
The size of the planet can be determined by seeing how much light from the star it blocks. The bigger the planet, the bigger the dip in starlight, and if the star’s size is known (and that can be determined), then the diameter of the planet can be found as well. Of the planets detected in this survey, the vast majority are actually smaller than Neptune (which itself is about four times the diameter of Earth). This is in contrast to most of the previous planets found, which are more like Jupiter in size (10 or so times the Earth’s diameter).
Of these, an amazing 106 are less than 1.25 times the diameter of Earth! Previously, only 16 had been found in Kepler data, and only about 20 were known in total (including those found using other telescopes). This is a major jump in known planets that are around the same size as our own world. The number sextupled.
Of all the new planets found, four orbit their stars at the right distance to sustain liquid water. This region around the star is called the habitable zone, and it’s really just an estimate; it depends on a lot of factors and has very fuzzy borders. Technically, the Sun’s HZ goes from Venus to Mars, more or less, but we know that Europa, a moon of Jupiter, and Enceladus, a moon of Saturn, have liquid water under a frozen shell of ice. So take the HZ size with a grain of salt; in reality, it’s probably bigger than these conservative estimates.
All four of the planets in their stars’ HZs are bigger than Earth, ranging from 1.8 to 2.5 times our width. We know almost nothing else about them, but just because they’re bigger doesn’t mean they aren’t Earth-like. Surface gravity depends not just on size but on mass, so a lower density but bigger planet can still have very Earth-like conditions. Either way, we can’t tell, so I won’t speculate.
The final bit of interesting news is that the planets found orbiting each star tend to orbit in the same plane, much like the planets do in our solar system. Seen from the side, our system forms a thin disk, and the same is true for these other systems as well. This makes it pretty likely that other systems formed the same way ours did. That’s reassuring!
All of this put together is pretty striking, and very exciting. We’ve been compiling evidence for years that stars with planets are common and that planets in the galaxy might outnumber stars. These new results support that; multiple-planet systems are common. Not only that, Earth-sized planets are also common, and Earth-like planets may be huge in number too. We think there are billions of them in our galaxy alone. Billions.
I’ll remind you: In 1990, we didn’t know of a single planet orbiting an alien star. Not one. Just a few years later the first was discovered, and now we have confirmed the existence of more than 1,700! Mind you, these new results only come from using the first two years of Kepler data; when the technique is applied to all four years of data there’s no doubt a new treasure trove of planets will pop out.
The Milky Way, the whole Universe, must be fairly buzzing with planets. Billions upon billions of them, just waiting to be discovered. This new technique shows we can find them, even better than before. As time goes on we’ll build better telescopes, better detectors, and find new methods that will make this even faster and better. This is truly a magnificent time to be alive, and to stretch the realm of our knowledge ever farther.
Correction, Feb. 26, 2014, at 20:00 UTC: I originally wrote that the number of Earth-sized planets quintupled. However, since 20 were known, and an additional 106 were found, the number more than sextupled.
Sculptures That Are Literally Head-Expanding
This is not an illusion per se, but I have to admit the first 30 seconds or so did freak me out.
Weeeeeeeeird. Those are actually paper sculptures by Chinese artist Li Hongbo. The paper leaves in the stacks are connected, a bit like honeycombs. They start off as a block, which can then be carved into different shapes just like stone. Hongbo sculpts them into beautiful classical heads, and then when you pull on them, well, you get that bizarre video above.
The first two segments are pretty nifty. I wasn’t sure what to expect, and I thought for a moment this was going to be just an optical illusion, not actually motion of the medium itself. This was strongly reinforced in the second shot, where the camera moves down as the head is pulled up, making it look like the changing perspective is what’s causing the change we see. But it really is because the head is physically being pulled apart!
I suspect this is so engaging because of the “uncanny valley” effect, where artwork depicting faces looks almost—but not quite—real. It disturbs us. That’s why simple cartoons like Homer Simpson look just fine when we watch the show (the drawings are flat and not at all realistic), but when it’s turned into a 3-D photorealistic picture, it will haunt your nightmares for all eternity (seriously, you may not wish to click that link unless being drastically and soul-clenchingly disturbed for the rest of your life is something you truly desire).
In this case, the heads look like classic Greek sculptures, which are clearly representative of humans, but lack the depth of reality, so they are beautiful, not disturbing. When they become distorted as they are pulled apart, accordion-like, the eyes get stretched, the ratios of various features distort, and some atavistic part of our brain is activated. We’re repulsed. The creepy music only adds to the effect.
I often wonder what will happen when humanity meets its first true alien—not just a planet covered in single-celled goop but an actual complex creature from another world. Much of my own thinking has been triggered by a voracious consumption of science fiction, which unsurprisingly covers this topic extensively. Assuming we can even recognize a life form as being alive, will its shape repel us? If it looks something like us, but not quite like us, will we be betrayed by our own brains, tripping some ancient reflex of loathing?
I hope not. I can hope that by understanding our own minds better we can overcome this fear of “other.” In all the books and stories I read about first contact, though, I don’t think any used the idea that our own art might help us if and when we do meet our kin across the stars. I think it’s an angle worth exploring.
Tip o’ the chisel to my friend Lucky Yates.
Should Public Schools Have Mandatory Vaccinations for Students?
In most states, parents have to show proof that their child is vaccinated before enrolling them in public school. In my home state of Colorado, it’s pretty easy for parents to opt out of that. All they have to do is check a box on the enrollment form that says they have either a religious or personal belief that exempts them from vaccinating their kids.
When it comes to decisions about personal matters, I tend to lean libertarian; your body, your choice. This gets stickier when that choice affects other people, and the situation can be complicated further when other choices are involved. …
In some areas, public school authorities have mandated that students be vaccinated for various diseases, and that of course can run afoul of parents’ beliefs. I’ve wrestled with this problem for a while, and I eventually came to the conclusion that a parent does not have the right to have their child in a public school if that child is unvaccinated [except for medical reasons], and for the same reason health care workers should not be unvaccinated. It all comes down to a very simple reality: It puts other children at risk. If you want to rely on the public trust then you have an obligation to the public trust as well, and part of that obligation is not sending your child to a place with other children if they aren’t immunized against preventable, communicable diseases.
(Emphasis mine, but then, that’s me talking there; I added the part about medical reasons to be clear.)
I do understand that people might have a religious belief against vaccinations. However, I think religious exemptions can and should only go so far. Certainly they stop dead when religion impinges on my rights to have my child attend a school that is safe. I have even less patience for the “personal belief” exemption because that strikes me as being aimed at people who are anti-vaccination. And they are most certainly wrong. I’ll note that “personal belief” dominates the reason why parents opt out of vaccines for their children in Colorado.
So I’m very glad to see new legislation being considered in Colorado that will make it tougher to opt out of vaccinations for children going to public schools. House Bill 1288 requires either a physician’s (or similar health care provider’s) signature or the completion of an online education course about vaccines before a parent can claim personal belief exemption. It’s not perfect, but it’s a good start. Since that belief exemption is so dominant, this may significantly cut back on unvaccinated kids attending public schools.
Last semester there was a whooping cough outbreak at my daughter’s school. She’s vaccinated, so I wasn’t concerned for her, but I was for all the other students who weren’t vaccinated against this contagious and dangerous disease.
So this quite literally hits home for me. Even if it didn’t, I would’ve contacted my state representative to urge her to vote yes on HB 1288. If you live in Colorado, please do the same (here’s how to find your legislators). Here is what I sent my rep, Dickey Lee Hullinghorst. Feel free to write your own version:
Dear Representative Hullinghorst—
I am writing to urge you to please vote YES on House Bill 1288, "Student Immunizations Prior To School Attendance", which will make it more difficult for parents to opt out of vaccinations for their children who attend school.
Vaccinations are one of the (if not the most) successful medical advances in the modern age. They save quite literally millions of lives every year, and their risk is extremely small compared to their enormous benefit. In Colorado, and Boulder specifically, we have seen recent outbreaks of dangerous and potentially fatal diseases such as pertussis that are vaccine-preventable. Recently, in San Francisco, a single unvaccinated person exposed thousands of people to measles, which is highly contagious... if you're unvaccinated.
Right now, all a parent has to do is check a box on a form to opt out of getting their children vaccinated before entering school. This means many if not most will not get the correct information about the safety of vaccines and the health risks of not being vaccinated. HB 1288 will increase awareness of vaccine benefits and in many cases will make sure parents have talked to a doctor before opting out. This will hopefully greatly reduce the number of unvaccinated — and therefore at-risk — children in our schools.
(Note: I added links to make it easier for you should you wish to read more.)
I hope this passes. It isn’t perfect—I would prefer that unvaccinated children not be sent to public school at all unless they have a medical reason; that would keep the number of vaccinated kids up into herd immunity territory—but it’s a solid start.
Tip o’ the virion capsid to RunMonkeyMama on Twitter.
Climate Change Deniers Lose Their Cool
What the heck, climate change deniers? I mean seriously, what the actual heck?
For some reason, the past week has seen some climate change deniers totally lose their [expletive deleted]. I keep up with this stuff, so I’m used to seeing forehead-slappy moments, denial so abrupt and profound it’s hard to imagine the promulgator lives on the same planet the rest of us do. I mean, c'mon, the bar has already been set by comparing a climate scientist to a child molester and saying more carbon dioxide in the atmosphere is just fine because plants love it.
But this week has seen the dumbosity go up a solid notch. If I went into details this post would eat up half the available electrons on the Net, so let me give you just a taste of outrage permeating the anti-science realm with a brief commentary.
1) A Hoary Op-Ed
Charles Krauthammer, writing an op-ed in the Washington Post, managed to cram in something completely wrong about climate change and global warming into nearly every paragraph. It’s practically a how-to of, um, how to deny reality. His nonsense is sensibly dismantled by scientist Scott Mandia, in detail by Jeffrey Kluger at Time, and ironically by Stephen Stromberg at, you guessed it, the Washington Post. It would be hard to pick the most head-desky moment, but calling climate scientists (and science journalists) “whores” is way up there. Claiming he’s neither a believer nor denier is another. It’s pretty clear where he falls.
Bonus: biblical quotations about whoring.
Dr. Roy Spencer is in a teeny majority; the 3 percent or so of scientists (he has a degree in meteorology) who think global warming isn’t real and human-caused. Since he is a scientist you’d think that would give him leverage—certainly Republicans in Congress think so, since they keep empaneling him in their hearings—but when you actually read his claims, they tend to fall a bit short of reality.
And when you read his latest screed, your eyes might roll so far back in your head you can see the inside of your skull.
Why? He says that people who use the word “denier” are … wait for it, waiiiit for iiittttt … “global warming Nazis”.
Yup, you read that right, he went there. He goes on and on about the use of the term “denier,” claiming it’s associated with Holocaust denial. However, that’s just hooey. It’s used in lots of ways by lots of people because it means “one who denies,” and I’ve been very clear about that. More than once.
And if you think this doesn’t matter, remember that Spencer is a darling of the denial community. Also, shortly after I posted about Spencer on Facebook, a guy actually used the comments section there to call me a Nazi. Nice, eh?
Bonus: Spencer himself (with David Legates) wrote an op-ed in the Christian Post saying, “we deny ‘that most of it is human-caused, and that it is a threat to future generations that must be addressed by the global community.’” [Emphasis mine.] Huh. Doctor, heal thyself.
3) Defending the Status Erratum
Also among the 3 percent are atmospheric scientists John Christy and Richard McNider, who took to that Mos Eisley tavern of global warming media, the Wall Street Journal. As usual for a climate change op-ed in the WSJ, the account they weave is perhaps not an accurate representation of reality, as is made clear by Our Changing Climate and Climate Science Watch. From what I could gather not much they say in the op-ed is really new, either; they use long-disproven arguments about atmospheric heating and cooling. In fact, their claims were debunked before they even made them by John Abraham and Dana Nuccitelli in an article last year in the Guardian. The article they recently wrote about Spencer pertains to the WSJ op-ed, too.
Bonus: Christy and McNider get their flat Earth and scurvy history wrong.
4) … And the Rest
Round and round we go. Fox News still claims global warming can’t be happening because 2 percent of the planet is cold. Ted Cruz concurs. There was a “debate” between Bill Nye and Marsha Blackburn; guess who had the facts on his side?
And I could go on and on, et cetera ad nauseum.
Bonus: There is no bonus here. Just an unending torrent of anti-science.
If anyone should be losing their minds, it’s those people who have been predicting all this for years only to be met by partisan and fossil-fuel-funded resistance. Yet they are the ones who are level-headed, and it’s the deniers who seem to get more shrill and more outrageous with every article written. I’m not a huge fan of the idea of “moving the Overton Window,” but sometimes I wonder.
Maybe it’s just because it’s an election year. Maybe it’s because without facts on their side, all they have is volume. But as the temperatures continue to go up, you can bet the noise will, too.
Boom! The Sun Blurts Out an X-Class Flare!
Remember that ginormous sunspot that was seen in January and was so huge and strong it actually survived long enough to be brought back around the far side of the Sun and face us again in early February?
Incredibly, it’s still there! And it just announced its return by literally exploding, blasting out a very respectable X-class flare. It started at about 00:30 UTC on Tuesday morning (7:30 p.m. Eastern time), and was still ongoing when I wrote this post (at 01:30 UTC).
The image at the top of this post is from the Solar Dynamic Observatory, taken in the ultraviolet where flares are very obvious. As I’ve described on the blog before, solar flares are where the huge magnetic energies stored in sunspots get let loose all at once, creating an explosion that dwarfs all of humanity’s weapons combined. This flare was accompanied by a spectacular eruptive prominence as well, a towering plume of solar plasma bursting out into space:
Gorgeous. But terrifying to think of the energy being violently released! I’m glad it’s 150 million kilometers away, and facing away from us. The classification of the flare is X 4.9, because that’s where it peaked on the detectors on the GOES satellite's X-ray detectors:
That plot shows the X-ray emission (technically the flux, the amount detected) over time, and the flare is pretty obvious. The plot tick marks are logarithmic, but the flare class is linear, so the first line going into the X range is X1, then X2, which is twice as bright as X1, then X3, which is three times as bright as X1, and so on. The flare is currently fading. Last month this spot blew out an X1 flare; this one was nearly five times as powerful.
But this sunspot is coming back around now. Over the next week the Sun’s rotation will bring it back to the center of the Sun’s disk, before once again sweeping it around to the Sun’s far side. We’ll have to keep our eyes on this one. A big flare can block radio transmissions, damage satellites, hurt astronauts in orbit, and (on the plus side) create dramatic aurorae. Let’s hope for the latter, but not the three former!
Stay tuned to Spaceweather.com for more info.
Correction, Feb. 25 at 16:30 UTC: I originally mislabled the red line in the caption of the graph, saying it was from higher-energy X-rays. My apologes; it's been corrected.