Bad Astronomy Blog

Do You Want Some REAL Fireworks?

15 hours 39 min ago

Today is the Fourth of July, a national holiday in the US where we celebrate the signing of the Declaration Of Independence (we didn’t actually win our independence until 1783, depending on how you look at it).

It’s traditional to celebrate with fireworks, which I’ve always enjoyed (though some people are making the case that we should be aware of people (and pets) who don’t). But as an astronomer, my idea of fireworks is maybe somewhat more expansive than most folks…

Like, the explosion of an entire star. Called a supernova, they’re among the most violent events the Universe has to offer. The amount of energy they emit can be equal to the total amount of energy the Sun emits over its entire lifetime. The closest example is the Crab Nebula, seen above. Want a fun little bit of cosmic trivia to astound your friends? The light from this explosion reached Earth in the year 1054… on July 4.

Anyway, the good news is that these ridiculously huge events tend to happen very far away. But what if one were a lot closer? Well, if it got close enough, we’d be in trouble. I wrote a chapter in my book Death from the Skies! about that.

But I also talked to science communicator Rose Eveleth about what would happen if a supernova were too close to comfort for her podcast Meanwhile In the Future. Also appearing is my friend and astrophysicist Katie Mack.

That was fun. She starts off each episode with a little vignette talking about some event in the future, then uses that as a springboard to talk about the science of an event. Clever.

I wrote more about the Crab in a recent post, and it turned out to be a little more poetic than I expected. But hopefully, it’ll give you an impression of the cosmic forces out there, ones which craft the Universe we live in.

If you’re celebrating July 4th today, have fun! But remember, have some perspective. The fireworks you’re watching could be a lot, lot bigger.

Categories: Astronomy Headlines

Crash Course Astronomy: Meteors!

Fri, 07/03/2015 - 04:00

I’m not gonna lie to you: This is one of my favorite episodes of Crash Course Astronomy we’ve done so far. It was a lot of fun, and this is just such a fantastic topic to talk about. So here you go: “Meteors, Meteoroids, and Meteorites, Oh My!”

Those meteorites I held up in the intro are mine; they’re examples of Sikhote Alin, an iron meteorite that rained debris over Russia in 1947. They’re my favorite; they come in all sorts of exotic and bizarre shapes, and their color is gunmetal blue-black. They’re a bit pricey, but you can buy them for yourself. I suggest perusing the store of my friend Geoff Notkin (you may have seen him on the Discovery Channel’s “Meteorite Men” TV show). He has great samples.

I’ve written about meteors about seventy-four bazillion times. If you’re looking for a generic meteor shower viewing guide, I’ve written them for several showers. Here’s one from the 2014 Geminids. I’ve written about the Russian Chelyabinsk impact several times, including the night it hit, a followup a year later featuring what we’ve learned, a cool video where you can see a small chunk hitting a frozen lake, and another video where they hauled a big chunk out of a lake.

I also wrote about the Perseid astronaut Ron Garan saw from the space station… including a calculation for how often the space station gets hit by a meteor on average.

You can see why I had so much fun making this episode. I’m endlessly fascinated by meteors, and hopefully, now, you are too. 

Categories: Astronomy Headlines

Washington State Woman Is First Measles Death in U.S. in 12 Years

Thu, 07/02/2015 - 11:52

In Clallam County, Washington, a woman has died of complications from measles. This is the first U.S. death from measles since 2003.

Clallam County had an outbreak of measles earlier this year, when five people were diagnosed with the disease. The woman who died brings this to a total of six.

She likely contracted measles when she visited a health facility; a person who was later identified as having measles was there at the same time. The woman who died was apparently taking a series of medications that lowered her immune system’s ability to fight off disease. Although she didn’t present a rash or other obvious external symptoms, she died of pneumonia caused by the measles infection.

Vaccination rates in that area of Washington are lower than they should be. We—and I do mean “we”—need the public to have as high a rate of vaccination as possible, to ensure herd immunity, so that the bacteria and viruses that can cause such illness and death have as few places to hide as we can muster. When rates drop, we get outbreaks, like the one in Disneyland that sickened so many and spread the highly contagious disease to many parts of the country.

One person who came down with measles in the Clallam outbreak had been inoculated, but it was decades ago, when the shot was less effective. It’s important to make sure your immunizations are up-to-date.

This death comes on the heels of California making it harder for parents to opt out of vaccinating their school-age children; only a medical exemption will be accepted (before, they also allowed religious and personal reasons). I’m very happy this law passed. I’ll note that Washington state, where the woman died, still allows personal exemptions. Hopefully their legislature will rethink that policy.

It also comes right after a huge and awful backlash against the new California law by the anti-vax crowd, including actor Jim Carrey, who tweeted a series of foolish and blatantly incorrect statements about vaccines. He brought up the zombie ideas of mercury poisoning (a non-issue) and conspiratorial Big Pharma nonsense.

Let me be very, very clear: Anti-vax rhetoric like that makes people scared to get vaccinated. Rates drop, herd immunity drops, outbreaks occur, and people get sick. Some die. This is a direct, step-by-step chain.

No one is forcing you to get vaccinated. If you want your children to attend school in California, then yes, you have to get hem vaccinated unless there’s a pressing medical reason. But no one is coming to your door, holding you down, and injecting you with anything. You still have a choice. That choice boils down to this: If you want to rely on public services, then you have to support those services. One method of support is making sure you have minimized the risk of your child giving other children dangerous infectious diseases.

And it’s not just children. It’s elderly people who are at risk, too, and people—like the woman who died in Washington—who are immunocompromised. I have family members in both these categories, which is why my entire family is up-to-date on our vaccinations.

When you get vaccinated, you are helping not just yourself, but also many, many people around you of all ages. Read up about measles, and what you need to do. Ask your board-certified doctor and see if you need to be vaccinated (or need to get your booster). If they recommend it, then listen to them.

Read more of Slate’s vaccines coverage.

Categories: Astronomy Headlines

Is Star Trek Tech Possible?

Thu, 07/02/2015 - 08:00

My friend Veronica Belmont is pretty cool. Nerd, writer, TV host… and now she’s doing an online video series with Engadget called “Dear Veronica”, where she answers tech/geek questions sent in by viewers. It’s a lot of fun.

In this week’s episode, she was asked, “Which Star Trek technologies will still be invented? Which are truly impossible and will never happen?”

Hey, I like Star Trek! So I’m really glad she asked me to field this question.

That was fun to record. But it was hard, too, since I only had 30 seconds, which didn’t give me much time to really dig deep.

But hey, I have space on the blog (haha – “space”! I kill me) so why not give a little more detail here?

Before we get started: Almost everything below is conjecture, based on physics as we know it. But I’m not an expert in all these fields, and I’ve been known to be wrong before. If you have better evidence, please let me know! Also, I’m assuming no major breakthroughs that negate or heavily modify the laws of physics as we see today. Keep that one in mind. All of these might be possible, but would involve huge breakthroughs that seem pretty unlikely to me — still, I'm no curmudgeon, and I'd love to see any of these technologies come true. I’m also trying to be brief here, to cover a lot of the quadrant. If you want details, Commander Riker might have already looked it up for you.

So let’s leave spacedock and take these ideas out for a shakedown cruise.

FTL

There are lots of problems with the idea of going faster than light. You can’t just accelerate past it like you can the speed of sound; it would take infinite energy according to relativity. And relativity tends to be right.

Other ideas include making a warp bubble, or punching a hole through space, or wormholes, but they all still have the same problem: causality. Moving faster than light is like time travel, and that opens up an entirely new can of Gagh.

So, I’m giving this a Nope until proven otherwise.

Transporters

In Trek, they’ve said many times that the transporter works by converting someone to energy, beaming that across space, and then re-matterizing them. The problem with this is that converting a standard redshirted human body (say, 50 - 70 kg) into energy is the equivalent of detonating well over a thousand 1-megaton nuclear bombs, which is a lot.

Even if you can contain that, how do you record someone’s “pattern”? That’s a lot of information. A lot. Theoretically, there’s an equation that describes every single subatomic particle in your body, but it’s a tad complex. Describing a hydrogen atom is already pretty hard, but put ten of them together and it gets fantastically complex. There are very roughly 1028 atoms in your body. That’s a big equation.

A better retcon would be to say you’re creating a subspace tube, encasing the traveler in a small force field, and plunging them through it. But even then, I don’t think subspace is quite so much real.

So: Nope.

Phasers

Phasers are like lasers but instead they start with a digraph.

OK, how they work is never really stated, but I heard from a friend who worked on Next Generation that they don’t vaporize you, they send you into subspace, where you die (see “Transporters”, above, except don’t use a force field). That’s clever, and I like it, but again with the not-real subspace.

Nope.

Artificial gravity/Inertial Dampening

These are tough. As far as we know now, there’s no way to do either (well, you can spin a spaceship to mimic gravity, but that has other complications; and besides, is clearly not what they mean by the term in Trek). These are fundamental properties of space and mass, and as far as we know, the laws of physics give these a big Nope.

Replicators

Replicators work on the idea that once you convert something to energy, you can then reconstitute it back as a different kind of matter. Cool, but transporters don’t work, so Nope.

Tricorders

Now we’re getting somewhere. Lots of things a tricorder can do we already have tech for. Infrared meters can read your temperature from a distance. Phones can listen for sounds, and do some basic image stuff too. This idea is based on reality well enough that there’s an X Prize for it.

So: Yup. Eventually, and kinda sorta now.

Communicators

Please. A device for talking to people over long distances that you have to flip open? What is this, the 2190s?

Nanotech

The idea of teeny tiny machines that can be programmed to do simple tasks doesn’t strike me as being all that far-fetched. We have some basics of this developed now. They’re a far cry from nanites escaping and taking over our (nonexistent) FTL starship, but this field is interesting. I wonder if they could be made generic such that in tandem they can do more complicated tasks. This sounds more like an engineering problem than one of physical laws, so I have to give this one a Maybe.

Force fields

The term force field is pretty generic. If you have a dense (strong) enough magnetic field it can deflect charged subatomic particles (electrons and protons) away from you, so in a sense we have those now. But something that can protect you from the force of an explosion, deflect bullets, and so on? I’m not even really sure how that would work.

But ignorance is no excuse, so to be honest I’ll give this a Maybe, just not according to what we know now.

Cloaking

I love this. YES. In principle, this can be done. You just need to deflect any photon coming at you from any direction so that once it’s past you it continues on in that direction.

Or, you could, for example, surround yourself with a device that can both detect and emit photons. It absorbs a photon, figures out what direction it came from, then finds the emitter on your opposite side and tells it to shoot off a photon of the right energy in the right direction. If you’re sitting still, and the light source isn’t changing, this should work. If you’re moving, then you better have really fast processors on your cloaking computer.

This would be very hard to build, and might be clunky, but it doesn’t violate any laws of physics, so I give this a Yes.

Universal Translator

We already have primitive but sortof effective translators online now. However, these take previously known languages and basically do really fast table lookups of the translations. This won’t work for an unknown language, let alone the squeals, grunts, clicks, whines, buzzes, pheromone exudate, cilia waving, and rapid eye blinks used in alien language. In Trek, that thing basically reads minds, so I’m pretty skeptical. Nope.

Turbolift

An elevator that goes up, down, and sideways? Willy Wonka had one of those in the 1960s.

Tractor Beam

In Next Gen they refer to the tractor beam — a device that can grab distant objects and be used to tow them — as using gravitons. These are theoretical particles that mediate the force of gravity in quantum mechanics, like photons mediate electromagnetism. However, gravitons have never been detected, and may not actually exist, which is a prerequisite for actually, y’know, existing. That doesn’t mean they don’t, it just means that a tractor beam is speculative, so I can’t give it the thumbs-up here. But Maybe, someday.

Artificial Intelligence

This is a funny one. I won’t worry about the existential issues of what intelligence is, because that’s a rabbit hole I don’t want to go down (though in detail it’s important; is intelligence an emergent property of anything that has enough complexity, or is it something that has to be specifically built into the hard/wetware?). But if we accept that humans possess intelligence, can we replicate it in non-human devices?

In principle, I have to say yes. But I wonder if we’re going about it the right way. Our brains simply don’t work like computers, despite the scifi trope. But if we can build machines that process information more like our brains do, then perhaps intelligence will emerge.

I’m no expert, and I’m spitballing here, but clearly it isn’t easy. I’ve been hearing that we’re just 25 years away from true AI for the past 40 years. Every time some breakthrough is made, it shows us that things are still a lot harder than we thought. Still, evolution seems to have done this naturally after just cooking slightly polluted hydrogen for a few billion years. People whose brains work a lot better than mine are working on it, too, and they seem to think it’s possible. So who am I to say no? Until proven otherwise, I’ll go with Maybe.

To Boldly Go…

So where does this leave us? Beats me. But whether the tech or the science of Trek is real or not, I still love the show. And while this stuff is fun to think about, they’re not the point of the show.

The point is the story, and the story is fun.

So: Second star on the right, and straight on ‘til morning. Engage.

Categories: Astronomy Headlines

C'mon, How Much Weirder Can Pluto Get?

Thu, 07/02/2015 - 04:00

Seriously, Pluto, what the heck are you up to?

As New Horizons gets closer every day, more details on the tiny world come into view. The latest? A very weird set of four similar dark streaks on the surface, stretching for hundreds of kilometers, and fairly evenly spaced.

What the WHAT.

Those streaks are really too small to say much about them just yet. They only appear to be on images from June 27, when New Horizons was close enough to see them and Pluto had rotated them into view (greyscale pictures from the long range camera were combined with lower resolution natural color images from another camera called, seriously, Ralph). The probe is only taking a few pictures per day as it approaches, trying to keep data storage to a minimum to save space for the big show coming in just over 11 days now.

It’s possible they’re multiple impact sites, but that seems really unlikely. They’re so evenly spaced… they’re also located very near the equator, and on the hemisphere pointed toward Pluto’s moon Charon. There’s been some suspicion that Pluto might be geologically active, spewing out jets of some material. Neptune’s moon Triton has dark geyser-like plumes, probably nitrogen from under the surface mixed with dust or some other dark substance.

Also, Triton (like Pluto) is a Kuiper Belt Object, an icy and rocky body from the outer solar system, captured by Neptune. Hmmmm.

What could drive such activity on Pluto? On Earth (or rather, under it) it’s the hot mantle moving under the continental plates that causes our tectonic activity. For Io’s volcanoes and the geysers of Enceladus (moons of Jupiter and Saturn) it’s tides from their parent planets.

Pluto and Charon are locked in both orbit and spin, so the tidal forces should all be balanced… now. However, it’s thought that Charon may have formed after a big impact on Pluto, blasting material into orbit that coalesced to form the moon. For some time after that event there would have been considerable tidal stress on Pluto, and the jets may have been active back then, leaving their marks on the surface.

The same is true for Charon as well, and the tides on it would be 10 times larger (since Pluto has ten times the mass of Charon). Note that Charon is a lot darker than Pluto. Did it have even more activity than its big brother?

With close encounter just a week and a half away, we’ll be getting more amazing pictures every day. Unfortunately, New Horizons will be dipping low over Pluto’s opposite hemisphere from these weird features, so we won’t get super close-ups of them. But we’ll certainly get some better shots over the next few days.

This is getting so exciting! Stay tuned.

Categories: Astronomy Headlines

Carreyed Away

Wed, 07/01/2015 - 08:37

On Tuesday, California Gov. Jerry Brown signed SB-277 into law, removing the ability for parents to opt out of vaccinating their public school-age children for personal and religious exemptions.

In the wake of this, I knew the anti-vaccination cavalry would be mounting their steeds. What I wasn’t expecting was a series of tweets from actor Jim Carrey, showing exactly why those of us on the side of reality cannot rest, even after a lovely legislative victory.

Jim Carrey is a comedic actor, and I’ll note that I quite like a few of his movies and performances. But I stopped going to the theater to see them a few years ago, after he hooked up with Jenny McCarthy and joined her on her bizarre and fact-free crusade against one of the most successful medical procedures of all time.

He’s been vocal in the past; in 2009 he wrote an anti-vax screed for the Huffington Post (the journalistic equivalent of the Mos Eisley tavern for anti-vaxxers)*, and he joined McCarthy to publicly defend the disgraced and humiliated doctor Andrew Wakefield, whose unethical research, retracted paper, and conflicts of interest started the modern anti-vax movement and earned him an accusation of fraud from the British Medical Journal. When they were together, he and McCarthy were the public face of the anti-vax movement, promoting the long-debunked notion that vaccines cause autism.

They don’t.

But this hasn’t stopped Carrey. Tuesday night he went on quite the rant on Twitter, sending out a series of tweets that were, to be charitable, completely wrong. Let’s take a look.

Greed? Ah, a variation on the “Big Pharma shill” gambit, the claim that somehow pharmaceutical corporations make huge amounts of money on vaccines. Actually, if money were the only reason they did this, it would be far more profitable for those companies to let people get sick. Hospital and clinic visits make them way more money.

One of the basic claims made by anti-vaxxers is that there are toxins in vaccines. But there are toxins in everything. The concern isn’t that they’re there, it’s in the amount. Eating one aluminum atom won’t have any effect on you, and people tend to have a few dozen milligrams in their bodies all the time. Not all vaccines have aluminum in them, and ones that do have it in such a teeny amount it has negligible effect on you.

As for mercury, hang on a sec …

Yes, this does make sense! That’s because Carrey, despite having a vast amount of information literally at his fingertips, doesn’t understand the difference between ethylmercury and methylmercury.

Methylmercury (with an M) is a form of mercury that is bioaccumulative—that is, it builds up in the body over time. People get it in their systems in a number of ways, including eating some fish.

Ethylmercury (with an E) does not bioaccumulate, and breaks down after a couple of weeks, and your body eliminates it. Thimerosal, which used to be used in many vaccines, breaks down into ethylmercury. This process is quite safe, but after a public outcry spurred by misinformation and confusion on these two forms of mercury, thimerosal was discontinued in most vaccines. It’s now used in very small doses only in some flu vaccines.

Also? It’s been shown, conclusively, that there is no connection between thimerosal and autism. None.

Yes, Mr. Carrey, you are anti-vax. You can’t pick and choose what to believe in and what not to, and then say you’re not anti-vaccine. This gambit was tried by Jenny McCarthy and by RFK Jr. It rings just as hollow with them as it does now. If you’re trying to scare people out of taking vaccines because of obviously and provably false information, then you’re an anti-vaxxer.

As I’ve written before:

Saying in one breath that vaccines have done good but then in another attacking them and increasing fears of them based on nonsense puts [RFK Jr.] squarely in the anti-vax camp. It’s like saying that most UFO cases are just misidentified normal things, but the ones we  haven’t identified are definitely alien spaceships that come here to stick probes in our various orifices. Acknowledging one aspect of reality and then claiming absurdities does  not make you pro-science.

Speaking of which …

Here's a bit of free advice: Run, do not walk, away from comparing yourself to RFK Jr. That may not be the best line to take. For starters, he is indeed an anti-vaxxer. He’s also a conspiracy-monger, and, unfortunately, an influential one, since he does have political clout. And given that we can’t always trust our elected representatives when it comes to health issues, that makes him especially pernicious.

Jim Carrey can yell that he’s not anti-vax at the top of his lungs, but that doesn’t change the fact that he really, really is.

After his Twitter tirade Tuesday night, the replies started flowing in, and I was pleased to see just how many were against him. I guess Carrey didn’t learn the lesson from McCarthy that sometimes going on Twitter doesn’t generate quite the result you were hoping for.

In the end, though, SB-277 is now law, and if you live in California you have to vaccinate your children if you want them to attend public school, unless you have a valid medical reason for not doing so. I think that’s real progress

I’m happy to discuss the ramifications of laws like this on the basis of parental rights—as a parent myself I have very strong feelings about those rights. I’m also something of a social libertarian, wanting most rights to lie with the people, and not the government. But I also know those rights must have limits, because people make mistakes and in some cases need to be regulated.

The health and welfare of the public certainly constitute one of those cases. So again, I thank Gov. Brown, and I hope many more states follow suit.

*Correction, July 1, 2015: This post originally misspelled Mos Eisley.

Categories: Astronomy Headlines

Which Hunt?

Wed, 07/01/2015 - 04:00

In early June, Nobel Laureate Tim Hunt was asked to speak at a luncheon sponsored by the Korea Federation of Women’s Science and Technology Associations at a science communications meeting in South Korea.

What he said there is now Internet history. He made a series of sexist comments, saying that the problem with “girls” in science is that they fall in love with the men, the men fall in love with them, and when you confront them they cry. He then went on to suggest labs should be single-sex.

When I first read this, I figured it was a joke. A very poorly conceived one, and a really dumb one to make, especially given that crowd. But there’s a lot more to it than that.

Many science journalists were at the lunch and witnessed the whole thing, including Deborah Blum, Ivan Oransky, Charles Seife, and Connie St. Louis. After discussing what they saw and heard, they decided St. Louis should write an article about it on her blog at Scientific American. What’s very important to note here is that both Blum and Oransky have corroborated St. Louis’s report, multiple times. Seife did as well. Blum asked Hunt about his comments, and he confirmed that he thought women were too emotional to work with men in labs.

In other words, it’s clear that even if he framed it as a joke, he was being sincere in his meaning and intent.

Then it all hit the fan. For one thing, on Twitter, news of his comments went viral very rapidly. The hashtag #distractinglysexy went viral, an amusingly tongue-in-cheek way for women to mock the idea that women are too emotional or liable to fall in love in the lab. For another, Hunt was asked to resign from his honorary position at the University College London. He also resigned from the board of the European Research Council and the Biological Science Awards Committee of the Royal Society.

Mind you, he is a retired professor, and was not fired or asked to resign from any paying positions. He lost no employment over this, despite some people claiming otherwise.

At this point the backlash began. Richard Dawkins, who, honestly, should know better by now than to wade into controversies about sexism, defended Hunt against what he termed a “witch hunt.” However, there didn’t appear to be any organized campaign to get him fired, and furthermore the University College London says it did not ask him to step down due to the social media uproar, but because of Hunt’s own remarks.

A lot of electrons have been spilled over whether Hunt went on to say, “Now seriously…”, which would indicate he was actually joking. Seife (who, again, was there at the luncheon) says Hunt never said this.

Hunt’s comments and the defense of them were bad enough, but the situation has taken an even worse turn.

The execrable Daily Mail has waded into this. On Friday, it published what can only be called a hit piece on Connie St. Louis which, bizarrely, was endorsed by Dawkins.

To say the article is problematic is to severely understate the case. It attacks St. Louis’s credentials; however, she is an award-winning journalist, former President of the Association of British Science Writers and was recently elected to the Board of the World Federation of Science Journalists. The City University London (where she is a Senior Lecturer) has publicly supported her after the Daily Mail article came out. St. Louis points out numerous errors in the article there as well.

Not-so-incidentally, the very basis of the attack appears to be based on nothing as well.

This attack is deeply, deeply ironic, given that the Daily Mail has been known to brazenly plagiarize science journalists specifically, and has been accused of other less-than-savory tactics in journalism. Even when it’s original, the publication’s level of science journalism is appalling.

Not to put too fine a point on it, the Daily Mail is to journalism what ipecac is to digestion. Also, a perusal of links to their articles running down the right-hand side of their site doesn’t exactly show them to be champions of women’s rights.

I also found it very odd that the article also dismisses statements corroborating St. Louis’s claims by Blum and Oransky (and it doesn’t even mention Seife) — who, I remind you, were all there at the luncheon and agree on what happened. Why single out St. Louis here?

And now another attack piece on St. Louis has been posted on the far-right-wing Breitbart site, saying she has become immune from criticism because she’s black.

Yes, you read that right. And that’s not all. In a sentence so tone deaf I’d swear it’s parody, the author, Milo Yiannopoulis, writes:

St Louis is responsible for the sacking of Sir Tim Hunt, a Nobel prize-winning biochemist who became the target of an online lynch mob after his comments about women in science were taken out of context.

Yes, again, you read that right. You might ignore the obviously incorrect statements in that one sentence (Hunt wasn’t sacked, he was asked to resign from an honorary position; and as we’ve seen his comments were not taken out of context), but it’s much harder to ignore that, in an article attacking a woman because she’s black, Yiannopoulis used the phrase “lynch mob.”

Yikes.

Yiannopoulis, for his part, is a vocal advocate for Gamergate, a movement that claims it’s  “actually about ethics in gaming journalism” (a phrase so thin it’s become a standard Internet joke), but which has also been viciously attacking women online. Yiannopoulis appeared on the British 24 hour news channel Sky News to “debate” this topic with Dr. Emily Grossman; while glib, his arguments were unconvincing, and unsurprisingly Grossman has been receiving misogynistic backlash for her appearance (that link also shines a light on more of Yiannopolous’s incorrect statements).

Clearly, this is quite the rabbit hole.

A lot of people are trying to squeeze this whole Tim Hunt affair in a “he said/she said” frame, but what they’re missing is twofold: Even if he was making a joke initially he meant what he said, and that’s why he’s suffered the consequences of it, and either way this event has once again shone a spotlight on the rampant sexism in society in general and in the sciences specifically.

So what now? The good news is that at least this important issue is getting airtime, getting discussed. The problem is it’s also getting hijacked, distorted, and drowned out by nonsense. This happens every time institutionalized sexism is discussed.

But discuss it we must. Connie St. Louis has called for systemic change. Science writer Matthew Francis wrote about this in context of the Nobel Prize itself. Science philosopher Janet Stemwedel wants scientists to be more vocal in decrying statements such as Hunt’s. Emily Grossman shows we need to quash sexism so that at the very least women don’t feel unwelcome in STEM fields. Stemwedel has written along those lines, too. Uta Frith, writing at the Royal Society blog, talks about the impact this has and will have on diversity in the science.

As always, it’s important for men to speak up as well. This isn’t a women’s problem, clearly. It’s something we all need to be aware of and to speak up about.

And in the end, while the spotlight may be on Hunt and what he said, that light has certainly cast a very large reflection on the rest of us.

Here are other articles I’ve written on this issue:

Science Advice and Sexual Harassment
#YesAllWomen
The Silencing of Hate
Shirtstorm
Harassment as Art
I Stand with Emma Watson

Categories: Astronomy Headlines

Pluto Grows Under New Horizons’ Watchful Eye

Tue, 06/30/2015 - 10:12

Right now, Pluto is about 25 pixels across in the New Horizons space probe’s long-range camera. In a week it’ll be 50 pixels across. A few days later it’ll be well to 100 … and then it’ll grow by the hour.

What will we see? I wrote about all this for my twice-monthly column for Sen.com. Go see! It’s subscription only, but c’mon. I’m worth it.

Categories: Astronomy Headlines

A Refreshing Illusion: Flat Glass of Water

Tue, 06/30/2015 - 04:00

I love fun illusions, and I happened upon one that’s pretty interesting to see: An artist draws a glass of water that is startlingly 3D:

Oddly, the illusion is actually more convincing to watch at lower resolution and with a smaller window; that washes out the pencil strokes and actually makes the illusion more realistic. I can’t remember the last time I saw something like that.

This type of art is becoming common in street drawing; a web search will yield a bazillion very cool examples.

This technique is called forced perspective, in that it takes the cues your eyes and brain use to estimate relative distance (like, when one object is closer than another) and plays with them, forcing you to interpret those cues a certain way.

When the artist rotates the drawing so the top of the glass is toward you it looks all weird and distorted because your brain is confused. I love the irony; it shows you this is a drawing and not real, yet your brain may take a moment or two to actually settle with that. Our brains just love to be fooled.

My friend and evil twin Richard Wiseman* is a master at this. Watch this video he created:

Richard is a psychologist who studies things like this. I strongly urge you to watch the videos on his Quirkology YouTube channel and to read his books. It’s really good stuff.

... and please check out what I still consider the single greatest illusion of all time.

Tip o’ the Necker Cube to David Darling.

* He claims I’m the evil one, thus proving he’s the evil one.

Categories: Astronomy Headlines

Weighing A Galactic Monster 

Mon, 06/29/2015 - 04:00

How do you weigh a black hole?

That is, to be more precise (or pedantic), how do you figure out what the mass of a black hole is?

There are actually lots of ways, but they all depend on a very simple law of gravity: If you’re orbiting something (whether it’s a black hole, a star, a planet, or anything else), the closer you are, the faster you’ll go.

If you start there, and make a few assumptions, then all you need to do is observe stuff orbiting the black hole, figure out how quickly it’s moving, and boom. The black hole mass falls out.

Astronomers have been doing this for a long time. Observing stars in motion — literally, watching them physically move over several years — in the center of our own Milky Way galaxy shows that the supermassive black hole residing there has a mass of over four million times that of our Sun.

Another way is to look at the motion of stars and gas in another galaxy. We can’t see their stars moving directly, but as they zip around the central black hole sometimes they move toward us, and sometimes away. That creates a Doppler shift, a shifting of the light emitted toward the blue and red end of the spectrum. The amount of Doppler shift depends on the velocity of the population of stars and/or gas as they orbit, and that means you can get the black hole mass that way. For example, gas in the center of the galaxy M84 was used to find its black hole has a mass of over a billion times that of the Sun!

Now astronomers have used a different way, though based on this same idea. They used ALMA, the Atacama Large Millimeter/submillimeter Array, to look at light emitted by the molecules HCN (hydrogen cyanide) and HCO (there’s no specific formal name I could find for this, but it’s a carbon atom bonded to an oxygen and hydrogen atom) in the galaxy NGC 1097. ALMA is very precise, and they were able to find both the location of the gas and its velocity.

This gas orbits well outside the black hole, and there are stars there too, millions of them. To account for them (because if they don’t, they’ll get too high a mass for the black hole) they used Hubble observations of NGC 1097. They then fit a series of models, each using different black hole masses, to see which one fit the observed velocity of gas best.

Their result: NGC 1097 has a 140 million solar mass central black hole. That’s way beefier than ours. Also a bit higher than previous estimates of 100 – 120 million.

The reason this is important is that a lot of galaxy characteristics seem to be affiliated with how massive the central black hole is. We can only measure the motion of stars and gas near the center of nearby galaxies, but some of these other characteristics can be seen in galaxies much farther away. If we can get good measurements in different ways for nearby galaxies, we can use that to bootstrap our measurements for the more distant ones.

Also, NGC 1097 is a barred spiral galaxy, and for various reasons these can be very difficult beasts to observe and get the mass of their black holes. These new results should help resolve some of those issues.

So there you go. If you want to take the measure of a black hole, you have to see how things behave nearby it. That’s probably good advice for many things in life, but nothing more so than the heftiest single objects in the Universe.

Categories: Astronomy Headlines

Uncrewed SpaceX Falcon 9 Rocket Explodes After Launch

Sun, 06/28/2015 - 08:57

A SpaceX Falcon 9 rocket carrying supplies to the International Space Station exploded about 2 minutes and 20 seconds after launch this morning. No people were onboard; it was an uncrewed resupply mission. The cause is not yet known.

Here is video of the event (launch is at 51:48, the explosion at 54:05):

SpaceX has not released details yet; a press conference is scheduled for no earlier than 12:30 EDT. I’ll update here when I know more.

Looking at the video, the explosion doesn’t release flames, but instead you see a vaporous white cloud blow away. My guess — and I’m no expert — is that this was a pressurized cryogenic tank failure of some kind. But again, we’ll know more very soon.

Update 1, June 28, 2015 at 16:10 UTC: SpaceX CEO Elon Musk just tweeted that it looks like a tank overpressurization event, as I had guessed:

We should know more soon.

Update 2, June 28, 2015 at 17:25 UTC: At the news conference, SpaceX President Gwen Shotwell noted that first stage flight went well, and the problem that led to the loss of the vehicle lay elsewhere. They have telemetry from the Dragon capsule from the event, and they are investigating it.

Also, I think you can see the Dragon capsule falling away seconds after the explosion. This is a screen grab from a YouTube video, taken at the 54:09 mark. It’s about the right shape, and it’s not too much to think it would survive the destruction of the upper stage. SpaceX hasn’t said, so this is in no way official, but I’m speculating again that there was a tank rupture as per Musk’s earlier tweet. This would’ve led to a big blowout of gas, which caused the vapor cloud. Then the pressure of the rocket’s flight through the air led to the catastrophic collapse of the upper stage. Dragon may have just fallen away after that. It’s also possible the range officer exploded the rocket after seeing the problem. We’ll know more soon. But again, this is guesswork on my part.

The Dragon capsule on top of the rocket had food and supplies for the astronauts on ISS. The three astronauts on board have enough food to last for many months, so they should be OK for now. Also on board the Dragon was an adapter ring for the ISS that would allow future commercial vehicles easier docking access.

This is the first SpaceX failure since they began resupply missions to ISS, but the third overall failure to ISS, including the loss of a Progress vehicle in April and the Orbital Antares rocket in October of 2014. This comes at a time when the Senate has been trying (wrongly, in my opinion) to cut back on funding for SpaceX and other commercial companies, so I expect we'll see statements from those Senators on this event shortly. Read them with a grain of salt. Again, we'll know more shortly. Stay tuned.

Categories: Astronomy Headlines

California May Make It Harder to Opt Out of Getting Vaccinated. I'm OK With That.

Sun, 06/28/2015 - 04:00

California may be about to pass a law that only allows parents to opt their public-school-attending children out of vaccines for medical reasons. Personal or religious objections will no longer be accepted.

This bill, SB-277, has been approved by the state Assembly, and is going to the desk of Governor Jerry Brown to sign or veto. It’s hard to say what he will do, as he can be unpredictable.

I’m writing this to urge him to sign it. I support this bill.

While this issue can be subtle, when all is said and done I support mandatory vaccines for public school children. I’ve been pretty clear about it:

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.

Some people want to claim religious exemption from getting vaccinations, but I don’t find this argument compelling:

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. 

By the by, there are very few religions that preach against vaccination (one exception: the Dutch Reformed Church, and there was a major measles outbreak in one of their communities in the Netherlands in 2013). The idea of a religious exemption is, to me, something of a non-issue. But, in the end, I don’t think there should be a religious exemption, either.

Certainly there should be some medical exemptions; some children are allergic to some of the ingredients in vaccines, for example. But these too are relatively rare.

When it comes to refusing vaccines, the largest group is obviously composed of people who think vaccines are somehow harmful, or that mandatory vaccination is taking away their rights.

For those opposing it because they think vaccines are unsafe, well, they’re just wrong. There’s no delicate way to put that, no cushioning it. The claims of health concerns from anti-vaxxers are long, but completely unfounded. Vaccines don’t cause autism. Andrew Wakefield, whose research is the very basis of the modern anti-vax movement, has been called a fraud, has been shown to be guilty of scientific misconduct, has been shown to have had a massive conflict of interest in his study, has been shown to have acted unethically, and simply to have been wrong. I mean, sheesh.

Vaccines don’t have toxins in them at anywhere near the levels needed to cause problems (as doctors say, dose makes the toxin). Vaccines are effective, their benefits vastly outweigh any small risk, and are a medical triumph.

For those opposing the bill because they are concerned about parental rights, that’s understandable, but limiting parents’ rights is in some cases justified, especially for the child’s health or for the public welfare. In fact, your rights already are limited. As one obvious example, you can’t drive your child around in a car without them in a safety seat if they’re young, or without wearing a seat belt for older kids. Heck, the state has the right to take your child away from you if you are obviously endangering, neglecting, or abusing them… a sad necessity, but a necessity all the same.

If you don’t vaccinate your child, and there is not a medical reason for it, then you are needlessly endangering your child. It’s really that simple.

And it’s worse even than that. You’re also endangering every child who goes to school with your child.

There are a lot of horrid diseases with devastating health effects that we can stop dead in their tracks with vaccinations. Yet we see outbreaks of them all the time in America, and in many cases it’s because people aren’t vaccinating.

This recent bill in California was spurred by the outbreak of measles that occurred at Disneyland in early 2015. But the need for it is far more broad than that.

Governor Brown: Please sign that bill into law. You could be saving a lot of children's lives.

Categories: Astronomy Headlines

The Summer Triangle... Up Close

Sat, 06/27/2015 - 04:30

If you go outside after sunset — and can tear your eyes off of the spectacle of Venus and Jupiter slowly merging in the west — turn around and look to the east. Not long after the sky gets good and dark, you’ll see a trio of bright stars not far above the horizon. Day by day, as summer shambles on*, these stars will be higher in the sky, seemingly strengthening as the season does as well.

This is the iconic Summer Triangle, made up of three of the brightest stars in the sky: Vega, Deneb, and Altair. Straddling the Milky Way, to thousands of amateur astronomer the trio is a sure sign of the season.

I’ve seen countless wide-angle shots of them, placing them in context in the sky, but master astrophotographer Rogelio Bernal Andreo has done something different; taken close-ups of each stars, to show what they look like as individuals:

WOW.

All three are interesting stars. Altair is the brightest star in the constellation Aquila, the eagle. It has a bit less than twice the mass of the Sun, is more than 10 times more luminous, and is located about 17 light years away, making it one of the closest stars you can see with your naked eye. Its brightness is mostly due to its proximity; while it’s physically brighter than the Sun, from a hundred light years away you’d barely notice it.

Vega, in the constellation Lyra, the lyre, is somewhat more massive than Altair, but nearly four times as luminous. Even though it’s 25 light years away, it appears to be a bit brighter than its neighbor. If the name is familiar, try watching the movie (or reading the book!) Contact, by Carl Sagan. In the 1980s, Vega was found to be putting out more infrared light than expected for a star of its kind, and this is due to a vast disk of debris circling the star, possibly due to the collision of comet-like bodies orbiting it. This material is what’s emitting the infrared, and in fact many such disks have been found around other stars.

Deneb, though, is the bruiser of the three. The brightest star in Cygnus, the swan (also called the Northern Cross), it’s a monster. It has 20 times the mass of the Sun, and blasts out light at 200,000 times the rate the Sun does! It’s so massive it will one day become a supernova. At 2,500 light years away, though, there’s not much to worry about. Even if it doesn’t explode in a million years, it’ll still be too far away to hurt us. But it’ll be about as bright as the Moon in the sky!

Incredible, though, that even though it’s 100 times as far as Vega, it’s only a tad dimmer. It really is a brute. In fact, it’s one of the most distant stars you can see with your naked eye, contrasting wonderfully with nearby Altair. If Deneb were as close as Altair, it would shine so brightly you could read by it!

Look at all the stars surrounding the Big Three in Andreo’s photo, though. Each of those is a sun, each with its own particular uniqueness, its own history. The vast majority of them are likely to have planets too… and even then these are just a tiny fraction of the hundreds of billions of stars in the galaxy.

The sky is filled with stars, planets… and stories. Science helps us read them.

* For northern hemisphere observers, that is. The vast majority of people on Earth live near the 40° north latitude line, and for them the stars are highest in August around 10:00 at night local time. For southern observers, they’ll be low to the north in August.

Categories: Astronomy Headlines

What Lurks in the Outer Solar System?

Fri, 06/26/2015 - 04:30

Where does the solar system end?

You might think of the solar system as being the Sun, a bunch of planets*, and various asteroids and comets.

But it’s more complicated than that. Nothing in the Universe ever really has sharp boundaries when you look at it closely. And just because some stuff is big and bright, and other stuff faint and distant, doesn’t mean you can just pick and choose where the city limits lie.

Neptune may be the outermost big planet, but there’s a whole slew of icy objects out past it. And some are way, way past it. And, not surprisingly, they’re weird.

What may be surprising is how much these tiny, distant chunks of frozen water plying the deep black have affected the history of our solar system, and even our very planet. A large fraction of your body is water, and a large fraction of that may have come from The Space Beyond Neptune.

How? Why, I’m glad you asked. Let this guy and his loud shirt tell you all about it.

* How many? Oh, roughly a dozen. Maybe fewer.

Categories: Astronomy Headlines

What Is Glittering at Pluto’s North Pole?

Thu, 06/25/2015 - 12:23

As the New Horizons spacecraft nears Pluto, more details are coming into view, and we are beginning to see surface features on the tiny world.

And that means we’ll see things that are … odd. Perhaps “as yet unexplained” is a better term, since we’re seeing these markings for the first time in human history. The press releases have been amazing, but the images released have been enlarged and processed in complex ways to bring out details.

But as the probe gets closer, we can see details without such means. The raw data are posted online within hours of them being transmitted back to Earth, and that means they are available for perusal.

I was looking at a pair of fresh ones taken just today, June 25, at 05:37 UTC (just after midnight, more or less, U.S. time), when New Horizons was just 22.9 million kilometers from Pluto. They’re amazing. Both Pluto and its large moon Charon show all kinds of features, as you can see at the top of this article (the only processing I did was a straight enlargement and a brightness/contrast fiddle). Overall, Charon is much darker than Pluto, but even then surface features are clearly visible.

But that bright spot on Pluto surprised me. That’s near its north pole, and it’s been seen before in earlier images, basically as a splotch. In this image it’s quite obvious.

I wondered if perhaps this was an image artifact, like a particle hit on the detector, but in fact it’s the same in the other image taken 30 seconds earlier. Here are the two shots side by side:

The spot is very small, probably on the same scale as a single pixel or two in New Horizon’s long-range camera. That means a slight change in the pointing can make its shape look different. Remember too this image is enlarged by a factor of about 10, which can play with the shape as well. While the shape you see may not be real, the brightness contrast is.

But the important thing to note is that it’s seen in both pictures. I’ll note too that Pluto was in a different spot in the camera’s field of view, too, so this isn’t some bad lone pixel either, messing with the shot. This bright spot is quite real. Measuring the pixel brightnesses, it looks to be about twice as bright as the surface around it.

Right now, Pluto is only a couple of dozen pixels across in the long-range camera’s view. New Horizons is moving so rapidly that in 10 days Pluto will be twice this size, and will double again five days after that. Features that are tantalizingly fuzzy now will continue to sharpen, and then we’ll see Pluto as it truly is.

Is this spot at the north pole a fresh impact? Is it nitrogen in its atmosphere freezing out as Pluto slowly moves away from the Sun on its elliptical orbit? Is it one big spot or a lot of little ones (like the weird ones we see on Ceres)?

Give it a couple of weeks. Because that's how close we are. After more than nine years and 5 billion kilometers of travel, New Horizons is about to give us quite a show.

Tip o' the lens cap to Karl Battams for noting new images had arrived.

Categories: Astronomy Headlines

The 2015 Earth and Sky Photography Winners

Thu, 06/25/2015 - 09:56

The good folks at the World at Night—dedicated to preserving the night sky and raising awareness about light pollution—have announced the winners of the sixth annual International Earth and Sky Photo Contest, and as usual they are breathtaking examples of the art of astronomy.

They are all beautiful, and you should see them all, but I particularly liked “The Enchanted Forest” by Lyubov Trifonova (shown at the top of this article). The aurora sweep across the sky, set against snow-covered trees in Russia. The Moon illuminates the scene while the familiar stars of the Pleiades and Taurus hang nearby. This won first place in the “Beauty of the Night Sky” category. You can tell she had to endure some fairly inhospitable circumstances to get that shot.

I was pleased to see frequent BA contributor Brad Goldpaint take second place in this category as well.

All the images have been put into a video for ease of viewing:

The contest is open to people all ages anywhere in the world, a way to show that the sky belongs to all of us. I really do like TWAN and support them; check out their site and see what they do. The photographs they have there are surpassingly lovely and will give you an appreciation of the natural heritage of our night sky.

Categories: Astronomy Headlines

A Star Boils Away Its Own Planet, Turning It Into a Megacomet

Thu, 06/25/2015 - 04:15

Hey, remember last week when I wrote about a Neptune-sized planet (called GJ 436b) that orbits a nearby star, and how it may have an atmosphere that’s almost entirely helium? That’s really weird, since the bigger planets in our solar system have predominantly hydrogen atmospheres. We’ve got nothing like a helium-rich planet in our solar system.

I wrote that the planet seemed to have no methane in its atmosphere as it should; that could be explained by a lack of hydrogen, needed to make methane. Astronomers were guessing that the planet orbits so closely to its star that the lightweight hydrogen would get blown away by the star, and the planet’s gravity is too weak to hold onto it. Helium is heavier and the planet can hold on to it better.

But hang on. It takes a long, long time to strip a planet of hydrogen. Billions of years! So, if what these astronomers were supposing is true, maybe, just maybe, GJ 436b is still losing hydrogen now.

Yeah, about that.

Astronomers using Hubble have just announced that they’ve detected a huge cloud of hydrogen around the planet, and the long, curving tail-like shape to the cloud indicates it’s being blown away from the planet by the star.

Huh.

When I got the press release for this, I did a double take. You don’t usually get observational proof of an idea so shortly after it’s first announced! But here it is.

The planet GJ 436b is called a warm Neptune because, at 23 times the mass of Earth, it’s closer to Neptune's  mass than it is to Earth or Jupiter, and it orbits the star only a few million kilometers out. From our point of view it passes directly in front of the star, transits it, once per orbit. That’s how it was first discovered; once every 2.6 Earth days the starlight dims a bit as it’s blocked by the planet. The amount of visible light blocked is small, less than 1%, but measurable.

The astronomers observed the star, a red dwarf about 30 light years from Earth, before, during, and after such a transit. They used the Space Telescope Imaging Spectrograph (a camera I helped calibrate!) to observe the star in the ultraviolet, where hydrogen atoms just love to absorb light. What they found is that the amount of UV light they saw from the star dropped precipitously, by over 50%, starting about two hours before the transit, and lasting for three hours after.

Not only that, they could measure the velocity of the hydrogen atoms as they move around the star. Using 3D modeling, the best fit to what they see is a huge cloud of hydrogen around the planet, forming a comet-like tail sweeping out behind it. Here's a the video showing a depiction of the planet and cloud passing in front of the star. The graph below it shows how the UV light gets absorbed by the hydrogen over time.

Most likely what’s happening is that the lightweight hydrogen is very hot due to the planet being so close to the star. The atoms move so rapidly due to heat that they get flung far above the planet, where the light from the star can give them an additional push, freeing them from the planet’s gravity. That push isn’t terribly strong, so they don’t just fly off and away, but instead form a puffy cloud around the planet, and a long tail of material trailing the planet as it orbits. That’s much the same as how comets form long curving tails as they orbit the Sun, too. Anyway, that’s why they see a dip in UV before the planet transits (that’s from the puffy cloud) and for many hours after (that’s the tail blocking the light).

The image at the top of this post gives you an idea of what this looks like. The star is boiling away the planet! Well, part of it, at least. Calculating the amount of hydrogen they see, and how fast it’s leaving GJ 436b, it looks like it would take many billions of years for the planet to lose all its hydrogen (though it’s possible the loss rate was higher in the past). But still, the planet is already billions of years old, so this method has clearly caused a severe depletion of hydrogen, explaining the lack of methane in its atmosphere, too.

I love it when a plan comes together.

All in all, this makes me smile. What’s not to love? A giant planet, skimming the surface of its star, its atmosphere being slowly torn away and trailing behind it, leaving behind mostly helium… which, as I mentioned in the earlier post, will make the planet oddly gray in color.

This is nothing at all like any planet we have hear in our neighborhood. That’s so cool! The goal of science may be to learn as much as we can about the Universe, but the motivation for so many of us is the weird, the spectacular, the alien, the amazing.

This planet is all of those, and more.

Categories: Astronomy Headlines

Dancing Lights Against the Sky

Wed, 06/24/2015 - 09:44

When you look up in the sky enough, you'll see some really, really weird things. 

YouTube user QuadeM13 was out riding his bike and noticed a strange light beam flashing and twisting around above a cloud. He stopped and took some video of it, and it's, well, really really weird (warning, some NSFW language is muttered therein):

So what is this thing? An alien beacon? Thor going back to Asgard?

Nope. It's ... ice crystals.

Seriously. What's happening here is a wispy cirrus cloud, made up of ice crystals, is being impinged upon from below by a rising cumulus cloud. If the ice crystals in the cirrus are long and needle-shaped, they'll align themselves with the electric field of the lower cumulus cloud, which is generated by up- and downdrafts inside the cumulus cloud. When the electric field suddenly changes (due to, say, lightning discharges inside the cloud), the ice crystals can snap into a different orientation, reflecting and refracting sunlight in a different direction (note that the plume in the video is the same color as the Sun). They do this as a group, making it look like huge coherent structures are suddenly changing shape.

In the video the flare is pretty bright, and I imagine it would be easy to be freaked out by it. I watch clouds a lot and I’ve never seen this, so I doubt it’s terribly common; you need the right circumstances of the cumulus cloud rising into an icy cirrus layer as well as the right geometry to get the sunlight flashing of the crystals.

Back in 2011, I wrote this very odd phenomenon. I had to do some sleuthing to find out what was going on, but what I didn't know at the time is that they're called “crown flashes.” That would’ve made it a lot easier to find out more!

I found a letter to Nature magazine from 1971 describing the phenomenon, so people have been seeing this for a while. A Web search on “crown flash” turns up lots of interesting pictures and videos, too.

The Internet makes finding weird things like this so much easier. I’ve been able to identify iridescent clouds, pileus clouds, and many other weird atmospheric phenomena with just a few clicks. Like any other tool, the ‘Net can be used for ill or for good. I’m glad that it can help us see—and understand—the amazingness all around us all the time.

Tip o’ the Faraday cage to photographer Jerry Lodriguss.

Categories: Astronomy Headlines

Like a SciFi Sunset: Three Crescent Moons Over Saturn

Wed, 06/24/2015 - 04:30

Every time I think I’ve seen the most amazing picture from the Cassini Saturn probe, it sends back something even more devastatingly spectacular.

Like this shot of three crescent moons huddled in the black sky!

Are you kidding me?

Wow. This image was taken on Mar. 25, 2015. The big one is Titan, the one to the upper left is Rhea, and the little one is Mimas. Titan has a thick atmosphere, thicker than Earth’s, composed mostly of nitrogen (also like Earth’s). Sunlight hitting that air gets bent around, sent around the limb, so the crescent appears to wrap farther around the moon than it would otherwise. Mimas and Rhea are airless, so their crescents look much like the familiar one we see every month from our own Moon.

All of Saturn’s big moons orbit the planet almost exactly above its equator, so when the spacecraft’s orbit crosses that plane, the moons can appear to be close together due to perspective even when they’re hundreds of thousands of kilometers apart. The Sun is just off to the lower right in this shot, setting up the correct angles to get this spectacular and breathtaking scene.

Seriously, this looks like it came right out of a scifi movie. But it’s real. Those are worlds, real actual places, ones we can explore and understand.

And we have: Titan has a methane cycle on it much like Earth’s water cycle; the simple molecule can be found in clouds over the surface which rain it out as a liquid, forming rivers and giant lakes, where it evaporates to form clouds once again.

Mimas has a gigantic single crater named Herschel that makes it look like the Death Star. Though it was almost more like Alderaan: Had the impact that formed Herschel been much larger, it would’ve shattered the moon.

Rhea has deep canyons covering one hemisphere, giving it a wispy fairy-tale look, but they are actually the walls of steep canyons caused by deep fractures in the surface. 

I love science fiction. It’s inspired me over the years, given me a glimpse into places we can only imagine.

But I love science more. It shows us these places as they actually are, and reminds us that clearly, Nature is far, far more imaginative than we are.

Categories: Astronomy Headlines

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