Bad Astronomy Blog
Astronomers have announced what may be the most interesting exoplanet discovery yet made: five planets, all smaller than Earth, orbiting a very ancient star. And I do mean ancient: Its age is estimated to be more than 11 billion years old, far older than the Sun. These are old, old planets!
There’s a lot going on here, as far as the science goes. Let me explain. No, there is too much. Let me sum up. Here are the bullet points:
- The planets were found using the Kepler space telescope, which uses the transit method: If a star has planets, and we see those orbits edge-on, the planets pass in front of their star as seen from Earth. This blocks a bit of the light, and we can measure that. The amount of light blocked (compared with known properties of the star like its size) tells us how big the planet is. The length of time it takes the planet to transit the star also gives us its orbital period, orbital size, and an estimate of its temperature.
- The star is called Kepler-444. It’s a bit cooler, more orange, and smaller than the Sun (a K0 dwarf, if you want the details), and is about 117 light-years from Earth. That’s relatively close! Amazingly, it’s actually a triple-star system: There’s a pair of cool red M dwarfs orbiting each other, and the pair in turn orbits the K star. The binary is about 10 billion kilometers from the K star, about twice the distance Neptune is from the Sun.
- The five planets orbit the primary K star, and are called Kepler-444b up to Kepler-444f. All five are smaller than Earth, and get bigger in order with their distance from the star: Kepler-444b has a diameter of 0.403 Earth, Kepler-444c is 0.497 Earth, d is 0.530, e is 0.546, and f is the biggest at 0.741 our home planet’s size.
- The planets are not in any way Earthlike! The system is very compact; all five planets are quite close to their parent star—even the most distant one, planet f, is closer to its star than Mercury is to the Sun—and therefore pretty hot. They all orbit the star in fewer than 10 days. They’re pretty well cooked.
- The system is very old. This was determined using a method called astroseismology, a bit like using earthquakes to observe the Earth’s interior. In this case, the surface of the star vibrates, like standing waves in a bathtub or the way a drumhead vibrates. The character of these waves depends on a lot of the physical properties of the star: its density, mass, surface gravity, size, and age. Very careful observations taken over many weeks were used to get the astroseismological results, and the age was found to be about 11.2 billion years, give or take a billion years. (I’ll note that in part this work was funded through the Pale Blue Dot project, which lets people adopt a star for a small fee that goes toward astroseismology research. Previously, the smallest exoplanet found used research funded through this group, too! And someone named Brian Finley had adopted Kepler-444, so congrats to him, too.)
- Assuming the planets formed along with the star—a reasonable assumption—these planets have been around a long, long time. The Universe itself is 13.8 billion years old, and the Milky Way galaxy somewhat younger. These stars and planets formed when the Universe itself was young. Put it this way: When the Sun and Earth formed, these planets were already older than the Sun and Earth are now.
So what does all this mean?
Quite a bit, actually. For one, until now we weren’t sure just how old planets could be. We’ve found some Earth-sized planets older than us, but none this old.
Initially, the Universe was almost all hydrogen and helium, with the heavier stuff coming later. The iron and nickel in the Earth, for example, were formed in supernovae, massive stars that exploded billions of years ago. As the Universe ages, it gets more and more of these elements as more of these big stars explode.
When Kepler-444 formed, there were relatively fewer of these heavy elements, and spectra of the star confirm a paucity of elements like iron. We’ve discovered enough exoplanets now that we see an interesting relationship between heavy elements and planets: Gas giants (like Jupiter and Saturn) tend to form around stars that have more heavy elements; these elements aid in the formation of larger planets. But when you look at smaller, more Earth-sized planets, that relationship goes away. Smaller planets form around stars that have lots of heavy elements, and they also form around stars that have relatively few.
The Kepler-444 system supports this. A gas giant planet would’ve been seen, so it looks like these five planets are all it has (or the biggest it has), and each is small and presumably rocky.
But what of life?
Let me remind you, these planets are flippin’ hot. The coolest most likely has a surface temperature way above the boiling point of water. I wouldn’t think there could be life there.
But don’t be so specific. Take a step back and realize that what this means is that Earth-sized planets could form around Sunlike stars even 11 billion years ago! That may have profound implications for life.
You may have heard of the Fermi paradox: If life is easy to get started on planets, then where are the aliens? We do know that life formed on Earth not too long after the planet’s crust had cooled enough to support it. Let’s say it takes 4 billion years for those protozoa to evolve and build spaceships. It turns out that, even with the vast distances between stars and limiting your ships to far less than the speed of light, you can colonize the entire galaxy in just a few million years. That’s far less than the age of the galaxy.
Perhaps you see the problem. If planets like Earth formed 11 billion years ago, and happened to form at the right distance for more clement conditions on the surface, life could have arisen long enough ago and started building spaceships long before the Earth even formed! They’d have planted their flags on every Earth-sized habitable planet in the Milky Way by now.
Where are they?
We don’t know. There are too many “maybes.” Maybe Earth is special in some way that made life easier to form here. Maybe you need iron and nickel to build spaceships (but even then there are planets a billion or two years older than us that would’ve had plenty of such elements). Maybe evolution doesn’t always work its way to intelligence. Maybe every civilization advanced enough to manipulate its environment did so to its own detriment (cough cough). Maybe they blew themselves up. Maybe they’re out there but so advanced we don’t even recognize them.
Maybe we’re just the first.
That’s always been an idea in my back pocket to explain the Fermi paradox. Someone has to be the first. But that’s a bit tougher to swallow when you see rocky planets that are more than twice as old as our own home planet. Eleven billion years is a long time.
Clearly, we just don’t have all the information yet. We’re just getting started here! We’ve discovered thousands of planets orbiting other stars, but there are probably billions of them out there. Billions! We have a lot more data to collect, a lot more information to analyze, and a lot more thinking to do before we can solve this particular mystery.
But we’re working on it. Kepler-444 and its five, small, melted, ancient worlds are just one small piece of a puzzle that is vast and deep. And they’re a good start.
I’ve seen a lot of stuff when it comes to space science and astronomy, and sure, I’m easily excited about it all … but still, it takes a lot to get me to boggle at something.
So this is me, boggling: This photo below shows grains of comet dust caught on the fly by the Rosetta spacecraft!
Yeah. That is very, very cool.
To be more accurate, they’re the remains of comet dust caught on the fly by the Rosetta spacecraft. OK, let me explain.
Comets are essentially dust, gravel, and rocks packed together by various types of ice. Generally speaking, we’re talking water, carbon dioxide, ammonia, carbon monoxide, and other things that are usually gaseous on Earth, but which are frozen in the depths of space.
Lots of comets orbit the Sun on long, elliptical paths, taking them out into the black, then back in closer to the Sun. As they near the Sun, the ice turns into a gas and blows off, and the other junk making up the comet are blown into space as well.
The Rosetta spacecraft is currently following along a comet, called 67P/Churyumov–Gerasimenko. It orbits the Sun once every 6.5 years, going out as far as Jupiter’s orbit (it’s called a Jupiter-family comet, in fact, a member of many comets with similar orbits), dropping down to just outside Earth’s orbit. As I write this, the comet is about 370 million kilometers from the Sun, a bit more than twice Earth’s distance, and still outside the orbit of Mars.
Still, that’s close enough that it’s already becoming active, and we see streams of gas flowing out of it. That means dust particles are coming off too. The thing is, “dust” is a somewhat generic term for tiny flakes of stuff that can have wildly different compositions. Rosetta is in the unique position to find out what 67/P’s dust is made of. So engineers and scientists gave it a shot.
That shot is COSIMA, the Cometary Secondary Ion Mass Analyser. Have you ever been in a snowfall and caught snowflakes on your tongue? That’s COSIMA, except it has a plate exposed to space instead of a tongue, and instead of snowflakes it’s catching, well, comet snowflakes.
When 67/P was still more than 450 million km from the Sun, and just 30 km from the comet, Rosetta caught several flakes of material from the comet. They impacted the plate at speeds of just 1–10 meters per second, roughly bicycling speed. The photo above shows two such specimens (the scale bars represent 500 and 300 microns, where a human hair is roughly 100 microns wide).
When they hit the plate they fragmented. If there had been lots of ice in them, they would have been held together better and wouldn’t have shattered, so right away this tells us the flakes were dry (not like Earth snowflakes at all). They also have a high sodium content, which matches lots of other interplanetary dust particles, particularly meteoroids that burn up in our atmosphere during meteor showers. We know those come from comets, so that checks out! This means we’ve actually found a sample of the parent material of meteor showers. Cool.
But what’s also interesting is what this means for the surface of the comet. These particles were emitted when the comet “turned on” again, getting close enough to the Sun to become active. Scientists think these grains were actually left over from the last time 67/P came ‘round the Sun. As the comet began to head away from the Sun, the flow of gas outward weakened, and wasn’t strong enough to lift dust away. That material then sat on the surface, and was lifted off as the outflow became strong once again a few months ago.
That outer mantle of older dust will be shed, and then more stuff deeper down will start to get flung away. When this happens the dust content may change, possibly showing us other types of material as well. Rosetta will be around for that; it will follow the comet for many more months as it gets to its closest point to the Sun (called perihelion). The comet should become more active, and we’ll get to investigate what lies beneath.
That to me is incredibly exciting. We know a lot about comets, but the devil’s in the details, and every comet is different. Heck, even a single comet changes a lot over the course of a single orbit, so by monitoring 67/P for several months, we’ll learn a lot about these weird beasts. And that’s the whole point.
After a ten-year voyage, the Rosetta spacecraft entered orbit around the comet 67P/Churyumov–Gerasimenko in August 2014, the first time such an achievement had ever been made. Most of the images made public at the time (and since) were from the wide-angle NAVCAM instrument, and only a handful of the higher-resolution OSIRIS camera pictures were released.
But now the first results from the observations have been published, and quite a few close-up images from OSIRIS have been revealed… and they’re spectacular. The comet is a bizarre, alien place, where our notions of up and down get stymied, and where our “common sense” (from having grown up on a vast, heavy-gravity, be-atmosphered planet) is likely to betray us.
Here are some of those pictures that caught my eye.
To orient you, here is an annotated map of the comet’s surface. It’s shaped overall like a rubber duckie, with the small and large lobes connected by a relatively thin neck. The different regions are separated by overall large-scale appearance, probably due to ongoing processes shaping the comet’s surface. Note the names; Rosetta was named after the Rosetta Stone that allowed linguists to decipher the ancient Egyptian language, so all the features on the comet are named after various Egyptian gods (or possibly Goa’uld).
Comets are basically rocks, gravel, and dust held together by various ices (like water, carbon dioxide, and other things we normally think of as gases). As it nears the Sun, a comet becomes active; the ice turns directly into a gas (called sublimation), dislodging all that other material. 67/P is already becoming active as it nears the Sun. It’s been known that vents over the surface of a comet expel gas as the ice sublimates. The (overexposed) picture above shows depressions in the Seth region, and the center one is actively spewing out jets of gas. Those may look like impact craters, but they’re actually something of the opposite: pits that are growing as the material inside them is blasted out into space. It’s erosion, comet-style.
The comet is in the hard vacuum of space, so you probably wouldn’t expect to see wind-driven features on the surface… but that’s just what the above picture appears to show! Those ripples in the surface look very much like dunes. The obvious culprit is a temporary wind blown as the ice sublimates, the resulting gas streaming away and pushing surface material (probably very fine dust) around. That may be what formed these features, but right now scientists aren’t sure. Other features also indicate winda shaped them, too.
I found myself particularly drawn to this photo, showing the Imhotep region. The smooth floor looks like ponding, where flowing material builds up in a depression. This is seen on the Moon, for example, but it’s usually from ancient lava flows. In this case, it’s likely to be dust that’s built up. Note in the upper left there’s an area at slightly higher elevation that’s also smooth; did the material flow down from there? On the right is a step-like feature, probably built up from multiple ponding events. It’s unclear what could do this; seismic activity as the comet expands and contracts thermally? An impact from a small asteroid whacking the surface hard enough to create a cometquake? Particularly violent eruptions as new ice pockets are exposed to the Sun?
The comet spins once every 12 hours, and the rotation axis goes through the neck in such a way that the lobes go around each other, end over end. This may be why there’s a huge crack, over 500 meters long, in the neck of the comet! It extends from Hapi into Anuket, at one point disappearing and reappearing again farther along. This indicates it’s a large-scale feature.
Is the comet in danger of splitting in two? Comets do fall apart, sometimes even disintegrating completely, so it’s entirely possible this fate awaits 67/P. Measurements by Rosetta indicate the comet has a very low density, suggesting it’s porous, more like a loosely-bound collection of rubble than a solid body. It’s hard to saw what will happen as it erodes away, spilling its guts to space as it passes the Sun over and again.
The beauty of all this is that this adventure has just begun! The comet is still inbound, getting closer to the Sun, and the primary mission of Rosetta will last at least a year, tagging along to watch the comet change as it nears our star. It’s expected to become more active as it does so, outgassing more. Will this change the features we’ve already seen? I expect it will, and I’m eagerly awaiting more images of these regions, so we can see the incredible forces shaping this tiny—and extremely weird—world.
Ten Things You Don’t Know About Comets
Here’s What A Comet Looks Like When You’re Close Enough to Touch It (gallery of stunning comet photos)
Rosetta Arrives at a Comet!
Rosetta’s Comet Sprouts a Jet
Philae Spotted Hopping Away in Photo of Comet
Swedish astrophotographer Göran Strand took that picture above. It shows a halo around the Sun, replete with parhelia, over Lake Storsjön. That’s his son in the photo.
Besides being extremely beautiful and poignant, it’s also just an astonishing shot. Strand used a 14mm wide-angle lens, which he needed because the full halo is 44° across, a quarter of the way around the horizon. A lens like that really compresses distance, so I’d guess his son was standing right in front of him.
Haloes likes this are relatively common. They’re due to flat hexagonal ice crystals in the air. As sunlight enters a crystal it gets bent, refracting as it enters and as it leaves the faces of the crystal. The light gets bent by a total of about 22°, so crystals that distance from the Sun along your line of sight bend the sunlight toward you. Crystals closer to the Sun bend the light away from you so it’s darker inside the halo. Depending on the exact orientation of the crystal, some of the light gets bent more than 22°, so ice outside that 22° bright ring also bend light toward you, though not as strongly, so the halo fades away outside the optimal 22° angle.
When I say “degrees”, I mean an angular distance on the sky, where 90° is the angle between the horizon and the zenith, straight overhead. Your outstretched fist is roughly 10° (I have big hands, so for me it’s more).
The light forms a circle because that shape defines a constant distance from a point; for a halo that point is the Sun (the center of the circle), and the ice crystals 22° away from it fall along the circle of that size.
As it happens, red and blue light get bent by different amounts as they enter and leave the ice crystals; red light is bent a wee bit less, so the inner edge of the halo is redder and the outer part bluer. You can see that in Strand’s photo.
Parhelia—also called sundogs—are also caused by the hexagonal crystals. As the crystals fall through the air they align flat, face down to the ground. When the line between the Sun and crystal is parallel to the horizon, a lot more light gets bent toward you, so you get really bright spots on the halo on opposite sides.
It looks like he has a sun pillar in there, too: a vertical shaft of light caused when the flat crystals are slightly tipped, reflecting light toward the observer. That can only happen with crystals seen directly above or below the Sun.
I’ve seen haloes and parhelia I-don’t-know-how-many times. Dozens certainly. Hundreds? Maybe. I look up a lot. If you haven’t ever seen this incredible and lovely display in the sky, then you know what to do.
Sometimes what you see depends on where you are. And when you look around from orbit, things can look really, really strange.
Don’t believe me? Then watch this Vine video posted by ISS astronaut Terry Virts, an animation showing the Moon setting as seen from space:
See what I mean? The caption says,#moonset during high-beta a while back. It gets squished, turns red, and disappears- pretty cool.
There’s a lot packed into those few words. First, when the Mon sets as seen from the space station, it’s more a reflection of the space station’s movement around the Earth than the Moon’s. For us on the ground, the Moon sets once per day, but from the station it sets 16 times per day! The Moon appears to move around the sky faster, and it moves through its own diameter in just under eight seconds. From the ground that takes closer to two minutes. The video is sped up, but not as much as you might think.
Why does it get squished? That’s an atmospheric effect. The air acts like a lens, bending the light from the Moon; as the Moon sets the bottom is seen through thicker air, which bends the light more. In effect, the bottom of the Moon looks like it sets slower than the top, so the Moon gets squished.
The redness is due to another atmospheric effect: scattering. Light from the Moon comes in from space and encounters our air. Photons, particles of light, hit the molecules of nitrogen and oxygen and scatter, a bit like two pool balls hitting each other. Blue light is way more sensitive to this than red. When the Moon is on the horizon, we’re looking through a lot more air, so there’s a lot more scattering. The blue light gets sent off in random directions, away from our eyes, while the red light gets through, making the Moon look red. It’s more complicated than this (haze, pollution, smoke and other factors can amplify the effect) but that’s the gist of it.
You can see this photos, too: Appropriately enough, here’s one Virts posted right after the moonset video:
Finally, what’s all this about the “high-beta a”? In this case, for Twitter, Virts was being brief: He means the beta angle, which has to do with the orientation of the space station as it orbits the Earth. Here’s a diagram via NASA:
The angle between the space station’s orbital tilt and the direction to the Sun is the beta angle. In this drawing, the tilt is such that the station is nearly face-on to the Sun. That’s a high angle. If it were more edge-on to the Sun (as it would be three months later, when the Earth has moved around its orbit ¼ of the way) then it would be low beta angle.
This affects the orientation of the Moon. This gets complicated pretty quickly, but in general, if his video were taken during low beta angle, the Moon would have looked more like it was facing into its own movement, in this case moving more right-to-left (or maybe left-to-right, depending on orbital angles). At high beta angle, the movement is closer to perpendicular to that.
Another way to look at it: See that line dividing night and day on the Moon? That’s called the terminator. Speaking very roughly, seen from Earth the Moon tends to move across the sky in a direction perpendicular to that line. But because the space station was at high beta angle, the Moon’s movement is nearly parallel with it.
I know, this can be headache inducing. I had to draw myself some diagrams to make sure I understood this myself. The details get pretty maddening, like the Moon’s orbital tilt with respect to the Sun, the season, the latitude of the observer, and more. That’s why I’m saying my descriptions are very general! To make them specific would take a lot of words. A lot.
Anyway, the point is, there are more things in heaven and Earth than are dreamt of in your philosophy… unless you understand the physics. And play the angles.
Astronomy is a funny science. There’s all the technical, physical stuff: Orbits, planets, galaxies, stars, and all that. You can spend a lifetime—multiple lifetimes—learning that.
But there’s also going out and doing it. Looking up, observing the skies. And the easiest way to do that is without telescopes, binoculars, cameras or any other equipment: Just stand (or sit or squat or lie down) under the stars and watch them.
And I mean really watch them. What do you see?
A lot, actually. There’s an amazing amount you can learn about the Universe just by paying attention to what’s going on over your head… and that’s what Episode 2 of Crash Course Astronomy is all about: Naked Eye Observing.
This week is a great time to go out; the Moon is new, Venus and Mercury still grace the western horizon after sunset, Jupiter is on the rise in the east, and lots of bright, pretty, colorful stars are yours for the viewing.
All you have to do is go outside and look up. Go!
P.S. Don’t forget to watch Episode 1, too.
Ah, your government inaction. Yesterday, the Senate voted on whether reality was real. And they voted the wrong way.
The Senators were debating the bill to give a go-ahead to the Keystone XL pipeline. As is usual with a bill of this size, there were several amendments attached to it. One, by Sheldon Whitehouse (D-Rhode Island), was quite simple. It stated,AMENDMENT PURPOSE:
To express the sense of the Senate that climate change is real and not a hoax.
That’s it. That’s the whole amendment. The Senate voted, and it went 98-1 in favor (the one nay vote: Roger Wicker (R-Mississippi)). So the Senate voted that climate change is real, and not a hoax.
This may surprise some folks, given the GOP’s majority, and how so many of them are climate change deniers. But it didn’t surprise me at all, because I’m familiar with how deniers weasel their way around an argument… and sure enough, I was proven right.
James Inhofe (R-Oklahoma) is the most vocal science denier in the Senate, literally having written the book on it. You’d expect him to vote “nay” on the amendment, right?
Ah, here’s where I knew what he was going to do. He voted “Yea”. How? Because as the deniers like to say, “The climate’s always changing.” It’s a cheat, a cop-out. Yes, the climate is always changing, but we know that in the past few decades that change is due almost if not entirely to human activity. The amendment left out that last bit, giving deniers the wiggle room they needed.
And, as I expected, that’s exactly what happened. Inhofe, for example, was able to vote for the amendment because while the climate changes, he thinks that the idea of humans causing it is a hoax. He tweeted as much:
Knowing this, he even went so far as to co-sponsor the amendment!
This really shows is just how out of touch Inhofe and his compatriots are with reality. Even his “yea” vote was nothing more than a craven political ploy. It was simply a dodge.
And his ridiculousness just got worse when he took to the floor to give his speech; he said it was arrogant to think humans can change the environment. Um, Mr. Inhofe, I refer you to the ozone hole, which was caused by humans, and then actually put on the mend by humans, too.
Anyway, things got weirder with another amendment, sponsored by Brian Schatz (D-Hawaii), saying that the climate is changing and that humans are “significantly responsible”. That amendment, as I expected, was shot down, though interestingly only by a 50 to 49 vote.
One particularly brain-twisting bit about this came from Lisa Murkowski (R-Alaska):Republican Lisa Murkowski of Alaska urged her colleagues to vote down the amendment for one specific reason: the amendment says that human activity “significantly” contributes to climate change. That word was a matter of “degrees,” she said on the floor.
That’s really ironic, given that Merkowski’s understanding of global warming is pretty screwed up. She claims volcanoes spew out more emissions than cars. That’s exactly wrong, for two reasons: 1) Humans generate far more CO2 than volcanoes do annually, and b) volcanoes actually emit a lot of sulfur dioxide, which is an aerosol that acts to cool the climate. Despite aerosol emission, the planet’s getting hotter. Why? Humans.
Anyway, that amendment was Inhofe’s (and the other deniers’) out: They could vote that change is real (essentially with their fingers crossed behind their backs) knowing that they could also vote on the other amendment saying humans aren’t causing it.
I’ll note four GOP Senators voted “yea” on this: Kelly Ayotte (New Hampshire), Lamar Alexander (Tennessee), Mark Kirk (Illinois), and (to my surprise) Lindsey Graham (South Carolina). I will have to keep my eye on them; I don’t know if this means headway is being made into the atmosphere of GOP climate change denial or not.
This vote was largely for show anyway, since the resolutions aren’t binding in any way. And President Obama has said he’ll veto the pipeline bill in any case.
So in the end, this vote only shows us what we already knew: Climate change deniers in the Senate are still willing to ignore the overwhelming evidence of science, and are more willing to score cheap political points than take any real action. The real question now is, will they be able to come up with the number of votes needed to override the President’s veto?
Michael Shainblum is a photographer whose favorite target is the Milky Way (though he took one of the most amazing photos of 2014, lightning hitting the Burj Khalifa, the tallest building in the world).
He sent me a note recently that he caught an unusual scene in Big Sur, California, and, well, take a look:
How cool is that? The Milky Way is almost exactly vertical, plunging down into the Pfeiffer Beach Keyhole Rock, a natural arch carved by erosion. But what’s that glow in the hole? That’s the crescent Moon, setting into the horizon but blocked by the rock itself. The Moon’s path across the sky against the background stars passes fairly close to the center of our spiral galaxy, which we see edge-on because we’re inside it.
This shot is a mosaic of five panels, going from nearly to the zenith down to the rocks at the foot of the tripod supporting the camera. I suspect the subtle illumination of the arch is from the rocks, water, and beach that were lit by the Moon; their back-reflection would then light up the side of the arch facing the camera.
I’ve seen a lot of photos of the Milky Way on the sky, so sometimes you really need to pick your foreground—and the timing—just right to get a photo that really stands out.
You can see more of Shainbum's work on his Facebook page, too.
A team of astronomers made something of a news splash late last week when they announced they have indirect evidence that there could be one or more massive planets orbiting in the solar system well beyond Neptune.
I read their journal paper, and their argument is certainly interesting (I’ll explain it in a sec). But let me be clear here: Their evidence of any possible planets out past Neptune is indirect (they don’t have photos or anything like that), it’s based on a small number of objects, and we do have evidence that there aren’t really big (like gas giant–sized) planets past Neptune. And it pains me to even have to bring this up, but of course this has nothing to do with Nibiru crackpottery, either.
Bottom line: To me, this is an interesting and potentially promising line of research, but right now it is quite inconclusive about the existence of planet-sized bodies past Neptune.
How this works isn’t that hard to understand in principle. (Note: After writing this but before posting it, I found that the AstroBites blog also discusses this topic, with more technical info.) In our solar system we have the Sun at the center, and it pretty much runs everything. It has 98 percent of the mass of the solar system, so its gravity is in charge of how everything else moves. BUT, there are also planets that have gravity as well. Their gravity is weak compared with the Sun’s but is strong enough that, given time, the planets can affect the orbits of other objects.
Out past Neptune is a region occupied by objects that are similar to asteroids but made of ice instead of metal and rock (making them more like comets, really). There are various names for them, but in general they’re called trans-Neptunian objects, or TNOs. Some are on circular orbits, some more elliptical, some have orbits tipped to the plane of the solar system, some don’t.
A handful, about a dozen discovered so far, have really weird orbits. They are highly elongated, and tipped significantly to the plane of the solar system. The authors of the study call them Extreme TNOs.
Their orbits are difficult to explain from what we know about the solar system now. However, the authors note that there is a comet called 96/P Machholz 1 that also has an odd orbit. It goes around the Sun backward (retrograde) relative to the planets, and the shape and orientation of its orbit change over time. This is due to the influence of Jupiter; the comet’s orbit takes it out as far from the Sun as Jupiter’s orbit, so the huge planet pokes and prods the comet over time. This changes the comet’s orbit, making it undergo all sorts of peculiar behavior.
The authors then speculate that the weird TNOs may be explainable in a similar way. The TNOs fall into four groups according to distance, implying a series of planets at distances ranging from 40 to 150 billion kilometers from the Sun. (For comparison, Neptune is about 4.5 billion km out.) They don’t give specifics about the possible masses these planets would need, except to say they would need “at least several Earth masses” to affect the TNOs.
Again, the evidence they present is interesting, maybe even compelling, but it by no means is proof. They only look at the orbital characteristics of about a dozen extreme TNOs, and it’s hard to extrapolate safely from that. It seems clear something odd is going on, but the mechanism behind it isn’t clear. Planets? Maybe. But it could be something else.
I’ll note that a similar study was done with long period comets, which also found weird orbital characteristics that could be explained by a planet or planets past Neptune affecting their orbits. Unfortunately, this too relied on small number statistics and is interesting but not conclusive.
If these planets exist they can’t be too much bigger than Earth. Otherwise they’d have been seen by now; the NASA infrared survey observatory WISE has shown that no more Jupiter- or Saturn-sized planets can exist in our solar system, even way far out.
Personally, I’d love to have direct evidence of such planets. When I worked with Hubble, I spent some time trying to figure out ways of finding such planets! There’s no real theoretical reason they don’t exist, and we see evidence of planets orbiting other stars at great distances. So why not?
In the end, this research is perhaps motivation to keep looking. Even big planets would be terribly faint and difficult to detect at 150 billion km, so it may be quite a while before we have a confidently complete survey of the solar system. And even if they don’t exist, I’m glad people are still thinking about things like this. It’s best in science not to get too complacent with the “current understanding.” Nature is tricky and a lot more clever than we are.
This is a very wide-field shot showing the constellation of Orion on the left, Taurus in the right of center, the Pleiades star cluster on the right, and near the bottom, the lovely green hue of the comet. The comet is still bright and big; through a telescope the fuzzy head (the property that gave comets the nickname "hairy stars") is about the same size as the full Moon, and it’s really easy to spot in binoculars.
I have to comment on Orion in the photo; it shows some features you don’t usually see. At the top, where his head would be (just to the right of ruddy Betelgeuse), you can see a circular reddish glow. That’s the Lambda Orionis nebula, a huge star-forming gas cloud invisible to the eye. The red is the characteristic hue of warm hydrogen, the atoms in the gas excited by the fierce light of the stars born within.
Moving down, that long red C covering the left side of Orion is called Barnard’s Loop, an enormous bubble of gas probably blown out by the tremendous winds of luminous young stars born in the gas clouds dotting Orion.
Now look down, just to the right of the bright blue star Rigel. See that little blue smudge? That’s one of my favorite nebulae in the sky: the Witch Head Nebula. And yes, it really does look like a witch’s head.
One of my favorite astrophotos of all time features all these objects, taken by Rogelio Bernal Andreo; click that link and scroll all the way down to see it. It’s very much worth your time, I promise!
Anyway, Lovejoy will be sliding past the Pleiades for the next couple of days before moving on to the north. If you have binoculars, do yourself a favor and take a look.
Ceres is the largest asteroid in the solar system—about 970 km in diameter—but so far from Earth that it generally just looks like a blurry disk at best.
But that’s about to change. A lot. The Dawn spacecraft is slowly edging toward the asteroid, and on Jan. 13, 2015 it took a series (haha! I love homonyms) of images that have been stitched together to make this nifty animation:
Dawn was about 383,000 km (238,000 miles) from Ceres when it took those shots, which is the same distance the Earth is from the Moon. Details are still difficult to make out (the pictures were taken with the framing camera, which has lower resolution than the science camera that will be used) but you can see a bright spot (I suspect the same one seen in earlier Hubble images) and some large craters. You can also see Ceres is noticeably flattened; it’s about seven percent wider across the equator than through the poles (though to be fair I think that looks a bit exaggerated due to the location of the terminator, the day-night line).
These images are tantalizing—they rival but don’t quite surpass the best images of Ceres taken by Hubble—but in a little while we’ll be seeing much, much more detailed images of this world. It’ll eventually orbit only a few hundred kilometers over the surface, and the images returned will be quite high resolution indeed.
Dawn launched in 2007 after an interesting history (it was canceled by NASA, then reinstated), and reached the asteroid Vesta in 2011. It orbited Vesta for over a year, mapping its surface in exquisite detail. It left Vesta in September 2012, and spent the next couple of years moving toward Ceres. It’s approaching now, and is expected to achieve orbit in early March.
Dawn uses an innovative engine called an ion drive. Any engine to move a spacecraft uses Newton’s Third Law of Motion: Every action has an opposite and equal reaction. If you throw something really hard in one direction, it pushes on you equally hard in the opposite direction.
Rockets usually combine a huge amount of chemicals together, which get very hot, expand rapidly, and blow out the back of the rocket. This is a pretty violent effect, and produces a lot of thrust.
Ion engines are different. They use either magnets or electric fields to accelerate and shoot individual atoms out the back of the engine. The atoms have a lot less mass than what’s used in chemical rockets, but they move a lot faster. The overall effect is a very low but extremely efficient thrust, and you can keep the engine blowing out atoms for years at a time, building up a huge speed. Dawn’s engines use an electric field to fling out xenon ions, and its fuel tank only carries about 425 kg (940 pounds) of fuel; in a day it only uses about 280 grams.
But that’s why it’s taken so long to go from Vesta to Ceres; it thrusts low but long. Now it’s approaching the giant asteroid, and soon it will go from a fuzzy disk to a fantastically detailed and amazing world. Stay tuned. This is going to be great.
My friend Cara Santa Maria hosts the science podcast “Talk Nerdy to Me” where she talks to scientists and science communicators about, well, science. She invited me on, and the episode is online.
We talked about a wide range of stuff: Meteorology, clouds, snow, why we love to do and talk about science, as well as (being who we are) the politicization of science and why that’s so dangerous right now. She brought up the recent issue of the QVC hosts trying to figure out what the Moon is, and the appointment of anti-science Senators to subcommittees that oversee critical science agencies.
It was fun to talk to her (and I apologize—she was in LA and I was at home in Colorado, and I don’t have good headphones; she had to edit it a bit to minimize a slight echo of her voice coming through my speakers. I really need to get a good set of headphones!) and let the conversation cover so much ground. I’ve been so busy lately writing and working on other projects that it’s been a while since I just sat and had a random-access conversation about science. I need to do this more!
Thanks for having me on, Cara. It’s always cool to get a little nerdery going.
So, it’s official: 2014 was the hottest year on record. NOAA and the Japan Meteorological Agency both rank it that way, while NASA puts it in a statistical tie with 2005 and 2010.
I’m not a huge fan of “hottest year” type statistics, as I’ll get to in a moment, but this one is important for two reasons: One is that there was no El Niño this last year, which tends to drive global temperatures up (many record years were ones that had El Niños). 2014 broke the record without any help. The other is that, according to the NOAA and JMA, 2014 was statistically significant.
Let’s say you flip a coin 10 times, and it comes up heads 6 times. Is that significant? No, it’s very likely just a random fluctuation, because if you flip a coin 10 times you expect pretty big deviations from a 50/50 distribution of heads and tails. If you flip it a million times and get 600,000 heads, then you’re talking significant.
2014 was like that. Sometimes a year isn’t a whole lot hotter than some previous year, and may not be statistically significant. But 2014 was hottest by enough of a margin to make the claim.
Even then, I cast something of a skeptical eye when an individual record is broken. Maybe something else happened that was odd, unusual, pushing the temperatures that particular year to new heights. Maybe the next year, things will “regress to the mean”, head back down toward average.
So that’s when you bring in the most important issue here: Context. History. Trends. 2014 may be the hottest year on record… but of the ten warmest years on record, nine of them happened since 2000.
That’s the important tissue here: Not that any one year is the hottest, but that they’re all clustered in the past few years.
It’s getting hotter. This brief animation shows it very, very well. No one record is that exceptional, but they happen more and more now than they did a century (or even a few decades) ago. Few records for hottest year happened in the early 1900s, but now every year has a decent shot at it.
So much for the “pause”. As we’ve seen over and over again. If you’re claiming that temperatures haven’t gone up in the past 16 years, you’re looking more silly every year.
Of course, deniers gonna deny, but, like cooler years, they’re increasingly becoming something of the past.
I’ve posted a lot of images of cyclones from space… but I have never seen anything like this!
That is the view of the tropical cyclone Bansi, which has been blowing in the Indian Ocean, a few hundred kilometers east of the island of Mauritius, which is itself east of Madagascar. It looks like the storm is powering up some sort of weapon!
The photo was taken by astronaut Samantha Cristoforetti when the space station was still well to the side of the cyclone. What you’re actually seeing is a flash of lightning illuminating the eye wall of the storm. That’s incredible.
You can also see a thin green line over the horizon; that’s airglow; oxygen atoms energized by the Sun during the day, slowly releasing that energy at night. It happens in a relatively thin layer about 100 km up. When you look across the Earth in this way you’re seeing through the thin sheet of glowing oxygen, across it, so the light can add up enough to see.
Cristoforetti also took another picture when the station was directly over the eye.
That’s no less amazing than the other one; again, a lightning flash lights up the eye, but you can see it’s offset, in the dense and turbulent clouds in the eye wall. The stroke is bright enough to light up clouds for many kilometers away.
The cyclone is expected to weaken as it moves out into the open waters of the southern Indian Ocean to the south and east, happily away from Mauritius.
If you want to see more photos of cyclones from space—and you do—then here’s a list of some of my posts about them. Bonus: There’s science galore in these photos, and I do love to explain it. Hurricanes and typhoons are among the most dangerous and powerful events our planet has to offer, and while they can be terrifying to experience on the ground (and I’ve had my own share of that over the years), they are just as beautiful to behold from space.
Sam: I’m jealous you get this view. But I’m glad you shared it with us.
I’m not a big fan of definitions in astronomy. I’ve been pretty clear about this in the past; Nature is way less anal about boundary lines than humans are. Borders between categories of objects are fuzzy, and while it’s OK to put things in boxes (Jupiter is a planet, the Sun is a star, the Milky Way is a galaxy), it can get tougher when you have two similar objects that you nevertheless think should be on opposite sides of the line. It can be confusing.
And then you have what happened on QVC recently.
QVC is an online shopping channel. Recently, host Shawn Killinger was featuring a line of cardigans by designer Isaac Mizrahi. She described the pattern on one: “it almost kind of looks like what the Earth looks like when you’re a bazillion miles away from the planet moon.”
To her credit she laughs at herself and says she just meant to say “looking back at the planet from the Moon”, not “planet moon”. But then the conversation takes an odd turn. Watch:
Killinger at first correctly says the Sun is a star, and the Moon is not a star. But then Mizrahi says the Moon is a planet, and she questions that, saying the Moon was never included when you learn the planets. She also goes back to saying it’s a star.
Someone off screen then gets on Google, and says “the Moon is a natural satellite.” This confuses both Killinger and Mizrahi, who then quickly move on to selling more clothes.
Let me cut through the confusion: The Sun is a star, a huge object that has ongoing nuclear fusion in its core. At the lower mass limit, the definition of “star” can get fuzzy, but the Sun is way to one side of that line, so we’re good.
Is the Moon a star? No. No fusion in its core, and not even close. It’s not a star.
Is the Moon a planet? Well, not really, as a planet is an object that orbits a star, and the Moon orbits the Earth (and yes, wannabe pedants, it really does orbit the Earth and not the Sun).
A satellite is a generic term for an object that orbits another object. You could say the Earth is a satellite of the Sun and be technically correct, though that’s not usually how the term is used. The Moon is a natural satellite of the Earth; it orbits Earth, and is not artificial. Another term for “satellite” is (lower case m) moon, so the Moon is a moon. A weather satellite is then an artificial moon.
So there. We’re done.
… except of course we aren’t. It’s not hard to imagine the Moon were bigger, say the same size as the Earth. Would it be a planet then? You could say we’d be part of a binary planet, two planets that orbit each other while orbiting the Sun.
Now you might remember that a few years ago, the International Astronomical Union tried to write in stone the definition of what a planet is. I think this is a mistake, and a foolish one; as my friend and astronomer (and the man who wrote the book How I Killed Pluto and Why It had It Coming) Mike Brown points out, a planet is a concept, not a definition. It’s like “continent”; we have no definition for it; it’s more of an idea that helps you categorize things in general terms.
Is Australia an island or a continent? Yes.
By the definition decreed by the IAU, a planet orbits the Sun. But each component of a binary planet orbits the other one. So are they a planet, or two planets, or two satellites, or what? I could argue any and all of these. The fact that the definition falls apart so easily is a pretty good indication that using a definition is a bad idea in the first place.
The center of mass of the Earth-Moon system is inside the Earth, so we can safely say the Moon orbits the Earth. But if the Moon were a bit more massive, it wouldn’t be quite so clear. Ceres, the largest asteroid, was thought to be a planet for a few years before it got reclassified into the new category of “asteroid”. And it’s way smaller than the Moon.
What if the Earth didn’t exist? The Moon is pretty big, and if it orbited the Sun where the Earth is now, would we call it a planet? I don’t think so, since according to the IAU definition, a planet has to be massive enough to gravitationally affect all the objects that share nearby orbits (it’s “cleared the neighborhood around its orbit” is how it’s confusingly stated), and I think the Moon would fail that criterion. But that’s not a great definition either, to be honest. It’s complicated and weird and still mighty fuzzy along the borders. My gut feeling is that if we saw a solar system exactly like ours, but with a Moon-sized thing where the Earth is now, we might call it a planet.
Happily, I have a brain as well as my gut, and my brain says, “So what? That object is a big, round, interesting world, so who cares what you call it? Let’s study it!”
That’s science, and it’s way more interesting than nitpicky semantics.
And one final thought. A lot of folks online are making fun of the Killinger and Mizrahi for their discussion, but I think it’s fine. First of all, they’re curious about astronomy, and it led to getting an answer (even if I might quibble over how it happened). Second, it started a larger conversation about what all this means.
And third, what they were arguing over is a subtle, layered, and difficult concept that had astronomers from all over the Earth arguing for years about what it means. And they’re still arguing over it!
So if you want to feel smug and superior about the TV hosts, hey, that’s your choice. But people in glass planets shouldn’t throw asteroids.
Holy cow! Watch this amazing Vine video of the SpaceX Falcon 9 booster crashing as it attempted to land on a barge last week after a successful launch to the space station. Make sure the volume is up, because holy wow.
The Jan. 10, 2015, launch of the Falcon 9 rocket went well, but the attempt to reland the first stage booster vertically on a floating platform/barge in the Atlantic didn’t go quite as planned.
Amazingly, the booster slowed, found the barge, and was able to target it for landing (all autonomously, mind you). But then something went wrong at the last moment. The fins used to steer it ran out of hydraulic fluid. The booster tipped at an angle, and the engines couldn’t compensate. It crashed, released fuel, and exploded.
A lot of people are calling this a failure, but as I said in my original post about the landing, it’s more fair to call it a near-success. Most of the procedure to land the booster went nominally, and now the cause of the crash is known. As Elon Musk points out, the next flight will have more of the hydraulic fluid on board, so the fins should continue to work.
Speaking of Musk, I have to hand it to him: He’s a master of PR. His tweets about the crash were good-natured and even funny:
"Rapid Unscheduled Disassembly" may have to become a new phrase in the lexicon.
I liked his next tweet even better:
This was a serious event, and I have no doubt it’s taken very seriously inside SpaceX. But the public sees this differently, and sees Musk differently, so these tongue-in-cheek tweets put a great spin on the event.
The next scheduled launch of a Falcon 9 is no earlier than Jan. 31, when it will loft the Deep Space Climate Observatory over a million kilometers from Earth.
In late December, 2003, the European Space Agency’s Mars Express spacecraft entered orbit around the red planet. Part of the mission was to send a lander, the Beagle 2, down to the surface to study the geology and other conditions at a site where water was known to have existed long ago.
Things didn’t go as planned. The lander went down, but never sent a signal back home. Efforts to recover anything were for naught, and on one even knew if it landed successfully or if it had crashed onto Mars. The lander was declared lost in February 2004.
But now it’s been found! Using images from the HiRISE camera on the Mars Reconnaissance Orbiter, the Beagle 2 has definitely been spotted on the surface. Not only that, but it looks intact; that is, it didn’t crash into the surface. It appears to have landed safely… but it also looks like the solar panels needed to power it didn’t fully deploy.
That spelled doom for two reasons. It couldn’t get all the juice needed to operate, but also the panels, which were supposed to open like flower petals, needed to be fully deployed to uncover the antenna used to communicate back to Mars Express and therefore to Earth. With the antenna blocked, the mission was doomed.
In some sense this is, well, not good news, but welcome. The lander, sadly, is dead and has been for a decade; there’s nothing that can be done about that. But, it shows that the mission did touch down safely, and that’s a very big deal to the engineers who designed the mission and who want to know what went wrong. Follow-up images will hopefully show which panels opened and which didn’t, and that may lead to a better understanding of why they failed.
It’s taken so long to find it because the lander is just a couple of meters across, and it landed in a region more than 15,000 square kilometers in size. Here’s an image that has the Beagle 2 in it. See if you can find it. Have fun.
It’s awful that this part of the mission failed—and mind you, the Mars Express Orbiter itself has been running beautifully and taking images and data of Mars for 11 years now!—but this is not the last time the ESA will want to land on Mars. A failed mission is a learning opportunity, and finding Beagle 2 means the chances of the next landing being a success just went up.
I tip my hat to the Beagle 2 team and to the lander itself. May its travails lead to better fortunes down the line.
It is my pleasure to introduce you to the very first episode of my new online video series, Crash Course Astronomy.
I’m not gonna lie to you: I’m pretty happy about this. It was a lot of fun to write, and a lot of fun to film it. I hope y’all like it.
We have a lot more episodes planned, going from naked eye astronomy (hubba hubba), through the solar system, out to the stars, to the galaxies and the Universe itself. There’s a lot of stuff out there, so there’s a lot of cosmos to cover.
And allow me to indulge myself for a sec here. I’m really excited about this series. I’ve wanted to do something like this for years, but lacked the resources to do it myself (also, I’d rather pull my own head off than edit video). Working with the Crash Course team has been fantastic. They’re dedicated, talented, smart, fun, curious—pretty much all the characteristics I like to see in human beings.
And the thing is: They’re honestly excited and motivated to work on these series (which also include SciShow and Sexplanations). Visiting Montana to film these episodes is like pure fuel for the brain; seeing everyone work so diligently makes me want to work harder to make better content.
So my sincere thanks to Hank and John Green, and to the folks who work on my show: Blake de Pastino, Nicholas Jenkins and Michael Aranda, Nicole Sweeney, and of course my dear friend Dr. Michelle Thaller, who has been essential in helping me not forget to mention obvious stuff in the videos (and correcting me when—rarely, of course—I’m totally off base). Thanks also to the folks at Thought Café, who make the adorable videos, including me as, apparently, a Canadian from South Park. And of course, thanks to PBS Digital Studios for making this all possible (read this to see how).
But mostly, just thanks for watching. I was pleased to find I learned things writing these episodes. I hope you do too.
I’ve written a few times* about how the aurorae—the northern (and southern) lights—aren’t just static or slow-moving displays but can positively flash and flap in real time, moving in waves that take less than a second to explode across the sky.
Still, every time I see a real-time video of them, I’m astounded. Science isn’t magic, but it can be magical. From “skydivephil” comes such a video, but it has some extras. It’s lovely and fun for about the first 1:51, but then prepare to have your brain saturated at the 1:51 mark.
How cool is that? Did you also see the meteors at 0:19 and at the very end? Cool. The polar bear was a nice touch too. That’s a hazard to aurora watching I hadn’t considered.
But that moment at 1:52 when the music turns up, and so does the camera … that display is called a corona. The aurorae are due to subatomic particles from the Sun’s solar wind getting funneled into our atmosphere by the Earth’s magnetic field. The air gets energized and glows in characteristic colors due to oxygen and nitrogen atoms and molecules.
The particles sweep down in sheets, and when seen from the side can look long and thin. But if you’re directly underneath them, you get that amazing perspective effect of the corona, looking straight up into the vertical sheets. They appear paper thin, curling and whipping, moving in graceful and mesmerizing patterns, apparently radiating away from the sky’s zenith. And it all happens so quickly, like someone throwing a bucket of neon paint into the sky!
Every time I see video like this I vow to get somewhere north to see an aurora. Despite all the time I spend looking up at night, I’ve never seen one. That has to change.
Seeing a polar bear—from a distance—would be pretty cool, too.
On Tuesday, I wrote about the GOP taking over the Senate and putting a cohort of anti-reality science deniers in charge of oversight of key scientific agencies: Ted Cruz (R-Texas) on the committee that oversee NASA, Marco Rubio (R-Florida) over the NOAA, and James Inhofe (R-Oklahoma) overseeing the EPA.
All three have been vocal about denying that humans have any link to climate change—especially Inhofe, who has said global warming is a hoax.
I’m most concerned about the EPA, since Inhofe appears hellbent on hobbling the agency (which he once called “a Gestapo bureaucracy”; yes, seriously). But I’m also concerned about Cruz overseeing NASA, since about 10 percent of their budget is for Earth science, including monitoring global warming and climate change.
A lot of media covered this, some of it more histrionic than others. Yesterday, a couple of new articles went up, taking a different tack. Space policy expert Marcia Smith, for example, wrote a thoughtful piece for Space Policy Online questioning Cruz’s ability to “derail” NASA. She points out that his ability to change NASA policy is limited. She says,Cruz… has authority over policy and theoretically could write a NASA authorization bill that restricts what climate science research NASA could do or even abolishes NASA’s entire earth science program. Such a bill, however, would have to get through the full committee, the Senate, the House and be signed into law by the President before becoming law. While one should “never say never,” the chances of that happening are extremely small.
I hope she’s right (and she is very informed on these matters), but I’m not completely convinced. What little legislation the Republicans in Congress haven’t obstructed over the past few years have hardly been compromises in the dictionary sense; the Democrats and White House have caved on quite a bit. Since the NASA budget is part of the overall Federal budget, I’m not 100 percent sure they won’t try to excise what they don’t like.
As Smith points out, Senators Shelby (R-Alabama) and Mikulski (D-Maryland) are big supporters of NASA, and they have the most power over the budget (unfortunately, in my opinion, when it comes to Shelby). But Shelby is “equivocal” on climate change, and may side with Cruz if it comes to cutting back on NASA’s Earth science work. I hope we don’t have to find out.
Over at the Houston Chronicle, space and science writer Eric Berger concurs with Smith’s article; Cruz may not have much power to wield over NASA policy. He also notes that Cruz’s state includes the Johnson Space Center, but apparently the Senator hasn’t shown much interest in it. Berger speculates that Cruz (along with Shelby) may be in favor of the NASA Space Launch System and Orion spacecraft; that doesn’t make me entirely happy, but it may help protect NASA.
And what does Cruz himself have to say? His office issued a statement, and there’s a lot of pro-space exploration in there, as well as a pledge to cut waste. I hope that’s the case… if it really is waste. I’ve said it before: NASA could use better administrating, and less waste. But a lot of that waste is thrust upon it by Congress and the White House, and it’s maddening to hear a Senator talk about cutting it when his own chamber is responsible for so much of it.
In Cruz’s statement there was no direct mention of climate studies, but I wonder. He does say,We must refocus our investment on the hard sciences, on getting men and women into space, on exploring low-Earth orbit and beyond, and not on political distractions that are extraneous to NASA’s mandate.
I have to say, in the minds of Cruz and other global warming deniers, climate science might very well fit in that latter box. So I worry.
Look. Perhaps we who understand the reality of climate change are seeing too much in Cruz’s appointment. I certainly hope so. But when those of us who agree with the science have seen it attacked, mercilessly and baselessly for so many years, and have seen action postponed again and again, and have watched as people like Cruz, Inhofe, and Rubio poopoo what’s literally going on all around them, perhaps we’ve earned our right to be concerned.