Note (12/2015): Hi there! I'm taking some time off here to focus on other projects for a bit. As of October 2016, those other projects include a science book series for kids titled Things That Make You Go Yuck! -- available at Barnes and Noble, Amazon and (hopefully) a bookstore near you!

Co-author Jenn Dlugos and I are also doing some extremely ridiculous things over at Drinkstorm Studios, including our award-winning webseries, Magicland.

There are also a full 100 posts right here in the archives, and feel free to drop me a line at with comments, suggestions or wacky cold fusion ideas. Cheers!

· Categories: Astronomy, Physics
What I’ve Learned:

Trans-Neptunian objects: Stuck where the sun don't shine (very much).
“Trans-Neptunian objects: Stuck where the sun don’t shine (very much).”

In the beginning, there was the Earth.

Meaning, that’s the first solar system object humans knew about, mostly because we kept tripping and falling face-first onto it. Early humans weren’t particularly coordinated.

The sun was also pretty hard to miss, what with the light and heat and occasional scary eclipses. By the 2nd century B.C., eagle-eyed up-gazers had also spotted Mercury, Venus, Mars, Jupiter and Saturn. Not bad for people who didn’t have a LensCrafters at the local mall, probably.

It took a couple thousand years — and eyeglasses, binoculars and telescopes — to find the remaining (current) planets, Uranus (1781) and Neptune (1846). And then we had a problem. Based on calculations of the outer planets’ masses and shapes and favorite Hostess snack cakes, it appeared they were being influenced by some unseen astronomical force — other objects, further out, pulling the strings on Neptune’s orbit. (And pre-packaged dessert preference, apparently. Team Ho-Hos forever.)

So scientists went looking for these mystery bits of rock, called “trans-Neptunian objects”, because they spent (most of) their time chilling outside the orbit of Neptune, thirty times further from the sun as Earth. In 1930, they found the first trans-Neptunian object, and called it Pluto.

On the good side, Pluto was pretty much where astronomers thought it would be. On the bad, it wasn’t large enough to explain the discrepancy in Neptune’s behavior. Better measurements of Neptune determined its orbit actually made perfect sense, so they chalked it up to dumb luck, Pluto became the ninth planet, and nobody looked much for more trans-Neptunian objects for a while.

But Pluto seemed awfully lonely, way out there in a dusty corner of the solar system. So when a second trans-Neptunian object was spotted in 1992, the search was on again. Since then — because even our telescopes have LensCrafters now, probably — more than 1,500 trans-Neptunian objects have been found. So many, in fact, they get grouped into weird classifications like “twotinos” and “cubewanos” and “plutinos”.

(It sounds like the lineup for a Saturday night at the Mos Eisley cantina. But that’s really what they call them.)

All this family reunionizing was great for Pluto, presumably — until it wasn’t. In 2005, a trans-Neptunian object called Eris was found. It looked like Pluto. It had a moon, like Pluto. And it was bigger than Pluto — but no one was quite convinced it should be called a planet. So astronomers got together in 2006 and worked out criteria that said no, sorry, Eris is not technically a planet.

And oh, by the way, if you use the same criteria, neither is Pluto. Ouch. Finding Eris was like going on a date with someone who you don’t like very much, and instead of making you miss your previous relationship, you just realize you had bad taste in dating all along. Maybe you should try OKComet instead.

But there’s more. As astronomers discover even further-out hunks of rock — called extreme trans-Neptunian objects, because they drink Red Bull and get tattoos and stay out past curfew, I assume — an old problem reemerges: they don’t look quite right. In fact, a recent paper studying the orbits of some of these way-out objects says that apparently they are being influenced by something (or somethings), legitimately planet-sized and dark and mysterious even further out. So far, scientists haven’t seen them — or agree they exist — but some are now squinting their telescopes outward, just in case.

Here’s hoping they have a good LensCrafters nearby.

Image sources: NASA/JPL-Caltech (Sedna, the sexy TNO), and FreePik (‘Scopes heart LC), Princess Burlap (“I said, Team Ho-Hos!”), Electronic Cerebrectomy (Mos Eisley cantina band), FB-Troublemakers (sad Pluto)

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· Categories: Astronomy, Physics
What I’ve Learned:

Heliosphere: It's the sun's Twinkie. We're just along for the ride.
“Heliosphere: It’s the sun’s Twinkie. We’re just along for the ride.”

There are many complicated models of what our solar system looks like. Then there’s my model: the solar system is like a giant Twinkie, with a Red Hot candy jammed in one end.

Seriously, NASA. Why make things hard, when they could be so delicious?

So here’s how the Twinkie squishes:

The Red Hot, naturally, is the sun, radiating loose particles and waves of heat in all directions. With the candy, most of the particles are artificial cinnamon flavor and FD&C red #5, and they only make it as far as the nearest taste bud.

With the sun, the particles are solar wind — a plasmafied soup of protons and electrons — and they shoot outward at roughly 1.2 million miles per hour, give or take a speeding bullet or two.

The sun is therefore much more powerful than a Red Hot candy, but considerably less appetizing. And, so far as we know, non-fat. If you’re into that sort of thing.

Back to the model. The Twinkie represents the full spread of solar material, a region called the heliosphere. This bubble of sun-spewed plasma extends roughly 120 astronomical units — or A.U., the distance from the earth to the sun. That’s a very long way. Even wasabi pea particles don’t make it out that far.

The heliosphere doesn’t extend equally in all directions, though; hence the “Twinkie-shapedness” of the model. Remember that our sun is also constantly whirling around the galaxy at breakneck speed, which stretches the plasma bubble out behind it. Imagine the Twinkie as a speeding race car, with the Red Hot near the nose.

Or a Twinkie jet plane, if you like. Any method of theoretical Twinkie locomotion you prefer is fine. This is one of the main perks of stellar science, from what I understand.

The final bit of the heliosphere model is the outer part, where the delectable Twinkie cream turns into scrumptious Twinkie cake. In space, this interface is called the termination shock, and it’s where those plasma blasts from the sun finally slow down below the speed of sound. This happens when the solar wind interacts with the interstellar medium, a haze of gas and dust and cosmic rays flowing between the stars.

As the interstellar medium slows down the solar rays, the plasma stagnates and bubbles and clumps up — much like the spongecake cradling our Twinkie. This layer is called the heliosheath, and is immediately followed by the heliopause, where the solar wind finally disappears entirely. It’s the thin brown crust that marks the final boundary between Twinkie and not-Twinkie. When you pass the heliopause, you’re no longer in the solar system.

So how many man-made objects have made this journey out of the heliosphere, to boldly go where no Twinkie has gone before? One — or possibly none. Voyager 1, launched in 1977 to explore the outer planets, has been hurtling directly away from the sun at eleven miles per second since 1980. It’s believed that in August of 2012, Voyager 1 passed through the heliopause and out of the sun’s fiery clutches.

But because we don’t precisely know what the end of the solar system looks like, researchers are still proposing and conducting tests to determine exactly how “out” Voyager 1 is. If not yet, then it’s expected to pop through the heliopause within the next year or so, followed soon by Voyager 2.

(And if my petition to NASA goes through, next by Guy Fieri.)

Breaking an object out of the heliosphere will be quite an accomplishment, once confirmed. But why anyone would run away from a cinnamon-flavored Twinkie is beyond me.

Image sources: PlanetFacts (heliosphere diagram), Perfectly Crazy (Twinkie racer), DeviantArt / Jonnyetc (Winston’s big Twinkie), Rock ‘n Roll Ghost and GeekDad (Voyager Fieri)

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What I’ve Learned:

Exoplanets: When one Earth just isn't mega-super enough.
“Exoplanets: When one Earth just isn’t mega-super enough.”

Our planet is pretty okay, as far as it goes. Sure, we’ve come up with stir fry, chili cheese fries and Stephen Fry — but are we really being the best Earth we can be? Some astrophysicists make me wonder.

In particular, the astrophysicists scouring the visible cosmos for worlds circling other stars. Or in a word: exoplanets.

(Don’t let the “ex” part throw you. These are not planets who used to date Earth, then got upset when Earth made googly eyes with Venus, or slept over in the house of Mercury after a sexy session of grab and terrestrial tickle.

Rather, exoplanets are those big hunks of stuff that spin around a star that isn’t the one we happen to circle. Sorry, “Real Housewives of the Solar System” fans. It’s not like that.)

These world-watchers have detected nearly two thousand exoplanets to date, with more on the celestial radar all the time. And until recently, there were pretty well-defined rules for what these faraway planets look like. Basically, planets came in two flavors: rocky and gassy.

(Yes, just the two. Extrasolar planets are interesting. Nobody ever said they were Baskin-Robbins.)

When planets reach a certain size, they tend to accumulate gasses like hydrogen, helium, carbon dioxide or nitrogen. Scientists believed that any planet heavier than about ten Earth masses would largely be composed of gas pulled in by the hefty planet’s enormous gravity. The “gas giants” in our own solar system — Jupiter, Saturn, Uranus and Neptune — follow this formula precisely.

Smaller planets, on the other hand, are usually big round balls of rock. Venus, Mars and Mercury all fit this bill, in addition to the hunk of dirt we’re currently riding. As do a number of discovered exoplanets — but only those on the smaller side.

When these exoplanets are the same size-ish as Earth, they’re called “Earth-like”, but that only means that these worlds are generally the same shape and density. There’s no guarantee the inhabitants of any “Earth-like” planets have, for instance, independently invented Happy Hour or Taco Tuesday or Rice-A-Roni, the interstellar San Francisco treat.

(And without those things, how “Earth-like” could those planets be, really?)

The planets significantly bigger than Earth but smaller than our solar system’s gas planets are often called “super-Earths”. Technically, the super-Earth set is a mixture of rocky and gaseous planets, depending on the size and density of each. Like the saying goes, some super-Earths are like your Mars, and some are like Uranus.

(That’s not a saying? Well, it should be.)

The super-Earth label doesn’t mean these worlds are necessarily extra-special. It would be great if some “super”-Earth came up with even tastier chili cheese fries, or a Stephen Fry wittier than a speeding bullet. Or maybe a stir fry that stirred itself. But no. We’re on our own for those.

Recently, though, scientists discovered a new sort of planet that’s thrown them for an orbital ellipse. Named Kepler-10c, it’s a planet orbiting a star about 560 light years away. It appears to be made of rock — but its seventeen times more massive than Earth. The theory said it should be full of gas, but there it was when they looked — solid through and through, mooning us through our telescopes and thumbing its rocky core at us. Scientists have dubbed this jacked-up behemoth a “mega-Earth”, and it’s the only one of its kind yet known to exist.

Personally, I’d have gone with “Andre the Planet”. This is probably why I never get invited to any astrophysicist parties. Maybe this isn’t such a “super Earth”, after all.

Image sources: (planet parade), Metro UK (feathery Fry), Orange County Mexican Restaurants blog (Taco Simpsons) and Crustula (Andre with a whole world in his hand [a whole world in his hand])

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