Sciency Words: Nice Model

May 18, 2018

Today’s post is part of a special series here on Planet Pailly called Sciency Words.  Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together.  Today’s term is:

NICE MODEL

I recently assembled Lego’s Saturn V rocket set, and I have to say it’s a really nice model.  It even has these little orange pieces to represent the floaty things for when the Apollo capsule returns to Earth and splashes down in the ocean. That, I thought, was a really nice touch!

But as nice as that Lego model is, that’s not the model we’re talking about today.  Nope, today we’re talking about the Nice model, with a capital N.

In May of 2005, three papers were published in the journal Nature which did a nice job explaining some of the big mysteries of our Solar System.

  • First (in order of page number) was a paper on the anomalous orbital eccentricities and inclinations of the four gas giant planets.
  • Next came a paper on the Trojan asteroids which hang out around Jupiter’s Lagrange points, 60º ahead and 60º behind Jupiter in its orbital path.
  • And lastly, there was a paper on the Late Heavy Bombardment, a period of time when the Moon (and also the four inner planets) got pummeled with asteroids.

All three of these papers share a common idea: that the four gas giants of our Solar System must have started out much closer together, with a broad disk of rocky and icy debris beyond them, like a super-sized Kuiper belt.  Then, approximately 700 million years after their initial formation, three of those gas giants (Saturn, Uranus, and Neptune) started drifting farther and farther away from the Sun and away from each other.

Jupiter seems to have drifted slightly closer to the Sun, but stopped short of entering and demolishing the inner Solar System thanks to a last minute gravitational interaction with Saturn (thanks, Saturn!).

As the gas giants spread out, they threw that super Kuiper belt into chaos.  Some of that rocky and icy debris was hurled toward the inner planets, causing the Late Heavy Bombardment.  Some of the debris got stuck around Jupiter’s Lagrange points, becoming the Trojan asteroids.  And with so many complicated gravitational interactions happening at once, it’s no wonder the four gas giants ended up with some anomalies in their orbital paths.

This one idea—that the gas giants drifted apart after they formed—does a pretty nice job explaining three of the biggest mysteries about our Solar System.  But sadly, that’s not why it’s called the Nice model.  The name actually isn’t pronounced like the English word “nice” but rather like the French city of Nice (which rhymes with geese or fleece).  That’s because the model was originally formulated at an observatory in Nice, France.

Unfortunately, I didn’t find that out until I’d already sprinkled a bunch of nice puns into this post, and I don’t feel like taking them out.


NASA’s Next Flagship Mission

July 19, 2017

Let’s imagine you’re NASA. You have two big flagship-class missions coming up: one to search for life on Mars (launcing in 2020) and another to search for life on Europa (launching in 2022). These flagship missions are big, expensive projects, so Congress only lets you do one or two per decade.

After 2022, the next flagship mission probably won’t launch until the late 2020’s or early 2030’s, but still… now is the time for you to start thinking about it. So after Mars and Europa, where do you want to go next? Here are a few ideas currently floating around:

  • Orbiting Enceladus: If you want to keep looking for life in the Solar System, Enceladus (a moon of Saturn) is a good pick. It’s got an ocean of liquid water beneath it surface, and thanks to the geysers in the southern hemisphere, Enceladus is rather conveniently spraying samples into space for your orbiter to collect.
  • Splash Down on Titan: If there’s life on Titan (another moon of Saturn), it’ll be very different from life we’re familiar with here on Earth. But the organic chemicals are there in abundance, and it would be interesting to splash down in one of Titan’s lakes of liquid methane. If we built a submersible probe, we could even go see if anything’s swimming around in the methane-y depths.
  • Another Mars Rover: Yes, we have multiple orbiters and rovers exploring Mars already, but some of that equipment is getting pretty old and will need to be replaced soon. If we’re serious about sending humans to Mars, it’s important to keep the current Mars program going so we know what we’re getting ourselves into.
  • Landing on Venus: Given the high temperature and pressure on Venus, this is a mission that won’t last long—a few days tops—but Venus is surprisingly similar to Earth in many ways. Comparing and contrasting the two planets taught us how important Earth’s ozone layer is and just what can happen if a global greenhouse effect get’s out of control. Who knows what else Venus might teach us about our home?
  • Orbiting Uranus: This was high on NASA’s list of priorities at the beginning of the 2010’s, and it’s expected to rank highly again in the 2020’s. We know next to nothing about Uranus or Neptune, the ice giants of our Solar System. Given how many ice giants we’ve discovered orbiting other stars, it would be nice if we could learn more about the ones in our backyard.
  • Orbiting Neptune: Uranus is significantly closer to Earth than Neptune, but there’s an upcoming planetary alignment in the 2030’s that could make Neptune a less expensive, more fuel-efficient choice. As an added bonus, we’d also get to visit Triton, a Pluto-like object that Neptune sort of kidnapped and made into a moon.

If it were up to me, I know which one of these missions I’d pick. But today we’re imagining that you are NASA. Realistically Congress will only agree to pay for one or two of these planetary science missions in the coming decade. So what would be your first and second choices?


Sciency Words: Uranus (An A to Z Challenge Post)

April 25, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, U is for:

URANUS

I feel really sorry for the planet Uranus.

I’m really sorry, sideways buddy, but they’re not laughing with you. They’re laughing at you.

Rumor has it NASA wants to send a space probe to Uranus in the late 2020’s or early 2030’s. It’ll be the first time we’ve visited an ice giant since the Voyager 2 flybys of Uranus and Neptune, back in the 1980’s. I’m pretty excited about this, but I can’t talk about a Uranus mission without people starting to snicker at me.

So how did the seventh planet of the Solar System end up with such an unfortunate name? Here’s a quick rundown of how this happened:

  • On March 13, 1781, English astronomer William Herschel discovered a new planet beyond the orbit of Saturn.
  • As a good, patriotic Englishman, Herschal named the new planet Georgium Sidis, Latin for “George’s Star,” in honor of King George III (the same King George mentioned in the Declaration of Independence).
  • For obvious reasons, the name Georgium Sidis wasn’t popular outside of England. Several alternatives were proposed, including Herschel, Neptune, and Uranus.
  • Uranus went on to become the most widely used name around the world, until in the mid-1800’s even England officially accepted the name.

In ancient mythology, Uranus was the god of the sky, the father of Saturn and the grandfather of Zeus. He was an extremely important deity, so it made a certain sense to bestow this prestigious name on such a prestigious discovery: the first new planet discovered since ancient times.

German astronomer Johann Elert Bode proposed the name. As a German, he presumably didn’t realize how it would sound in English—or maybe he did know and was deliberately trolling King George! That’s my personal theory.

Whatever Bode’s intentions were, Uranus is now stuck with its name and all the jokes that come with it. Which is a shame. Such a strange and mysterious planet deserves better.

Next time on Sciency Words: A to Z, we’ll be working with volatile chemicals.