All posts tagged Pluto

I’m sitting in the hotel lobby at the Woodlands Marriott, waiting for my supershuttle to IAH and recouperating from my second Lunar and Planetary Sciences Conference, LPSC. Before I’m whisked away back to Boise, I thought to write about a few of the fascinating and mind-blowing things I saw this week.

First of all, LPSC is an annual conference that focuses on the geology, geochemistry, and geophysics of planetary science. There’s a lot of focus on solar system bodies with solid surfaces, as opposed to the annual DPS meeting, which has a bit broader focus.

I arrived on Sunday evening and dove immediately in, helping with the First-Timers’ presentation review, an opportunity for new-comers to the meeting to have more senior folks provide feedback on their posters or oral presentations.

Monday dawned cloudy, and I sat through several talks about our sister planet Mars. One that stuck out for me was one about field experiments to explain the perennially mysterious gully formations found on martian slopes with sleds of dry ice.

Tuesday saw me in a session on Saturn’s moon Titan, a cornucopia of geology and atmospheric physics. One particularly impressive talk discussed work to understand how methane deluges on Titan modified the surface.

Tuesday evening, I presented our group’s work flying drones through active dust devils.

Wednesday was packed with talks on sediment transport experiments and analyses, attempting to decipher the martian aeolian cycle, including a neat study of time-lapse imagery of martian dunes.

Thursday was packed with Pluto and results from New Horizons. One talk that stuck in my mind was an analysis of landslides on Pluto’s moon Charon, which, frankly, was a little bit of a tear-jerker. Hard to believe that not one hundred years ago, we didn’t even know Pluto existed. Now we’re trying to understand the system’s geology.

Friday morning wrapped up the meeting with a series of talks about glacial geology on Mars, including a fabulous presentation on mysterious geomorphic features on Mars. Even though these features look for all the world like glacial flow, they appear on totally flat ground, where flow shouldn’t be possible.

And now to catch the shuttle.

Join the Boise State Physics Department for a stargazing party with special guest Prof. Denise Stephens, astronomer from BYU.

Come learn about the New Horizons mission, the team, and the 20+ years it took to get this mission to Pluto. Take a closer look at Pluto, Charon, and the other 4 moons as we dive into the Kuiper Belt, and the extended mission to visit another Kuiper Belt Object.

The event takes place on Friday, Feb 3 and will start in the Multipurpose Classroom Building in room 101 at 7:30p and then move to the top of the Brady Garage at 8:30p, where telescopes will be set up for stargazing (weather permitting).

The weather forecast for this week is not promising, so we’ll cancel the stargazing portion. The lecture will still happen, though.

At journal club today, we discussed a recent paper in Nature from Tanguy Bertrand and François Forget that looks at how the topography and meteorology of Pluto conspire to produce the dramatic frosts and glaciers seen on the surface of Pluto during the recent New Horizons fly-by.

One of the most spectacular results from the fly-by was the discovery that Pluto has rugged mountain chains, enormous geographic basins, and flowing glaciers. The image below shows the evidence for glacial flow in Sputnik Planum, called the Heart of Pluto.

It had been suggested that the flowing nitrogen frost might have collected in Sputnik Planum from a source region connected to Pluto’s deep interior.

However, coupling a sophisticated meteorological model to a model for vaporization and condensation, Bertrand and Forget show in their study that the gathering of frost in Sputnik is likely just due to the fact that it’s a deep basin, about 4 km below the Plutoid.

As a result, the atmospheric pressure tends to be larger at the bottom of the basin than elsewhere on Pluto’s surface, which encourages frost deposition there. The authors point to a similar effect on Mars, where CO2 snows out preferentially at the south pole in Hellas Basin.

It’s worth keeping in mind that the atmospheric pressure at Pluto’s surface is one one-hundred-thousandth the pressure at Earth’s surface, but even with a dwarf atmosphere, this dwarf planet exhibits complex and fascinating meteorological and geological phenomena.

And just because it’s awesome, here’s a synthetic fly-over of Pluto’s surface, generated by the New Horizons mission.

As the only planetary scientist at Boise State, I was asked to present on the New Horizons mission to the Math REU program here, so I put together the presentation below.

After a cram session to prepare for the talk, I opted to have the mission PI Alan Stern present the mission himself and incorporated a really great NEAF talk he gave last year.

Here are the New Horizons links I give at the end of the talk:

Thanks to Drs. Scheepers and Babinkostova for the invitation to speak.

In anticipation of the upcoming New Horizons fly-by of the Pluto system, a really exciting result from Mark Showalter of SETI and Doug Hamilton of UMD — complex gravitational interactions among the moons of Pluto, Charon, Styx, Nix, Kerberos, and Hydra, have driven Nix mad and make it rotate chaotically. A simulation of its rotational evolution is shown in the youtube video above.

Showalter and Hamilton analyzed Hubble images of the Pluto system to understand how the moons’ orbits evolve as the result of the gravitational tugs between the moons. The three moons Styx, Nix, and Hydra are very near to and probably in a three-body resonance reminiscent of the Galilean satellites. Computer models of that interaction allowed them to constrain the masses of the moons, somewhere in the range of Mars’ moon Deimos‘ mass.

We would expect that the complex gravitational environment as applied to such elongated moons would likely lead to complex rotation, and indeed, Showalter and Hamilton find that the phase curve for Nix, observed from 2010 to 2012, varies erratically, consistent with a chaotic rotation. Their analysis also shows that Hydra rotates chaotically; probably some of the other moons (except for Charon) as well.

One bit of good news for the New Horizons flyby emerges from all this: the systems’ chaotic dynamics probably keep it clear of rings or additional small moons that would pose hazards for New Horizons. It seems nature has decided the system is complicated enough already.

Attendees at today’s journal club included Jennifer Briggs, Emily Jensen, and Tyler Wade.

Artist's conception of Pluto's and Charon's surfaces. From

Artist’s conception of Pluto’s and Charon’s surfaces. From

We talked briefly about several things at Friday’s Journal Club. First, we discussed, a great blog that covers the interesting nitty-gritty of astronomy research. I pointed out that they are requesting submissions from undergrad researchers.

Second, we discussed the New Horizons mission’s request for suggestions for names of features on the surface of Pluto and its moons. After the mission flies by the system, there will be mounds of high resolution images, probably showing a variety of complex surface morphologies. And all that stuff is going to need names.

Third, Jacob presented a recent paper that extends the Titius-Bode relation to extrasolar systems and predict there are about 2 planets in habitable zones per star in our galaxy. A potentially fascinating result, but unfortunately, the T-B relation is probably just an interesting coincidence for our solar system — it has no theoretical basis, and so there’s no reason to believe it can be generalized to other planetary systems. Nevertheless, the article got a lot of press last week.

Finally, we talked about coding in astronomy, and I wanted to post this resource I just heard about, Looks to have a lot of helpful tutorials relevant to astronomy.

Friday’s attendees included Jennifer Briggs, Trent Garrett, Nathan Grigsby, Tanier Jaramillo, Emily Jensen, Liz Kandziolka, and Jacob Sabin.