DPS 2015 Days 3 and 4: Venusian Aircraft, Pale Orange Dots, and Magma Oceans!

Yesterday on the third day of DPS, Dr. Yuk Yung of Caltech, towards the end of his acceptance speech after having been awarded the Gerard P. Kuiper Prize at this year’s DPS meeting, stated the following:

“Life is the ultimate poetry of the universe, written with the alphabet of molecules.” – Yuk Yung

This one sentence sums up the beautiful truth that Life is an emergent property of the universe.  It is a beautiful consequence of the four fundamental forces that govern our universe.  This one statement seems to embody the spirit of the DPS and its members.  By studying the planets, both inside and outside our solar system, we gain understanding about ourselves and where we come from.

The past two days have been a whirlwind.  I was very tired last night, so I didn’t post an article.  So tonight I plan to give a smattering of some of the more interesting talks I attended.

Venus Atmospheric Maneuverable Platform (VAMP)

At the poster session yesterday, I came across a particularly interesting mission concept, presented by Northrup Grumman.  This mission would involve a buoyant winged aircraft that would be powered by solar panels and would be able to glide through the Venusian atmosphere, taking samples and reporting back to an orbiting spacecraft.  This is a beautiful idea, and could well be used on other planets as well.

Pale Orange Dot

Giada Arney of the University of Washington gave a talk today about Exoplanets. She pointed out that when we look for habitable exoplanets, we typically look for planets that we consider Earth-like, or having liquid water and oxygen, etc., on their surface.  However, in the early archeo-Earth environment, as Arney points out, the world looked much different than it does today.  Early in the Earth’s history, the skies were filled with an orange hydro-carbon haze, similar to that of Titan.  This atmosphere would kill a human, but would be the perfect environment for early life on the earth, and would shield them from nearly all of the UV radiation that might otherwise harm them, just as the Oxygen and Ozone in our atmosphere do for us today.  This is an intriguing idea, one that will broaden the possible search criteria for identifying Earth-like exoplanets.

Magma Ocean Dynamo!

Alexander Bourzutschky of the California Institute of Technology gave a fascinating talk today about exoplanets with global oceans of magma on their surface.  These oceans, Bourzutschky says, could sustain their own magnetic field, acting much the same way that our iron-core dynamo works on Earth.  These global magnetic fields could potentially be detected by radio telescopes here on Earth.

Using Cassini VIMS to view Earth, Exoplanet Analog

It’s important to know what the limits of our current instrumentation are, and how to best utilize them.  Roger Clark at the Planetary Science Institute spoke today about using the VIMS instrument (infra-red spectrometer) on board Cassini to look back at the Earth to determine what kind of information we might expect to glean from an extra-solar planet using similar instrumentation.  This is an excellent test case, because Clark et al. can compare their findings to what we know to be present on the Earth.  This can help to design future missions and observations of other planets outside our solar system.

Well, it’s getting late, and I need to get some sleep.  Tomorrow will be the last day of DPS 2015, sadly.  I will report back tomorrow with and end-of-DPS wrap up.

-Josh

 

DPS 2015 Day 2: Planetary Rings Poster Session

IMG_0920Today was my first experience presenting at a scientific poster session.  I’ve attended many of these in the past, but have never had the pleasure myself.  I have to say, it was a truly rewarding experience, and I feel honored to present along side colleagues and friends.

For the uninitiated, a poster presentation session is a way to share current research in a public forum and to promote discussion about said research in an open and accessible way.  Each presenter brings a poster which summarizes their research with relevant plots and equations which they will use to highlight their work.  This particular conference has a massive conference room with hundreds of posters being presented.  Presenters stand by their posters and converse with conference attendees about their research.  Attendees are free to wander about to investigate the posters that interest them the most.  This creates a forum which facilitates scientific discussions, and is also an opportunity to network with colleagues and other interested parties.

As I mentioned this was surprisingly my first time presenting at one of these.  I’ve published work on planetary rings in the past in the journal Icarus, but presenting in this format was a first for me.  The work I presented today was an update to my prior work.

I thought for this blog-post, I would go over the general ideas that I presented today (don’t worry, I won’t get too into-the-weeds).

The question that my coauthor and I are attempting to investigate is that of the age of Saturn’s rings.  Some controversy exists as to the age of the rings.  Namely: How old are Saturn’s rings?  One leading theory suggests that the rings may have been created by the destruction of a small moon (queue the Star Wars quotes now…).  A moon can be destroyed if it enters the zone close to its planet, in this case Saturn, referred to as the Roche Limit.  Inside this boundary, the tidal forces generated by Saturn’s gravity acting on the moon will rip the moon apart.  This is certainly one possibility.  However, Saturn’s rings may also be primordial, or left over from the formation of the solar system.  Indeed in many ways, Saturn and it’s rings and system of moons, is very much like a small solar system.  Our work shows that it is possible that the rings may in fact be as old (or nearly as old) as the solar system itself, or about 4.6 billion years old.

We arrive at this conclusion by creating a computer simulation of the ring system, which calculates the composition of the rings over time.  The composition of the rings change over long time scales because they are constantly bombarded by small micro-metoroids, which then combine with the rings.  The rings are known to be almost entirely (more than 90%) water ice (H2O).  So over time, as meteoritic material is added to the rings, it changes the color of the material that we observe, to a reddish or yellowish hue.  It also affects other wavelengths of light, such as ultra-violet light, and infra-red light.  The Cassini spacecraft has very sophisticated light sensors on board, called spectrometers, capable of examining the different wavelengths (or colors) of light reflected off the rings in great detail.  In particular, we looked at data from the UVIS instrument on board Cassini, which measures the ultra-violet spectrum of the rings.

So, what does color have to do with the age of the rings?

Our computer simulation models impacts by these meteoroids over time, giving us a snapshot of how the ultra-violet spectrum (think color) of the rings should change over time.  We then attempt to match that up with the real data from UVIS to see at what time during our simulation does the color match what is actually observed now by Cassini.  This gives us the length of time that it took to make the rings look the way that they do now.  That length of time is effectively the approximate age of the rings.

We are still working out the details of our model, but the initial results are very interesting.  Our model shows that the rings could in fact be quite old, and may not simply be a transient, or temporary, feature.  The question is not settled yet, and there is still a lot of debate about this particular topic.

This also relates to the mass of the rings, which is also an open question.  If, for example, the rings are very massive (think heavy), then they could absorb more meteoritic material before changing their spectra (color), which would result in an old ring system (4 billion years for example).  If on the other hand, the rings are not so massive (think light), then they should become “polluted” much faster, which would imply a young-ring system (much less than 4 billion years).

We will know for sure in 2017 when Cassini dives between the rings and the planet!  That will be truly exciting and should settle this debate.  In the mean time, I’ll keep plugging away at this model to see if I can predict what Cassini will find.  That, perhaps, is what makes this so exciting!

I will post more tomorrow.  I promise, more on Pluto!  There were a lot of highly interesting findings on Pluto over the past few days.  But for tonight, I need to get to sleep so I’m fresh for the next day of the conference.  I’ll also try to report a little on Ceres, which is also an exciting object.  I missed the session on Ceres today unfortunately, so I may have to poke around a bit to get the details.

-Josh

DPS 2015 Day 1: Mountainous Pluto

Greetings friends.  Just a short post tonight.  This week, I am attending the meeting of the American Astronomical Society Division for Planetary Science, aka DPS 2015. I’m very excited to be presenting my work on planetary rings during tomorrow’s poster session. More on that tomorrow. I plan post to this blog once per day all this week.

Today was largely all about Pluto and some very exciting results coming from the data from the New Horizons spacecraft. I also attended a session on Planetary Rings, which is near and dear to my heart.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

One of the more beautifully interesting pieces of information was the announcement that some of Pluto’s mountains may in fact be cryo-volcanos. 3D models of the terrain have revealed that some of these mountains have deep hollow centers. Cryo-volcano’s, unlike the volcanoes here on Earth, erupt icy materials rather than rocky magma.

This finding is one of many that point to geologically active Planet, with many features that were largely unexpected prior to the flyby.

 

 

 

 

 

I’ll report back tomorrow with more of the findings from the New Horizons mission, and talk a bit about my own research related to Saturn’s rings.

Stay tuned!

-Josh

Pluto lovers rejoice! New Hi-Res Pluto Data From New Horizons

lor_0299167608_0x630_sci_4_stitch_lowres
Hi-res mosaic of pluto. Click to see full resolution copy.
Raw data: NASA / JHUAPL / SwRI
Mosaic: Stellar Aperture

Pluto lovers rejoice!  Today the NASA New Horizons team released a new set of high resolution images of the surface of Pluto from the LORRI instrument on-board the New Horizons spacecraft.  The images are truly breathtaking.  The team announced the results over a Google Hangout earlier today.  During the hangout Alan Stern, director of the New Horizons mission, said that this marks the start of a data down-link phase which should last about a year.  Over the course of the year we will learn more and more about Pluto and its system of moons.

As I watched the live hangout, new images kept posting to their website.  Each time I created a mosaic, I noticed more data on the page.  It was a lot of fun trying to keep up to work with the data as it was posted in real time.

I for one will be very excited to see the data from the Alice instrument, which is an ultraviolet imaging spectrometer.  A very similar instrument is currently flying on the Rosetta spacecraft currently orbiting comet 67P/Churyumov–Gerasimenko.  Comet 67P is thought to have originated in the Kuiper Belt, the same region of the solar system where Pluto resides.  I will be very interested to see how the UV data from Pluto compare to that of 67P.  This should tell us a great deal about the origin and evolution of our solar system.

Check out the hangout for the full scoop.  It’s definitely worth a watch.  I’ve embedded the video below.

Send Your Name to Mars!

Just a quick micro-post today.

Looking for a great way to participate in the next Mars mission?  NASA is giving you the opportunity, as it has for other missions in the past, to send your name along for the ride!  Just go to http://mars.nasa.gov/participate/send-your-name/insight/ and you can creating your own Mars Boarding Pass!  It’s lots of fun, and a great way to get kids interested in this exiting mission.  Have fun!