Other than Monday, the week here has been devoted to the outer planets, and before I leave that subject, I want to work in the findings of a team of astronomers looking at the early history of the asteroid belt. Recent numerical simulations suggest that many of the objects found in the ‘main belt’ between the orbits of Mars and Jupiter actually formed far out in the Solar System, moving inward during a violent spasm of planetary evolution.

That points to an early system that, at particular times, underwent upheaval caused by a rearrangement of the gas giant planets. This is the so-called Nice model, so named because much of the work on it was performed at the Observatoire de la Côte d’Azur in Nice. The model proposes that the gas giant planets migrated to their present positions long after the protoplanetary gas disk had dissipated, playing a role in the Late Heavy Bombardment of the inner planets some 3.9 billion years ago, and producing many other effects, including the formation of the Oort Cloud and the Kuiper Belt.

What’s interesting for our view of the asteroid belt is that the ‘main belt’ asteroids between the orbits of Mars and Jupiter range widely in their composition, from igneous rocks to mixtures of rock and ice. And while it’s long been assumed that these asteroids formed in place out of a primordial disk that experienced chemical changes, the new simulations suggest that many asteroids formed in the outer system and, at the time of the Late Heavy Bombardment moved inward to their present positions.

Image: The asteroid belt lies in the region between Mars and Jupiter. The Trojan asteroids lie in Jupiter’s orbit, in two distinct regions in front of and behind the planet. Credit: Lunar and Planetary Institute.

The LHB was clearly not limited to the Earth, but devastated the Moon and other planets as well. Kleomenis Tsiganis (Aristotle University, Thessaloniki) notes the evidence for this idea in the asteroid belt, which the team used in its modeling:

“Some of the meteorites that once resided in the asteroid belt show signs they were hit by 3.5 to 3.9 billion years ago. Our model allows us to make the case they were hit by captured comets or perhaps their fragments. If so, they are telling us the same intriguing story as the lunar samples, namely that the solar system apparently went berserk and reconfigured itself about 4 billion years ago.”

This is a new view of the asteroid belt, one that will need follow-up through studies of meteorites, asteroids and the moon. Needless to say, data we can also gain from missions to the Kuiper Belt, like the Haumea orbiter we’ve been discussing, would materially benefit this analysis. The paper is Levison et al., “The Contamination of the Asteroid Belt by Primordial Trans-Neptunian Objects,” Nature 460 (16 July 2009), pp. 364-366 (abstract).

Gentry Lee (Jet Propulsion Laboratory) discusses the question of extraterrestrial life on a program called Are We Alone, which airs this evening on the Discovery Channel at 2100 EDT (0100 UTC on the 17th). Lee is chief engineer for the Solar System Exploration Directorate at the Jet Propulsion Laboratory, a veteran of Viking and Galileo, and a co-author of Arthur C. Clarke. He was also involved with Carl Sagan on COSMOS, so he knows something about video productions.

Pushing Back Astrobiology

As I’ve noted in the two previous posts, we’re moving into an era of re-examination of the Solar System. It’s one that leads inevitably to a new understanding of the concept of habitable zones, with life now being considered a possibility on places that were once thought off-limits. Europa is unusual enough, but the evidence for that ocean beneath the ice is persuasive. Can we extend the paradigm all the way out to the Kuiper Belt? If so, missions like the Haumea orbiter or probes to other trans-Neptunian objects become imperative.

At the Aosta conference, I had the chance to talk to Joel Poncy after his presentation on the Haumea project, a conversation that led to astrobiology. Poncy referred me to a paper by Steve Desch (Arizona State) and colleagues discussing cryovolcanism on distant objects like Charon, and making some startling statements about the possibility of liquid water 40 AU and more from the Sun.

Liquid Water in Cold Objects

Desch looks at the evolution of Kuiper Belt Objects using a model his team constructed that shows how they might retain enough heat to keep subsurface water in a liquid state. Listen to what these people are saying about Pluto’s large moon Charon:

We predict that Charon contains a rocky core… of radius 330 km, surrounded by a slushy layer about 30 km thick containing a mix of ADH [ammonia dihydrate] and liquid water and ammonia. Above this layer is a layer of solid water ice… from 360 to 470 km, surrounded by an undifferentiated crust of rock, water ice and ADH, about 130 km thick. Only about half of the mass of Charon ever experiences differentiation. Our thermal evolution models suggest that within a few x 10⁸ yr, the subsurface liquid will freeze entirely.

Of course, a few hundred million years is well down the road. The news is that Charon may contain liquid water now. The paper continues:

We conclude that objects with a densities similar to Pluto and Triton, 2.0 g/cm³, as small as 500 km in radius, could retain liquid to the present day. Our time-dependent thermal models of KBOs show that it is possible for Charon and Quaoar and many other small KBOs to retain liquid water to the present day.

Cryovolcanism on Other Worlds

Thus the interesting reflectivity of Haumea, which may well indicate cryovolcanism, a mechanism that should also be at work on objects like Charon as liquid is delivered to the surface. Another world with evidence for water ice is Quaoar. We could nail this process down, Desch notes, if we find evidence of cryovolcanism when New Horizons flies past the Pluto/Charon system in 2015. It’s hard to imagine these coldest objects in the Solar System maintaining sub-surface water, but even the Uranian moons Miranda and Ariel show recent resurfacing, and we all remember Triton.

It’s a long way from possible cryovolcanism to astrobiology, but finding liquid water in the Kuiper Belt would at least open a long-shot window for life in the most unexpected places. The paper is Desch et al., “Cryovolcanism on Charon and Other Kuiper Belt Objects,” 38th Lunar and Planetary Science Conference (2007), available online.

Yesterday’s look at a fast orbiter mission to Haumea raises useful questions. The mission, developed conceptually by Thales Alenia Space and presented at Aosta by Joel Poncy, is particularly demanding because this outer system object has no atmosphere. You can make the case for a Neptune orbiter with associated study of Triton, as several readers have already done, but if you want to orbit Haumea, no aerobraking is possible to ease orbital insertion.

The Haumea mission, in other words, deliberately pushes the state of the art in both propulsion and power generation. Poncy noted in his talk at the Hotel Europe that his team had adapted an in-house software model to optimize the propulsion possibilities. The team considered only electric or magneto-plasma technologies (for the latter, think VASIMR — Variable Specific Impulse Magnetoplasma Rocket). They assume a direct trajectory to Haumea with arrival around 2035, when the object is at 49 AU, and they weigh the benefits of a gravity assist by Jupiter to help shorten the journey.

Image: The orbits of Hi`iaka (outer satellite) and Namaka (inner satellite). Namaka’s orbit is nearly edge on as viewed from Earth. Every nine days Namaka passes directly in front of or behind Haumea as seen from Earth. Credit: University of Hawaii/D. Ragozzine.

Taking the hardware to its limits, Poncy and colleagues come up with what looks to be a feasible mission concept, one with a specific impulse of 10000 seconds, a launch mass of 3000 kilograms and a flight time of about 21 years. Says Poncy:

This set of parameters corresponds to what should be achievable in a near future, provided that VASIMR and beta-voltaic technologies are implemented into respectively propulsion and power units by adapting their design and operating point to this class of spacecraft.

A lot is in play here. For one thing, VASIMR is more promise than reality at these levels — will it perform as advertised? For another, Poncy himself notes the problem with generating the power needed to fly this mission. Here’s his thought on that:

…the current technologies would fall short of the needs. The beta-voltaic technology looks promising, as values up to 24W/kg might be within reach in the coming years providing that the packaging design and the battery assembly are adapted to the production of several kW… If we want to go beneath 20 years [flight time], then the industry and the agencies will have either to undertake even more ambitious developments for the power generation, so as to reach about 50W/kg in terms of power density, or find new disruptive technologies.

Yesterday I talked about the scientific value of a Haumea mission, but the second motivation for going to this distant object is to use the mission as a technology driver. Poncy was exactly right when he told the audience at Aosta that if we’re going to get serious about Solar System colonization and, ultimately, interstellar travel, we need to develop the near-term technology to reach and orbit objects in the outer system with less than ten to twenty years of cruise. And don’t forget, these trans-Neptunian objects (TNOs) are rich in volatiles and organics, interesting places for future robotic or even human outposts.

Image: Haumea and its moons. Credit: NASA GSFC.

Moreover, we’re intent on exploring the moons of the gas giants, which is going to demand developing next generations orbiters, landers and deep-drilling capabilities. A fast journey to an object like Haumea thus becomes a way to extend our science to planetary objects within 100 AU that can at the same time increase our capabilities for reaching Jupiter or Saturn space with the kind of heavy payloads we want to see in operation there. Poncy sees Haumea as a targeting goal for developing the next tools we need as we expand our studies of closer worlds like Europa and Titan.

The paper is Poncy et al., “A Preliminary Assessment of an Orbiter in the Haumean System: How Quickly Can a Planetary Orbiter Reach Such a Distant Target?” It’s in Proceedings of the Sixth IAA Symposium on Realistic Near-Term Advanced Scientific Space Missions, and should therefore pop up in the near future in Acta Astronautica.

One of the surprises of the Aosta conference was Joel Poncy’s presentation on a fast orbiter mission to Haumea. Poncy (Thales Alenia Space, France) and colleagues have been developing ideas for the extraordinarily difficult challenge of not just sending a probe to the outer system, but slowing it down for orbital capture. It’s one thing to do this, say, for Neptune, where a thick atmosphere can be used for aerobraking, but it’s quite another to contemplate doing the same for an airless trans-Neptunian object (TNO) like Haumea.

Nonetheless, there are solid reasons for thinking about such a mission. The first is purely scientific. As Poncy did, I’ll use outer planet specialist Mike Brown’s illustrations of what has happened to our Solar System in the last few decades. The first illustration shows the Solar System most of us grew up with, a system with nine planets that were more or less clearly defined, with what was assumed to be a certain amount of debris and cometary material further out.

Now, of course, we see a new Solar System. Depending on how we define planets, we can declare that we have numerous such objects in the outer system — call them ‘dwarf planets’ — along with, much further out, the enormous, spherical system known as the Oort Cloud. Think about this: The number of objects with a diameter beyond 500 kilometers has doubled in just ten years from thirty-five to more than seventy as we’ve continued our investigation of trans-Neptunian objects. It is fully assumed that within another decade or two, we’ll know of hundreds more of these objects.

Let me quote Poncy on this:

If we now recap all sizable Solar System planetary objects larger than 500 km, we get 19 objects closer than the orbit of Uranus, orbit-able after a decade or so of cruise with current technologies. Uranus itself can be flown by but not orbited for a decent travel time. We have already more than 40 objects at Uranus and beyond and this number will grow considerably by 2020. This is even starting to change the appellation ‘Outer System,’ which was previously used to name the part beyond the frost line at 4 AU, and is now sometimes used to designate the part beyond 30 AU.

Image: A new Solar System emerges. Credit: Mike Brown/Caltech.

Consider, too, that we once thought of the the Solar System as being enclosed in a well defined heliosphere that separated it from true interstellar space. Now we have objects like Sedna, with an aphelion (942 AU) that is well beyond the heliosphere. In moving to its perihelion at 76 AU, Sedna moves from interstellar space into the heliosphere and then gradually works its way back out again. The new Solar System is packed with objects that defy all the definitions we once brought to the term.

As for Haumea itself (once known as 2003EL61), we’re looking at a most unusual little world. You can study its light-curve to determine that it’s spinning quickly, about once every 3.9 hours. More unusually, rather than being spherical, it appears to be a flattened ellipsoid with its largest axis in the range of 2000 kilometers. One of the thirty largest objects in the Solar System, it is orbited by two moons, the largest — Hi’iaka — being rather large in itself, with a diameter estimated to be 300 kilometers.

Image: Relative sizes of the larger outer system objects. Note the ellipsoidal shape of 2003EL61, now known as Haumea. Credit: NASA/ESA/A. Feild (STSci).

The current thinking is that Haumea is the result of a major collision, one that produced the entire system of TNO and two moons. Adding to the interest is that Haumea is quite reflective, its surface covered with crystalline water ice. This could be interpreted as evidence for cryovolcanism (think Triton), and brings home the usefulness of an orbiter. After all, a flyby mission is not going to be able to track transient phenomena over time. Moreover, the orbital dynamics of the system, including the interactions of its moons and the tidal effects of Haumea itself, are complex and will need long study to understand.

Can we get to this unusual object, which is now close to aphelion at 51 AU from the Sun? It’s certainly within range of our probes, but orbiting it would not be easy. We’ll look at the why and how of such a mission tomorrow.

One of the things that makes travel both entertaining and exasperating is the assurance that the best laid plans will come up against events beyond your control. Thus I arrived at Milan’s Malpensa airport in plenty of time for my Delta flight, only to be told that the flight had been canceled. But Delta moved quickly on setting me up with an Alitalia flight to New York that left only thirty minutes after the first had been scheduled to leave, and after two more connections (and a twenty-three hour day on the move) I arrived back home. The photo is a shot of the streets of Aosta one early morning, from a walk I took on the last day to remember it by.

I returned with a satchel full of notes, the conference proceedings, numerous business cards and the world’s worst back-ache, a consequence of trying to move too fast in crowded airports with laptop and luggage. While the latter heals, I’ve also decided not to try to move through the Aosta material in one go — there’s too much of it, and too many papers I want to tell you about. So I’ll fold in the Aosta talks with a gradual return to other news items. Tomorrow, for example, I want to discuss a potential mission to Haumea, the curious object that may have much to tell us about the composition of the outer Solar System. So let me sort my notes and we’ll discuss it.

For today, a return to the news suggests a look at an article on the msnbc site discussing spacecraft at the nanotech level. This one caught my eye because of its reference to ‘needle-sized spacecraft.’ Robert Freitas was the one who told me about the ‘needle’ starship, a tiny vessel packed with nanotechnological assemblers that, arriving in a destination system, could use raw materials from asteroids there to build a scientific station for analysis and data return. I mentioned this idea in a recent Washington Post story, and in the current article, work at the University of Michigan using a new kind of thruster comes into play, with possible interstellar ramifications.

From the story:

The technology is called a “nano-particle field extraction thruster,” or nanoFET. The tiny thrusters that work much like miniaturized versions of massive particle accelerators. The device uses a series of stacked, micron-thick “gates” that alternate between conductive and insulating layers to create electric fields. These small but powerful electric fields charge and accelerate a reservoir of conductive nanoparticles, shooting them out into space and creating thrust.

The engine is evidently etched onto silicon via micro-electromechanical systems technologies, with tens of thousands of accelerators fitting into a tiny area. Translate very small effects into constant acceleration over years of time and you could theoretically achieve something like the needle probe idea of Freitas, though Gilchrist does not talk about nanotechnology inside, but rather the propulsive force that will send the probe, whatever its payload.

Image: nanoFET characteristic size scales. Credit: University of Michigan Department of Aerospace Engineering.

Gilchrist’s Web site at the University of Michigan shows a bibliography with papers related to this topic, but most are at least six years old — I assume the site just needs updating. But a university page on NanoFET propulsion offers more, describing the new electric propulsion system as a way to “….utilize electrostatically charged and accelerated nanoparticles as propellant. Millions of micron-sized nanoparticle thrusters would fit on one square centimeter, allowing the fabrication of highly scaleable thruster arrays.” Obviously not suitable for launch to orbit, these field emission thrusters are intended for acceleration and attitude control.

The page offers a look at how the system works:

Conductive nanoparticles would be transported to a small liquid-filled reservoir by a micro-fluidic flow transport system. Particles that come into contact with the bottom conducting plate would become charged and pulled to the liquid surface by the imposed electric field. If the electrostatic force near the surface can cause charged nanoparticles to break through the surface tension, field focusing would quickly accelerate the particles through the surface. Once extracted, the charged nanoparticles would be accelerated by the vacuum electric field and ejected, thus generating thrust.

So we now know to keep an eye on the Plasmadynamics & Electric Propulsion Laboratory at Michigan, whose concept would offer a highly efficient engine — and one with variable specific impulse — that should be scalable for a wide range of future space missions. nanoFETS are said to be able to adjust their specific impulse over a range from 100s to 10,000s with a high efficiency range throughout the entire specific impulse regime. A useful paper for learning still more about them is Liu et al., “Nanoparticle Electric Propulsion for Space Exploration,” American Institute of Physics 978-0-7354-0386-4/07, available online.

One more thing: The Plasmadynamics & Electric Propulsion Laboratory at Michigan offers an updated list of publications here, a number of which (particularly the conference references) relate to the nanoFETS concept.

The driver who took me from Aosta to Milan yesterday evening spoke no English, but he was an affable young man who had a love for fast cars. As we drove along a fine Alpine highway, a low red sports car moved fast us so quickly that I almost didn’t see it. But suddenly the driver, who had said next to nothing thus far, erupted with “Italian car! Beautiful!” He stretched out the last word as if savoring the idea, then looked over at me making a thumbs up. Well, it was beautiful, and it was followed by two more similar cars making speeds I could only guess at. I wondered what it felt like to drive such a car, and how quickly it would get to Milan.

One of the best things about wrapping up the Aosta conference, which we did with a farewell party yesterday afternoon, is that I head back to the States with a satchel full of papers. I’ve only been able to mention a few of them thus far, but next week I should have the chance to talk about them at more leisure. Here in Milan I have a few minutes before I have to leave for Malpensa airport, so I thought I would mention Greg Matloff’s paper on using Near-Earth Objects in a novel and intriguing way. Greg (New York City Technical College, CUNY) has a student named Monika Wilga who worked with him on the concept of using NEOs to hitchhike to Mars.

Now Mars wouldn’t seem to have much to do with this conference, because it is, after all, explicitly focused on missions to the outer Solar System and beyond. But it turns out there is an interesting outer system component here, not to mention a fascinating concept in and of itself. Greg put Ms. Wilga to work on finding any NEOs that cross close enough to Earth to make a mission there a viable one within a relatively short time, thus minimizing the danger of exposure to high-energy cosmic rays, whose health hazards on a long mission could be severe. He then asked her to further constrain the list to those NEOs that went on to pass close to Mars.

Image: Greg Matloff, taken at our visit to Giancarlo Genta’s summer house high above Aosta.

The idea here is that the astronauts can use the NEO as a radiation shield, digging in to its surface and exploiting its resources on the way to the red planet. Greg presented a table showing candidate objects that could fill the bill, including two — 1999YR14 and 2007EE26 — that have one Earth-Mars transit time amounting to one year or less. Let me quote the paper (and then I need to pack it and get going to Malpensa):

Since orbital characteristics are known for a few thousand NEOs, it is reasonable to assume that about 0.1% of the total NEO population could be applied for Earth-Mars or Mars-Earth transfers during the time period 2020-2100. Because a few hundred thousand NEOs must exist that are greater in dimension than 10m, hundreds of small NEOs must travel near-Hohmann trajectories between Earth and Mars or Mars and Earth. It seems likely that a concerted search will find one or more candidate NEOs for shielding application during any opposition of the two planets.

The outer system wrinkle to all this is that when Greg had his student repeat the study with the maximum aphelion distance of the NEOs stretched to 2.5 AU, no new Earth-Mars candidates were found. But a NEO called 2000WO148 passes Earth in January of 2041 and goes on to the main belt asteroid Vesta in October 2043. Now there’s an interesting mission possibility built right into the local NEO population. We should be able to find more candidate NEOs as detection sensitivity increases, so human journeys to other main-belt asteroids by this method may become feasible. Fascinating stuff and I’d like to say more, but I have a plane to catch.

I’m just in from an early morning walk around the streets of Aosta, enjoying a brisk spring morning. The streets at this hour are largely empty and the Sun lights the nearby peaks. We have a heavy session of papers on this last day of the conference, and we had an even longer day yesterday, followed by my public lecture at the Aosta town hall last night. Following the talk, Giancarlo Genta, his lovely wife Franca, and Guido Cossard, the assessore of cultural affairs (who turns out to be an astronomy buff and something of an expert on archaeoastronomy), took me on a walk around town looking at medieval and Roman sites. We wound up having a late night beer and I didn’t get in until 1:30.

This is a travel day, as I change hotels in preparation for tomorrow’s flight from Milan. So I’m going to hold any of the discussion about the papers yesterday, which were so rich that I’d prefer to get into them when I have more than a few minutes. In particular, the solar sail sessions opened my eyes to a signficant problem in sail missions. Run a sundiver mission near the huge gravity well of our star and you experience effects including frame-dragging and other consequences of General Relativity that can have a serious impact on where your sail winds up going. The effect is particularly noticeable for fast, long missions and hence of interest to us here. More on this when I can — I hope I’ll have a good Internet connection in Milan.

Today we get into the heart of this interstellar conference, with multiple sessions on propulsion via solar and electric sail, as well as looks at specific mission concepts and robotic applications in deep space. I spent a good part of our bus ride back from Bard castle yesterday talking to Pekka Janhunen, creator of the electric sail concept, about its possible interstellar applications. Pekka does not believe this system, based on electric tethers riding the solar wind, could muster the velocity to go interstellar, but he does see it as a viable candidate for braking into a destination system, and just as important, exploring it. I’m anxious to get the latest on his work and also to look at fusion alternatives, which Claudio Maccone will present now that we’ve learned that Claudio Bruno can’t make it here.

As I get ready for the day to start, I’ll drop in here some notes from the first day. These are no more than a skeletal outline — I’ll use the conference proceedings when I get back to take a close look at some of these presentations, but I don’t want to rush through any complex arguments out of a need to get a post up.

Image: The opening session. That’s conference organizer Giancarlo Genta at the left, then (left to right) J.-M. Content, Guido Cossard (assessore of cultural affairs in Aosta) and Giovanni Vulpetti at far right.

Our opening session of the Aosta conference — technically, the Sixth IAA Symposium on Realistic Near-term Advanced Scientific Space Missions — got off to a late start, as so many meetings do, at the Aosta town hall on Monday. The keynote was a genial overview of the International Academy of Astronautics by its secretary general, J.-M. Content, who walked us through the major events that had shaped the organization. My session on ‘Interstellar Flight and the Public Imagination’ followed after a coffee break and we were off. Marco Bernasconi (MCB Consultants) followed me, which was fortuitous because we discussed many themes in common. Dr. Bernasconi has been working on human motivations for deep space travel for some time now and has developed an interesting libertarian perspective on the issue.

A short lunch at the hotel allowed us to get back on schedule in the conference rooms on the lower level, where Les Johnson (NASA MSFC) discussed NanoSail-D. Interesting to learn that there is no NanoSail-A, B or C — the ‘D’ stands for drag, and refers to the fact that in order to get the attempted launch funded, the Marshall Space Flight Center team had to sell the sail on the basis of its drag properties, useful in deorbiting satellites. That launch, of course, failed, another sail attempt wrecked not by the sail technology itself but by booster problems. Remember, a second NanoSail-D is still on the shelf in Huntsville. When will it fly?

Roman Kezerashvili (New York City College of Technology) talked about solar sails in the context of non-Keplerian orbits, but what I remember most about the afternoon was Kezerashvili’s impassioned defense of nuclear technology as the propulsion choice for the next step in space exploration. Giancarlo Genta, the organizer of the Aosta conference, spoke in his talk about the ‘nuclear renaissance’ in terms not only of the space program but also of the power industry. I want to get back to both the Genta and Kezerashvili talks later when I can go through their papers in detail. A second part of Kezerashvili’s argument will be presented on Thursday.

Image: Giancarlo Genta (Politecnico di Torino) answers a question during the afternoon session.

My erstwhile opponent in the interstellar bet, Tibor Pacher, made a pitch for unconventional thinking in presenting interstellar issues — these included a discussion not only of how we are using the Long Bets site to provoke discussion and commentary, but also of his own ‘Crazy Ideas’ section on the peregrinus-interstellar site and broader uses of social networking to get the public involved. Tibor made a huge and telling point when he looked around the room and asked: “Where are the young people?” Indeed, he himself was one of the youngest in the room and, as he told the crowd, he was almost 50. Here we were in Aosta discussing some of the cutting-edge technologies that might one day get us to the stars, and where were the students you would expect to find, the young intellects anxious to push that agenda? Tibor hopes his methods will help to remedy the lack, and so do I.

Image: Tibor Pacher (on the left) and I had paused to take in the view from Bard Castle when Claudio Maccone took this picture.

We also had an interesting talk on the psychological aspects of long-term flight from Nick Kanas (University of California at San Francisco), who brought his psychiatric credentials to bear in discussing how crews on long missions aboard Mir and the ISS have fared. All in all, a fine first day, capped by a banquet in the hotel dining room which was, as all our meals here have been, excellent. Giancarlo Genta turns out to be one of the great dinner companions in addition to being a crack symposium organizer. I’ll long remember our conversation about the history of the Aosta region. And Tuesday’s travels — we had a sightseeing day rather than any scientific sessions — were capped with a stop by his just completed summer home high above the valley, a glorious view of snow capped peaks dominating the sky, followed by a traditional Aosta dinner at a nearby restaurant. I’ll post some pictures of this in a day or two.

I had intended to use today’s post to talk about yesterday’s sessions here in Aosta, but it’s going on midnight here, and tomorrow will clearly not afford any opportunities to write. Tuesday turns out to be our sightseeing day. We leave the hotel at 9:00 and head for Verrès, where we visit the Mechatronics Laboratory of the Politecnico di Torino. Then we head up into the mountains, visiting the Bard fortress, with individual visits to the Museum of the Alps. After lunch at what is said to be an excellent restaurant called La Polveriera, we go to an exhibition called ‘Verso l’alto, l’ascesa come esperienza del sacro’ — Towards the heights: The ascent as experience of the sacred. Then to dinner at the Hotel Notre Maison, where we are promised traditional Aosta Valley food.

Image: The Aosta town hall, where our opening sessions were held. Later, we moved to the Hotel Europe.

As for tomorrow, we don’t get back to the hotel until midnight. No more today or I’ll be late for the bus, but I’ll hope to get more posted on Wednesday, when we return to our scientific schedule. Until then, imagine me bumping up narrow mountain roads looking at Alpine scenery in a bus stuffed with space scientists!

Image: A motley crew. From left to right, Giovanni Vulpetti, Claudio Maccone, Greg Matloff, Les Johnson, as we stood outside the hotel waiting for last night’s banquet to begin. If these guys can’t get us into deep space, nobody can.

What I’ll surely remember the most about arriving in Italy is the sight of snow on the Alps as the plane descended out of a cloudy morning sky into Milan. But right after that comes the two hang gliders that soared past an alpine peak as the van that was taking me to Aosta moved north toward the town, the landscape becoming a series of valleys cutting through the steep clefts. The second of the two hang gliders looked for all the world as if it were going to land right on the highway, a daunting thought given how the traffic was moving, but as we rounded a turn I saw that it had caught an updraft and was angling out and away. What a view the pilot must have had.

Image: The view from my room at the Hotel Europe in Aosta. It was hot and humid when I took this, but cooled off dramatically during the night. If the air conditioner worked, all would be perfect. Below is a photo from the street in front of the hotel. As you can tell, this is the place to be for a guy who loves mountains the way I do.

The day after, it’s a glorious morning in northern Italy, the humidity and heat of yesterday afternoon giving way to cool, dry air, although space scientist Giovanni Vulpetti told me last night at the welcome party that the weather in these parts changes by the hour. Indeed, a brief rain had blown in as he was speaking, cooling and freshening the night. The party was a welcome chance to renew acquaintances, but I was so tired from the flight that I retired early. This morning, in a few minutes, we head to the Aosta town hall for the opening session of the conference. I’ll report on matters when possible, but I may have to hold most of my remarks until I get back. The Net connection here is tricky and usable only from the hotel lobby, and time may become a factor as well. Meetings and hallway conversations are burning ninety-nine percent of my time (well, not to mention the chance to have some fabulous food — the vegetable risotto last night was unforgettable).