Thursday, November 27, 2014

Easter Island (Rapa Nui)

Southwest corner of the Island: Orongo

Setting of on our tour, we headed to the southwest corner [travel map] of the island, going up the side of the extinct volcano Rana Kao.  [Important safety tip for future visitors: we stopped at the national park entrance and I had to pay my entrance fee for the day.  It's 30,000 CLP or $60, and they don't take credit cards.  My guide, an islander, related with some unhappiness how the money does not stay on the island but goes back to the mainland government, where only a share comes back to Rapa Nui.]

From a lookout point on the slope of the volcano, we could look back to the north and east:


That view afforded us a look back at the only town on the island, Hanga Roa, with a long stripe stretching from side-to-side in the photo in the way: the airport.  Mataveri Airport is noteworthy for its seemingly excessively long runway; the generous length of runway One Zero has a fascinating back story - namely, it was extended at the request of (and funding by) the US Government, as a potential landing site for NASA's Space Shuttle.  

The shuttle, during a potential "Transoceanic Abort Landing" scenario, would have had the option to put down here on Easter Island.  "But wait," you say, "Rapa Nui is nowhere near Kennedy Space Center - would it have really ended up here from a launch in Florida?"  Well, no, it wouldn't have - but it could have aborted down to the island when it flew out of California.  You see, there was a time when there were desires on the part of NASA - the US Air Force, really - to launch out of Vanderberg AFB, from the "Slick Six" launch complex.  Why?  This would have put the shuttle into a polar orbit - a rather favorable location from which spy satellites could be deployed.  In the end, this did not come to pass, but things were very close to turning out this way - a launch was scheduled for October of 1986, and then the Challenger accident happened in February of that year and all the shuttle's plans changed.

Continuing up to the rim of the volcano, you can look back down into the remains of the caldera.  It's strangely reminiscent in appearance to Meteor Crater near Flagstaff, yet wholly different.  It's a crater that is volcanic on origin, not meteoritic, and the floor is filled with water.  In fact, this latter fact is very important for the historic inhabitants: it's fresh water, collected from rainfall, and is a source of drinking water.  My guide told me how his grandmother would come here in years past, before modern water systems were installed, to do laundry and take care of other chores associated with fresh water.
Continuing along the rim of the volcano, you arrive at the ceremonial city of Orono.  Here the leaders of the twelve tribes that inhabited the island would gather yearly.  Each tribe would bring a champion warrior and the 12 champions would embark on a competition to see which tribe would rule for the next year.  The champions would climb down a thousand feed down the cliff side, swim a mile across the ocean to the island of Motu Nui ("the big island", past Motu Iti, "the little island", and past pointed Motu Kao Kao, "the sideways island"), seen here:
Up for a swim?
There the champions would await the return of the Sooty Terns, who roosted there.  The first champion would could sieze an egg of these birds, and return to Orono (via the swim and cliff climb, mind you), presenting the egg to his sponsor and the judges, would win the title of tangata manu ("bird-man") for his sponsor, bestowing great power on that sponsor for the next year.
A view of the chief's houses from the cliffside.
The huts had very small entrances, forcing anyone entering to crawl - making it very defensible for the occupants.

A view of the Rana Kao caldera from Orono.

To the East Coast: Akahanga

From Orono we went along the coast over to the eastern side of the island [travel map] (it's a pretty small island overall - only maybe 10 miles from side to side).  The ancient village of Akahana lies here, deserted, and is a good example of how the islanders used to live.
This is an example of the remains of a "boathouse", so named because it's shape looks like an upside-down boat.
The base rocks of a boathouse had holes ground into the rocks, allowing thick branches to be arced from side to side, forming the frame of the house.  The frame was then covered with materials to form the roof.
A nearby cave was a secure refuge in times of severe weather or warfare.



All the boathouses had their doorways facing the platform where the moai were located, so it would be the first thing one would see in the morning.  All the moai on the island had been toppled by the end of the 19th century - aside from those seen at the quarry, any erect moai seen now on the island are recent re-erections.

A toppled moai, face-down.
A closeup of the toppled moai of the village, face-forward (away from the ocean) from the platform.
Many of the toppled moai had their heads snapped off.  My guide told me that one way you can tell if a moai had been erect was if it had eye sockets carved in the head: such carving took place only have the moai was erected in place.  In the eye sockets, coral eyes were inset, but only a few relics of this past had ever been found.

The seaward side of the platform, showing topped moais here as well.

An intact example of a toppled moai, lying on its back.

Off to the Quarry

The numerous moai scattered around the village ruins prompt the question: where did they come from?  Out of the side of a mountain, of course.  So, from Akahanga, we drove further east to Rano Raraku [travel map], the quarry.  
The quarry is center-left on the mountainside.  The brown dots on the lower green part of that slope are completed moai, standing.
At the quarry, the stone monoliths that are the moai were mined out of solid rock.  It is at the quarry where the all the strangeness and magic that is Rapa Nui hits will the force of a sledge hammer: not a few moai in pieces upon their side, but dozens upon dozens of the somber images stand in place, apparently awaiting a delivery that never happened.
At the quarry, you park, wander past the ever-present tables of souvenir trinkets, check in with the ranger station with your very expensive park entry ticket, and then wander up the path to the quarry.
"Toto, we're not in Kansas anymore."
And there they are, jutting out of the sloping green hillside.  Big moai, not-so-big moai, and then even bigger moai.  Further at the bottom of the hillside are toppled moai.  Failures during attempted deliveries?  It wasn't clear.  
"Stuck here for hundreds of years, and we still can get pizza delivered here."

Not a bad likeness.
The moai were commissioned by rich families and carved out of solid rock; you can see two of these works in various stages of preparation here:
"Everybody needs a moai - order yours today!"
(If you're keen-eyed, you can see a third on the far right as well.)  Around the corner from the quarry, on the east slope of the mountainside (the quarry is on the south), there's a particularly unusual moai:
My guide told me that the name of this particular moai translates as "He Who Stares at Stars" (if I remember that correctly).  The upward stare of this figure is unique amongst the moai on the island, as is the beard on the chin, and the hand position on the knees.   

Coming back around to the quarry, we encounter "El Gigante" - the largest moai ever started.  At roughly 75 feet tall, it's a true monster.
"Does this mountainside make my butt look big?"
It's unclear if the islanders ever intended to move El Gigante - my guide was optimistic that his ancestors would have done so if so inclined, and that the collapse of the overall moai culture precluded that event, not any lack of technical capability.

Tongariki: The Postcard Picture Place

From the quarry we did the short drive over to Tongariki [travel map], which is the place everyone has in mind from the postcards.
15 monoliths, all in a line
As with most moai, these have their back to the sea.  From the side, the somewhat unique dual-tier structure of the platform the moai stand upon can be readily seen:
Also visible is the top nut on the 2nd closest moai.  What is interesting about the Tongariki site is its recent reconstruction.  As with the other seaside moai, it was completely toppled, and then further destroyed by a tsunami the hit the island in 1960, from an earthquake on the mainland.  In the mid-90's, an agreement between the Chileans and the Japanese brought heavy equipment - including a crane - to this site, and was rebuilt (complete with some judicious use of concrete reinforcement).  As such, it now stands with an impressive majesty: 
These moai stand around 20 feet tall each.
A somewhat battered placard on the site commemorates the reconstruction work.
What do you think the original islanders would have thought of using heavy equipment?

Continuing Around the North Side: Te Pito Kura

Leaving Ahu Tongariki, we continued around the perimeter of the island to Te Pito Kura [travel map].  At this site is one of the final moai to be erected during the monolith building era, and the largest.  Having stood roughly 30 feet tall, this particular statue was reported standing by the earliest European visitors to the island.
As such, this particular moai - named "Paro", and weighing roughly 80 tons - was toppled at some time after 1838.  Just around to the side of this site is another interesting site, which my guide informed me was the real site of Te Pito Kura:
The large rock in the center was supposedly brought by the first explorers who discovered the island, using the rock as ballast in their ocean-going canoes.  

The four rocks around the perimeter allow you to sit by this rock.  Since this rock has great power, you can benefit from it if you put your head on the rock: 
Now that's putting your head into it

Last Stop on the Tour: Anakena Beach

We did the quick drive over to Rapa Nui's picture-perfect beach, Anakena [travel map].  The cove here has a lovely white-sand beach, replete with palm trees.
It believed that the first settlers arrived at this beach first.  There is a moai platform here, complete with a number of re-erected moai: 
These moai are particularly well-preserved, having been toppled face-first into sand; the facial features are still quite sharp with relief:
Another unique feature of these moai is that they, unlike most of the rest found at the other ocean-side sites, have elaborate decoration on their backsides as well as the front.
At the beach there are a number of ocean-view cafe huts, which are a perfect place to wrap up the tour with a cool drink.
Hopefully the drink comes with a little umbrella in it.

Friday, April 25, 2014

May: One Crazy Month

As much as I was hoping to not be going anywhere during this next month (since next month is Cool Stars 18), the exact opposite has happened.  Murphy's Law of Unexpected Travel in full force, I guess.  I start off going off to Nashville - a visit to Vanderbilt for a meeting of the dissertation committee of my grad student, Victor Garcia.  The following week it's off to Munich, to take care of some business and visit with the elusive Herr Dr. Kaspar von Braun, when then gives way to three days in Nice for the 'Hanbury Brown Intensity Interferometry' workshop.  That trip is followed a week later by going to Ames, Iowa for Lee Anne Willson's retirement symposium, "Stars: Old, Young, and Variable".  The month gets wrapped up with a visit to Santa Fe, for a star party for the Santa Fe Conservancy.

So, it's a simple bit of bookkeeping to figure out that my average speed - for the entire month of May, 24/7 - will be about 28 miles per hour.

Thursday, January 5, 2012

New Digs!

Lowell Observatory's Hall 42", located at
Anderson Mesa near Flagstaff, AZ
So, it has been a while since I've posted to my blog, and there have been some big changes. In the intervening time, I've taken a new job back in the US at Lowell Observatory. This has meant a relocation back to the states, and my family and I are now new residents of the lovely town of Flagstaff, Arizona.


An aerial view of the NOI & Anderson Mesa

In the end, there's little difference between this and rocket science:
it's all about the plumbing
Lowell is an interesting place for me, because it means that I have the opportunity to work on the Navy Optical Interferometer (NOI), a large telescope array located on Anderson Mesa near Flagstaff.  The NOI currently operates baselines in the visible up to 80m in length, which means resolving stars down to ~1mas in size is fairly straightforward; an ongoing upgrade means its longest 437m baselines will be open in ~12-24 months, with a corresponding increase in angular resolution.

Monday, February 2, 2009

Countdown to Kepler & Terra Nova


The Kepler field of view,
straddling the Summer
Triangle (Altair, Vega, Deneb).
On March 6th, at 3:48 UTC, a Delta II launch vehicle will rise off the ground at Cape Canaveral's pad 17B, riding a fountain of fire being belched from its RS-27A main engine and 6 GEM-40 solids strapped to its sides like oversized fireworks. Three additional GEM-40 solid rockets get an air start about 2 minutes into flight, and burns of the Delta K second stage and Star 48B third stage will loft the Kepler spacecraft into an orbit around the sun, drifting away from the Earth at slow rate over the following years. After the roaring earthquake-in-a-thunderstorm ride to that orbit, Kepler will settle into the deep interplanetary quiet - an ever waking, watchful sentinel, on the lookout.

During its long stare, Kepler will seek - and find - planets like Earth: the size of Earth, orbiting stars similar to our Sun, separated from their host stars at distances similar to the Earth-Sun system. Places where liquid water are thought to be likely, where life can flourish. Terra Nova.

Kepler will do so by looking with its large, unblinking eye, at a huge, heavenly (literally) host of stars - initially, about 200 thousand - taking a digital picture and measuring the brightness of each of those stars once every few minutes. The exact same field of stars, for 4 long years (and even longer if a mission extension comes to pass). If one of those stars happens to be Sun-like, if it happens to have an Earth-like planet, if that planet happens to be in a Earth-like orbit (about 93 million miles from its host star), if that orbit happens to pass between us and that star, and if Kepler is looking during the transit event, then a detection might occur. Stare long enough, the planet's orbit will swing it around for a second transit, establishing the duration of the orbit - and then later, a third: confirmation. A lot of if's - and the mission design attempt to solve that: look at a lot of stars, with a regular rate, for a very long time - four years or more, in fact. Each one of the "if's" I mentioned has a small likelihood of success associated with it, but if you beat enough targets, for long enough, against those small probabilities, one can still come up with non-zero discovery rates.

Assuming the rocket doesn't blow up on launch (yet another 'if' - but the Delta II's are about as resoundingly reliable as they come), and if the satellite functions properly, what is the expected haul of planets? This is difficult to say, actually - astronomers don't have much information on how common Earth-like planets are - this is a major motivation for the mission. But, if current models are true (they are, every blue moon), the expectation is that roughly 50 Earth-like objects will be found, in addition to a large number of bigger objects (such as Neptune-sized objects).

Currently there's a similar smaller scale mission, CoRoT, flown by the French space agency CNES, which in turn was predated by an even smaller scale mission, MOST, flown by the Canadian Space Agency. CoRoT just celebrated its 2nd year anniversary, and MOST has been orbiting since mid-2003. Both CoRoT and MOST can detect large-ish planets (giant gas bags like Neptune and Jupiter) - particularly if the host star is smaller than our sun - but Kepler's scope (roughly a factor of 10 larger than CoRoT) allowed it to be designed specficially for the goal of finding distinctly Earth-like planets. It's an exciting prospect - one more step on the Copernican Revolution started over 400 years ago, one that will not only expand the frontiers of our scientific knowledge, but one that will distinctly impact humanity's sense of its place in the universe.

* :)

Sunday, February 1, 2009

Observing Challenges



Four little telescopes, all in a row



So I am, once again, at the Paranal Observatory, observing with the Very Large Telescope Interferometer (VLTI). VLTI uses multiple telescopes to synthesize a single, larger telescope - one of a size that is far beyond what is practical to build by itself. For example, we are able to configure our telescopes to act like a telescope more than 100-m in diameter - something that would be nice to have but is not economically feasible.

We are in the process of commissioning a new instrument for VLTI called PRIMA - I'll save you the pain of what the acronym means and cut to the practical impact of it: PRIMA allows us to observe two objects simultaneously. It effectively lets the VLTI behave like an interferometer, times two. This setup lets us do a couple of tricks - first, it will allow us to look at things fainter than we normally can, by using one of the two channels to lock up the optics on a bright star, while the second channel stares at something dim. Second, PRIMA will let us measure the angle between those two objects to an unprecedented level of accuracy, something south of 100 microarcseconds.






Twilight - getting ready to observe
Hmmm... a microarcsecond: this is a pretty daunting science-type term. How small is such a measure? Well, let's put it this way: if you & your friend are standing on opposite sides of a soccer pitch (or football field) - about 100 meters - it's the angle subtended by the apparent distance that one of his hairs grows in a second, as viewed by you.

Pretty cool, huh? But here's the catch: VLTI is a rather complicated beast, and PRIMA makes it all that much worse. So, we shipped PRIMA out to the site last August, and we've been working to get it functioning ever since. It'd been expected that there would be an extended period of commissioning to shake out all the bugs (think of it as a test flight regime for a new aircraft), but some times the observing runs associated with commissioning can be a challenge when new & exciting optomechanical system do new & exciting - and unexpected - things. So at times we're left scratching our heads. ("Huh? The star separator did what?")



The moon and Venus in conjunction
This particular observing run has been like that. We fix one thing and something else breaks or misbehaves. It's currently day 4 of 10 - and things overall are only getting better - but it's turning into a long haul. We'll be ready for the bus in a week! However, as we like to say (and first attributed to Albert Einstein), if we knew what we were doing, it wouldn't be research...

[nb. tip 'o the hat to The Blog Doctor for tips on image posting in Blogger.]

* :)

Wednesday, January 28, 2009

Separated at Birth?

Working in the field of astronomy, there are many and wondrous things that one often encounters during the course of one's travels. In many cases, the sights are sufficiently novel as to leave one scrambling to place them in context in an inadequately rich cultural backdrop. This is, of course, ever-so-true for the images that astronomers pluck out of the sky each and every day.

Telescopes are often located at the very extremes of the earth (and beyond). These locations are generally selected for environments that are as benign as possible - but not from the point of view of their human operators: these considerations are purely driven by the needs of the machines. Locales that are very dry, cold, and high atop mountains figure prominently on the wish list for sites for observatories. These locations often have staggering vistas associated with them - stark landscapes that seem to have been ripped off the surface of the moon, rather than having anything to do with Mother Earth.

And finally, the telescopes themselves often defy convenient categorization, being objects of purpose-built wonderment that have lines that curve and swoop in unfamiliar ways. These machines are often reflections of their times (for example, the 100" Hooker telescope looks a lot like other large things of its era - battleships!) - the fingerprints of the technologies out of which they were born are all over them, even if they themselves look nothing like the more conventional applications of that technology. Think of what would have happened if Andy Warhol had been locked in a Dunkin' Donuts kitchen and told produce some art. It'd be something wacky & cool & unexpected, but you know it'd have a certain familiarity because it'd be deep fried and covered in powdered sugar, too.

Having recently come back to ESO's Paranal Observatory to use the VLTI, I sometimes reflect upon these things as I wander around outside on the observing deck. On the deck are the 4 outsized domes for the UTs (the cleverly named 'Unit Telescopes'), the VLTI building, and the 4 AT telescopes (the also cleverly named 'Auxiliary Telescopes'). The ATs are specifically designed to be used with the VLTI, and as such, rank high on my list of personally important astronomical glass. The ATs are interesting little telescopes1, designed to be compact and can even be driven around like futuristic street cars. The flat white finish could easily have been designed by Apple, like some outsized iPod (is it too late to trademark the term iTelescope?), but recently I have discovered an even closer cultural link for them.

It's something that nagged at me for some time - that "I've seen this before" feeling that I couldn't put my finger on. And then it hit me: the ATs could easily be mistaken for Marvin, the oppressively depressed robot from Douglas Adam's ever-so-delightful Hitchhikers Guide to the Galaxy (at least, the movie version). The resemblance is striking - so much so, it gives me pause: did any of the film's producers visit Paranal before filming? Where did that Marvin design come from, anyway? And using Alan Rickman's voice in the movie for Marvin - it's just like when Rickman was in Die Hard, and they blow up the place, which of course is what happened to Paranal in Quantum of Solace. Coincidence? I think not.

1"Little" being a relative term - at 1.8m (71") in size, they're small only next to the 8.2m UTs.

* :)

Friday, January 23, 2009

Crisis at ESO!

Didn't I see this on a Space:1999 episode?
Wow, talk about an alarmist headline. But it's true! Why? There is a machine at ESO, a magic machine, one that single-handedly fuels the engine of astronomical discovery. I have often remarked that it is the single most important machine at the facility. What is it? Tucked away in the heart of the ESO cafeteria, sitting atop a shiny stainless steel countertop that has been devoted to it alone, like an altar, is the ESO espresso machine.

Its sheer size and glittering controls are sure to elicit a mouth-dropping expression of wonderment from the newcomer. ESO veterans know to make a beeline every morn immediately upon arrival at work for this cathedral of caffination and pay homage to its wonderous powers of brewing and steaming. Wizened oldtimers of the institute remark that its prodigious mind-enhancing output - estimated to be well in excess of 30,000 cups of black, liquid lightning a year - has single-handedly led to more discoveries than any comparable device in the modern world.

But alas, this morning, a mournful sign hung like a rude stoplight on the front of the machine. "Out of order," was its tale of woe. Progress today at ESO? Perhaps not. Perhaps the ephemeral mysteries of the universe will hide yet one more day behind the mists of uncertainty, with no minds coffee-sharpened like razors to cut away at the fog that hides discovery. But, "a technician has been called", the sign goes on to read - so there is hope for yet more insight will eventually come in seeking the secrets of the universe...

* :)