SciScoop is pleased to announce that astrophysicist Michael C. B. Ashley has agreed to an interview with us!
Not long ago SciScoop featured
Dr. Ashley’s recent accomplishment proving the feasibility of robotic telescopes at Dome C in Antarctica, where his team discovered the seeing to be very good indeed. Dr. Ashley is an associate professor in the school of physics at
The University of New South Wales in
Sydney.
His prime focus is creating the tools to allow excellent ground-based astronomy, from the Antarctic (where the very same conditions that allow for good viewing make remote control imperative!) to
robotic wide-field telescopes.
His Antarctic astronomy work also includes Automated Astrophysical
Site-Testing Observatory (AASTO) at the South Pole. (Check out the associated south pole webcam page, where you can watch a movie of the sun circling the sky over the course of a polar summer day!)
The Automated Astrophysical Site Testing International Observatory (AASTINO) at Dome C, over a thousand kilometers away from the south pole, was described in a recent
letter in Nature. Dr. Ashley has been answering some FAQs about the Dome C work
here,
and he welcomes the chance to answer further questions.
Here at SciScoop, YOU ask the questions! Submit your questions for Dr. Ashley all week long on this story. If you don’t already have a free account, sign up now and rate each other’s posts during the week to determine which questions will be passed on to Dr. Ashley. At the end of Thursday, October 14, the top-rated questions will be sent to him, and his responses will be posted here when ready.
Dr. Ashley, it’s a pleasure and an honor to have you as our guest here on SciScoop; thanks for your particiption. I have a couple of questions about specific telescope types; here’s one.
I’ve been very interested in reading over the years about so-called liquid mirror telescopes, which as you probably know are revolving circular disks that contain a small amount of liquid mercury which then spreads out into a near-perfect telescope mirror surface. Their ease of setup and relative low cost is apparently offset by the fact that they can only point stright up and depend on the Earth’s rotation to bring targets into view. Two specialty areas I’ve read about where they might be useful are orbital debris census and extremely deep-field faint-magnitude cosmological surveys.
Questions: What’s your opinions of Liquid Metal Telescopes? Any plans to build one as a permanent observatory to do serious work that you know of? What extra challenges are posed by trying to operate one in cold temps like a mountaintop or someplace like Dome C? Wouldn’t heating them to keep the mercury fluid cause the air to have thermal atmospheric distortions around the mirror?
You might be interested to know that I did some work about 10 years ago for Boeing looking at how to separate minerals from lunar soil and I came up with the idea (never patented, and now I guess it never will be because with this article it’s public domain!) of using a liquid selenium bath on the mooon to separate different mineral grains in lunar regolith. Because of the densities of selenium and the various mineral types, some would sink and some would float. The vapor pressure would be low enough where the system should work in vacuum. Anyway, maybe there’s a future for LMTs based on selenium on the moon someday!
One of the advantages of operating at the poles is the months-long winter night. Can a polar optical telescope take advantage of this by running very long exposures to detect very faint objects? Could you do almost as well as the Hubble deep field images? Are there any other practical applications for the potential long exposure times?
Your FAQ mentions a couple of things that required or would have worked better with human intervention – first of all the initial setup of the telescope, the alignment etc, and then second the failure on May 17th, which with an onsite presence could likely have been easily solved.
Have you looked at relative costs of a fully automated system (one that you could drop on the ice by parachute, and assembles and aligns itself), versus, at the other extreme, one that is continuously human tended? Do you think your setup is in a happy medium? How does that depend on the cost and size of the telescope?
I’d never heard of a jet-fuel based generator before so that caught my eye. I read the PDF about the engine at AASTO featured on the Whispergen website and it was very interesting. It sounds like a certain amount of engine customization is needed for the Antarctic. Does your team perform the modifications, or does the vendor? What about the fuel tank modifications (allowing the “topping-off” procedure you describe)? Is jet fuel dangerous to have around?
One of your goals for the antarctic telescope is to image extrasolar planets. Do you think we’ll be able to image any that resemble Earth? When that first Earth-like planet is discovered, will it be a bit of an anti-climax, or will space suddenly seem that much more exciting again?
Do you think hands-on experience before becoming a professional astronomer is still a major career motivator? If not, what do you think is the current motivator for new youngsters to enter your field of observational astronomy? So much of astronomy now is number-crunching instead of pretty pictures – has this shift changed the kind of people who now take up astronomy as a career? And if someone is going to crunch numbers, why would you say a prospective student should do it for astronomy and not do it for a biotech or drug company that gives stock options?
I ask these questions because I believe the past motivators are becoming increasingly obsolete. Light pollution has dramatically decreased the pool of people who see the wonders and feel the awe of the night sky for themselves, and pictures from Hubble and NASA planetary probes easily available on the internet can make anything an amateur can obtain or see for themselves through a personal telescope seem rather paltry…
If the Moon or Mars had the exact atmospheric and temperature range as the Antarctic location of your Dome C observation post, there would be a major push on to colonize those habitable areas in space. Why do you think there is no similar romantic notion in the public mind to colonize Antarctica as a new, independent nation of volunteers? Do you suport the eventual opening of Antarctica to international colonization in addition to its current research-only status? Why should we bypass an entire continent with miles-deep water ice and breathable air to go to places vastly farther away and vastly more expensive to reach that offer only vacuum or near-vacuum with meager surface frost and tundra?
What other kinds of science, besides extra-solar planet search, are the large-scale interferometers (as discussed in your FAQ) good for? Is planet search your particular interest?
Antarctica has no energy resources – the sun is gone for half the year. A colony there would be forced to rely on importing fuel across hundreds of miles of ice. And what exactly would you do there? There’s no exciting low-gravity, no great new sports or amazing view back to planet Earth, or of the landscapes of Mars. You’re not going to be growing your own food there. There are already a number of “bases” for scientific purposes – and a bigger telescope there would add yet another. Those bases are certainly useful; similar bases on Moon and Mars would be a big step forward for space exploration.
Any group prepared to risk their life on top of the controlled explosion that is a rocket to get to a colonization site that is bathed in hazardous levels of natural radiation is going to be willing to obtain their energy from a nuclear reactor when they get there. Thus using nuke power in Antarctica for a colony is a no-brainer. There’s tons of highly enriched uranium available from decommissioned nuclear weapons that could be used for ultra-small power plants like subs use instead of the huge utility giant units that are forced to use uranium fuel diluted to 3% that isn’t weapons grade. And before you nix giving small groups of colonists chunks of weapons-grade uranium as their power source, there’s ways to selectively contaminate it so it can’t be diverted for weapons use. Whoever first colonizes the Moon and Mars is going to use a nuke power source; why not Antarctic colonists? Lack of indigenous energy is not a barrier to Antarctic colonization.
I see no reason why Antarctic colonists can’t grow their own food just like lunar and Martian colonists are eventually going to be required to do. You don’t think Loonies and Martians are going to phone in to Earth for pizza delivery, do you? It’s going to be really no different doing closed-loop greenhouse farming on our seventh continent that is going to teach us some things we’ll be glad we’ve already learned when we finally get around to closed-loop greenhouse-farming on our second and third world. The need to develop closed-cycle greenhouse farming we’ll need eventually in space anyway is not a barrier to Antarctic colonization.
Humanity isn’t ever going to view low gravity sports, views of a marble-sized Earth in the sky and sunsets on Mars as sufficent reasons to live for decades and die of old age offworld. Besides, Antarctica has some spectacular vistas and terrain, too – and even a pretty good view of the sky, I hear. Lack of local color is not a barrier to Antarctic colonization.
There’s got to be other, selfish reasons which may or may not turn out to be accurate in the long run. The original American colony in Jamestown Virginia was sold to investors as a way to use local Virginia trees that were far more common than those left after centuries of human use in England to stoke fires that would be used to melt local sand into glass bottles for export back to England. Obviously America was ultimately established for more than cheap bottles. Today the lunar He-3 hype is the same thing. We’ll ultimately colonize the moon for a totally different reason we probably don’t even appreciate today – probably political. Today people all over the world clamor for ownership of an American passport – why not an Antarctic passport that designates you as a scientific explorer and politically a world citizen that is not aligned with any nation? The Swiss have built up quite a rep as negotiators and bankers on just such a world-neutral basis; why can’t Antarctic citizens hold the same rep for say, cyberspace matters? The lack of knowing what good Antarctic citizenship would be isn’t a reason not to try and establish it as a political experiment.
And finally, Antarctica is a fine place to do space exploration. In addition to analogue and testbed efforts, the ice flows and collects meteorites against mountain ranges; there’s extraterrestrial samples all over the place down there just waiting to be picked up. Make no mistake about it: we’ve currently gotten more samples of Mars from the efforts of ANSMET than the efforts of NASA, and this will be true for decades to come. A desire to do space exploration is no barrier to Antarctic colonization.
Think about it – what would efforts ranging from an X-Prize to ten years of $15B-per-year of NASA level funding of Antarctic colonization efforts ultimately yield? And more importantly, why don’t we care?
Another robotic Antarctic telescope effort is Vulcan South. Have you ever met or been in contact with the crew of the Vulcan telescope? Any idea how their effort is going, or if your results are influincing their efforts? Please comment on whether Dome C would have advantages over other Antarctic locations for attempting to find transiting planets via continuous high-resolution photometry.
I have my doubts about a nuclear reactor – they’re more complicated than you seem to think, to keep running safely. All robotic space nuclear stuff so far has been simple thermal energy from radioactive decay, which is an extremely expensive source of energy if you want a lot of power. Aside from all the likely objections from “tree-huggers” :-)
By the way, it’s Canadian passports people want, as I’m sure Drog can confirm. Nobody wants a US passport these days. Not even most Americans!
Anyway, to me Antarctica means 2 miles of solid ice. Certainly there are some regions where you could dig up some dirt and make a garden in a greenhouse (with artificial lights for winter?) but wouldn’t the ice get in the way of any substantial garden there?
The key to why people are interested in the Moon and Mars is being able to use their local resources – what local resources does (most of) Antarctica have, other than cold and ice?
How stable are Antarctica’s weather conditions? Is there any reason to worry that they will deteriorate, astronomically speaking, in the near future (decades) due to global warming and the already alarming loss of ice shelf?
Does the presence of the hole in the ozone layer over Antarctica have any bearing on the planning of astronomy there? That is, I believe the presence of ozone makes the atmosphere opaque to ultraviolet. Is the atmosphere translucent to UV in the absence of ozone? Is there anything worth seeing in that part of the spectrum?
The letter in Nature states that “an interferometer based at [Dome C] could work on projects that would otherwise require a space mission.” Is the Dome C plateau big enough that all the telescopes of a single interferometer would fit on it? If not, where are the other locations that would yield the best possible interferometer? How much difference does it make if the seeing is better at one part of an interferometer than at another?
The letter in Nature states “Although it is expected that the turbulence conditions at Dome A, the highest point on the Antarctic plateau at an altitude of 4,200 m, will be superior even to Dome C, the complete lack of infrastructure at this site (it has never been visited) means that Dome C may be a preferable location.” What’s your WAG (wild-ass guess) of the seeing at Dome A? The AASTINO seems to be self-sufficient – it doesn’t rely on any infrastructure from the Concordia station structures – could a Dome A project be done simply (hah!) by moving AASTINO to Dome A?
Dr. Ashley, thanks again for agreeing to this interview! And now for the more personal side of astronomy: are you originally an Australian? If so, whatever prompted you to trek all the way to Caltech for your master’s? If not, how did you end up in Australia?
Dr. Ashley, while I follow research astronomy avidly, I always wonder what amateur astronomy the pros do for fun. I as an amateur always wonder what I’d do with pro equipment, but what, if anything, do you pursue on an amateur level with retail equipment? What astronomy do you do for fun outside of your research?
Thank you!
-Mark Ensley
I’m sure this has been thought of, but I’m curious as to why freezing the liquid mercury while spinning it into lens shape would not work.
Would crystal formation dull it? Density changes affect the lense shape (though it seems like that could be accounted for)? Would it freeze too slowly and unevenly, no matter how fast one removed heat?
What do you think is the holy grail of astronomical observation technology? Is an array of telescopes scattered throughout our solar system feasible, for instance? If so, how (more or less) would it work? How many telescopes would we need and where would we put them so as to produce the best combined images? Would they need to be arranged in the same plane as the planets or could they also be arranged along a perpendicular plane so as to look along the plane of our solar system? What sort of capabilities might such an array give us compared to what we have today?
opens up in the spring, when daylight first comes back. UV observations in daylight would be difficult because the atmosphere is tremendously good at scattering short wavelength light like UV (the daylit sky is blue for this same reason) even without the ozone. The maximum extent of the hole comes during perpetual day. Thus the ozone hole is open during the wrong seasons for UV observation.
There certainly are a lot of interesting things going on in the UV, which is one reason the Hubble S.T. will be sorely missed. Oddly enough, Antarctica is a favored location for releasing balloon-borne telescopes, because winds carry them around the continent and return them to approximately where they were released.
Ok…So hear me out. I really hope that someone responds to this…I recently watched a discovery channel special on Dr.Stephen Hawking and (Forward) time travel…
Ok, so here it is….
If you look up into the night sky at the stars or let’s just say one star…you’re looking at history right? I.e. it takes x number of years for the light to reach us or “your eye”…Okay so now lets set up one of those artic telescopes to look at the same exact star…THIS HAS BEEN KEEPING ME UP AT NIGHT!!…
Aren’t you looking through time?….
And let’s just go a step further…Let’s say that star went supernova and blew up a long long time ago and that light is just now reaching us…So what happens when you look at that point through a telescope?…Are you looking at nothing at all?…Does that mean you’re looking thru time?
SOMEONE PLEASE HELP!!
@Alan I don’t get what you’re asking. Yes, the light takes a finite amount of time to reach us as does light from any object you look at. Even the image on your coputer screen is how it was in the past not “now”. This strikes at the heart of relativity, but it’s not that you’re “looking” through time, you’re just responding to photons that have travelled from some obect striking the retina in your eye and being processed by your brain a fraction of a second later, and then entering your conscious awareness. What’s you’re actual question?
There are countless supernovae out there, some exploded a long time ago (you might see them when the light gets here, after that there will be nothing. Some may be exploding right now, depending on how distant they are depends on when our descendents will see them.