Balloon-borne telescope returns first photos in search for dark matter The world's first wide-field, balloon-borne telescope has begun returning images to Earth, with scientists keen to begin months of imagery to help investigate the existence of dark matter. The Super Pressure Balloon-Borne Imaging Telescope, or SuperBIT, has returned two publicly-shared images so far: The one of the Tarantula …
It isn't a novel approach. I'm reminded of the BLAST telescope from around a decade ago, although I don't think it itself was the first.
Indeed it is not a novel idea. I am reminded of two stories I was told when on a course for new PhD students (which times the telling of the stories in the summer of 1982):
[1] An infra-red telescope was launched in a balloon just as a thunderstorm hit the area (which should have caused the launch to be aborted). There are two special features about infra-red observing: [a] the Earth's atmosphere absorbs strongly in the infra-red, which is why the balloon launch was required, and [b] the telescope has to be cooled with a liquid helium jacket (because otherwise most of the infra-red radiation observed is heat radiated from the telescope itself).
Inevitably, the balloon was struck by lightning, and the canopy deflated. This meant that the basket and the telescope were dropped from a great height. Now, if the liquid helium jacket cracks and the coolant escapes, there is then contact between the air and liquid helium with boiling point of about 4 Kelvin, which would cause the helium to boil rapidly. There is a name for a device which generates a lot of gas quickly; it is called a bomb.
The next slide showed how the basket and contents landed. The basket fell into a wooded area, and the telescope and jacket stripped out the branches of three trees, coming to rest - intact - about 3 metres from the ground.
[2] Another event was a manned launch in France: there were three men in the basket with the telescope [by the early 1980s, all three held distinguished positions at various UK universities; however this particular event happened in their younger days]. The observations were taken as planned, but there was a a substantial wind which carried the balloon far across the landscape. They had a couple of chase cars (Land Rovers or similar) whose job it was to keep up with the balloon and collect the balloon, passengers and equipment when the balloon landed. As the time for landing approached, the passengers noticed a large mansion with a large expanse of grassland - an apparently good landing site, so they decided to put down there ... only immediately to be surrounded by several gendarmes. They then had to explain why they had landed a balloon in the grounds of the official country residence of the Vice-President of France.
I'd assume some sort of gyroscopic gubbins or other means of lens stabilisation. I have a few lenses for my DSLR which include tiny motors to counteract any unsteadiness of hand - that's consumer/prosumer grade kit so I assume if you've got budget for doing proper space science stuff then similar tech is very much available.
Since the balloon is above most atmospheric weather at 35km height, winds up there are less of an issue. And since most of the southern regions are comparatively flat (bar the Andes stretching down into Patagonia to meet Antarctica across the Drake Strait, and maybe parts of New Zealand's Southern Alps, the rest is all ocean), you don't have the massive upswells and turbulences that you get when air currents hit obstructions.
The balloon probably travels at high speed laterally, but you can compensate for that relatively well with gyroscopes.
Helium is a natural product of radioactivity, alpha-particles are essentially Helium nuclei, so the Earth emanates Helium all the time, all we have to do is collect it. I expect there will be enough for several years to come.
Not at the rate we're squandering it. The helium produced by surface background radiation goes into the atmosphere from where it would be fiendishly expensive to harvest and also from where it diffuses into space. We get our helium from fossil sources, which are replenished very slowly by the Earth's internal radioactivity.
You could equally argue that we'll never run out of oil & natural gas because there will be some more along in a few hundred million years.
"33.5 kilometers (20.8 miles" is, to 3 decimal places, 110,000 ft. No prizes for guessing how aeronauts measure altitude. But the universal unit adopted for aerial navigation is clearly not good enough for us vultures. May I suggests Everests, for example 4.39 Everests is a very obvious choice of altitude for an astronomical balloon.
I thought the standard Reg unit of length was the linguini.
I would be confused were the Everest to be used for altitude because firstly, the summit of Everest is, by definition 'ground level' and secondly the alp (or mountain) is the unit of belief* and I'd get confused if mountains were used for units of two different things.
*In 'Good Omens' by Terry Pratchett and Neil Gaiman, Adam believes things with great strength of mind: "It may be worth noting here that most human beings can barely raise more than .3 of an alp (30 centi-alps). Adam believed things on a scale ranging from 2 through to fifteen thousand six hundred and forty Everests." (Footnote numbered 4, in "Thursday", part 7.)
"I would be confused were the Everest to be used for altitude because firstly, the summit of Everest is, by definition 'ground level'
Altitude is internationally defined above sea level, not ground level. Units of height are another thing altogether, IMHO better measured in flea-jumps or lions rampant or similar.
I take it you mean AMSL: Above Mean Sea Level. Both are important for flying aircraft. The most frequent cause of loss of aircraft is CFIT: Controlled Flight Into Terrain. However high above mean sea level the aircraft was, it was not above ground level when it crashed.
https://en.wikipedia.org/wiki/Controlled_flight_into_terrain
Khalifa as a unit could also confuse rapper Wiz Khalifa (6'4"/1.93m) with Mia (5'2"/1.57m)
Khalifa the tower is different enough that an error should be easy to spot. Mia based versus Wiz based is like short/long ton measurements, close enough that a quick estimate isn't enough to ID which unit is in use.
University of Toronto wasn't specific about the duration of the mission, and didn't respond to our email asking for some additional details.
According to the news item on Durham University's site, it's a three month mission; "Carried by seasonally stable winds, it will circumnavigate the southern hemisphere several times on its three-month flight - imaging the sky all night, then using solar panels to recharge its batteries during the day."
"dark matter, a term given to the invisible-yet-mathematically-required quarter of the matter in the universe that we're unable to see or detect in any way"
I would argue changing "required" to "predicted" in the above.
Our best mathematical solutions for a problem change as science progresses e.g. "Newtonian gravity" was happily used for centuries with great success however it does not work quite so well at larger distances e.g. solar system scale and "Einsteinian gravity" is a better solution in that situation e.g. for explaining motion of the planet Mercury that Newtonian gravity failed on.
Our current models of the universe predict dark matter/energy .. but it is extremely likely that our current understanding is incomplete and likely to change in the future so wording ought to reflect that... If you want some heated debate get a group of astrophysicists* in a room together and ask them their views on the cosmological constant.
*I'm not one, though did study some astronomy modules at university & so got to know lots of the researchers / staff & it's got far more complex in terms of competing ideas since those days
Or Canada the-us-airforce-may-have-shot-down-an-amateur-radio-pico-balloon-over-canada
So if it might land in water, why no airbags/floats on the project. Just asking. For the sake of a small additional weight, the ability to recover enough or it to reuse seems a missed opportunity.
[resisting voting on the ground level v above mean sea level / chart datum thing]
And if they add airbags I claim patent rights!
I'm wondering that, too. Hydrogen probably escapes thin films (even) faster than helium..but don't know about the relative escape rates. Hydrogen is fairly reactive, so maybe it reacts with the balloon while it is permeating the bag, and that might be bad.
Sure, it's flammable, but if something has allowed air/oxygen to get into the balloon, you got bigger problems than a high-altitude "pop".
I'm assuming more knowledgeable people have thought of and rejected this idea for a reason, so I'm curious what we are missing.
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