from the come-scan-the-skies-in-my-beautiful-balloon dept.
Helium is way cheaper than rocket fuel, and the pictures are just as good if you get high enough:
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 Nebula in the header of this article, and a second of a pair of colliding galaxies known as "the Antennae."
SuperBIT's main scientific objective is to measure the properties of 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 other than its interactions with gravity.
The telescope, a collaboration between the University of Toronto, Princeton University, Durham University and NASA, lifted off from New Zealand on April 16, and was carried to an altitude of 33.5 kilometers (20.8 miles) by one of NASA's stadium-sized super pressure balloons. At that altitude, SuperBIT is floating above all but the last half-percent of the Earth's atmosphere, giving it a level of visibility that ground-based telescopes can't match.
Because it sits outside of most of the atmosphere, SuperBIT isn't limited by anything but the laws of optics, and is able to take images with resolutions as high as the Hubble Space Telescope. It's also the first balloon-borne telescope to be able to capture wide-field images.
"SuperBIT will test whether dark-matter particles can bounce off each other, by mapping the dark matter around clusters of galaxies that are colliding with neighbouring galaxy clusters," said the University of Toronto.
SuperBIT is taking images via practice known as gravitational lensing, which takes advantage of how areas of dense gravity, like a pair of colliding galaxies or a massive stellar nursery, bend rays of light. Various theories suggest dark matter may slow down, spread or be chipped apart during a galactic collision, making the Antennae a particularly good observation point, according to the University of Toronto.
While it's in the air, SuperBIT will circumnavigate the southern hemisphere, taking images at night and using its array of solar panels to gather energy during the day. University of Toronto wasn't specific about the duration of the mission, and didn't respond to our email asking for some additional details.
The University of Toronto adds that the telescope would be "carried by seasonally stable winds for about three months," which may point to its mission duration corresponding to how well its giant balloon keeps the 3,500 lb (1,587 kg) gondola in the air.
[...] Funding for the upgrade has already been secured, meaning for its next mission SuperBIT will have ten times the ability to collect light and help scientists learn just what exactly dark matter gets up to out there in the depths of space. ®
(Score: 3, Funny) by Tork on Wednesday April 26, @07:17PM (4 children)
I found an example image [npr.org] of dark matter emissions the balloon detected.
Slashdolt Logic: "25 year old jokes about sharks and lasers are +5, Funny." 💩
(Score: 4, Interesting) by Tork on Wednesday April 26, @08:10PM (3 children)
I dabbled a little in long-exposure photography and stabilization was my biggest challenge.
Slashdolt Logic: "25 year old jokes about sharks and lasers are +5, Funny." 💩
(Score: 5, Interesting) by GloomMower on Wednesday April 26, @08:55PM
https://sites.physics.utoronto.ca/bit [utoronto.ca]
40km up, above 99.2% of the atmosphere, so it is pretty thin.
It seems to have quite a bit of mass actually, once stabilized it probably doesn't move very much. Outside the main structure, I'm sure it has some type of adaptive optics that will keep it stable on a target star.
https://stratocat.com.ar/fichas-e/2019/TMS-20190917.htm [stratocat.com.ar]
It does have gyroscopes and magnetometers. The gondola has a reaction wheel. Piezo controled mirror for small.
(Score: 0) by Anonymous Coward on Wednesday April 26, @09:02PM
Optical aberrations from atmospheric effects are negligible for this, but this thing is hanging from the bottom of a balloon so it will sway and rotate about due to the winds you do get up there. To compensate for that, it has a three-axis stabilized mount that can handle 360-degrees of yaw and up to 6 -degrees of sway or roll. The elevation pointing is limited to angles between 20 degrees and 55 degrees because of the Earth (below) and the balloon (above). Here's a paper on the design [arxiv.org]. The 3-axis mount stabilizes it to within about an arc-second, then it has back-end tip-tilt optics that does fine stabilization down to less than 50 milli-arcseconds (about 24 microradians) over time scales of an hour.
I can't find anything on the optical design right now, otherwise I'd try to relate its performance to your long-exposure photography experience.
(Score: 1) by khallow on Friday April 28, @04:16AM
Don't know over here, but the balloon launches I participated in weren't turbulent once they got to altitude (above 80k feet, ~25 km) without exception. We never launched in bad or extremely windy weather and thus, might have missed out on the primary causes of high altitude turbulence.
(Score: 3, Funny) by Rosco P. Coltrane on Wednesday April 26, @10:10PM (1 child)
Joe Biden didn't order it shot down.
(Score: 2) by Freeman on Thursday April 27, @06:13PM
Hey, rednecks love their guns. Also beer and shiny things. Just be glad he didn't claim it was an alien invader.
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
(Score: 1) by anubi on Wednesday April 26, @11:52PM (5 children)
It's unmanned, well away from everything, ignition sources nonexistent. Does hydrogen give more lift, or is He about the same density as H²?
Is it some phenomena up there that could
I post this as a query.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 1) by anubi on Wednesday April 26, @11:55PM
That could...make this posit nonsense?
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by Rosco P. Coltrane on Thursday April 27, @12:14AM (1 child)
Despite the fact that the world is about run out of helium [npr.org] in a minute, and that helium should be prohibitively priced for all but the most critical applications urgently (i.e. medical), I have a feeling it's still cheaper to use than hydrogen. Hell, you can still buy it to make stupid party balloons, which is a scandal considering the scarcity of the resource.
(Score: 2) by PiMuNu on Thursday April 27, @12:28PM
The cost of hydrogen is low, the cost of ATEX certification is high.
(Score: 3, Interesting) by ElizabethGreene on Thursday April 27, @10:05PM
The balloon is filled on the ground by flammable people that can be damaged severely by even relatively small overpressure waves. Would for that, it would be an excellent way to avoid using Helium.
For scale, ignition of a 1 m diameter hydrogen balloon in my back yard was sufficient to convince someone to call the Police re: "Explosives going off". It was louder than (recreationally small quantities of) tannerite going up.
(Score: 2, Informative) by khallow on Friday April 28, @04:23AM
H2 is less dense by a factor of two and gives a little more lift. Keep in mind that regular atmosphere is on the order of 30 g per mole while helium is 4 g and hydrogen 2 g per mole. So when you have a mole of helium in a bag, you have effectively 26 g * acceleration of gravity (let's call it "G") in lifting power (the weight of the air being displaced by helium minus the weight of the helium). For hydrogen, that goes up to around 28 g * G. So lifting power of normal hydrogen is around 8% greater than the lifting power of helium. It won't give you a huge edge.
The real advantage is that hydrogen is vastly cheaper and can be made locally by cracking water via electrolysis. The real disadvantage is that a lot of energy is released when that reaction is reversed as can happen in a hydrogen balloon suspended in an oxygen-rich atmosphere.