Funny how this is the same misleading language that tripped up Bard during the Google demo [0]. What's with telescope image headlines and the use of ambiguous language?
> The Super Pressure Balloon-Borne Imaging Telescope (SuperBIT) was flown to the edge of space
> SuperBIT flies at an altitude of 33.5 kilometres
Just no. I could understand say, shaving a few km off to get the project into "space". Maybe ten. I get that space is a bit of a blurry boundary and somewhat arbitrary up there.
Something like 99.6% of the atmosphere is below you at 100,000 feet. This is what matters, not the fact you're in space, but the fact you're not looking through a hot(ish) dense gas filled with moisture.
Except thay the mars atmosphere contains considerable amoints of dust and weather. Earth's atmosphere at these altitudes is bone dry and homogeneous. Presssures may be similar but the optical properties are totally different.
Still good enough to take some great infrared pictures. Sure, it’s not even close to the same league as JWST, but most astronomers on the planet are jumping over each other to submit proposals for observation on that.
Who cares, given that for a telescope what matters is the fraction of the atmosphere below it and that it is viewing things that are for all practical purposes at infinity it might as well be in space, the images wouldn't be any different unless the angle was very oblique, and even then the difference between being on the ground and being truly in space would be rather smaller for the second.
Interesting. Apparently some people consider the Armstrong Line [1] (where pressure is low enough that water boils at body temperature, at about 18km) to be the start of "near space". As opposed to "outer space" which starts at the Kármán line at 100km (unless you are in the US, where outer space starts at 50miles/80km instead)
It is a normal human thing to make categories when nature is like "nah we got a continuous spectrum here y'all" and then humans argue about the categories forever.
Mammals, animals that give birth to live young, have fur. Monotremes say wat!!?
According to the description of this NASA image [1], they flew a 7-million-cubic-feet super-pressure balloon in 2009. Approximating as a perfect sphere, that's around 120 feet in radius / 80 yards in diameter. And "When development ends, NASA will have a 22 million-cubic-foot balloon", which is around 170 feet in radius / 110 yards in diameter. These things also look squashed when inflated [2], so they're probably even wider horizontally. Basically, you can fit an entire football field inside along with some stands.
The stabilization mechanics must be very interesting. The earth rotates so it will need to move to track objects. There’s probably also still some vibration from the atmosphere. Then it’s on a tether so any movement will cause it to swing. Pretty cool!
For some scientific purposes, eliminating 99.6% of the Earth’s atmosphere is approximately the same as eliminating 100% of it. E.g. precise imaging and characterization of nearby interstellar bodies, those projects get Hubble-tier data thousands of times cheaper.
For other scientific purposes, eliminating 99.6% of the Earth’s atmosphere is approximately the same as eliminating 0% of it. E.g. trying to divine the values of physical constants in the earliest moments of the universe by looking as far into the past as possible, those projects are far too sensitive and their observations would be completely swamped by the noise of the remaining 0.4% of Earth’s atmosphere.
Because orbital telescopes can stay up there for years.
That said, there's a need for both. It takes a whole lot less capital and time to get a telescope up under a balloon, and it can come down, be refurbished, and sent back up again.
The James Webb's unique selling point is that it's cooled to -233 degrees science, eliminating a lot of infrared "noise" that an earth-bound telescope would not have.
So, the balloon flies above 99.5% of the atmosphere, but the telescope hangs under the balloon, so it have to take photos more sideways than straight up? Got to be a lot more than 0.5% of the atmosphere in the frame then.
Good picture, but at least part of that length is yet-to-be-inflated balloon. I'm guessing that the thicker section is the canopy of the descent parachute, so everything above that is likely part of the balloon. Assuming it is, and the balloon inflates to a sphere with the top at the same height, it looks like the telescope can point about 60° above the horizon.
Nice. Surprisingly, although balloon-borne optical telescopes were a thing in the 1950s and 1960s, there have been very few since. Wikipedia has a list of balloon-borne telescopes for microwave and X-ray bands.
I couldn't even find a repository of the images, which I would assume would have information on exposure time. Makes me wonder if these are testing images. The closest I could find was 17 minutes for an image from their 2016 run.
