Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Telescope Ranchers

kottke.org

Post reply on HN
Print view View original

51–60 of 66 posts

Re: Telescope Ranchers

#51

Post by db48x »

ck2 wrote: post #3

sadly won't be possible for anything serious next decade as each space trillionaire and country launches their own 10,000+ constellations sky will be constantly twinkling, will be weird we'll have to switch to space telescopes above LEO https://satellitemap.space

It’s worth noting that the latest trillionaire lowered launch costs by ~10×. It has never been cheaper to launch a telescope into space. I’m surprised that no universities have launched their own space observatories. Harvard has a $50 billion endowment, but all they ever seem to spend it on is more administrators. They could launch a dozen space telescopes without making a dent.

Re: Telescope Ranchers

#52

Post by bluGill »

jjav wrote: post #46
gehsty wrote: post #38

Earlier quoted context omitted.

Maybe they could just like look at photos someone else has taken? If you are using someone else’s equipment, at a location you’ve never been too, it feels like you may as well just look at bubbles images of things.

> Maybe they could just like look at photos someone else has taken? If you are using someone else’s equipment, at a location you’ve never been too, it feels like you may as well just look at bubbles images of things. Yes.. this is an interesting philosophical question about the hobby. If you just rent some time one someone else's telescope on some location you don't visit, to take some photos.. how different is that…

The real gain is that you get to choose where and when to point the telescope. If you don't care this makes no sense. However if you get interested in anything other than the most common objects odds are nobody has good long term pictures of it. Even if you are a professional getting time on a big telescope when you want it is a problem.

Re: Telescope Ranchers

#53

Post by dredmorbius »

Retric wrote: post #45
dredmorbius wrote: post #42

Earlier quoted context omitted.

Averaging isn't the only option. It's possible to use other image-processing techniques which look at outlier values. This is way outside my area of expertise, but I believe sigma clipping is one of the standard go-tos, see: https://www.gnu.org/software/gnuastro/manual/html_node/Sigma... >. More generally, you're clipping outliers : https://www.gnu.org/software/gnuastro/manual/html_node/Clipp... >. This applies not o…

That’s an option. However, these satellites provide a predictable path so you don’t needed to detect them from image data. Which means you can even prevent them from showing up on long analog film exposures.

In balance, shorter exposures, stacking, and track-removal is technically easier.

Long exposures made sense when photgraphic plates were a scarce resource, and replacing them risked disturbing the observation.

Stacking is premised on the idea that individual exposures are cheap, and that noise tends to affect a small number of those exposures, in small regions. The same predictability of satellite tracks you name means that they can be removed through image processing rather than brute force (avoiding sky regions, physical masking, interrupting exposures during overflights, etc.).

And the other phenomena I mention (meteors, cosmic rays) are not predictable, and also degrade deep-space images.

Re: Telescope Ranchers

#54

Post by phrotoma »

js2 wrote: post #21
jimmy76615 wrote: post #15

Really great idea! But one still has to buy a telescope and send it to this guy, I think it would be cool if one could just rent everything at once. For non-serious people that have a lot of money that they would like to put to use looking at the stars. Or maybe a time-share like concept.

Nothing stopping you from buying a few scopes, sending them to him, then subletting access. :-)

Astronomy arbitrage!?

Re: Telescope Ranchers

#55

Post by Retric »

dredmorbius wrote: post #53
Retric wrote: post #45

Earlier quoted context omitted.

That’s an option. However, these satellites provide a predictable path so you don’t needed to detect them from image data. Which means you can even prevent them from showing up on long analog film exposures.

In balance, shorter exposures, stacking, and track-removal is technically easier. Long exposures made sense when photgraphic plates were a scarce resource, and replacing them risked disturbing the observation. Stacking is premised on the idea that individual exposures are cheap, and that noise tends to affect a small number of those exposures, in small regions. The same predictability of satellite tracks you name mea…

Image processing is a great way to get clean pictures but takes you further from direct observation. You could if extremely unlucky remove a supernova from your image not just meteors and cosmic rays.

Re: Telescope Ranchers

#56

Post by QuadmasterXLII »

asxndu wrote: post #16

What do people do with this astronomical data? Why do they pay for this?

Back in the crypto craze I spent a fair amount of time trying to work out a Blockchain where mining a block requires spotting a supernova before anyone else and verifying a block requires checking that the supernova is there, but I never quite got the game theory to work out.

Re: Telescope Ranchers

#57

Post by js2 »

whartung wrote: post #33
asxndu wrote: post #24

Earlier quoted context omitted.

Cool, makes sense.

I'm putting one of the modern "Smart Scopes" on my Christmas list this year. I had a friend with a 10" Meade with which not much happened. Just a bear to lug around and set up and mess with, not even including trying bumble through getting astrophotography started. But the new-ish Smart Scopes looks fun and accessible, so gonna see if I can get one of those to play with.

I've had an 8" Celestron SCT since I spent my Bar Mitzvah money on it shortly after I got hooked on astronomy by Haley's comet. There were no smart scopes then and the Miami skies didn't lend themselves to astrophotography. Still, I tried.

I still have that scope. It's on a wedge mount with motorized but manual tracking. Even an 8" is a pain to drag out and you really have to be dedicated because it turns out most folks don't have the patience to spend much time outside looking through a 1.25" eye piece. So when you drag it out, expect to be spending alone time with you and the sky.

Still, I'm glad I have it. It's good for looking at the moon and planets, and the sun with correct filter. I still drag it out now and again. I'll never take the sorts of photos you can find easily on the internet. So I prefer to look at the universe with my own eyes. That's still exciting.

Re: Telescope Ranchers

#58

Post by pfdietz »

zippyman55 wrote: post #44
pfdietz wrote: post #34

Earlier quoted context omitted.

Lasers would probably be more practical. Maybe a whole array of lasers w. telescopes? At (say) 500 km, a 20 cm aperture would have a spot size of maybe 50 cm. So let's take that telescope array, hook a kW laser to each one, and roast some LEO satellites? (Note: this is not an actual suggestion this be done.)

I know you are joking on this one, as I was on mine. But with people being arrested for shining pet toy lasers at objects, best everyone stay clear of this one.

It's more a thought experiment on perhaps how easily this could be done.

Re: Telescope Ranchers

#59

Post by dredmorbius »

Retric wrote: post #55
dredmorbius wrote: post #53

Earlier quoted context omitted.

In balance, shorter exposures, stacking, and track-removal is technically easier. Long exposures made sense when photgraphic plates were a scarce resource, and replacing them risked disturbing the observation. Stacking is premised on the idea that individual exposures are cheap, and that noise tends to affect a small number of those exposures, in small regions. The same predictability of satellite tracks you name mea…

Image processing is a great way to get clean pictures but takes you further from direct observation. You could if extremely unlucky remove a supernova from your image not just meteors and cosmic rays.

Extremely unlikely.

A supernova peaks over the course of days, and fades slowly over months to years. They also remain static relative to the background stars, as do all astronomical phenomena outside our Solar System, even over the span of a day.[1]

Even a very-rapidly-peaking kilonova (neutron-neutron star collision) though they peak quite rapidly (short gamma-ray bursts, or SGBs, last about two seconds) have durable remnants lasting weeks.

The transient phenomena discussed here occur largely at the scale of a few seconds at most, often far less, and most move across a significant span of sky within that time.

More likely is that a meteor impact on the Moon (or other Solar System body) might be missed, but those are sufficiently small targets that interference such as we're discussing would not be a significant noise source. Space-based observation of, e.g., comet collisions with Jupiter or Saturn would eliminate LEO satellite noise entirely, though cosmic ray interference would remain a concern.

________________________________

Notes:

1. An object moving at 0.99c at the distance of the nearest star, 4 light years, would cover slightly less than 0.04 degrees per day. Much of the Universe is at somewhat greater distance than even this.

Re: Telescope Ranchers

#60

Post by rtkwe »

gehsty wrote: post #38
jimmy76615 wrote: post #15

Really great idea! But one still has to buy a telescope and send it to this guy, I think it would be cool if one could just rent everything at once. For non-serious people that have a lot of money that they would like to put to use looking at the stars. Or maybe a time-share like concept.

Maybe they could just like look at photos someone else has taken? If you are using someone else’s equipment, at a location you’ve never been too, it feels like you may as well just look at bubbles images of things.

Renting, controlling and taking the pics yourself is still a step more involved than just googling a picture of something. Comes down to how each person individually feels about how much that involvement is worth.
Post reply on HN