What does the night sky look like on Mars? • Hacker News Board

Re: What does the night sky look like on Mars?

#81

Post by astrophysician » Wed, Jan 27, 2021, 2:27 PM UTC

Retric wrote: post #57

tokai wrote: post #32

Earlier quoted context omitted.

Astronomers, both amateur and professional, have a legit issue with starlink. SpaceX are even trying to mitigate the issue - because of astronomers pointing it out. So I can see nothing wrong in a magazine for hobby astronomers taking a jab at starlink.

According to the astronomer I talked to, starlink has a negligible impact on professionals. Some disruption at the beginning, but fairly easy to account for. There is already plenty of man made objects that need to be accounted for like the ISS, any of which could cause an issue but it’s a tiny fraction of data that’s impacted and therefore it can be removed fairly easily. That said, amateur astronomers doing long ex…

Simply not true, starlink will have a real impact on research (see e.g. https://www.lsst.org/content/lsst-statement-regarding-increa... for the impact on LSST) and will make some science impossible to do. Ironically, amateur long exposure shots will be fine because amateur astronomy doesn’t rely on pixel-level brightnesses and you can easily subtract out streaks in a way that’s pleasing to the eye. Whether or not you think it’s justified, it’s not true to say this will not impact astronomy. Some science cases will be fine, others will be significantly impacted and still others will be SOL and impossible to do.

Re: What does the night sky look like on Mars?

#82

Post by titzer » Wed, Jan 27, 2021, 3:06 PM UTC

Uhrheber wrote: post #67

perl4ever wrote: post #44

Earlier quoted context omitted.

The aspect of amateur astronomy culture that discouraged me was the awful code published in Sky & Telescope back in the late 80s or early 90s. They used to have a policy that in order to be compatible with the least common denominator of their readers, they required published programs to be in BASIC. And not just BASIC, but basic BASIC, with line numbers. As far as I was concerned, it was unreadable and obsolete sinc…

Fortran is still popular in scientific computing, and modern compilers are pretty good.

Not only that, but modern compilers are insanely good at compiling numerical Fortran code. The very first optimizing compiler was for Fortran and it's consistently been on the forefront of compiler techniques ever since.

Re: What does the night sky look like on Mars?

#83

Post by Retric » Wed, Jan 27, 2021, 4:08 PM UTC

astrophysician wrote: post #81

Retric wrote: post #57

Earlier quoted context omitted.

According to the astronomer I talked to, starlink has a negligible impact on professionals. Some disruption at the beginning, but fairly easy to account for. There is already plenty of man made objects that need to be accounted for like the ISS, any of which could cause an issue but it’s a tiny fraction of data that’s impacted and therefore it can be removed fairly easily. That said, amateur astronomers doing long ex…

Simply not true, starlink will have a real impact on research (see e.g. https://www.lsst.org/content/lsst-statement-regarding-increa... for the impact on LSST) and will make some science impossible to do. Ironically, amateur long exposure shots will be fine because amateur astronomy doesn’t rely on pixel-level brightnesses and you can easily subtract out streaks in a way that’s pleasing to the eye. Whether or not you…

So the “Rubin Observatory is an extreme case for the sensitivity of astronomical observations to satellite constellations because of its unprecedented ability to repeatedly monitor the sky widely and deeply.”

And their worried about potentially losing as little as 0.3% of pixel level data, that sounds about right. I am not saying it’s impact is meaningless, just they could offset their impact with funding, rather than it being a massive issue on it’s own.

Re: What does the night sky look like on Mars?

#84

Post by perl4ever » Wed, Jan 27, 2021, 11:21 PM UTC

titzer wrote: post #82

Uhrheber wrote: post #67

Earlier quoted context omitted.

Fortran is still popular in scientific computing, and modern compilers are pretty good.

Not only that, but modern compilers are insanely good at compiling numerical Fortran code. The very first optimizing compiler was for Fortran and it's consistently been on the forefront of compiler techniques ever since.

I know that's the cliche, but I don't think that something like VSOP87 would be noticeably faster compiled with Fortran vs. C, in the early 90s. If there even was a Fortran compiler available for Mac or Amiga, it was probably priced obscenely, too.