[HN Gopher] ESASky
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ESASky
Author : xioxox
Score : 226 points
Date : 2024-06-15 17:10 UTC (5 hours ago)
(HTM) web link (sky.esa.int)
(TXT) w3m dump (sky.esa.int)
| brink wrote:
| All these stars, and every one of them is unique. It boggles the
| mind.
| diggan wrote:
| > every one of them is unique
|
| How sure of this are we? Feels like we've can only confirm
| that's true for a small selection of the vast total.
| chrisan wrote:
| Think of them like snowflakes
| recursive wrote:
| So not all unique.
| brink wrote:
| They are.
| Etheryte wrote:
| To quote [0]:
|
| > Although snowflakes are all the same on an atomic level
| (they are all made of the same hydrogen and oxygen
| atoms), it is almost impossible for two snowflakes to
| form complicated designs in exactly the same way. While
| snowflakes can be sorted into about forty categories,
| scientists estimate that there are up to 10^158 snowflake
| possibilities. (That's 10^70 times more designs than
| there are atoms in the universe!)
|
| [0] https://ssec.si.edu/stemvisions-blog/are-all-
| snowflakes-real...
| butz wrote:
| "ESASky is an application that allows you to visualise and
| download public astronomical data."
| yuumei wrote:
| Beautiful, but could do with using quaternions for rotation to
| avoid gimbal lock. At least I assume that's the problem with
| getting stuck on the poles
| sigmoid10 wrote:
| For interactive navigation on a sphere (remember, this is just
| a sphere looked at from the inside) you actually want absolute
| euler angle based rotations, otherwise compound rotations
| around any closed loop on the sphere's surface will change the
| orientation of the camera and make further navigation extremely
| confusing. Source: many years spent designing 3d applications.
| Also, Google Earth and every other major app do it the same
| way.
| LegionMammal978 wrote:
| Im fact, if you zoom out all the way, you'll see that we're
| actually looking at a sphere from the outside, as if the
| stars are situated on a celestial globe. It seems to be a
| relatively common convention for interactive night-sky maps.
| amelius wrote:
| How fixed is all this? It would be nice if we could scroll
| through time.
| crote wrote:
| Pretty much everything beyond our solar system is essentially
| fixed on a human timescale. Over 2000 years, a typical star
| will move about half a degree. That's the width of the moon in
| the sky. There are of course notable exceptions like Barnard's
| Star, whose movement is pretty obvious on photographs taken
| over several decades.
|
| If you want to explore how space changes over time, I recommend
| you look into something like Celestia[0]. It allows you to
| simulate star movement over thousands of years, and show you
| how the night sky looked to the Ancient Egyptians.
|
| [0]: https://celestiaproject.space/
| kuschku wrote:
| Some what related, two awesome links:
|
| Nearest star to us, over time:
| https://commons.wikimedia.org/wiki/File:NearSunStarsSimple.j...
|
| Star closest to the north pole, over time:
| https://en.wikipedia.org/wiki/Pole_star#cite_ref-Meeus_6-2
| arendtio wrote:
| When I scroll out, I would expect to reach a point close to Earth
| or our solar system, but somehow, I look at a sphere from the
| outside.
| nativeit wrote:
| You are The One.
| bongwater_OS wrote:
| Hacker News is real obsessed with lookin' at the sky on their
| computers. Don't y'all know there's a real sky
| cydodon wrote:
| well... it's not always night time... it's not always clear
| skies.. it's not often that a power outage happens in my city
| to actually see the stars...
| crote wrote:
| To get a halfway-decent view of the night sky I'd have to drive
| about an hour away from my home. To get a _good_ view of the
| night sky I 'd have to fly to another country half a continent
| away.
| lukevp wrote:
| Where do you live that you don't have a good view of the sky
| within your country?
| nativeit wrote:
| If this even remotely resembled "looking at the sky" I
| seriously doubt there would be much demand or response to it.
| Fortunately, for the less incurious among us anyway, that's not
| what's happening here.
| nativeit wrote:
| To quote the immortal @butz quoting the very front page of
| the link...
|
| > ESASky is an application that allows you to visualise and
| download public astronomical data.
| OldGuyInTheClub wrote:
| Yes but I'd have to drive way out into the Southern California
| desert on a moonless night to have a chance to see it. Those
| areas aren't exactly safe.
| moffkalast wrote:
| Light pollution has made damn sure that we don't know. If you
| live in a city (statistically extremely likely) it's a drive of
| few hundred km to a place where one can see anything remotely
| similar. If you're lucky.
| VoodooJuJu wrote:
| They know, they just cant see it because they live in cities.
| dackle wrote:
| The title immediately brought to mind 1980s baseball "star" Nick
| Esasky (https://www.baseball-
| reference.com/players/e/esaskni01.shtml)
| hoppushoppard wrote:
| I found some kind of artifact @ 70.3169798 +19.0238259 FOV:
| 1.3degx2.4deg. What is that? Some kind of antenna?
| Ladsko wrote:
| I think it is the shadow or a reflection of the camera itself
| within the telescope. It's visible in multiple places.
|
| https://sites.astro.caltech.edu/palomar/about/telescopes/ima...
| mnadkvlb wrote:
| exactly. I see it as well in multiple other spots as well. eg:
| 1. 05 49 04.008 +01 09 47.27 FoV: 1.3deg X 2.2deg 2. 05 44
| 35.074 +01 52 52.36 FoV: 3.4deg X 5.9deg 3. 06 37 17.795 -47 18
| 20.97 FoV: 1.4deg X 2.4deg
|
| many more that i didnt list.
| bradknowles wrote:
| Not nearly as easy to navigate and discover as apps like
| Stellarium.
|
| Now, if they had the database with hundreds of terabytes of
| objects that NASA has for their OpenUniverse simulation they're
| running for the upcoming Roman space telescope (see
| https://www.jpl.nasa.gov/news/nasas-roman-mission-gets-cosmi...),
| then maybe I could understand why it is so confusing.
|
| As it is, I don't really understand why it has to be so
| confusing.
| aadhavans wrote:
| Agreed, especially with regards to Stellarium, although this
| seems more of a researcher's tool than a hobbyist's tool.
|
| There's an excellent web version of Stellarium, if anyone's
| interested: https://stellarium-web.org/
| moffkalast wrote:
| Does anyone know what's the deal with the fairly consistent
| discoloration of the individual images? The edges are often
| orange and the middle blue. You'd think they'd colour correct
| this out when doing the stitching...
|
| Also, are these [0] artefacts a result of adaptive optics since
| they shine out those lasers to keep track of distortions? And
| these [1] which seem to be the same but larger and less focused.
| I remember seeing similar ones on Google Sky years back but never
| really figured out what causes it.
|
| [0]
| https://sky.esa.int/esasky/?target=94.25875681534997%2020.97...
|
| [1]
| https://sky.esa.int/esasky/?target=218.7659069213465%20-59.6...
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