hpr-knowledge-base/hpr_transcripts/hpr1533.txt

Episode: 1533
Title: HPR1533: Beginner's guide to the night sky 2
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr1533/hpr1533.mp3
Transcribed: 2025-10-18 04:46:07

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Yeah this is a good time.
Thank you.
Hello and welcome to episode 2 in the series of podcasts that I've entitled A Beginner's
Guide to the Night Sky. So two apologies. First of all, I apologise for not mentioning
HPR Hacker Public Radio in the previous episode. This was because when I recorded it, I had
no idea where it was going to be released and it was at the suggestion of Nibble, also known
as Enwai Bill, and when to go, I think, on the status net ferry verse, that I released
it in Hacker Public Radio. So thank you to them and a big hello to all you out there in
Hacker Public Radio. Please do consider recording this jewel if you haven't already done so.
The second apology I have to make is for the huge gap between episodes 1 and 2, is it
six months? Is it really six months? Well, I think it does. Well, that's just life, isn't
it? It gets in the way sometimes. So I got some lovely feedback on the first episode I
have to say. In no particular order, Dave Morris got in touch to see how much she enjoyed
it and actually, coincidentally, I was quite enjoying a couple of episodes that Dave has
put out in the recent past. Also, Neander Geek got in touch to let me know about an
HPR episode that I had missed. I can't believe I missed it. It was episode 1366, and he was
talking about K-stars and using this Raspberry Pi with a telescope, and I do recommend that
you go and listen to that. Thank you, Neander Geek, for getting in touch. Also, Poki left
a nice comment on the HPR website, and Vanden said some kind words, but felt that I gave
the moon illusion short shrift. Maybe I'll return to the moon illusion in a future episode.
But anyway, thank you for all that feedback. Always welcome. So I think six months ago,
I promised in the second episode I would look at astronomy software, and I'm going through
my word. I am going to do that, and I'm going to look at four bits of software. The first two
are on Android, and the second two are GNU Linux based applications. So let's start. I'm going
to do this in reverse order of how much I like and use them. So the first app that I have on
my Android phone, and I am currently using a Google Nexus 4, although I do have some old HTC
desire Zs, or desire Zs, also known as G2s, that I've tested these on. And the first one is
Starmap. Now Starmap is unique amongst the four I'm going to talk about because it's proprietary,
and I think it came out on iOS or iOS first. I don't know that, but it doesn't feel like a lot
of Android apps that I have used. In particular, it seems very keen to extract money out of you
at every twist and turn. Although I think the basic app is actually free on Android, certainly.
Well, the reason I came across it is because I was teaching an astronomy class. It was first year
students at Glasgow University. And to get them engaged with astronomy, I thought, well,
let's get them using their phones. So I put up a challenge to them, find whatever app you can
in your phone, and they all had iPhones, as it turns out, these poor and poverty university
students, and well not all of them, but most of them are 20, 25, 30. And a lot of them came back
with the Starmap app, which was pretty good and available on Android for free. So I gave it a
look. Now, it's by a games developer, which shows, because it has absolutely gorgeous looking
graphics, and it looks beautiful, striking, milky way, and gradient filled backgrounds,
and you know, it just all looks just like, you know, like a computer game, and a gorgeous computer
game graphics. And that actually would also be by main criticism of it. It is all looks, and not
much substance, and to get more substance out of it, you have to pay money. So yes, it looks
lovely, and it has the wild factor, and if you hold it up against a patch, the night sky, it will
show you, you know, hold your phone up against the patch, the night sky, it will show you what's
there. Which is all good, but I feel done with rather too much fuss, which brings me on to the
second app, which is Google Sky, also I think called Google Skymap. Now, I think something to do
with the extension to the Google Earth desktop application, but in my mind, it really was the first
app on my first smartphone, which was a, a Google HTC G1, back when it first came out. It's
actually October 2008, it's a long time now, and I remember when I got my phone, the first app
that really made me go, wow, this is something I could never do before, and indeed I could show it
to other people. I think even the iPhone, my iPhone brethren were impressed by this, I don't know if
such a similar app was available on iPhones at the time. I don't recall exactly, but I remember
them being impressed and poking away to see if they could get something up the app store,
and their phones. Anyway, it's Google Sky, and it is now, I think, open sourced in a patchy
two license, and really what it does, it does one thing, does it very well, you hold your phone up,
and it will show you what is present in the next guy. An unlike start-up, it has very basic
graphics, but it has all the things I would want in it, all the objects you can see with the
naked eye are there, the planets are labeled, and you've got enough menus and options to cover
all my basic ones. The only thing is, and I don't remember this being a problem with my G1,
but it seemed to be a problem with more modern phones, and it could be in my imagination, maybe my
expectations have risen, is that it does seem to trigger about, so you hold up the phone against
the night sky, and it will show you the stars and the constellations, etc, that are there, but
it seems to just jitter about in the screen, with backwards and forwards in the screen, quite sensitive
as if it's amplifying, just letting natural emotions in your hand, and I don't remember that
being a problem with my own G1, but maybe it's because accelerometers and phones have become more
sensitive, could be, or maybe it's my memory, maybe my expectations as I say are raised.
So I would really recommend that it's available on Google Play, or you can get it through
F-Droid, and the latter is generally my preference, although if you get it through F-Droid,
sees on location, finding services provided through Google are removed, and there's a bit of a
warning about that, although I haven't encountered a problem as far as I know, but then I haven't
really travelled about it, I'm just using it at home, so my phone probably isn't too bothered
about it, but I might have gone a few ways in order to spin, how difficult is it really to look
up along a given latitude of another place, if that's what you have to do. It's slightly annoying,
but I don't think it's a major deal, so go with the version of that on F-Droid if you can.
And that brings me on to the apps available for GNU Linux, and when I say GNU Linux, I guess,
technically these apps are available on other platforms, because I haven't tested them in
anything other than GNU Linux, and the first one I'd like to review is K-Stars. Now K-Stars was
the one recommended to me by Nyandru Geek, although I have actually looked at it before
because it comes with KDE, and KDE is the desktop that I use with Slackware on my day-to-day laptop,
so I have used K-Stars before, and I think one occasion, because it was just present on my laptop,
and I hadn't installed anything else, I just used it with a class I was teaching. Now I am privileged
in that people actually pay me to do astronomy, and one of the things I do is, or one of the things
I like to do are evening classes, and so I need to be able to show people on a screen, your laptop,
connector projector, project up into a screen, I need to be able to show them what's up in the
night sky. As K-Stars does the job, it's not pretty, but there's nothing, there's no problem with
it either, it works really well, and as I say it comes in the default software compilation of KDE,
so just as they are at the box for me, I don't often install anything when I'm using my Slackware
laptop, and it shows you what's in the night sky, you can turn on things like the Eclipse Tick,
which is the line across the sky where you'll find the sun, the moon, and the planets,
technically the sun should always be on the Eclipse Tick, the moon can be a little bit off it,
but you know for, to give you an example, it shows to be Eclipse Tick, where these objects would be
found in it, of course it shows, and labels the planets as well, and the sun and the moon etc,
and you can turn this on and off, and as a security application you can configure it through your
blue in the face. So I haven't, I have to say used K-Stars too much, so I can't comment on
its in depth features, but I noticed it did offer to download an extra pile of star catalog goodies
on its first run, and I didn't look too much into what that involved, but I thought that was nice,
it gives you the option of just on use it, or I want the in depth stuff, like that, that's a good
option to have up front, and I noticed that it had a plethora of options for displaying information
pages from various sources on the internet, so you could view images, view further information,
link to observing pages, all kinds of things, I mean it just was superb. I don't know if K-Stars has
been updated all that much in recent years, but that isn't, as I've learned, a system of software,
if it's reached a stable state, and frankly the night's guy, most of it isn't changing very much,
and will the bits that do change that are largely predictable out of the motions of the planets,
then that's not a bad thing, I presume it's got plugins so you can put in satellites and
comments that have only recently been discovered, but I haven't looked, but as I say, K-Stars is
a fully featured grade, a GPL licensed planetarium software, and it brings me to my final
piece of software, which is Stellarium, which to me is the bees knees, it's the Stellarium
package that I would use, it's available on Grool and Exx, it's available on Mac, OS10s,
available on Windows, and I've used it on all of these platforms, and it's just grade,
and it's got a beautiful user interface that keeps up your way, it's got excellent keyword shortcuts,
and it looked pretty as well, actually, and it's a nice understated sort of a way.
Now, I use Stellarium in two different ways, I use at my desktop, as I mentioned,
projected up into a screen, and for that, I do tend to use the gray interface that comes with it,
and I think I like about this interface, and I believe there's a number of different interfaces
you can get, but the one I use is the one where it slides out the way into the bottom left
and the bottom left of the screen, and there's two panels, one that comes in from the left side
of the screen, and the other one that comes in from the bottom of the screen, oh, and you put the
mouse down there, these slide gently into view, and they're really quite understated and faintly
drawn, but not so faint that you can't see it, but this is what you want in a darkened room, you don't
want a bright white window dazzling everybody, and also what would mean is that it's used
for actually, in real night sky conditions, where your dark adapted your eyes are used to the dark,
again you want a nice black background, and as dim as possible foreground displays,
and out the box, still the game delivers that for me,
as I see these gooey controls are very easy to use, but when I'm in the planetarium, the real planetarium,
that is a darkened room with a dome ceiling, and the one I use that's in the observatory down the road
from my house where I give classes, actually the dome ceiling is a giant umbrella, when I say
giant umbrella, I mean a 5 meter diameter job hung from the ceiling, full of spokes and stretched
fabric in between, and it hangs from the ceiling by another old looking rope, so I do caution
my guests in the planetarium that is in principle possible for the sky to fall in them, but
as never happened yet, and when the sky has a big spoke sticking out of it, yeah you don't want
that to happen, anyway, so the setup in there is that you have a computer projector,
and it's mounted quite high, so it's sitting about six feet off the ground and especially
constructed stand, and it is connected to, it's a normal computer projector I should add,
and it's connected to a laptop, which is an ancient MacBook, not my choice, but that's what was
provided, and on that is an ancient version of Stellarium, is it 0.4, maybe it is well with
8 enemy, but that's what's on it, and an important bit is that the projector projects in a completely
normal way, but not on to a screen, but on to this curved mirror, and it's like a convex
mirror that's a couple of feet across, if you imagine like it being like a quarter of a rug
people, that's what it looks like, and then when the reflection of this is reflected up
onto the inside of this giant umbrella, which is going to be the sky, and you get this image
of the next sky projected up, and now the first thing to say about that is that the view just above
the mirror is pretty poor, but the rest of the night sky is okay, quite usable, I have to say
that the quality of the night sky is nowhere near as good as the old-fashioned type of projector,
no, we used to have one in the observatory where it was on mechanical, and it was a ball with
the like pinpricks where all the stars were, well professionally machine drill pricks if you like,
holes, and there was just a lamp inside, a very bright lamp that ensured you got nice sharp
star images, now that produced a more realistic and a better view of the night sky, and I loved
operating the old-fashioned, you had six knobs in front of you, a couple of switches in that
was it, but you could dim the sky down, you could have a bit of red glow at one side and you could
stop and start things with like a switch, I appreciated the minimal simplicity and the mechanical
elegance that went into it and see the engineer dismantle it, but you can't do an awful lot with
it, and with this new setup, although with the projector you get this nice night sky, it is
aesthetically not quite as nice, but as I say you can do a lot more with it because you've got the
whole power of Stellarium under your belt, now the first thing is, is that when you're operating
the planetarium, you're in the pitch, in the pitch black, you can't even allow the back of a
backlit keyboard, that's too bright, so you have to do things by touch, I'm not a great touch
typist, and it's not like touch typing, but Stellarium is good because it is all operable via
keyboard shortcuts, which is what you want, unfortunately in the dark, when an alien keyboard
in the MacBook, which is particularly alien to me, it's quite hard to find your way around,
so I do have a little red torch on a hand to show you in the keyboard, briefly if I can't find the
key, and it's occasional giggles where I hit the wrong key and something bizarre happens,
like I said I've seen Jupiter, they get a constellation or appearing all over the sky,
or they get transported to the wrong place in Earth, something like that, it does occasionally
happen, but you know I usually have a bit of a laugh with the audience about it when that does happen,
but with Stellarium you can do a number of really quite cool things, I mean my favourite thing to
do, and this does bring in audible gasps when I do it, people have not seen it before,
is that for example I show them, let's say a Ryan, and they can see a Ryan's belt underneath the
belt in the planetarium display projected up, they can see this Ryan Nebula little fuzzy patch,
and I can click in that, and then I hit, I think it's the forward slash key, and then that
causes you to zoom in, but not only zoom in, it will then move Ryan Nebula to the zest, the point
directly above your head, zoom right into it, and a nice smooth zooming action, and you zoom right
into a beautiful big telescope, long exposure picture of the Ryan Nebula with all the colours,
and it fills up the top portion of the dome, the zenith, that's the zenith, the zenith is the point
we're right above your head, and the altitude of 90 degrees, technical astronomy speak,
incidentally people often use the word Nadir in everyday language, but an astronomy Nadir means
the opposite, it means the point directly below the zenith, directly below your feet, the point
which is least observable, you'd have to drill a hole all the way right through the earth to be
able to observe something in the Nadir, anyway, I digress, this picture of the Ryan Nebula above
people's heads doesn't fail to get a gasp if they've not seen it before, it is quite impressive,
and then you can do the same with Jupiter, and the positions of the moons will be visible,
and when you're finished you press, I think it's the backspace key, which is located in a
weird position in a mat keyboard, and you'll zoom back out again to where you were, which is really
handy because you can pick up where you're left off, and you can do all kinds of other things,
you can speed up, slow down time, reverse time, set time, move, latitudes go to the North Pole,
North Pole's always fun because the insured and the sun is just trundling along above the horizon,
not getting much higher or lower as the day goes by, and certainly not rising in setting,
that's another favourite, and then you can demonstrate like you go to the equator, and demonstrate
that the equator, that the sun, especially like the equinoxes in the 21st of March and 21st of
September, the equinoxes sunrise, the sun comes straight up, 92 degrees up from Eastern point
with the horizon, passes right through the zenith, there's zenith again, you know what that is now,
and then we'll set down in the Western, not Western, but in due west on the equinox,
and it comes vertically down and disappears below the horizon, and so sunset and sunrise
are over very quickly at the equator compared to a high latitude like Glasgow where I am,
which is 56 degrees north, and Stellarium is really well set up for this, now I think there's a
planetary mode you put Stellarium into, although I can't comment on how you do that because I never
said to upwards, the very good technician at Glasgow University Observatory who looks after that.
Anyway, so Stellarium is a great piece of software, whether in a real planetarium or in the
desktop, the other thing I should mention about it is that you can put in various other objects,
so when we had comment eyes on last year and comment pan stars just over a year ago,
greater skies, that wasn't by default loaded into the list of objects in Stellarium's database
because when the last release took place, nobody had discovered those comments yet, let alone realize
there were going to be, well, actually neither of them turned up to be that visually exciting
in the real night sky, although they could have been, but the point is that Stellarium didn't include
them, but it's not too difficult in Stellarium to add in these objects. Now, I'm not going to attempt
to describe the details of how you would do that, but I think in the show notes, I'll provide you
a link of how to, like, the grocery how to add a comment in, so that if comment super-duper,
wonderful seven appears and promises a spectacular view, promises it to be a spectacle in a night
sky later in the year that you can go and add it in yourself and find out exactly where to look
and prepare yourself for the ultimate disappointment, which is any almost every
spectacular comment, or meet your shower that is predicted. Well, not everyone, no, I'm exaggerating,
there are some, been some real corkers of comments in my lifetime, comment, hillbop, comment,
hike, tacky, to need a book to. Anyway, so that's my roundup. Now, apologies if you feel I've given
to Boroughland and its expression short shrift to the other applications, in particular case to
ours, that's really because I use Stellarium more than anything else. Another piece of software
which I'll probably come back to in a future episode is Celestea, which lets you leave the
surf to the earth and fly around through space in a very scientific and accurate and mind-bogglingly
confusing 3D sort of a way. I think I will talk about that in the future, but I think that's
enough for this episode. So thank you very much for listening and thank you to the good folks
at HPR and its community for allowing me to be a part of it and providing so many other podcasts
that I've enjoyed. Thank you very much for listening and please do let me know if you've got any
feedback on the website or wherever it is, see you prefer to leave feedback. Thank you very much.
Bye-bye.
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