Leon and Shana share the April edition of Audio Guide to the Galaxy, a stargazing companion for Perth (WA), starting in the western sky at sunset where bright Venus returns to the evening sky and Jupiter sits slightly northwest. After dark, Orion is highlighted as a useful pattern for spotting satellites by repeatedly checking for new, steady lights moving through the constellation, with a challenge to beat 40 satellites in an hour. As Orion sets, Scorpius rises in the east, identified by the slightly red star Antares, with a close Moon–Antares pairing before sunrise on 7 April. They note that before sunrise around 16 April, Mercury, Mars, and Saturn are visible in the east (with Neptune and Uranus requiring a telescope), and mention International Day of Human Space Flight on 12 April and Earth Day on 22 April. The constellation of the month is faint Libra above Scorpius, including discussion of the planet-hosting red dwarf Gliese 581 about 20 light years away and a message beamed there expected to arrive around 2030.

Good evening everybody.

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My name is Leon.

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Sharna: And I'm Shana.

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And this is the Audio Guide to the

Galaxy Your monthly Stargazing Companion

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for the Night Sky in Perth on WA land.

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Leon: So Shana, what's up in

the sky in this month of April?

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Sharna: Great question, Leon.

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Uh, so if we start, as we

always do, facing the sunset.

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Watching the beautiful sunset,

uh, looking towards the west.

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Leon: Yep.

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Sharna: And we can actually begin

our kind of stargazing journey

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before the sun's even set this

month, which is pretty exciting.

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Leon: Ooh.

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Sharna: Um, so just as the sun's setting,

you can see something very bright

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over in the west in our night sky.

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Ooh.

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Leon: Like

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Sharna: a sunset sky,

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Leon: A bright object.

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Sharna: Yes.

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A very, very bright object.

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And this month it's gonna be Venus.

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So Venus is finally coming back.

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We'll be able to see it in our skies.

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That's

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Leon: exciting.

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We haven't seen Venus for months.

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Sharna: Yeah, a long time.

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Leon: Well, not in the night sky anyway.

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Sharna: Yeah.

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Um, so it'll slowly move.

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Up the sky throughout the month and

we'll be able to see it more and more.

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Leon: Awesome.

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Yep.

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So that's pretty easy.

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Don't even need to do anything.

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Sharna: No.

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And then Jupiter will be up there

as well as it has been over the

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last couple of months or so.

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Leon: Yep.

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Venus.

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So Venus is in the west, where's Jupiter?

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Sharna: Venus is pretty

much almost due west.

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And then, uh, Jupiter's gonna

be slightly more northwest.

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Leon: Ah, cool.

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Sharna: Is,

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Leon: yeah.

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Yeah.

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That's, I think that's kind of where

it's been the last couple of months.

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Yeah.

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Yeah.

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Makes sense.

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I've got a cool story about

the western sky this month.

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Uh,

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Sharna: I would love to hear it.

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Go for it.

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Leon: So you do need to wait until the sun

has gone over the horizon for this park.

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Sharna: Yep.

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Leon: Um, because in the western sky there

is the very famous constellation of Orion.

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Um, you can spot Orion with the

three stars that make up his belt.

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Yep.

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It's so big.

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It's so bright, you can't miss it.

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But, uh, one of my

favorite things to do with.

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Orion in the Western sky is to

actually use it to look for satellites.

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Sharna: Oh, cool.

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Leon: And there's a special trick to it.

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It's because, I mean, you can do

this anywhere on the sky, but uh,

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you need a recognizable patch of sky.

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The idea is you look at the

constellation of Orion and you look

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at all the stars there, and you

just make a note of where they are.

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Make it, you know, take a mental picture.

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Mm-hmm.

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Sharna: And

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Leon: then just look away for

one minute, you know, maybe look

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on the other side of the sky.

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I dunno.

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Check your phone.

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Come back, look one minute later.

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Look at Orion again

and see if there's any.

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New bright objects that

have appeared there.

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And if not, look away for a minute.

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Look back again and just keep doing this.

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And eventually, because Orion is such

an easily recognizable pattern of stars,

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Sharna: eventually.

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Oh, really?

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Bright stars.

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Yeah,

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Leon: Yeah.

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You'll notice a new bright object

has appeared, and that will be a

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satellite if it's moving across the sky.

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And I say you can do this anywhere on

the sky, but because Orion is so easily

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identifiable, you very quickly will notice

these satellites zipping through Orion.

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Um, they're these bright, solid lights.

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They don't flash, they don't blink.

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Uh, they're just solid lights

moving across the sky and on, on

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any, on a good night, you'll easily

see a satellite every few minutes

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passing through the constellation

of Orion, which is pretty exciting.

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Sharna: It.

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Yeah.

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Exciting, scary,

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Leon: both.

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Yeah, that's right.

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There used to be, you know, satellites

were something you'd go out from, you'd

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set your alarm to go and see and then

these days, yeah, you just go and look

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to the sky and they will come to you.

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So

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Sharna: many of them up there.

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Leon: So many.

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Yeah.

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Yeah.

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But, um, it is a fun way to, you know,

you can easily while away, an hour just

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counting how many satellites you can see.

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I was doing this a couple of weeks ago.

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I saw about 40 satellites in one hour.

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Whoa.

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And so, yeah.

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Yeah.

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That's your challenge.

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If you can see more than 40 satellites.

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Sharna: Now in this little patch

of sky, once Orion has set, or

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once Orion's starting to set in the

sky it's actually something else.

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Pretty cool.

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We can see in our night sky this month,

uh, Scorpius is gonna come back into view.

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Leon: Ooh.

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Okay.

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Sharna: Yeah.

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So as soon as Orion's starting

to set Scorpius, it's gonna start

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to rise on the opposite side.

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So if we're looking west to see.

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Orion, uh, we turn around and look east

and you're going to be able to see, uh,

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scorpius, the scorpion rising in the sky

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Leon: right

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Sharna: now whilst Orion we

kind of find it by using those

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three stars Orion's Belt.

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Leon: Yep.

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Sharna: Um, Scorpius is a little

bit harder to see, but you

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can definitely still spot it.

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Mm-hmm.

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Leon: We've

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Sharna: gotta look in our east sky for a

star that's tinged ever so slightly red.

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Leon: Right.

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Sharna: Um, so this will be Hans.

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Leon: Yes.

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Sharna: Okay.

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Um, yeah, the heart of the scorpion.

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Leon: Yep.

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And that's how we identify.

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Sharna: Yeah.

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Leon: Yep.

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Sharna: And it kind of looks like

a, like a J pattern in the sky.

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Leon: Yeah.

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Yep.

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I have definitely gone out and

seen, uh, Scorpius probably

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about this time last year.

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Mm-hmm.

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Because it's kind of making a

return to the sky now, and Yeah.

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Yeah.

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As you said, they are, they're

on opposite sides of the sky.

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I was actually looking at this

in the planetarium the other day,

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and I, to notice that on the.

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7th of April in the morning.

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Um, the Moon and Antares

are actually like.

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So close together in the sky.

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Sharna: Oh, awesome.

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Leon: So

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Sharna: even easier to find.

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Leon: Even easier.

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Yeah.

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Yeah.

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So if you are out before sunrise on

the 7th of April, and it's only on

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the 7th of April pretty much straight

above your head, you'll see the moon.

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And then just next to the moon

you'll see Antares, which is,

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uh, yeah, that they're so close.

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Sometimes the moon actually

even passes in front of Antares.

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This time around, it's a

near miss, but it's so close.

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Uh, and yeah, I just happened to

notice that while I was mucking around

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in the planetarium the other day,

which is, uh, pretty cool actually.

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What else can we see?

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So, scorpius in the east, the

moon's there that seems like

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this is a pretty busy month.

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Sharna: Yeah, yeah, it is.

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Um, but let's maybe, maybe

stick with the kind of.

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Pre-do early morning sky.

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Leon: Okay.

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Sharna: Uh, this month, if you feel

like getting up quite early there is

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gonna be four planets in our eastern

sky visible just before sunrise.

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Leon: Oh, okay.

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Sharna: Yeah.

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So the, uh, the morning of the

16th is gonna be the best day to

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head on out, to have a little look.

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Leon: Yep.

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And, uh, what, so what

planets are we seeing?

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We've got Venus and Jupiter in the

night, sky in the west, so, yeah.

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What are we looking for in the morning?

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Sky In the east?

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Sharna: Yeah.

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So you're gonna be able to

see Mercury, Mars, and Saturn.

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Leon: Okay.

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Sharna: There will be

a fourth planet there.

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Uh, so Neptune will be there.

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But obviously too far away.

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You'd need a telescope

to, to get to see it.

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And then the last planet would be.

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Uranus and that will be over amongst

kind of satin and Jupiter, but

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again, too far away for us to see.

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Leon: But yeah.

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So the 16th is also in the

moon, is there as well?

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Sharna: Yeah.

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Leon: Yeah.

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That's cool.

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So yeah, I guess if you are not out

on the 16th, maybe it's cloudy or

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something like that, you can go on

either side of those days as well.

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Sharna: Yeah.

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So those planets will all still be

there, but it'll just be even easier to

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find 'cause of the moons there as well.

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Leon: Yeah.

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On

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Sharna: that day.

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Leon: Oh, that's really cool.

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All right.

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I know I'm setting my.

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My alarm for that.

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There's a couple of cool dates in April

that I just wanna quickly mention.

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One is the, uh, the 12th of April.

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It's like a celebration day.

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It's the, uh, international

Day of human space flight.

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Ooh.

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Do you know what happened on

the 12th of April 65 years ago?

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Sharna: This is first human space flight.

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This is Yuri g Garran, is that right?

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Leon: Bingo.

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Sharna: Yes.

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Leon: 61 on April 12th, 1961.

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Yes.

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Yuri Gagarin

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Sharna: said, stay with great confidence.

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And it's definitely right.

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Leon: Yeah.

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Actually, he also orbited the

earth, which is, uh, on his,

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on the very first space flight.

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Uh, so that's on April 12th.

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We, you know, it's just a, a nice day to

celebrate and think about the progress

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that humankind has made in sending

people to space and space exploration.

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Sharna: Yeah, it's a pretty amazing feat.

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Definitely.

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Leon: And the other cool gate is, um.

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22nd of April, uh, it's

uh, another symbolic day.

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It's Earth Day.

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And, uh, earth Day is when we

sort of take a moment to think

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about how important our planet is.

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And it's to try and sort of ways raise

awareness of being conscious of our

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planet and our environment and how human

beings need to care for our planet.

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Uh, so that's on the 22nd of April.

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That's Earth Day and, uh, I'll be,

uh, admiring nature just a little bit

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more than I usually do on that day.

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Sharna: Lovely.

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Leon: What's the constellation

of the month this month?

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Sharla?

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Sharna: Uh, yeah, so this

month's constellation is Libra.

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Leon: Okay.

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I've definitely heard of Libra.

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Sharna: Yeah.

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So just above Scorpius in the sky.

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Uh, so it's one of our zodiac

constellations, so it's probably

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one that a lot of people

have maybe heard of before.

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Leon: Yep.

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Sharna: Even if they haven't

quite seen it in the sky.

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'cause it's quite a faint constellation.

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It's

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Leon: Yeah.

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Sharna: Like a decently sized,

but it is, uh, a a little bit less

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bright and distinctive in the sky.

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Leon: What does it look like?

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Sharna: So I think it kind of

looks like a triangle with.

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Legs, like, it's kind of like a little

triangle and then like two little legs.

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Yeah.

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Standing on top of Scorpius a scorpion.

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Leon: Okay.

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Sharna: Um, but some people say

it looks like a, some sort of

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four-sided shape in some way.

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Leon: Oh, okay.

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So

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you,

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Sharna: yeah.

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Leon: Either a triangle with

legs or maybe like a diamond,

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Sharna: something like that.

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Yeah.

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Yeah.

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Leon: Because I know it's interpreted

as like scales where like, um.

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The balancing scales where you put

weights on one side and weights on the

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other and try and balance them out.

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Sharna: Yeah.

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So the mythology goes,

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Leon: yeah.

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Yeah.

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So I guess those two scales might

be the legs you're talking about.

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Sharna: I think so.

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I think that's the way

it's supposed to be.

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Yeah.

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So it's supposed to be these kind

of weighing balancing scales,

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Leon: And it's right next to

Scorpius in the sky, is that right?

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Sharna: Yeah, it is.

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So if you imagine scorpius is that.

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J shape.

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Leon: Yep.

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Sharna: It's directly on top of the J.

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Leon: Yeah.

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Sharna: Okay.

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Um, so they actually, the, these

two constellations used to be

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linked or related in some way.

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So Scorpius, a scorpion used to be bigger.

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So the stars that make up Libra used

to be these massive, like big claws on

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the scorpion, like much, much bigger

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Leon: Yeah.

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Sharna: Right.

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Than what they were.

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But yeah, they're kind of split up now.

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Leon: Okay.

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So that gives you a pretty good

idea of where I'm looking as well.

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'cause if I find Antares and I find the.

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That J shape or that hook of

stars that you're talking about.

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Sharna: Yeah.

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Leon: That's obviously

the tail of Scorpius.

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Um, and then so in the other end was,

would be where these giant claws are?

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Sharna: Yeah.

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These big exaggerated claws.

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You've gotta, yeah.

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Leon: Yeah.

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Okay.

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So

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Sharna: these, they, they would look

quite ridiculously big on a scorpion.

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They're huge.

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Leon: The Mummy returns was

on television the other night.

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Sharna: Oh yeah.

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Leon: Yeah.

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And uh, I watched it with such

enthusiasm just 'cause I was waiting

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to see the rock as a scorpion huge

exaggerated giant course, but, uh, okay.

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So, and, and then I guess

sometime, I dunno, in thousands

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of years ago, or modern history

astronomers split the scorpion

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into, into Libra and the scorpion.

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Sharna: Yeah.

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Leon: Instead of a

scorpion with huge claws.

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I've got a, a cool story about, uh,

one of the stars in Libra actually.

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There's a, a very, very faint star

inside Libra called Gza 5 8 1.

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And it's a really interesting star gza.

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It was the name of an astronomer

who just started making lists of.

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Stars that were close to the sun.

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And, you know, the 581st

star on that list from Mr.

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Gza has since been known.

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We've discovered that it's,

uh, it's got planets around it.

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And it, there are many stars

we know of that have planets.

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But the thing about Gza is that,

uh, GZA 5 81 is that it's a

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very interesting type of star.

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It's a tiny, tiny, tiny red

star called a red dwarf star.

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And, uh, red dwarf stars are.

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Dangerous.

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You think?

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Oh, they're small, they're red,

they're cold, they're not really

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Sharna: doing much.

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Yeah, it does, doesn't sound

like it should be terrifying.

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Yeah,

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Leon: yeah.

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But, uh, no, it's, it's

quite contrary there.

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Red dwarf stars are like really volatile.

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They have like huge regular eruptions.

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They just spew out material into space.

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And so whenever you, you find planets

around a red dwarf star, the often

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the common assumption is, ah, I

mean, they're gonna be sterilized

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by this outbursts from the star.

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Sharna: Yeah.

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No.

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Yeah.

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Leon: Um, but yeah, astronomers

noticed that Gza 5 81, for whatever

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reason, the star was a lot more stable.

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There was less of these bursts going on.

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Sharna: Okay.

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And

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Leon: so, yeah, there's

lots of speculation.

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They've found a couple of planets

around Gza 5 81 and obviously there's no

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guarantee that anything lives on them.

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But yeah,

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Sharna: they just, yeah.

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There any.

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Chances of aliens on any gza planets.

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Leon: Yeah, that's what

everyone's excited about.

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'cause yeah, this might actually

be a good place to look,

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because at least we can say.

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The, the star wouldn't have absolutely

destroyed these planets just yet.

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Unlike most other planets

around red DW stars would've

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just been sterilized, so Yeah.

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Yeah.

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Lots of research still need to be doing.

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But yeah.

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There's a couple of planets around

the glee of 5 81 star and Yeah.

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They might be more stable.

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I think that's the point

I'm trying to get at

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Sharna: across.

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Okay.

400

Yeah.

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Yeah.

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It

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Leon: might be more stable.

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Yeah.

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Compared and so

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Sharna: slightly more likely.

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Leon: Yeah.

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Sharna: Ever.

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So slightly more likely.

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Leon: Yeah.

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Yeah.

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Astronomers are keen to keep

exploring that and in fact,

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uh, some number of years ago.

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They, uh, just for fun some scientists

beamed a message to this star system.

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No

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Sharna: way.

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The

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Leon: radio message, and

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Sharna: do you know what it said?

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Leon: Uh, I think it was like

just a collection of comments

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from some old defunct social

media platform from 20 years ago.

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Sharna: Oh, that does not bode well.

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Leon: Yeah, but it might've

been like, hello from Planet

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Earth or something like that.

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Uhhuh.

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Sharna: Um,

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Leon: and then, yeah, if, if

there's anyone there at GLI

428

listening, then it'll arrive.

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Round about 2030 is when the message

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Sharna: should, oh, so how far away is.

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Gleer 5 8 1 from

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Leon: us.

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It's about 20 light years away.

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Sharna: 20 light years.

435

Okay.

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Leon: So yeah, it takes this message

that travels at the speed of light.

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It takes it 20 years to reach there.

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Sharna: Yeah.

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Leon: And then if anyone's listening

on the other end in 20 years time,

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In 2050, we might expect a response

if there's anything living there.

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And

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Sharna: I gleer

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Leon: Yeah.

444

I mean, it's more for fun than

actual legitimate search for life.

445

But, uh, it's a fun

thought to think about.

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Sharna: That's a cool thing to get to do.

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Yeah.

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Very cool.

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Leon: Well, I think this month

is gonna be very exciting.

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Uh, we've got planets in the east,

we've got planets in the west,

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we've got satellites in the sky.

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I'm looking forward to going outside.

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So thanks for being here and

thanks for listening to the

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Audio Guide to the Galaxy.

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Thanks for being here, Shawna.

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Sharna: Thanks.

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Leon: And we'll uh, see you next

month while we talk about the

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Night Sky in the month of May.