Hello and welcome to another bonus episode of the Supermassive Podcast from the Royal Astronomical Society.

With me, science journalist Izzy Clark, astrophysicist Dr Becky Smethurst and the Society's Deputy Director Dr Robert Massey.

We are getting ready to dive into your questions. Remember, you can email them to

podcast. rass.ac.uk or you can send us a message on Instagram at supermassive pod. Okay, Robert,

let's start with this email from Jimmy Muir. They say, hi, I love listening to your podcast and I'm

fascinated with everything space related. A quick question for you is,

how far would you have to go before our own sun would be invisible to the naked eye? Could you see it

from Pluto maybe? And if so, how far away would you be before it disappeared? Thanks for

everything and keep up the amazing work.

Well, Jimmy, the sun is definitely visible from Pluto and even there it's about 300 times

as bright as the full moon is on Earth. So magnitude minus 18, that's really quite bright.

And it varies a bit depending on how far away Pluto is. It's got quite an eccentric orbit.

So you know, you could probably knock a magnitude or two off that sometimes, but it would still be bright, still be really, really bright. And intriguingly, Nasser actually have a bit of a website where you can look up Pluto time, which sounds bizarre, which is when the sky on Earth is as bright as it is at noon on Pluto. And I check this. And for me today, here in Sussex,

it's five minutes after sunset. Still, still quite a bright twilight sky. It's not a faint star.

And you have to go a really long way for the sun to be invisible to the naked eye. You know,

it's a brighter than average star, but nothing like as bright as the brightest ones in the

galaxy. So if you assume a limiting magnitude

of 6.5, which is the definition that astronomers use, you know, the weird magnitude system where

higher numbers means fainter, then the sun is that bright from a distance of just over 70 light

years. So to put in perspective, the nearest stars are a bit over four and a bit light years,

the alpha centauri system. And from there, the sun would are a bit over four and a bit light years, the Alpha Centauri system.

And from there, the sun would be about magnitude.5, so quite bright, but fainter than some in the sky.

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