Hello and welcome to another bonus episode of the Supermassive podcast from the Royal Astronomical Society with me, science journalist, Izzy Clark and astrophysicist Dr. Becky Smithurst.

Yep, this is the place where we dive into the supermassive mailbox and take on more of your questions because we can't leave you hanging like we have done

for so long. Okay, so Robert Becky. Let's talk about to get that reference. I apologize. So Robert

and Becky, let's get to it. Becky, Jason on Twitter wants to know, given that the universe is expanding,

is there an example of a galaxy that was visible and is now not? As it has moved over the

cosmological horizon, if not, how long would a vanishing like that typically take?

Unfortunately not, Jason.

You've got to remember the universe is expanding, yes,

but that doesn't mean that galaxies are moving away from us.

It means that space expanding is moving those galaxies away from us.

It's not that the galaxies are moving,

is that space expanding makes them appear as if they're moving.

So if that's a case of space expanding, the cosmological horizon also expands with it.

So everything is moving away from us at the same rate, the galaxies and the horizon.

So nothing will ever cross that horizon because everything is moving away from the same rate.

Yeah.

And Robert, Hussain Mustafa Goddra Walla emailed to ask, can we theoretically change the orbit

of a comet as we did with an asteroid just so we can see them in our skies more often?

I love that.

It's a wonderful and at the time sort of Armageddon-like idea, isn't it really? You know, the idea you divert all these comments into the solar system. I don't know. I like the way the Hussein thinks. He's thinking outside the box. We know what asteroids. Less asteroids, more comments. Thank you very much. I mean, I suppose we could've not actually, it's a great idea really because you don't want to add to the population of stuff in the inner solar system, but some of which comes near the year. Such a party, people, Robert. Boo! But, you know, that doesn't seem like a brilliant move to me, but I don't see any reason in theory why you couldn't do it. However,

with big enough devices, but if you do do that, then you divert these comets into the

inner solaceism. What happens is if they go around the sun more often, they run out of their

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