Earth's new mini-moon swings by, then ghosts us by late November

Everybody be on their best behavior: Earth has a visitor. 2024 PT5 is an asteroid that took up residence in orbit on Sunday to become a "mini-moon." Alas, even if humanity could clean up our space junk, the asteroid would not be staying with us. It's lingering in the neighborhood until November 25, when the forces of gravity …

[42656e4d203239]

Thread the needle?

IF one were a galactic megalomaniac one could line up all the planets, side by side, between the earth and the moon¹ without the aid of Gru's shrink ray gun. Its quite a big eye in that there needle!

¹Only if the moon is at its furthest away from Earth and the planets are squeezed in narrow sides touching... don't get technical it spoils the story!

[MajorDoubt]

It could have hit us

thank random luck it didn't

[KittenHuffer]

Re: It could have hit us

If you increase the diameter of the centre bullseye of a regulation dartboard by about 2mm, then imagine that the outer edge (outside the scoring numbers) is the orbit of the moon, it will give a good visualisation of how 'lucky' you'd have to get for an asteroid crossing the Moon's orbit to hit the Earth.

[Michael Strorm]

Re: It could have hit us

> thank random luck it didn't

Is that the polite "rhyming slang" version of the word most of us would want to use?

[45RPM]

I’m not saying that it’s aliens. But you know it is. It’s an alien battlecruiser in disguise. And Bruce Willis won’t be able to save us this time.

[Roj Blake]

It's clearly the Annunaki returning. Or the Pleideseans. They're both great bunches of lads.

[Eclectic Man]

How do you know it is not the Grebulons?

https://hitchhikers.fandom.com/wiki/Grebulons

[Will Godfrey]

Quite Wrong!

It's definitely the Ramans.

As Mr Clarke told us, they always do things in threes.

[Geoff Campbell]

Nah.

I mean, sure, it *is* aliens. But they're just hanging out in the asteroid belt. playing Planetary Pool.

GJC

[Michael Strorm]

Old meme is old

> I’m not saying that it’s aliens. But [it's aliens].

You're that guy off of "Ancient Aliens" and I claim my £5.

Also, is that hairstyle a homage to the Centauri, or are you actually one of the Centauri?

[Danny 4]

Re: Old meme is old

When I see him in AA I wonder what he has in the satchel.

No doubt, it includes a towel.

[Eclectic Man]

Geocentric energy

its "geocentric energy will remain negative for 56.6 days due to a temporarily captured flyby."

I know how it feels, my own geocentric energy has been negative for years.

[mr.K]

Re: Geocentric energy

I think it is important to point out that MY egocentric energy is great...

I think that statement is both cause and effect.

[Eclectic Man]

Re: Geocentric energy - Aside

There was a manager in my old company about whom it was noted that he had a very large egoshpere. (First time I ever heard that word.)

Wen he left' there was no announcement at all, in fact I only discovered his absence accidentally some months after the event. Other managers of a similar level who departed were thanked for their contributions and wished well in their future careers (messing up* pubic utilities or health care trusts or some other such 'beneficial' activity).

*Matter of opinion, I suppose, but considering the state of the UK's infrastructure, and the fact that several senior managers went into the public utilities / NHS management, I'm going to put my foot down with a firm hand and say that they were not all as competent as they thought they were. So there!

[Anonymous Coward]

explode harmlessly in the upper atmosphere

Tell that to the 1000+ people injured in Chelyabinsk. Yes theirs was bigger, but if this hit over a big city, I can't imagine this being harmless.

[I am David Jones]

Re: explode harmlessly in the upper atmosphere

Chelyabinsk injured only 1000 people out of over 3 million.

Compare

18 vs 11 m diameter (a fifth of the volume)

42,690 mph vs 3,100 mph

Even if both were the same mass, the Chelyabinsk meteor would have had 200 times more kinetic energy than 2024 PT5.

So yes, I think it’s pretty accurate to call it harmless.

[Michael Strorm]

Re: explode harmlessly in the upper atmosphere

Did you know that they changed the name of the place to commemorate the explosion? Now it's known as Chelyabinsk o' blast.

[brainwrong]

Not a moon

People have been taking QI too seriously if they think this is a moon. It's just experiencing a minor gravitational slingshot as it passes nearby.

[bigphil9009]

Re: Not a moon

That's no moon! etc etc etc

[Michael Strorm]

Re: Not a moon

That's *exactly* what I thought when I first heard this story.

Does anything that hasn't completed- and *won't* complete- even a single orbit or anything near it seriously get to be considered a "moon", even by the loose and hyperbolic standards of popular science?

(Also, if it *were* able to complete at least one orbit of the earth, how likely is it that it would go on to complete further objects and get permanently captured? It strikes me that if this were to happen, it would be bad news for us, since such an orbit would be unlikely to be stable, and an asteroid in a potentially-decaying orbit around earth is... er, something we really, *really* wouldn't want).

[Pascal Monett]

"he forces of gravity will coax it back into a heliocentric trajectory"

It is not in orbit around the Earth then, it's just accompanying us for a little while.

[heyrick]

Re: "he forces of gravity will coax it back into a heliocentric trajectory"

Watching. Observing. And drawing up plans for at7dteg*#@.; <click>

[chivo243]

Re: "he forces of gravity will coax it back into a heliocentric trajectory"

My question is how large is a Uranium PU-36 Explosive Space Modulator anyway?

[Will Godfrey]

Re: "he forces of gravity will coax it back into a heliocentric trajectory"

That's nice. It must be pretty lonely out there all alone.

[Jason Bloomberg]

"only a 0.00151 percent chance"

So more likely than the proverbial "one in a million", much more likely than wining the National Lottery jackpot. Just sayin'.

[Wexford]

Re: "only a 0.00151 percent chance"

So you're saying...there's a chance?

[Ken Hagan]

"not an overly reassuring time period"

I am not perturbed by this. If it had been big enough to be a worry it would have been spotted sooner.

[IGotOut]

No really. Space is big, very big. And you have to looking in the right direction, at the right time, for a very dark object.

That's ignoring all the crap that's getting thrown up there in the way these days.

Put it in context. How hard was it for a bomber in WW2 to fly over a bloody great city during a blackout, and not actually see it.

[Eclectic Man]

re: perturbation

"I am not perturbed by this."

You may not be, but it is.

One thing about the animation is that it seems to pass quite close to the Moon (the BIG one we can see in the sky) at about eccentricity 1.3, but its trajectory does not evidence any change, so I was wondering whether the animation was based purely on the Earth's gravitational field, and omitted the (BIG) Moon's?

https://x.com/tony873004/status/1833588006353310110

El Reg astro-boffins please advise.

[Allan George Dyer]

Reclassify Earth?

Do we need to reclassify Earth as a dwarf planet, because we clearly haven't cleared our orbit of stuff like this?

(A friend of Pluto)

[The Jon]

The closest we'll get is 1994 PC1, ...and will have a close encounter with Earth in 2525.

If man is still alive, that is.

(Mine's the one with a copy of Zager and Evans' Exordium and Terminus in the pocket)

[Michael Strorm]

Sorry, but...

...they got there before you. I was going to make the same joke until I noticed they'd already linked "2525" in the article!