this post was submitted on 13 Oct 2023
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The Parker Solar Probe's new top speed could get you from NYC to LA in just 20 seconds. It's not done yet.

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[–] [email protected] 115 points 1 year ago* (last edited 1 year ago) (2 children)

Just remember not to try and impress a girl back on Ceres by trying to slingshot through the ring.

RIP

[–] [email protected] 34 points 1 year ago (2 children)
[–] [email protected] 20 points 1 year ago

Speed never killed anyone. Stopping quickly - that’s what gets you.

[–] [email protected] 1 points 1 year ago

I wonder if his teeth were moving fast enough to cause a problem for the integrity of the hull

[–] [email protected] 6 points 1 year ago (2 children)
[–] [email protected] 12 points 1 year ago* (last edited 1 year ago)

Fa real, sa sa ke?

Edit: oye kopeng, don't forget check ya seals an filters

[–] [email protected] 5 points 1 year ago (1 children)

Ah yes. And the epic Kenny Roger’s song “The Slow Zone” playing in the background.

[–] [email protected] 32 points 1 year ago* (last edited 1 year ago) (2 children)

I'm theory, the fastest man made object is actually a particular man hole cover involved in operation plumbbum. Some napkin math put it at somewhere around 37 miles per second. A high speed camera pointed at it only caught one or two frames of moment.

[–] [email protected] 20 points 1 year ago

The related Wikipedia page, in case anyone else was curious

[–] [email protected] 9 points 1 year ago (3 children)

Ah yes, the manhole cover made in Neenah, Wisconsin. Probably the furthest man made object from Earth at this point for sure.

[–] [email protected] 15 points 1 year ago

Probably the furthest man made object from Earth at this point for sure.

The article says "Scientists believe compression heating caused the cap to vaporize as it sped through the atmosphere."

[–] [email protected] 5 points 1 year ago

This, and Chris Waddle’s penalty kick for England against West Germany in the 1990 World Cup semi final.

[–] [email protected] 4 points 1 year ago

It's unlikely it kept it though the atmosphere. But it's possible it was traveling so fast it didn't even have time to vaporize.

[–] [email protected] 31 points 1 year ago

Breaking news: The thing we put in a highly elliptical orbit around the sun is in a highly elliptical orbit around the sun (and hasn't yet reached its perihelion).

[–] [email protected] 31 points 1 year ago (1 children)

My butt is orbiting the center of our galaxy at around 500K mph so that thing still has some ways to go.

[–] [email protected] 29 points 1 year ago (3 children)

It's too bad they can't fling the probe in the opposite direction once it's done with the sun. I know it's instruments are probably tuned specifically to take measurements of various solar phenomenon from close-up and probably aren't sensitive enough to be useful for any deep space science, but it'd be cool to use that speed to launch it on an escape trajectory and see how long it takes to catch up to the Voyager probes.

[–] [email protected] 49 points 1 year ago (3 children)

PSP is travelling at 394,736mph. Voyager 1 is about 15 billion miles away and travelling at about 35,000mph.

Time taken to catch up t is roughly 394736t = 15000000000 +35000t or about 4.75 years.

[–] [email protected] 10 points 1 year ago

Thanks for the math! Here's hoping we can fling the records of our civilisation far enough out for another civilisation to learn about our demise. And not, like, just accidentally flinging it into a burning star or space imperialist Klingons or something. Even though that would be poetically appropriate too.

[–] [email protected] 4 points 1 year ago (1 children)

So like .06% of light speed?

[–] [email protected] 3 points 1 year ago

I had a couple more zeroes when I did the math. I'm not sober though.

[–] FatAdama 1 points 1 year ago

I’m just going to trust you calculated that correctly.

[–] [email protected] 38 points 1 year ago* (last edited 1 year ago) (2 children)

So, it doesn't work the way you think.

It's only going that fast because it's near the sun. The same way a satellite close to Earth needs to move faster than one farther away. You can't really use that velocity to go elsewhere. It had to lose a lot of energy to get as close to the sun as it is. It would need to gain that back to get to earth.

I'm really blanking on a way to explain this concisely and I can't explain orbital mechanics in a Lemmy post.

If you play Kerbal space program, you can definitely use that to get a very intuitive understanding of this concept.

[–] [email protected] 26 points 1 year ago (1 children)

Drop a ball. It goes fastest just before and after it hits the ground, and slows down until it gets back to near the height you dropped it from

The probe is the ball, and slingshotting around the sun is like bouncing off the ground. The potential energy (height of ball/distance from sun) gets converted to and from kinetic energy (speed).

[–] [email protected] 13 points 1 year ago* (last edited 1 year ago) (2 children)

That's a pretty good answer. I was definitely overthinking it.

A little correction. They would be slingshotting around either Venus, Mercury, or both to lose energy.

Going around the sun is like just bouncing a perfectly elastic ball.

Close enough for this mental model, though.

Edit: in my own defense I am in Vegas doing minor Vegas things.

While I'd really rather be talking about orbital mechanics or some other geek shit, I do get to see an annular eclipse in totality in a beautiful national park. That's certainly a once in a lifetime event.

[–] [email protected] 8 points 1 year ago (1 children)

Seeing an annular eclipse is an excellent application of orbital mechanics! Enjoy!

[–] [email protected] 7 points 1 year ago* (last edited 1 year ago)

I intend to. Provided I don't get trapped in the desert for days. We're bringing extra food, water, and eclipse glasses to auction to the highest bidder, though.

We didn't even plan this. The opportunity came up before I even knew that I could take a tour and see this.

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago)

Glad you are having fun. I never want to fly through Vegas again. That airport was outrageous, even by airport standards. Ended up paying $45 for a Shake Shack meal. Thankfully I had my rolling machine, tubes, and tobacco. They wanted $20 per pack of cigarettes, I forgot my lighter though, and paid $10 for a BiC lighter.

[–] [email protected] 6 points 1 year ago (3 children)

Thanks! I didn't think about the fact that it'd lose velocity to gravity as it gets further away.

I wonder if you could slingshot a probe by firing it to fly by the sun and then shedding mass at its perihelion. The idea being that the craft would be mostly dead weight, increasing the force exerted on the craft by the sun's gravitational pull. Once you reach the perihelion, you eject the mass behind the craft so that there's less force acting on the craft as it moves away from the sun.

[–] [email protected] 9 points 1 year ago* (last edited 1 year ago) (1 children)

👍. I like science.

You wouldn't just drop mass along side you in space. It would just continue to float along beside you.

You definitely have to throw it behind you, like you said, but that's what rockets do. They throw mass behind them to make them move forward. That's a rocket.

When you throw mass behind you at one point in your orbit, you raise the height of your orbit on the opposite side of the orbited object (this is simplified).

So you're basically right, it's partially about the mass of the object, but it's mostly the firing of the rocket.

You've got some pretty good intuition though. That's basic orbital mechanics.

[–] [email protected] 2 points 1 year ago

It even has a name, the Oberth effect

[–] [email protected] 4 points 1 year ago

Just "shedding mass" won't do it. Uncouple a payload from the mass of the ship at perihelion, and they will just float along together, side by side in their original orbit.

But, if that "mass" is "rocket fuel", and you "shed" it by burning it behind you, you've got the right idea. As the other commenter said, the Oberth effect means the closer you are to the sun, the faster you are moving, and the greater the effect that burning will have.

[–] [email protected] 2 points 1 year ago

Yes, the Oberth effect means that firing a rocket at the periapsis changes your orbit more than at any other point in the orbit.

[–] [email protected] 9 points 1 year ago (1 children)

Well yeah, that's how orbits work. You accelerate down to your periapse, the closest point to the body you're orbiting, then slow down on the way up to your apoapse, the furthest point. Thus the probe will keep accelerating until it gets to its closest point to the sun.

[–] [email protected] 2 points 1 year ago

Thanks, Jimmy Neutron