How The Moon's Bumpy Gravitational Field Can Help Launch Things From Its Surface

[@kooskroos]

Strange why this channel does not have atleast twice the number of subscribers, best astro content of youtube.

[@deant6361]

I agree 100% with you it’s a great channel always so interesting.

[@biomechanique6874]

I hadn't noticed. 80% click bait is low and 99% of KZbin watchers are terminally gullible so that would seem to be odd more people haven't subscribed.

[@dieselgoinham]

@@biomechanique6874The gullible thing is so true, it’s how we got Orange man back as president.

[@GhostofReason]

It’s true, where else can you see intelligent interviews with cutting edge researchers on a consistent basis?

[@SidMajors]

Because the amount of people actually interested in watching something about these subjects on a daily or even weekly basis, is very tiny. Because his videos, thumbnails and titles aren't sensationalist driven. Even though he added some funny faces to them lately :-) It's not a matter of not enough people finding Fraser. It's a matter of not enough people wanting to go this deep. They just want "Why the Dino's got wrecked 64m years ago".. (cough.. look at half of Astrums videos.. cough) There's a reason why Discovery Channel kept upping their game with sensationalism.. It gets the most views unfortunately. So.. in a way.. be glad there aren't double the subs :-) Even though I do wish this man all the best ofcourse. Mixed feelings!

[@rhoddryice5412]

Always enjoy your interviews. And this is one of the most interesting. Thanks to both you and Dr Janhunen.

[@blueredbrick]

In highschool physics class we calculated the trajectory of a bullet fired from a sniper rifle. With the right (or wrong(!)) input parameters we found that it will hit you in the behind. It was asumed that moon is a perfect sphere :)

[@doncarlodivargas5497]

Now, today, you know you was safe all the time, the moon would protect you

[@blueredbrick]

@doncarlodivargas5497 lol 😅

[@rowshambow]

So glad to hear about the Ceres megastructure concept still 👏 Would love to see an artist render of the inside of the cylinders. Would be awesome if they had different biospheres in each one. So you could move from one to another every few months and experience a different view

[@Libertaro-i2u]

Though it might be unnerving to see land when looking up rather than a horizon or sky. Though I suppose if a cylindrical spacestead is large enough, you would get an actual horizon.

[@peterkeyson8232]

Thank you for this very very interesting interview.

[@alfonsopayra]

amazing interview, thanks!

[@kaarlimakela3413]

This was a story device in Heinlein's sci-fi book 'The Moon is a Harsh Mistress'.

[@MrJPI]

Thanks again Fraser, interesting interview you had! Ceres's synchronous orbit distance from the surface = 722 km "only". So the space elevator's counterweigh needed to be only say 100 km further or less depending of course of its mass!

[@icaleinns6233]

Thanks Fraser. I had to go back through your videos to find out what electric sails were and how they worked. Great stuff! I'd think that for farther ranging missions, such as Jupiter and beyond, that the craft would want an RTG or two in order to provide electricity. Sunlight is just too weak out there, just look at the size of the solar panels on the Europa Clipper mission.

[@snygg1993]

Your link to the guest *Pekka Janhunen* actually links to *Sebastian Rabien.*

[@frasercain]

Oops, fixed.

[@muleskinnerfilms6719]

Excellent as always!

[@hildawilliamson6988]

Husband of the science teacher pictured.. Space tethers, sky-cables.. Do they have to be anchored to the surface of what they orbit? Why? Have them rotate around themselves so a simple tether approaches a reachable altitude with one end at a time before rising up and away from the surface again to return to that altitude as it continues to rotate like a single spoke. These might be stacked in ways that allow mass to be tossed and caught, tossed and caught, from low in the gravity well up to higher and higher orbits.. Couldn't mass be lowered into a gravity well in with the same mechanism? Lowering more mass than lifting might even empower the lifing of mass from a gravity well.. Peace .. and thank you..

[@grenzmosaik6879]

what a very interesting man! learned do much! thanks for posting videos that are not traditional cash cows yet. 20 years from now these will be!

[@MrGoesBoom]

Not really related to the main meat of this vid, but wasn't there some theories that one of the Apollo landers ( I forget which one ) might actually still be in a weird orbit of the moon thanks to the gravity field being a lumpy potato? I swear I remember something like that

[@robwalker4548]

There is no upper stage of the LM in orbit. They were intentionally crashed into the moon so they could create a seismic event for the Seismometers they left on the moon.

[@bbartky]

@@robwalker4548 That’s my understanding as well. However, Scott Manley has a video where he talks about one person’s theory that the ascent stage of the Apollo 11 lunar module is still in lunar orbit today.🤯 I was a kid during the Apollo missions and I read at the time that all of ascent stages had crashed to the surface within a few weeks. I asked Scott on Twitter about this and he responded and said the math and physics for this theory work out. I don’t have as much technical knowledge as Scott so I don’t have an argument against it. 🤷‍♂️ *EDIT* Added a reply to the OP with a link to Scott’s video.

[@bbartky]

In 2021 Scott Manley made a video where he argues that the ascent stage for the Apollo 11 lunar module is still in lunar orbit. I was a kid during the Apollo missions and I read at the time that all of the ascent stages, with the exception of Apollo 10, all crashed to the lunar surface. So, I have a hard time accepting this, but Scott is much more knowledgeable about space exploration than I am. Here’s a link to Scott’s video: kzbin.info/www/bejne/mnOrk3-MbN14nsUsi=8g_v7e81jYPjU9V_

[@MrGoesBoom]

@@bbartky thanks, that was the vid I was thinking of. Granted, it's a theory and noevidence either way if it's true, but a neat thought IMO

[@MelindaGreen]

The feasibility of a space elevator at Ceres makes me wonder how feasible might the same be on the Moon? At the very least it could reduce the number of lunar landings kicking up dust, and it will be immune to the bumpy gravitational field since it will be static relative to it.

[@BryanM61]

Sounds good in theory. The issue here is that the moon has no synchronous orbit, so any space elevator would have to pass through and past either the L1 or L2 points: a desperately long tether.

[@MelindaGreen]

@@BryanM61 Oh right, a Lunar day is a month long. Too slow for a practical space elevator.

[@JamesCairney]

This was good

[@DaFinkingOrk]

For shelter, why not land in a crater and use a tunneling machine to dig into the crater rim, instead of building up stuff above ground. Never heard someone say that before but it sounds easier and better. Like digging into a mountain on earth. If you want lots of thickness then that's the way to do it, like Cheyenne mountain.

[@Kurukx]

Amazing conversation about what we could do and why we should not ... Practical engineering dreaming

[@richardzeitz54]

Can oxygen be used effectively as propellant in VASIMR engines? All that oxygen in those rocks...kind of knocks a hole in the plot of The Expanse: all those belters should've been breathin' easy!

[@JohnTorrington-ut4ev]

I can propel a ship with enough slow cooked beans.

[@jamesmatheson9624]

I would imagine that they would crash 10,000 ships into the moon with an electromagnetic pad on the ship so that eventually a ship will land on the moon and the electromagnetic pad will catch the ship and prevent it from crashing on the moon and I believe thats how they will safely land on the Moon

[@phrankus2009]

Take me to school! A highly eccentric orbit, with a very low perigee will, likely, not be seriously perturbed, by said gravitational anomalies .. U have also been wondering about the viability of a lunar Space Elevator, because no weather and low gravity BUT, the SLOW rotation of the moon probably would make the counterweight far too distant, to be practical.

[@phrankus2009]

LUNAR SPIN-LAUNCH, of processed "ingots", **would be practical; ... A solar powered flywheel could accumulate angular momentum, gradually, like an "inertial capacitor".

[@stephendeaton8689]

It has been 2 months since an episode of Astronomy Cast, have you stopped making it?

[@stephendeaton8689]

Nevermind, I found it again, just under KZbin now and not podcasts.

[@SolaAesir]

With easy and cheap access to oxygen and the solar wind, don't you have access to water fairly trivially? You'd need to concentrate the solar wind into wherever you have your oxygen, and maybe slow it down a little, but that's should be a pretty basic magnetic field to make. Earth's does the same thing naturally after all and it's basically the same as a really big bar magnet.

[@samedwards6683]

Thanks so much for creating and sharing this informative video. Great job. Keep it up.

[@andrewdillon7837]

Spinlaunch would work on the moon,,fire ingots, or He3 to orbit,,

[@shadowlord8580]

Should use a long magnetic rail trake to launch from the moon

[@davidharvey3743]

@shadowland An electric rail trake?

[@GadZookz]

The Moon is a harsh natural satellite. 🙂

[@MausMasher54]

Hmmmm, Musk's Starship could deploy such an auxiliary propulsion????

[@GhostofReason]

Frasier, your consistent dedication to bringing accurate, interesting, and fun content is so very appreciated! In a sea of bloated non-tent, it’s an easy click to come to your channel!

[@smorrow]

Why wouldn't you just discover these trajectories by brute force?

[@allurbase]

Hey Fraser, question popped, say we had a giant particle accelerator pointing at Mars, how much energy would it take to heat up Mars core until it gets a magnetic field again? In units of all the sun light accessible to earth in a year please. :)

[@thrombus1857]

Could you shoot an orbiting satellite with a gun from the surface of the Moon?

[@JohnSmith-sk7cg]

Yes if you could get it to about 2.4km/s. That's also the amount necessary to hit Earth which covers every possible altitude for the periapsis in an orbit around the moon.

[@jonathanhughes8679]

Could those electrons you captured in power your ship?

[@snygg1993]

To power something, you need *moving* electrons. Usually you have a source with "too many" electrons and a drain with "too few" so that the electrons "flow" from the source to the drain to reach equilibrium. With the captured electrons, I don't know what the drain would be.

[@robertmontague5650]

Now this is curious. If gravity emerges from the curvature of spacetime then how do these bumpy anomalies on the moon create gravitational effects on orbits? I'm getting tired of the argument that gravity is not a force.

[@frasercain]

They come from mountains and valleys as well as different densities of rock under the surface

[@robertmontague5650]

@@frasercain "what" comes from the anomalies--gravitons? This is where the discussion always seems to peter out.

[@frasercain]

The amount that the mass distorts spacetime.

[@robertmontague5650]

@@frasercain I very much appreciate your weighing in, however, I still wonder about the concept of gravitons, if in fact gravity is not a force.

[@bdr420i]

Hydraulic Press Channel 😅😂😂

[@jonathanhughes8679]

Now you can use an elevator to space from the moon to a good candidate for it.

[@antonychipman3088]

If human activity increases the albedo of the moon, the biosphere of Earth’s oceans will experience terrible consequences.

[@FLPhotoCatcher]

How so? Why would a slightly brighter moon harm ocean life?

[@antonychipman3088]

there's ostensibly 2 kinds of life in the oceans, for our purposes. Stuff that hunts all the time, and stuff that hides all the time. The critical factor that tips the balance between diner and dinner, is whether the lights are on. More?

[@saumyacow4435]

Any future civilisation is going to want to extract resources from the moon.. is it? Emphasis on "civilisation".

[@FinnishArmy]

Torilla Tavataan!

[@nadahere]

These solutions are sub-optimal [i.e. poor]. Someone lacks broad knowledge. =] My solutions to NASA's 6 challenges to colonizing Lunah were far superior to anything the hundreds of mainstream solution providers have to offer, including these offerings, but the w0ke [sic] tw0ts at Johns Hopkins physics department ousted me for not acting st0-0pid like them. In the immortal words of Meat Loaf, '_So don't be sad cause 2 out of 3 ain't bad._' . You ain't the only one . Mainstream science doesn't understand gravity and the 'lumps' on Lunah. I do and use it in my Lunar low altitude 'atmospheric' flier. Me, I'm a well rounded triple engineer and prolific inventor among other skill sets. BTW, the Big Bong theory👎 will be imploding soon. 👍 👑🤜🇺🇸🤛👑𝕄𝕒𝕜𝕖 ℂ𝕠𝕤𝕞𝕠𝕝𝕠𝕘𝕪 𝔾𝕣𝕖𝕒𝕥 𝔸𝕘𝕒𝕚𝕟‼☝🏼❤🎩 👑🤜🇺🇸🤛👑ℳ𝒜𝒦ℰ 𝒞𝒪𝒮ℳ𝒪ℒ𝒪𝒢𝒴 𝒢ℛℰ𝒜𝒯 𝒜𝒢𝒜ℐ𝒩‼☝🏼❤🎩 [copy and paste at your will] .

[@orange1599-u1n]

And we are meant to believe that man landed in 69, complete joke.

[@contra_plano]

Why not? Concord Also is not running anymore, and by that it is not possible to make comercial flights?

[@AdrianBoyko]

Fact: “Lunar orbit requires ongoing propulsive adjustments.” Idiot: “Hahaha! Then its Impossible to Land on moon!!!!”

[@solarsystemtimelapse3480]

Wernher von Braun was a genius which helped the Apollo Program, not every generation has a talent of these quality it seems.

[@JamesCairney]

It looks like the annoying orange found something to be annoying about.

[@JohnTorrington-ut4ev]

NASA had the highest budget ever in history back then. We have sent humans to walk on the 6 times and stopped after Apollo 17. No more money.