Asteroid Collision Shocked NASA Scientists, They Can't Explain Why This Happened | DART
ฝัง
- เผยแพร่เมื่อ 23 พ.ย. 2022
- Real NASA images of the DART impact with Dimorphos. Enter at www.omaze.com/astrum for your chance to win a Custom Tesla Model S-APEX and support a great cause, the Petersen Automotive Museum. The experience closes on January 27th at 11:59pm PST and I promise, you don’t want to miss this!
Astrum merch now available!
Apparel: astrum-shop.fourthwall.com/
Metal Posters: displate.com/promo/astrum?art...
SUBSCRIBE for more videos about our other planets.
Subscribe! goo.gl/WX4iMN
Facebook! goo.gl/uaOlWW
Twitter! goo.gl/VCfejs
Instagram! / astrumspace
TikTok! / astrumspace
Astrum Spanish: bit.ly/2KmkssR
Astrum Portuguese: / @astrumbrasil
Donate!
Patreon: goo.gl/GGA5xT
Ethereum Wallet: 0x5F8cf793962ae8Df4Cba017E7A6159a104744038
Become a Patron today and support my channel! Donate link above. I can't do it without you. Thanks to those who have supported so far!
#dart #nasa #dimorphos #astrum
I love the term "Rapid scheduled disassembly"
I just love nerd humor like this.
Sounds like self destructive disassembly
@@fisherforrest More like rapid scheduled vaporization...
...about as rapid as disassembly gets. 🛰
They really should've called it the First Asteroid Redirection Test.
I can imagine someone at NASA trying that, then everyone getting the prank and scrambling for a "suitable" backronym. 🤣
Bart, SART, DART, E-art, ... Nope, nobody can make fun of that.
@@lc3853
cart
hart
mart
part
tart
wart
...... you're right , not amusing !
They couldn't use that acronym because it's already reserved for the next method they want to try
Fume-jet
Asteroid
Redirection
Test
In the far future, we may see the Second Heliospheric Asteroid Redirection Test
I just saw this now and what a mind cleanser from the awful things happening now. To see Dart smash in real-time and not by artist renderings is beyond words. We as mankind need more exciting projects like this. They give a sense of hope. ☺
True that Mary Mac . ☄
We need reset to the bottom of the food chain. Natural selection for president
This is the only justifiable reason for space exploration. Curiosity isn't enough. I dont want to go to Mars. I want to save this planet.
So if its anything but saving earth. Stay on the ground with ur ego projects.
There are no words yet invented that would give enough praise and glory to the people who accomplished this amazing event. I hope we never become so jaded that we think this was just a normal mission. This is truly incredible. Just think of the distances covered, the speed achieved, matching the trajectories, the perfect timing and the genius engineering of the thousands of people involved working in harmony to make this a complete success. If only we could do on Earth what we do in space.
I wish we could do on earth as it is in Heaven
there is an ungodly amount of logistics and coordination that goes into keeping our world running day to day, but yes these missions are very impressive and aspirational.
You forget the one who has created it all. To Him belong the praise, the power, and the glory. Jehovah the father, not jesus the son.
It's insane, that just over a 100 years ago, we were barely able to fly. Now we have autonomous, unmanned space kamikazes. Incredible!
and don't forget we have a fully autonomous helicopter on Mars.
Should of just launched a metal dart at the asteroid
@@Omba820 Can't collect data without instruments to record the event.
Help by Aliens
@@Omba820 yes, I also wonder why they did not leave a carcass or something shortly before the impact . I mean the bulk of the tech for navigation, shielding, power, heating etc. could have been ditched, but a decent camera, antenna and a few batteries should not have clocked in more than 0.1% of its mass in exchange for some close up pictures. ... ok after roughly looking into the energies involved , I get now that even in the best scenario you would possibly not get the pictures you want but still jeopardize the whole mission with trying this in the last moments. their option for the cube sat much earlier was the best choice.
Anyone else think its super cool we have a genuine planetary defense initiative? Sci fi as hell!
Long time coming. Bet these things have reset humanity more times than we know.
I think my favorite part of it is just 'lets smash something going really fucking fast into a space rock just to see what happens'.
The way you speak is atrocious
@@DD-sw1dd we know they’ve reset us 0 times
They hit an asteroid ON PURPOSE! Fuckin incredible
This mission is one of the most important in human history and is simply amazing. Congratulations to everyone involved and thanks for sharing this content 🙏🏽
I disagree. I don't think it was "one of the most important" missions by any means.
Hopefully these frivolous projects will not end catastrophically by re-directing a previously harmless small asteroid into a collision course with Earth.
@@deemika Ok troll.
?🤷🏻♂️
This is one of the most impressive and worthy things the species has ever accomplished, and if we ever have to do this for real - it will be the absolute pinnacle of anything we will ever do. We can protect all life on Earth.
I remember watching the live feed from the spacecraft as it impacted, was a bit surreal to be rooting for the destruction of a spacecraft like that, but definitely an exciting moment!
Except when the§pacecraft is a chinese missle guidance §atellite
@@charlesvaughan3517 wat
The spacecraft was going 14,000 MPH. That is so ridiculously fast. I find it amazing that the pics were so clear. That was very cool.
LMMFAO!
*Exactly where would one watch these live feeds??? Is it on a TH-cam channel?* 🤔
I just want to thank you for rejuvenating my love for physics and astronomy that I've lost in recent years. Your channel is fantastic, and you obviously take so much time to put each video together with fantastic visuals. This is top-tier stuff, and you should seek a career in documentary filmmaking
Astrum is awesome! Wanna strengthen your love for physics and astronomy even more? Go to @melodysheep and @kurzgesagt channels.
Checkout @SEA. My favorite channel.
yeah, this guy is unique.
So, … not someplace I’d want to spend a summer at, …!!!
Somewhere in the back of my mind, I wonder, what if this changes directly into us? How do we know it will divert it and not aim it more directly.
This is amazing. Bravo to the teams who who put this mission together. It really is fantastic.
Absolutely a worthwhile endeavor with existential ramifications! Also a very good presentation.
Great distinction with "non-avian" dinosaurs. I've had to deal with a few of the "if dinosaurs are extinct, how did they turn into birds" people.
The problem with people saying that is that most of the avians were killed also. Most dinosaurs died with only as small percentage surviving to evolve.
@@cchavezjr7 nuance isn't their strong suit.
@@scottscotty2537 that has nothing to do with this comment
@@cchavezjr7 who asked that dude (or bot)?
If humans evolved from apes or monkeys then how are there still apes and monkeys around?? Do those species take longer to evolve into humans?😂😂
The DART mission was and is SO very exciting, not least because I recall reading about how sci-fi authors way back in the 60s and 70s had discussed exactly this kind of defense, as well as a type of defense using lasers! (very, very big lasers, based on the Moon, but still a really neat idea) Getting to see LITERAL science fiction become science reality has been such a rush!!!
Hitting something so small, so far away, what an achievement.
Let us hope that when we'll all live long enough to say to our grandkids "back in my day, we fought with bullets, not lasers! And we didn't have planetary defense mechanisms, we just had cold, hard cosmic paranoia!"
You must be in constant euphoria then, because science fiction has been becoming science fact daily for years now. Or maybe you don't get as excited about Aldous Huxley's vision of the future being so spot on...
@@mylesleggette7520 I am euphoric about space exploration yes.
About some of the rest of the "accurate predictions," less so, haha!
Imagine if redirecting an asteroid causes more harm than good. I feel it might cause a butterfly effect and create chaos. Interrupting a synchronized system and turning it into an erratic system, which could've worked out if nasa didn't meddle with it
I love how in these stories, scientists are always “shocked” and can’t explain stuff.
What is this click-baiting fucking nonsense? At no point in the video were any scientists 'shocked' or 'unable to explain' a goddamn thing and everyone is just lapping it up like the title isn't RANK clickbait and utterly misleading. Feel like I'm taking crazy pills over here.
Thanks for providing such a multi-faceted view of the event. Very nicely done.
Awesome content again from Alex and the Astrum team. Thank you!
impressive work, thanks.
Yes , the Hollywood made graphics are mesmerizing 😮
Great video. I was very fortunate to work on this mission. Great project with a great team.
You and the team are true heroes. You quite literally may have, and more than likely saved lives with this mission. Thank you for your contributions to Humanity Jeffrey
You have my respect and thanks. Even at worst this only "likely" saves lives and best saves our world many times over, I believe this will branch off into technologies that will break ground into space travel. Thank you. I would love to be part of scientific research like this. Keep up the fine work. Honestly, I'm very curious about the heliosphere and deep space as well as the physics behind space. Quantum mechanics is truly amazing, imo.
I hope your other projects go as great as this one. Take care as you travel into the beyond. :)
Are you real? 😱
@@PersonausdemAllHe's for real. He's a satellite hardware engineer. Google the name.
@@brucer.5403 Cool, thanks
Terrific article.
I've only just recently discovered Astrum but what a brilliant channel.
Thank you Astrum.
It’s amazing that they can hit an object that small from so far away, I can’t even hit the recycling bin with an empty soda can. Great work ladies and gentlemen, congratulations. 💫💫💫💫
This was the event that really cemented how much the asteroids need to prepare to launch spacecraft redirect missions.
The human response, when I’m doubt destroy and kill.
The best space content channel on YT, no doubt about it.
ParralaxNick *cough*...
If you aren't familiar with Anton Petrov's channel you really should check it out.
Kurzgesagt is nice too.
Anton for sure, Astrum has great production though
@@gteaz Sorry - prove it or don't throw out accusations. Anton posts very frequently, often only a day or two after an article is published and links right to the papers that he references - and has been doing it for years. You can like this channel and like another without it being a competition or disparaging someone.
So much click bait recently on this channel.
10:44 It's because Dimorphos is orbiting a larger object. Some of the ejected material is further away and slows down, yet still being dragged along. This creates curved patterns of debris.
can't wait for the follow up mission BONK
Wow! You really nailed it Alex! The way you present the facts are second to none... Thanks.
This video made me slightly emotional for some reason. I don't understand why, though I think it is realizing how far we have come in the development of creative ideas to protect humanity. I am a professional designer, so I get really charged up when things are made in the support of creating a better future for everyone. Something so pure and helpful. The creative minds on these NASA fellows is amazing.
The fact that the collision generated some form of reactive jet with much enhanced momentum transfer is a great discovery which totally changes the way asteroid deflection will be carried out in future. Well made documentary.
Fantastic! It's amazing to think that the distances and speeds out there are so large and yet just a relatively tiny modification can cause so many (in this case fruitful) consequences.
man that title had me rolling KEKW
Explain, it seems normal
It's a sneaky KSP nod
Well done all who participated! Finally some good news. 🌟❤️
Shout out to the camera man who risked his life to give us these wonderful shots 🙏🏿
The streams possibly changed direction due to interference of shifting debris. For example: a jet coming from the bottom of the crater has a rock come loose from the edge and cross the stream. As the stream stretches out you can see the exact spot the rock crossed. Every shift in the stream was some physical occurrence such as that.
Interesting suggestion, however I am not sure that could happen, due to the fact that the source of all the debris was on the same point. So I believe a rock could only fly outwards, not sideways to intersect other debris rays. But we never know, space is weird and I wouldn't be surprised if NASA found out that it's exactly what somehow happened :D
My guess is that it might have been caused by some big rotating chunks flying away, tearing themselves apart by centrifugal forces and flying in different directions, thus creating the apparent twists in the ejecta. What do you think?
@@kalkovonschpritzendorf1914 well that was possibly an erroneous scenario but the general idea I think holds true. That being the variations in the streams are formed by physical structures interacting. Perhaps the gap the vent is coming from changes shape over time, the amount of outgassing varies over that same time, and also the physical obstructions beyond the gap itself can change over time... (perhaps the big chunks you mention among them). And probably some other things like the orientation with solar radiations, spin rate, and other factors, all graphable over time.
@@jonathanryals9934Cool theories eh. If I may add one. Have you ever seen a firework spiral out of control? Could the best fit to the zigzag-like ejecta pattern, be a spinning chunk of debris off gassing and continually changing its trajectory. I only say this as a spiral looks like a zigzag from the side and that was lots of energy input. Maybe some of those boulders had volatiles in them.
Likely an interplay of all the above and more. Looking forward to the follow up.
@user-jo1gy3kx3j i swear ive seen you before
@Phoenix 🤣0% on topic.
I'm still sad the cubesat didn't perform as hoped. It would have been amazing to see this from a "3rd person" perspective. Oh well, better luck next time!
I hope we see more and more missions documented this way - rendezvous, docking, spacewalks, reentry... All would be amazing to see filmed from the outside!
Well that was a refreshing scientific review of a NASA experiment without having to embellish the science for a wider TH-cam audience. This is how all such video science reviews should be conducted: Factual, well explained, and without any click bait nonsense. Well done.
Amazing video! Thanks for the upload. Exciting things are happening in space.
This is so awesome ive been wondering how the dart went thank you for the in depth review and for releasing it on Thanksgiving
Terrific video. You really compiled and presented us with everything currently known about this mission, great job... and Nasa, SpaceX amd ESA, too!
It looks magnificent especially with the multiple images of the before and after impact and the different images from different sources. We will definitely need to use something like this in the future, of course given the current circumstances that are going on with things on our planet, hopefully there's a future for civilisation firstly. Hoping that we don't destroy ourselves at such a important time in history.
The technology was amazing and your videos are incredible. Keep up the good work.
Astrum, you help to keep my love for existence alive, & I thank you for that.
Thank you, fantastic work, as always!
Asteroids are not a Threat, but a Solution!
Great presentation!! I struggled to remain interested in the middle, but well worth it. Thank you
The implications this has for earth cant be understated. It seems like a small thing but its really an incredible task they've accomplished. They moved a celestial body. A small one, but its a start.
This mission reminds me so much of the Ranger 7 lunar impactor mission form late July of 1964. I remember that day as a nine year old watching the incoming photos on tv relayed to the networks from NASA starting at 15 minutes before impact as each photo showed a closer picture of the lunar surface until just seconds before impact the final partial photo came through because the transmission of the full photo was cut short by the impact itself. Each photo was taken on rapid developing film and then scanned by an onboard tv camera and transmitted to earth so there was a delay between each photo because of this process. Both missions are truly remarkable for their accomplishments.
Ranger 7 produced 4,308 images in those 15 minutes before impact-truly rapidly developing film, nearly 5 frames per second.
that all sounds amazing!
I reason the response with Dimorphos was greater than expected was due to the model they used of the little target. Thinking it more spongy than rocky. More rock more reaction and maybe conservation of momentum. They hit it face on - so it slowed down, not from behind that would speed it up.
8:20 One of the true oddities of orbital navigating is if you want to speed up~ slow down, if you want to slow down~ speed up. By slowing you come in closer orbit to the object you're orbiting thereby speeding up relative to that object. If you speed up you'll move into a higher orbit~ slowing down relative to the object being orbited.
About half of what the Mercury Project was about was learning how to navigate and learn how to get two objects to meet and join up; getting Apollo to the moon would have been impossible.
This was a FANTASTIC video, & just ONE beautiful example of why we subscribe to this channel!!!!!!
The real hurdle right now for planetary defense capability is detection, monitoring, and modeling. We have probably spotted (edit: and modeled future paths of) all of the extinction level threats but only some of the smaller rocks.
“Yeah, yeah, but your scientists were so preoccupied with whether or not they could, that they didn't stop to think if they should.” - Jeff Goldblum as Dr. Ian Malcolm.
Just plain and simple Thank You for sharing this video as it was awesome
This has to rate as one of the best small missions so far once the 2024 craft gets to the impact site.
I find it so interesting that their calculations for the effect of the impact was so different from the results. It almost seems like an assignment you could get in a college class, but there are still so many unknowns about the real physics of asteroids.
I think they partially do this on purpose to calibrate the public and government's expectations. I've always noticed NASA expecting and promising the bare minimum and then exceeding it by folds when it comes to space missions
Every step of the estimates probably assumed some worst-case values, and all that adds up when combined. I'm sure there were probably some all-best-case estimates, too, that weren't exceeded. But you have to use the worst-case when establishing criteria for success.
5:56 True, especially with space missions where a meter of error now can mean kilometers after
The precision is just amazing. They hit a tiny satellite of a tiny asteroid in just the right way to decrease its orbital size so as to present no possible danger to earth and for the effects to be easily detectable with simple brightness plots. It was the perfect test mission for asteroid defense technology. Well done NASA!
With long term observation we may know what effect the impact had on Didymos' own trajectory, because though small, Dimorphos has a slight gravitational tug on the larger body it orbits.
Good point, and not recognized very often. The impact of one little tug, even if it only changes the trajectory by a tiny fraction of a degree, over large distances can mean a huge change in where an object ends up. The thing you need to be effective is time. A lot of the "big chunks" have been found and their course derived, and that effort is continuing.
I liked the visual's with this story they were great.
Good explanation! There's more hope than I thought...
The spiraling plume from the impact struck me as the only unanswered question. Did the impact create a momentary “atmosphere” of finely pulverised dust which, when ejected, bounced off each other causing a non linear ejection? I remember on the Cody’s Lab channel he said sound can travel in space if there is a plume of gas in which it can propagate.
The debris plumes are non-uniform, I would imagine, in part because the impact kicked up some debris which did not achieve escape velocity, and when it re-impacted it set off other plumes of fine debris. It likely also caused some outgassing, which would have produced secondary plumes that rotate with the asteroid and generated forces that would affect the plumes from the initial impact. All of the debris would have been minorly affected by the larger asteroid's weak gravity. Finally, minor local variances in the solar wind could have "blown" some of the fine debris around. All of these actions and interactions resulting in the complex waves and spirals of the debris trail we saw. That's my guess, I can't wait to see what the scientists who study this stuff for a living conclude.
The Electric Universe tells us that all bodies are "charged" and the flash and the tendrils are to be expected, when the electrical equilibrium is disturbed. Twitted plasma filaments are seen throughout the cosmos on all scales, and they are indicative of the way electric current or charged particles travel inside a plasma medium. We are not just witnessing a simple kinetic event of dust having been strewn in space.
Just incredible!! WOW!! Thank you Alex, I echo the many positive comments about your content. I love the way you present this awesome information and continue to learn so much. Sincerely appreciated.
I have a small kernel in my mind that keeps saying "The nudged that thing a tiny bit, then it hit another that hit another and eventually nudges the asteroid that takes us out into a collision orbit."
It’s the punch that you don’t see coming, that knocks you out…
Awesome video as usual. Amazing use of space tech. In this case, definitely worthwhile.
Awesome content! Thanks you!!!
Now, imagine a projectile caring a payload of antimatter lunched into our sun, our sun going supernova, and aliens watching from far away celebrating that their experiment worked.
"Are you sure there were no intelligent life forms in that system?"
"Yes, only little entropy life forms. Just bugs"
This type of research and effort is probably the most important work in regards to space. Considering that asteroid impacts are even more devastating than nuclear bombs. Can you imagine the force that would be released and the destruction it would cause if Ida and Dactyl hit Earth?! Speaking of Ida & Dactyl they are my favorite binary asteroids ever they are the first asteroids I've ever read about when I first started getting into astronomy in 2003. So they're very nostalgic for me.
So cool that Hubble and Webb were able to lend their "eyes" to this event. Amazing!
This mission gave me hope that humans are not all dumb enough to aim weapons at each other but at the stars where all weapons should be aimed at. We have the power to defend this planet against threats like meteors and we abuse it to kill each other. If aliens are watching us they are going to wait until we are done with homicide/genocide only then will they contact us and welcome us into the galactic federation. I hope i get to witness that world changing event.
Don't you think if some galactic federation existed some scientist somewhere would have picked up some engine plumes as well as wireless communications by now?
@@GalladeTheWarrior space communication is different than ground communication
That, will never happen, to many people in our world want power and domination, and I'm not only talking about leaders and governments.
@@Ragnarok182 in hundred year yes since space armed race started since 2017. Nasa was way behind space since 1991.
The space aliens avoid us for the same reason we avoid violent wild animals.
Exceptional quality commentary and well presented graphics. Clear.
I want to edit the time lapse video on final approach to stabilize it and increase the number of frames so it will play super smooth.
scientists be like "smashing into an asteroid at many km/s will probably alter its orbit, let's smash this spacecraft into some asteroid and see it"
That is how science works.
@@juhajuntunen7866 "the only difference between fooling around and doing science is writing it down"
I definitely agree with you on that last partial image being the most amazing one. It's weird, much in the same way that a room of nasa etc people cheering at a loss of signal is weird, but well. That happened too didn't it? Just goes to show how extraordinary this mission was
"How was work today?"
"We built a radio, launched a rocket, watched some photos, crashed a drone, played astronomical billiard and rolled a rock and my boss can't wait to do it again"
You asked if it was worth it? Well, let's see. The Mercury program gave us Tang. The Apollo program gave us rocks. Saving Earth from destruction? Uh, yeah, I'd say it was worth it.
I'd say yes that we would definitely need to use this option at some point in the future. However there have been times that we didn't notice these objects until it was too late to do anything. Unless we could already have them in orbit ready to go, I'm not sure they will always be the correct choice.
A few questions: Is the smaller body likely to impact the larger one any time soon, because of its reduced distance to the larger body? Did changing the track of the smaller body also change the course of the larger body, due to the shift in mass? How much mass did the smaller body lose? I understand that the impact cause the expulsion of mass at high speed, adding a "Rocket thrust" to the action, moving the smaller body more than expected, could that be expected on more solid bodies? How much, if any, of the ejected mass resettled on the larger body? Could it be that the spiraling ejected material may be parts of the space craft, such as the solar panels?
No, yes, insufficient data, not to the same degree, insufficient data, maybe...
A fast rifle bullet does about 1 kilometer per sec just after leaving the muzzle, then it starts slowing (fast).
Dart apparently impacted at 6 kilometers per second.
I am sure there was nothing recognizable of the solar panels within 1 millisecond of impact.
I think this is one of my favorite shows. Great content and narration. 👍🏻🇺🇸
Fantastic! Thank you for explanation.
So...this is good. After this intiial successful test, I assume there will be others, but how many more will be needed I am not enough of a scientist (um, not at all) to know just how many. Given the timeline regarding Hera, I'm wondering if any useful version of this technique will be out of the testing stage before my actuarially projected lifespan is over; I'm 55.
Ok, then there's the use of a satellite to use it's tiny bit of gravity to slowly over time change the orbit of the asteroid into a safer one. Are there any test missions slated for this Idea? Beats me, but even if fully functional this takes a lot of
lead time to implement.
Really, the same is true of other ideas as well; mass drivers, the painting of part of the asteroid black to use sunlight to effect it's orbit...all are slow to carry off and may require years to discover if any of these are, in fact viable.
Bummer.
But, we still have time.
Hopefully.
Thanks
S.W.
well, since an impact is expected only once every 2,000 years for a football field size asteroid and only once every few million years for one a few miles wide, there's practically no chance that you, your children or your children's children will ever see one of these crafts deployed or actually used. they will each be purpose built for the specific threat when its detected.
"Paint It, Black"
@@nickhowatson4745 finally, someone who thinks in reality. This is another washing machine/vacuum for our $$$
Any mission that can lead to saving us from extinction is important.
I stand corrected. Here I was thinking WEBB was launched after this impact test.
Love ur channel. Keep up the great work!!
It’s amazing how they can calculate exactly. For the probe to hit the asteroid, which was millions of miles away. Credit to them 👍👍
Great vidio. Every dollar spent and being spent on that project is well spent. Congrats to all evolved.
Second viewing. Not last.
Thank you!
Hell yes, I think this was worthwhile! How is this not celebrated, broadcasted everywhere! Those pictures were astonishing, and to actually see what an astroid, meteor, or whatever looks like! This is just so extremely fascinating to me!
✝️🇺🇸✝️
Hello there👋👋,Good morning , how are you feeling today! Hope you have a great day❤God bless you!!!❤
Scientists are permanently shocked.
Excellent video! The only comment I would make is I wish documentary makers would include a tiny label in the bottom corner of the screen, for every single image and video, labeling it as "unedited photo," "processed/enhanced photo," "illustration," "real video or real photo sequence," "animation". They should do this for every single image, even the ones they feel are obvious.
With the number of asteroids that have been found and are being tracked and looking like a heavy snow storm, it seems more likely than not that this technology is necessary and will be needed fairly soon. Great video.
Amazing. I am grateful on how human civilization has evolved.
I'm amazed at how compact an agglomeration of dust and rocks can result in such low gravity
It´s an electrical discharge. Plasma filaments use to form double spirals just like we see it on this image.
Since there was something received, a composite can be produced because it's the very same shot but closer, plus the last picture shows us a simple size/pixel for the complete picture!
It really is amazing!! The math involved!! Bravo!!
I think this test was absolutely worth the money. To do anything less would be irresponsible. Now scientists can evaluate the data and do further testing, if needed, or develop an arsenal of “deflector” designs for future use - when needed.
It amazing getting old... you've already learned all the answers to pass the tests, but age makes you realize the answers are always changing.
3:29
That caught me off guard.
"About the size of a refrigerator"
An excellent, highly informative video. Thank you so much.
All space studies are worthwhile. The only way to move forward.