APOD: Rover 1A Hops on Asteroid Ryugu (2018 Sep 24)

[APOD Robot]

Rover 1A Hops on Asteroid Ryugu

Explanation: Two small robots have begun hopping around the surface of asteroid Ryugu. The rovers, each the size of a small frying pan, move around the low gravity of kilometer-sized 162173 Ryugu by hopping, staying aloft for about 15 minutes and typically landing again several meters away. On Saturday, Rover 1A returned an early picture of its new home world, on the left, during one of its first hops. On Friday, lander MINERVA-II-1 detached from its mothership Hayabusa2, dropped Rovers 1A and 1B, and then landed on Ryugu. Studying Ryugu could tell humanity not only about Ryugu's surface and interior, but about what materials were available in the early Solar System for the development of life. Two more hopping rovers are planned for release, and Hayabusa2 itself is scheduled to collect a surface sample from Ryugu and return it to Earth for detailed analysis before 2021.

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[Ann]

Today's APOD reminds me of July 20, 1969, when Neil Armstrong and Buzz Aldrin became the first human beings to land on the Moon. I remember seeing what I guess was Neil Armstrong filming Buzz Aldrin as he descended from the lunar module to set foot on the Moon.

What I really remember was that the transmission quality was beyond awful, and I had no idea what I was seeing and hearing. Okay, my English was lousy back in 1969, but the sound quality, too, was horrendous. "One small step for a man, but a giant leap for mankind" - say that again, Neil, OK?

In later years, when so many people have begun questioning the Moon landing, I have come to think of the terrible quality of the transmission as one brilliant piece of evidence that the Moon landing was for real. Because if Hollywood had staged the whole thing, there is no way they would have allowed a fake Moon landing to look and sound so bad!

So, back to today's APOD. It looks pretty terrible to me. So I guess that, given what else we have reason to think we know about the Hayabusa2 mission to Asteroid Ryugu, the terrible quality of the picture suggests that the scene "depicted" - or something - is authentic. The image quality may be at least corollary evidence that Rover 1A really made it to this asteroid and is really hopping around there, while its asteroid visitor buddy (the Buzz Aldrin rover? Rover 1B?) is trying and failing to take a good picture of its rover mate!

Ann

[Boomer12k]

Hopefully it has faster exposures?

I hope for some good images...maybe not on a hop?

But hey...it is on an Asteroid!!!! And a great job!!!

:---[===] *

[APODFORIST]

I don't think the quality of the photo is so bad. If you turn the picture 90 degrees to the left and cut out only the middle half, you get a good impression of the surface.

The blur nicely reflects the dynamics of the robot jumping around.

[JohnD]

Looking for details of the landers/rovers, and especially how they 'hopped', I found this excellent film from the German partners of Japan in this project. I shows how the MASCOT lander moves, so I assume that the MINERVA rovers do likewise.
https://www.youtube.com/watch?v=8H4aZX_8hMA

John

[neufer]

The blur nicely reflects the dynamics of the robot jumping around.

It took me a while to figure out that that bright white region was due to direct sunlight
(hence: Minerva was NOT seeing her own shadow) so an annotated version would have been nice.

Click to play embedded YouTube video.

<<In 1980, Mort Walker published a charming book titled The Lexicon of Comicana. For example, any line used to show something moving is called a sphericasia. Shake something hard enough and these lines are called agitrons, while the lines that show which way a comic strip character is pointing are called digitrons. And when Sarge punches Beetle Bailey in the comics, the punch is made up of three distinct elements: A little dust cloud called a briffit to show where the punch started, a swalloop to show the arc of the fist as it smashes across Beetle’s jaw, and the terminating point at the end, which is a whitope. Speaking of briffits, they are most often found in the comic strips in the accompaniment of hites: horizontal lines streaking between a cartoon character and his briffit to represent speed. “The more hites, the more speed,” Walker explains. There are also uphites and downhites, which come out of a character when he is jumping or falling. >>

[E Fish]

In later years, when so many people have begun questioning the Moon landing, I have come to think of the terrible quality of the transmission as one brilliant piece of evidence that the Moon landing was for real. Because if Hollywood had staged the whole thing, there is no way they would have allowed a fake Moon landing to look and sound so bad!

Ah, but Hollywood is so devious that they would have thought of that. Hollywood is all-knowing and in the pocket of the government/Free Mason/Jew/Satanic NASA program and they've thought of everything. (Except why faking the Moon landing would be so important...)

On a more serious note, I think this image is really cool. I have to admit that whenever I think of rovers on an asteroid, I get this image in my head of something like The Little Prince.

[starsurfer]

Today's APOD reminds me of this song.

Click to play embedded YouTube video.

[Ann]

In later years, when so many people have begun questioning the Moon landing, I have come to think of the terrible quality of the transmission as one brilliant piece of evidence that the Moon landing was for real. Because if Hollywood had staged the whole thing, there is no way they would have allowed a fake Moon landing to look and sound so bad!

Ah, but Hollywood is so devious that they would have thought of that. Hollywood is all-knowing and in the pocket of the government/Free Mason/Jew/Satanic NASA program and they've thought of everything. (Except why faking the Moon landing would be so important...)

On a more serious note, I think this image is really cool. I have to admit that whenever I think of rovers on an asteroid, I get this image in my head of something like The Little Prince.

Now that I've looked at it a bit more, I like it better than I did at first. Yes, it is cool. Just looking at that tiny, tiny world of an asteroid is pretty incredible! Imagine hopping about on that asteroid, which has hardly any gravity. Don't kick off too hard, or you will be lost in space!

Ann

[neufer]

Imagine hopping about on that asteroid, which has hardly any gravity. Don't kick off too hard, or you will be lost in space!

The Hayabusa2 mission – investigating a near-Earth asteroid

<<The low gravitational force of the asteroid, which amounts to just one 60,000th of the gravitational force on Earth, presents a challenge for the mission. This force is insufficient to 'pull' the lander out of the Hayabusa probe. As such, MASCOT will be pushed out of its holder by a spring mechanism and fall to Ryugu from a height of approximately 60 metres. If this happens too quickly, then there is a risk that MASCOT will bounce off the asteroid's surface. It is also important that the lander's 'hopping' on the asteroid from site to site is programmed from start to finish so that it does not reach escape velocity. The escape velocity from Ryugu is calculated to be 38 centimetres per second.>>

On Earth a vertical leap of 38 cm/s will only take one a mere 0.75 cm [=(38 cm/s)²/(2 x 981 cm/s²)] into the air.

Are there any insects or other animals
[e.g., snails, turtles, hippos, elephants, "some 400 pound guy sitting on his bed in New Jersey," etc.]
that can't jump 0.75 cm into the air

[Chris Peterson]

Are there any insects or other animals
[e.g., snails, turtles, hippos, elephants, "some 400 pound guy sitting on his bed in New Jersey," etc.]
that can't jump 0.75 cm into the air :?:

Aphids? Starfish?

[neufer]

Are there any insects or other animals
[e.g., snails, turtles, hippos, elephants, "some 400 pound guy sitting on his bed in New Jersey," etc.]
that can't jump 0.75 cm into the air

Aphids? Starfish?

Indeed...small creepy crawlies who can't jump are out of luck on Ryugu.

However, large animals capable of just standing up
[e.g., hippos, elephants, maybe even "some 400 pound guy sitting on his bed in New Jersey," etc.]
are capable of accelerating their bodies at at least 1g over distances greater than 0.75 cm
and hence would be able to achieve escape velocity on Ryugu.

[GoatGuy]

Well… it is pretty interesting to do a few calculations regarding Ryugu's mass, surface gravity, height of hops, and all that.

Doing a Google search, one finds a couple of key things about Ryugu:

• M → Mass of 4.5×10¹¹ kg
• R → Radius of 490 m
• P → Rotational period of 7.67 hr

Using G₀ of 6.66×10⁻¹¹ N/kg/m² as “the gravitational constant”, (and checking it against Earth and Moon and published values for Titan, Jupiter, Mars and so forth…):

G_SURFACE = 0.0001248 m/s²
Volume = 492,800,000 m³
Density = 913 kg/m³ (less than water)

V_ESCAPE = 0.35 m/s

Then working with "hops" supposedly lasting 15 minutes, which implies 7.5 minutes up, and 7.5 minutes down, if V = at … where t = 450 s:

V = at
V = 0.0001248 × 450
V = 0.056 m/s
… = 5.6 cm/s

That's brilliantly slow! A couple of inches a second? Wow. And it stays aloft for 15 minutes no less!!! Gives new meaning to “feeble gravity”.

Anyway, figuring the centripetal force of its rotation to see how close it is to surface rocks just flying off:

ω = 2π/(60 s/min × 60 min/hr × 7.67 hr/rotation)
ω = 0.0002276 radian/s

F_CENTRIPETAL = ω² R
F_CENTRIPETAL = 0.0002276² × 490
F_CENTRIPETAL = 2.54×10⁻⁵ m/s²

And the ratio 'atween F_CENTRIPETAL and G_SURFACE is 4.92!

Meaning that surface gravity is only about 5× greater than the centripetal force that would otherwise sling all the surface stuff forever off into space. Close shave!

And that's about that, from a calculations perspective.

Just saying,
GoatGuy

[Astronymus]

In later years, when so many people have begun questioning the Moon landing, I have come to think of the terrible quality of the transmission as one brilliant piece of evidence that the Moon landing was for real. Because if Hollywood had staged the whole thing, there is no way they would have allowed a fake Moon landing to look and sound so bad!

Ah, but Hollywood is so devious that they would have thought of that. Hollywood is all-knowing and in the pocket of the government/Free Mason/Jew/Satanic NASA program and they've thought of everything. (Except why faking the Moon landing would be so important...)

On a more serious note, I think this image is really cool. I have to admit that whenever I think of rovers on an asteroid, I get this image in my head of something like The Little Prince.

Now that I've looked at it a bit more, I like it better than I did at first. Yes, it is cool. Just looking at that tiny, tiny world of an asteroid is pretty incredible! Imagine hopping about on that asteroid, which has hardly any gravity. Don't kick off too hard, or you will be lost in space!

Ann

Totally fake. It's actually the area behind the Universal Studio. Just some greenscreen and filters added. If you go there and look now you can see how good they were in hiding their tracks after they finished filming some months ago. As nothing had happened. Evil geniuses.

[MarkBour]

So, this is an intentionally blurry image, because the point of posting this one was not to get a good look at the asteroid. The point of it, I surmise, was to evidence the "hop" of the Minerva probe.

[MarkBour]

Today's APOD reminds me of this song.
(Link to youtube of "Out of Space" by The Prodigy

Wow, impressive efficiency in their use of lyrics.

[A PODperson]

I think reaction wheels are Genuinely elegant

[GoshOGeeOGolly]

I don't think the quality of the photo is so bad. If you turn the picture 90 degrees to the left and cut out only the middle half, you get a good impression of the surface.

The blur nicely reflects the dynamics of the robot jumping around.

By making the photo blurry, a casual observer will get the opinion that the U.S. is still far ahead of the rest of the world in science and technology. That might make the Japanese hopping mad .. but .. they'll take to their hops infused drinks and smile.

[neufer]

I don't think the quality of the photo is so bad. If you turn the picture 90 degrees to the left and cut out only the middle half, you get a good impression of the surface. The blur nicely reflects the dynamics of the robot jumping around.

By making the photo blurry, a casual observer will get the opinion that the U.S. is still far ahead of the rest of the world in science and technology. That might make the Japanese hopping mad .. but .. they'll take to their hops infused drinks and smile.

---

<<Humulus japonicus, known as wild hop or Japanese hop, synonym H. scandens, is an ornamental plant in the Cannabaceae family. Originally found in temperate parts of Asia (China, Japan, Korea, Taiwan and Russia) and the tropical environment of Vietnam, it was imported to North America in the 1800s for use in an Asian tonic and as an ornamental plant. Since its arrival in North America, it has spread widely. It can be found throughout the Northeastern U.S. and eastern Canada. It is considered an invasive species in North America. The composition and chemistry of its oils differ from those of its relative the common hop, Humulus lupulus. As a result, the Japanese hop is not used in the production of beer.>>

[ChuggaLug]

If anyone would know how to hop, it would be you, Neuf!!

[neufer]

Click to play embedded YouTube video.

"I have seen it many times. I have had many friends involved in this stuff. It's called flipping and it almost ought to be illegal."

[bystander]

MASCOT Lands Safely on Asteroid Ryugu
German Aerospace Center (DLR) | 2018 Oct 03

The near-Earth asteroid Ryugu, located approximately 300 million kilometres from Earth, has a new inhabitant: On 3 October 2018, the Mobile Asteroid Surface Scout (MASCOT) landed on the asteroid and began to work. The lander successfully separated from the Japanese Hayabusa2 space probe at 03:58 CEST. The 16 hours in which the lander will conduct measurements on the asteroid’s surface have begun for the international team of engineers and scientists. The day before, the Japanese Space Agency’s Hayabusa2 began its descent towards Ryugu. MASCOT was ejected at an altitude of 51 metres and descended in free fall -- slower than an earthly pedestrian -- to its destination, the asteroid. The relief about the successful separation and subsequent confirmation of the landing was clearly noticeable In the MASCOT Control Centre at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) as well as in the adjoining room: “It could not have gone better,” explained MASCOT project manager Tra-Mi Ho from the DLR Institute of Space Systems. “From the lander’s telemetry, we were able to see that it separated from the mothercraft, and made contact with the asteroid surface approximately 20 minutes later.” The team is now in contact with the lander. ...

[bystander]

MASCOT Successfully Completes Exploration of Asteroid Ryugu's Surface
German Aerospace Center (DLR) | 2018 Oct 05

It was a day full of exciting moments and a happy team of scientists and engineers: late in the afternoon of 3 October 2018, the German-French lander MASCOT completed its historic exploration of the surface of the asteroid Ryugu at 21:04 CEST, as its battery ran out. On-asteroid operations were originally scheduled to last 16 hours after separation from the Japanese mothercraft Hayabusa2. But in the end, the battery lasted more than 17 hours. Upon landing in the early morning and subsequently relocating using the built-in swing arm, all instruments collected detailed data on the composition and nature of the asteroid. The on-board camera provided pictures of the landing, hopping manoeuvres and various locations on the surface. ...

[bystander]

Numerous boulders, many rocks, no dust:
MASCOT's zigzag course across the asteroid Ryugu
German Aerospace Center (DLR) | 2018 Oct 12

MASCOT's approach to Ryugu and its path across the surface

---

Six minutes of free fall, a gentle impact on the asteroid and then 11 minutes of rebounding until coming to rest. That is how, in the early hours of 3 October 2018, the journey of the MASCOT asteroid lander began on Asteroid Ryugu – a land full of wonder, mystery and challenges. Some 17 hours of scientific exploration followed this first 'stroll' on the almost 900-metre diameter asteroid. The lander was commanded and controlled from the MASCOT Control Centre at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) site in Cologne in the presence of scientific teams from Germany, France and Japan. MASCOT surpassed all expectations and performed its four experiments at several locations on the asteroid. Never before in the history of spaceflight has a Solar System body been explored in this way. It has now been possible to precisely trace MASCOT’s path on Ryugu’s surface on the basis of image data from the Japanese Hayabusa2 space probe and the lander’s images and data. ...

MASCOT had no propulsion system and landed in free fall. Six minutes after separating from Hayabusa2, and following the end of a ballistic trajectory, the landing module made its first contact with asteroid Ryugu. On the surface, MASCOT moved through the activation of a tungsten swing arm accelerated and decelerated by a motor. This made it possible for MASCOT to be repositioned to the 'correct' side or even perform hops across the asteroid's surface. The gravitational attraction on Ryugu is just one 66,500th of the Earth's, so the little momentum provided was enough: a technological innovation for an unusual form of mobility on an asteroid surface used for the first time in the history of space travel as part of the Hayabusa2 mission. ...