APOD: Verona Rupes: Tallest Known Cliff in... (2016 Nov 27)

[APOD Robot]

Verona Rupes: Tallest Known Cliff in the Solar System

Explanation: Could you survive a jump off the tallest cliff in the Solar System? Quite possibly. Verona Rupes on Uranus' moon Miranda is estimated to be 20 kilometers deep -- ten times the depth of the Earth's Grand Canyon. Given Miranda's low gravity, it would take about 12 minutes for a thrill-seeking adventurer to fall from the top, reaching the bottom at the speed of a racecar -- about 200 kilometers per hour. Even so, the fall might be survivable given proper airbag protection. The featured image of Verona Rupes was captured by the passing Voyager 2 robotic spacecraft in 1986. How the giant cliff was created remains unknown, but is possibly related to a large impact or tectonic surface motion.

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[/b]

[ta152h0]

like from here to Seattle, straitline

[Ann]

Click to view full size image

Miranda. Photo: NASA/JPL-Caltech

Miranda must be one of the totally weirdest-looking spherical bodies in the solar system. Look at that huge white "L" there!

Miranda should be renamed to something beginning on an L. Unfortunately, there seem to be no Shakespearian heroines with names beginning on an L. So let me suggest "Lady MacBeth", then. Or just, perhaps, Lady. Why not?

Ann

[Boomer12k]

And below the L looks like a C... or S...maybe...also to the left seems to be another "L"....or close...
How about Leonardo... THE NINJA TURTLE...

OMG!!! They are NAZCA LINES.....

Ok, I think it had some water or other liquid or gasses and out-gassed them long ago, and it got gouged a few times, or maybe when it formed it had several large contributors, that did not wholly melt...and places were smashed off...

But then why do they look like outlined GLYPHS???

:---[===] *

[MadCat-75]

Reminds me of a scene in the following video, at 2:40

https://vimeo.com/108650530

[geckzilla]

Reminds me of a scene in the following video, at 2:40

https://vimeo.com/108650530

I think this is exactly what that's supposed to be.

[neufer]

<<The Tempest is thought by many critics to be the last play that Shakespeare wrote alone. It is set on a remote island, where the sorcerer Prospero, rightful Duke of Milan, plots to restore his daughter Miranda to her rightful place using illusion and skillful manipulation.>>

Miranda must be one of the totally weirdest-looking spherical bodies in the solar system. Look at that huge white "L" there! Miranda should be renamed to something beginning on an L. Unfortunately, there seem to be no Shakespearian heroines with names beginning on an L.

<<Titus Andronicus is thought to be Shakespeare's first tragedy, and is often seen as his attempt to emulate the violent and bloody revenge plays of his contemporaries. Titus arrives to much fanfare, bearing with him as prisoners the Queen of the Goths (Tamora), her three sons (Alarbus, Chiron, and Demetrius), and Aaron the Moor (her secret lover). Despite Tamora's desperate pleas, Titus sacrifices her eldest son, Alarbus, to avenge the deaths of his own sons during the war. Distraught, Tamora and her two surviving sons vow to obtain revenge on Titus and his family.

Aaron persuades Demetrius and Chiron to kill Titus's son Bassianus, so they may rape his daughter Lavinia. They do so, throwing Bassianus's body into a pit and dragging Lavinia deep into the forest before violently raping her. To keep her from revealing what has happened, they cut out her tongue and cut off her hands. Later, Lavinia writes the names of her attackers in the dirt, using a stick held with her mouth and between her mutilated arms.>>

[Ann]

Thanks, Art!

So we can re-name Miranda Lavinia, then?

Ann

[neufer]

So we can re-name Miranda Lavinia, then?

She certainly looks more the part of a tormented Lavinia than a sheltered Miranda.

LAVINIA: Tumble me into some loathsome pit,

• Where never man's eye may behold my body:
  Do this, and be a charitable murderer.

[daryljanzen]

Reminds me of a scene in the following video, at 2:40

https://vimeo.com/108650530

Also at http://apod.nasa.gov/apod/ap141208.html. Too bad: Wanderers should've been referenced in this caption.

[Bellerophon]

The comparison to earth's Grand Canyon got me thinking, so I did a quick calculation. In terms of gravitational potential, Verona Rupes is actually about a tenth the "height." Miranda's surface gravity is .079 m/s², so the potential at the top of the cliff relative to the bottom is approximately 1580 m²/s². The Grand Canyon is 1587 m deep, so with earth's surface gravity of 9.807 m/s², the potential at the top is about 15500 m²/s². In the absence of air, a fall from the top of the Grand Canyon would terminate in an impact of about 900 km/hr.

[neufer]

In terms of gravitational potential, Verona Rupes is actually about a tenth the "height." Miranda's surface gravity is .079 m/s², so the potential at the top of the cliff relative to the bottom is approximately 1580 m²/s². The Grand Canyon is 1587 m deep, so with earth's surface gravity of 9.807 m/s², the potential at the top is about 15500 m²/s². In the absence of air, a fall from the top of the Grand Canyon would terminate in an impact of about 900 km/hr.

However, with air the terminal velocity is about the same for the Grand Canyon as for Verona Rupes:

Based on wind resistance, for example, the terminal velocity of a skydiver in a belly-to-earth (i.e., face down) free-fall position is about 195 km/h. Higher speeds can be attained if the skydiver pulls in his or her limbs. In this case, the terminal velocity increases to about 320 km/h, which is almost the terminal velocity of the peregrine falcon diving down on its prey. The same terminal velocity is reached for a typical .30-06 bullet dropping downwards—when it is returning to the ground having been fired upwards. Competition speed skydivers fly in a head-down position and can reach speeds of 530 km/h

[Chris Peterson]

The comparison to earth's Grand Canyon got me thinking, so I did a quick calculation. In terms of gravitational potential, Verona Rupes is actually about a tenth the "height." Miranda's surface gravity is .079 m/s², so the potential at the top of the cliff relative to the bottom is approximately 1580 m²/s². The Grand Canyon is 1587 m deep, so with earth's surface gravity of 9.807 m/s², the potential at the top is about 15500 m²/s². In the absence of air, a fall from the top of the Grand Canyon would terminate in an impact of about 900 km/hr.

The Grand Canyon, however, doesn't have any cliffs more than a few hundred meters high. You don't fall into the Grand Canyon so much as you tumble and slide down steep slopes.

[GeeOh]

VERY strange looking geology that moon has .. or is it even called geology on a moon, and I don't really care if it is or not, but it is VERY strange looking.

[neufer]

The Grand Canyon, however, doesn't have any cliffs more than a few hundred meters high. You don't fall into the Grand Canyon so much as you tumble and slide down steep slopes.

[b][color=#0000FF][size=150]Mount Thor and its steep west face[/size][/color][/b]

---

<<Mount Thor, officially gazetted as Thor Peak, is a mountain with an elevation of 1,675 metres located in Auyuittuq National Park, on Baffin Island, Nunavut, Canada. The mountain's west face features Earth's greatest vertical drop of 1,250 m (4,101 ft), with the cliff overhanging at an average angle of 15 degrees from vertical. The first rappel of the west face was in July 1982, led by Steve Holmes of Atlanta, using a mile long length of rope. This was at the time the longest rappel (and climb, via rope) ever done. The first ascent of the west face was achieved by Earl Redfern, John Bagley, Eric Brand and Tom Bepler in 1985. The first solo ascent of the West Face was completed by Jason 'Singer' Smith in 1998.>>

It would take about 28 seconds for a thrill-seeking adventurer to fall from the top of Mount Thor, reaching the bottom at the speed of a racecar -- about 195 kilometers per hour.

[ygmarchi]

Living in Verona (Italy) I'm led to wonder why this feature is named after my home town.

My guess world be Shakespeare and my town's ancient walls?

[Chris Peterson]

Living in Verona (Italy) I'm led to wonder why this feature is named after my home town.

My guess world be Shakespeare and my town's ancient walls?

Most of Uranus's moons are named after Shakespearean characters, and their features also reflect Shakespearean references. So yes, Verona for the setting of Romeo and Juliet, although I'm not sure if the city walls were a factor in the choice.

[neufer]

Living in Verona (Italy) I'm led to wonder why this feature is named after my home town.

My guess world be Shakespeare and my town's ancient walls?

Most of Uranus's moons are named after Shakespearean characters, and their features also reflect Shakespearean references. So yes, Verona for the setting of Romeo and Juliet, although I'm not sure if the city walls were a factor in the choice.

Mirandan scarps are called rupes. They are named after the locations of plays by Shakespeare.

Code: Select all

Rupes 	        Named after
--------------------------------------------------------
Argier Rupes 	Algiers (The Tempest)
Verona Rupes 	Verona (Romeo and Juliet)

Mirandan craters are named after characters in Shakespeare's The Tempest.

Code: Select all

Crater 	   Coordinate 	Diameter (km) 	Named after
--------------------------------------------------------
Alonso   	 44.0°S 352.6°E 	25.0 	Alonso, King of Naples
Ferdinand 	34.8°S 202.1°E 	17.0 	Ferdinand, Alonso's son
Francisco 	73.2°S 236.0°E 	14.0 	Francisco, a lord of Naples
Gonzalo 	  11.4°S 77.0°E 	 11.0 	Gonzalo, A lord of Naples
Prospero 	 32.9°S 329.9°E 	21.0 	Prospero, the magician
Stephano 	 41.1°S 234.1°E 	16.0 	Stephano, the drunken butler
Trinculo 	 63.7°S 163.4°E 	11.0 	Trinculo, the jester

Mirandan geological regions are called regiones. They are named after the locations of plays by Shakespeare.

Code: Select all

Regio 	        Coordinate 	Diameter (km) 	Named after
--------------------------------------------------------
Dunsinane Regio  31.5°S 11.9°E 	 244.0 	Dunsinane Hill (Macbeth)
Ephesus Regio 	15.0°S 250.0°E 	225.0 	Ephesus (The Comedy of Errors)
Mantua Regio 	 39.6°S 180.2°E 	399.0 	Mantua (The Two Gentlemen of Verona and R&J)
Sicilia Regio 	30.0°S 317.2°E 	170.0 	Sicily (The Winter's Tale)

Mirandan coronae (oval-shaped features that may be formed by upwellings of warm material below the surface.) are named after the locations of plays by Shakespeare.

Code: Select all

Corona 	          Named after
--------------------------------------------------------
Arden Corona 	    Forest of Arden (As You Like It)
Elsinore Corona 	 Elsinore (Hamlet)
Inverness Corona 	Inverness (Macbeth)

Mirandan sulci (long parallel grooves on a planet or a moon) are named after the locations of plays by Shakespeare.

Code: Select all

Sulcus 	          Named after
--------------------------------------------------------
Naples Sulcus 	  Naples (The Tempest)
Syracusa Sulcus 	Syracuse (The Comedy of Errors)

[CuDubh]

Although it is perhaps reasonable to call these "cliffs", they don't appear to be sheer cliffs (vertical, near vertical and/or overhanging). So I'm skeptical about the free fall references. Would guess given the low gravity these might be ski-able. Earth analogue is exposed normal fault scarps, which rarely dip more than 70 degrees or so.

Despite being a US space project, and despite presidential directive, the main reference here is not freely available.

http://www.sciencedirect.com/science/ar ... 3588900541

Thanks for nothing, Elsevier!

http://www.nytimes.com/2012/02/14/scien ... isher.html

[MarkBour]

Capture.JPG (15.22 KiB) Viewed 5999 times

I'm a bit confused by the image and its caption. Any clarification of what I'm seeing and reading would be appreciated. I am thinking that the portion of the image which I've excerpted here is the Verona Rupes cliff, and the arrow indicates an approximate trajectory for a thrill-seeker trying a cliff-dive. Is this correct? (I can see some alternatives.) Meanwhile, the other references I've followed seem to indicate that this cliff, conjectured to have been created by fault movement, is at least 5 km tall, perhaps 10 km, but not 20km. The other Wikipedia materials I found in the references indicate that some canyon on Miranda (perhaps this same canyon), is 20 km deep, but not that there is any 20 km high cliff, as the APOD caption seems to indicate. Then again, how to reconcile those statements. If the cliff is only 5-10 km, where on Miranda is there a depth of 20 km ?

And how do astronomers come to those figures? Was it done strictly from visual images, or was there some other data, such as radar data that help figure out such things?

[alter-ego]

Capture.JPG

I'm a bit confused by the image and its caption. Any clarification of what I'm seeing and reading would be appreciated. I am thinking that the portion of the image which I've excerpted here is the Verona Rupes cliff, and the arrow indicates an approximate trajectory for a thrill-seeker trying a cliff-dive. Is this correct?

Yes, that view perspective is correct

Meanwhile, the other references I've followed seem to indicate that this cliff, conjectured to have been created by fault movement, is at least 5 km tall, perhaps 10 km, but not 20km. The other Wikipedia materials I found in the references indicate that some canyon on Miranda (perhaps this same canyon), is 20 km deep, but not that there is any 20 km high cliff, as the APOD caption seems to indicate. Then again, how to reconcile those statements. If the cliff is only 5-10 km, where on Miranda is there a depth of 20 km ?

Yeah, there's some conflicting statements between wiki and the APOD. Even after looking up the Voyager NAC Camera Details and analyzing the and "original" image PIA00044, the numbers don't work out. (I estimated a minimum fault height ~3x larger!) It wasn't until I used basic measurable data: Miranda diameter coupled with a 20-plus km crater measurement in PIA18185, then using that crater size to compare the scarp in PIA01354 did I agree with the APOD description of ~20km cliff height.

And how do astronomers come to those figures? Was it done strictly from visual images, or was there some other data, such as radar data that help figure out such things?

Basically the same way I did - Voyager had no ranging instruments to get relative elevations. Additional projection corrections could be done, but the 20-km estimate looks sound to me.

[Ann]

Thanks, alter-ego. It is a such great thing that Starship Asterisk* has a contributor like you, who can work out complicated math problems like these and share your data with the rest of us.

Ann

[MarkBour]

Thanks, alter-ego. It is a such great thing that Starship Asterisk* has a contributor like you, who can work out complicated math problems like these and share your data with the rest of us.
Ann

Agreed. Thanks very much!

And thanks, Ann, for plotting the full image of Miranda. I see that Verona Rupes is in that deep gash at the lower right of the full image. It is just so amazing what the Voyagers captured, launched almost 40 years ago! I guess it only got this one-pass view of Miranda, so our knowledge of Verona Rupes is just from only a few images and all from this one side. Therefore, I assume we cannot know what lies around the bend of the curvature of Miranda's surface. That tremendous canyon could fade out quickly, or it could actually get deeper.

[alter-ego]

Thanks, alter-ego. It is a such great thing that Starship Asterisk* has a contributor like you, who can work out complicated math problems like these and share your data with the rest of us.

Very nice words, Ann (and Mark). Thank you.
I think it's a good niche for me here. I'm not the only one who can solve these problems, but my dogged persistence is a factor for some harder problems.
I like things to make sense and work out. I do my best, but checking me is always a good thing
Not to go unsaid, your comments are always colorful which the Asterisk* benefits from too.