APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

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APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by APOD Robot » Wed Apr 18, 2018 4:11 am

Image Milky Way over Deadvlei in Namibia

Explanation: What planet is this? It is the only planet currently known to have trees. The trees in Deadvlei, though, have been dead for over 500 years. Located in Namib-Naukluft Park in Namibia (Earth), saplings grew after rainfall caused a local river to overflow, but died after sand dunes shifted to section off the river. High above and far in the distance, the band of our Milky Way Galaxy forms an arch over a large stalk in this well-timed composite image, taken last month. The soil of white clay appears to glow by reflected starlight. Rising on the left, under the Milky Way's arch, is a band of zodiacal light -- sunlight reflected by dust orbiting in the inner Solar System. On the right, just above one of Earth's larger sand dunes, an astute eye can find the Large Magellanic Cloud, a satellite galaxy of our galaxy. Finding the Small Magellanic Cloud in the featured image, though, is perhaps too hard.

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Jack358

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Jack358 » Wed Apr 18, 2018 5:54 am

Is the SMC behind a tree branch--second from right?

1ponders

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by 1ponders » Wed Apr 18, 2018 6:09 am

I would be interested to know now he managed to get the shot considering the Namibia Government steadfastly refuses to allow photographers into the that part of the park between sun down and sun up and it's a 60 km drive from the park entrance.

heehaw

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by heehaw » Wed Apr 18, 2018 9:08 am

1ponders wrote:
Wed Apr 18, 2018 6:09 am
I would be interested to know now he managed to get the shot considering the Namibia Government steadfastly refuses to allow photographers into the that part of the park between sun down and sun up and it's a 60 km drive from the park entrance.
I had a rented VW in a park in Kenya ... but couldn't get out, because I left it too late! I slept between a tree and my car, and I thought about lions.

Sa Ji Tario

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Sa Ji Tario » Wed Apr 18, 2018 11:36 am

Good eye Jack358, the SMC "always" is in the direction that indicates the major axis of the Cross and where is the Cross? stuck to that macula that has the shape of South America (Coal Sack) in the right area of the image

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by orin stepanek » Wed Apr 18, 2018 11:40 am

I think Jack358 has it found!
MilkyVlei_Liebermann_960.jpg
The SMG
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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Cousin Ricky » Wed Apr 18, 2018 12:51 pm

I spotted the SMC before I read the description suggesting that it would be too hard to find.

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Wed Apr 18, 2018 3:16 pm

heehaw wrote:
Wed Apr 18, 2018 9:08 am
1ponders wrote:
Wed Apr 18, 2018 6:09 am

I would be interested to know now he managed to get the shot considering the Namibia Government steadfastly refuses to allow photographers into the that part of the park between sun down and sun up and it's a 60 km drive from the park entrance.
I had a rented VW in a park in Kenya ... but couldn't get out, because I left it too late! I slept between a tree and my car, and I thought about lions.
. I would have been more fearful of the geckos (and Godots):
https://en.wikipedia.org/wiki/Namib-Naukluft_National_Park wrote:
<<The Namib-Naukluft National Park is a national park of Namibia encompassing part of the Namib Desert (considered the world's oldest desert) and the Naukluft mountain range. The Namib-Naukluft is the largest game park in Africa and the fourth largest in the world.

A surprising collection of creatures survives in the hyper-arid region, including snakes, geckos, unusual insects, hyenas, gemsboks and jackals.>>
Art Neuendorffer

Jdx

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Jdx » Wed Apr 18, 2018 3:29 pm

You mean climate change was happening 500 years ago?

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by MarkBour » Wed Apr 18, 2018 3:31 pm

I wonder if some day it will be possible for a future version of Ferdinand Magellan to visit both of the clouds and return? A circumnavigation of the local group? A possible coincidence in this image, then, the pictured trees may have been alive, or just dying, in Magellan's day.
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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Wed Apr 18, 2018 4:09 pm

MarkBour wrote:
Wed Apr 18, 2018 3:31 pm

I wonder if some day it will be possible for a future version of Ferdinand Magellan to visit both of the clouds and return? A circumnavigation of the local group? A possible coincidence in this image, then, the pictured trees may have been alive, or just dying, in Magellan's day.
https://en.wikipedia.org/wiki/Juan_Sebasti%C3%A1n_Elcano wrote:
<<Juan Sebastián Elcano (c.1486–4 August 1526) was a Spanish explorer of Basque origin who completed the first circumnavigation of the Earth. Elcano settled in Seville and became a merchant ship captain. After breaking Spanish laws by surrendering a ship to Genoan bankers in repayment of a debt, he sought a pardon from the Spanish king Charles V, by signing on as a subordinate officer for the Magellan expedition to the East Indies.

They set sail with five ships, Concepción, San Antonio, Santiago, Trinidad and Victoria with 241 men from Spain in 1519. Elcano participated in a fierce mutiny against Magellan before the convoy discovered the passage through South America, the Strait of Magellan. He was spared by Magellan and after five months of hard labour in chains was made captain of the galleon. Santiago was later destroyed in a storm and the crew of San Antonio mutinied and returned to Spain. On 28 November 1520, three ships set sail for the Pacific Ocean and about 19 men died before they reached Guam on 6 March 1521. Conflicts with the nearby island of Rota prevented Magellan and Elcano from resupplying their ships with food and water. They eventually gathered enough supplies and continued their journey to the Philippines and remained there for several weeks. Close relationships developed between the Spaniards and the islanders. They took part in converting the Cebuano tribes to Christianity and became involved in tribal warfare between rival Filipino groups in Mactan Island.

On 27 April 1521, Magellan was killed and the Spaniards defeated by natives in the Battle of Mactan in the Philippines. The surviving members of the expedition could not decide who should succeed Magellan. The men finally voted on a joint command with the leadership divided between Duarte Barbosa and João Serrão. Within four days these two were also dead. They were killed after being betrayed at a feast at the hands of Rajah Humabon. The mission was now teetering on disaster and João Lopes de Carvalho took command of the fleet and led it on a meandering journey through the Philippine archipelago.

During the six-month listless journey after Magellan died, and before reaching the Moluccas, Elcano's stature grew as the men became disillusioned with the weak leadership of Carvalho. The two ships, Victoria and Trinidad finally reached their destination, the Moluccas, on 6 November. They rested and re-supplied in this haven, and filled their holds with the precious cargo of cloves and nutmeg. On 18 December, the ships were ready to leave. Trinidad sprang a leak, and was unable to be repaired. Carvalho stayed with the ship along with 52 others hoping to return later.

Victoria, commanded by Elcano along with 17 other European survivors of the 240 man expedition and 4 (survivors out of 13) Timorese Asians continued its westward voyage to Spain crossing the Indian and Atlantic Ocean. They eventually reached Sanlúcar de Barrameda on 6 September 1522. Elcano was awarded a coat of arms by Charles I of Spain, featuring a globe with the motto: Primus circumdedisti me (in Latin, "You went around me first"), and an annual pension.

Antonio Pigafetta, an Italian scholar, was a crew member of the Magellan and Elcano expedition. He wrote several documents about the events of the expedition.>>
Art Neuendorffer

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Wed Apr 18, 2018 4:26 pm

Jdx wrote:
Wed Apr 18, 2018 3:29 pm

You mean climate change was happening 500 years ago?
Sand dunes certainly move on time scales of 500 years.

The distant Sahara desert has experienced climate change on time scales of thousands of years.

Humans create climate change on time scales of hundreds of years.
https://en.wikipedia.org/wiki/Sahara#Desertification_and_prehistoric_climate wrote:
<<The climate of the Sahara has undergone enormous variations between wet and dry over the last few hundred thousand years, believed to be caused by long-term changes in the North African climate cycle that alters the path of the North African Monsoon - usually southward. The cycle is caused by a 41000-year cycle in which the tilt of the earth changes between 22° and 24.5°. At present, we are in a dry period, but it is expected that the Sahara will become green again in 15000 years (17000 AD). When the North African monsoon is at its strongest annual precipitation and subsequent vegetation in the Sahara region increase, resulting in conditions commonly referred to as the "green Sahara". For a relatively weak North African monsoon, the opposite is true, with decreased annual precipitation and less vegetation resulting in a phase of the Sahara climate cycle known as the "desert Sahara".

During the last glacial period, the Sahara was much larger than it is today, extending south beyond its current boundaries. The end of the glacial period brought more rain to the Sahara, from about 8000 BC to 6000 BC, perhaps because of low pressure areas over the collapsing ice sheets to the north. Once the ice sheets were gone, the northern Sahara dried out. In the southern Sahara, the drying trend was initially counteracted by the monsoon, which brought rain further north than it does today. By around 4200 BC, however, the monsoon retreated south to approximately where it is today, leading to the gradual desertification of the Sahara. The Sahara is now as dry as it was about 13,000 years ago.[/color]

During periods of a wet or "Green Sahara", the Sahara becomes a savanna grassland and various flora and fauna become more common. Following inter-pluvial arid periods, the Sahara area then reverts to desert conditions and the flora and fauna are forced to retreat northwards to the Atlas Mountains, southwards into West Africa, or eastwards into the Nile Valley.

It is also proposed that humans accelerated the drying out period from 6,000–2,500 BC by pastoralists overgrazing available grassland.>>
Art Neuendorffer

GoshOGeeOGolly

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by GoshOGeeOGolly » Wed Apr 18, 2018 5:12 pm

neufer wrote:
Wed Apr 18, 2018 4:26 pm
Jdx wrote:
Wed Apr 18, 2018 3:29 pm

You mean climate change was happening 500 years ago?
Sand dunes certainly move on time scales of 500 years.

The distant Sahara desert has experienced climate change on time scales of thousands of years.

Humans create climate change on time scales of hundreds of years.

Neufer, this is off topic, but do you think these diamonds are further evidence that the Asteriod Belt was once a planet?

https://www.msn.com/en-ca/news/world/di ... li=AAggNb9

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Cousin Ricky » Wed Apr 18, 2018 6:59 pm

So why are they called the Magellanic Clouds? Lots of people knew they were up there long before Magellan sailed south.

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Wed Apr 18, 2018 7:03 pm

GoshOGeeOGolly wrote:
Wed Apr 18, 2018 5:12 pm

Neufer, this is off topic, but do you think these diamonds are further evidence that the Asteroid Belt was once a planet?

https://www.msn.com/en-ca/news/world/di ... li=AAggNb9
  • Not as much as 16 Psyche is evidence that the Asteroid Belt once contained a planet:
https://en.wikipedia.org/wiki/16_Psyche wrote:
<<16 Psyche is one of the ten most massive asteroids in the asteroid belt. It is over 200 km in diameter and contains a little less than 1% of the mass of the entire asteroid belt. It is thought to be the exposed iron core of a protoplanet. It is the most massive metallic M-type asteroid. The symbol 16 Psyche, a semicircle topped by a star: Image, represents a butterfly's wing, symbol of the soul (psyche is the Greek word for 'soul'), and a star.

Radar observations indicate that Psyche has a fairly pure iron–nickel composition, consistent with it having one of the highest radar albedos in the asteroid belt (0.37±0.09). Psyche seems to have a surface that is 90% metallic (iron), with small amounts – 6±1% – of orthopyroxene.
Based on its composition Psyche appears to be an exposed metallic core or a fragment of a metallic core from a larger differentiated parent body some 500 kilometers in diameter. If Psyche is indeed one, there could be other asteroids on similar orbits. However, Psyche is not part of any identified asteroid family. One hypothesis is that the collision that formed Psyche occurred very early in the Solar System's history, and all the other remnants have since been ground into fragments by subsequent collisions or had their orbits perturbed beyond recognition. However, this scenario is considered to have a probability of just 1%. An alternative is that Psyche was broken by impacts, but not catastrophically torn apart. In this case, it may be a candidate for the parent body of the mesosiderites, a class of stony–iron meteorites.

Another possibility is that Psyche may be an end member of diverse relic bodies left by the inner planet formation. The asteroid's mantle may have been stripped away not by a single collision but by multiple (>3) relatively slow hit-and-run collisions with bodies of comparable or larger size. What is left is a metallic core covered by thin layer of silicates, which reveal itself spectrally. In such a case Psyche would be analogous to Mercury but much less massive.>>
https://en.wikipedia.org/wiki/Ureilite wrote:
<<Ureilite is a rare type of stony meteorite that has a unique mineralogical composition very different from that of other stony meteorites. This dark grey or brownish meteorite type is named after the village Novy Urey, Mordovia Republic of Russia, where a meteorite of this type fell on 4 September 1886. On 7 October 2008, tiny asteroid 2008 TC3 entered Earth's atmosphere and exploded an estimated 37 kilometres above the Nubian Desert in Sudan. Fragments of this asteroid were recovered the following December and were found to be ureilite. Scientists have discovered amino acids in meteorite 2008 TC3 where none were expected, taking into account high temperatures reached in the explosion of about 1000 °C.

A technical name for ureilite would be olivine-pigeonite achondrite. Compared to most other meteorites, ureilites tend to have a high percentage of carbon (average 3% by weight) in the form of graphite and nanodiamonds. The diamonds, which are rarely more than a few micrometres in diameter, are probably the result of high pressure shockwaves produced by collisions of the ureilite parent body with other asteroids.

Some groups of meteorites come from a single object (i.e. Mars, Moon, 4 Vesta), but there has been no parent body found as yet for the ureilites. Prior to impacting Earth, 2008 TC3 was identified as an F-type asteroid. According to one theory, Ureilites were formed in the interior of a parent body with cumulate crystals that formed crystal layers. Support for this comes from some ureilites in which the grains are aligned in a preferred orientation. Another suggestion is that ureilites represent a residuum of unmelted material after a partial melt liquid was drawn off. Yet other ideas are that they are unprocessed materials which never melted or that they are mixtures of carbonaceous chondrite and basaltic rock melts. It remains unclear whether ureilites originated on different parent bodies or in different regions of a single body. The presence of diamonds, which can form from graphite as a result of severe shock metamorphism, hints at a violent impact history.>>
Art Neuendorffer

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Wed Apr 18, 2018 7:25 pm

Cousin Ricky wrote:
Wed Apr 18, 2018 6:59 pm

So why are they called the Magellanic Clouds? Lots of people knew they were up there long before Magellan sailed south.
https://en.wikipedia.org/wiki/Magellanic_Clouds#History wrote:
<<In Europe, the [Magellanic] Clouds were first reported by 16th century Italian authors Peter Martyr d'Anghiera and Andrea Corsali, both based on Portuguese voyages. Subsequently, they were reported by Antonio Pigafetta, who accompanied the expedition of Ferdinand Magellan on its circumnavigation of the world in 1519–1522. However, naming the clouds after Magellan did not become widespread until much later. In Bayer's Uranometria they are designated as nubecula major and nubecula minor. In the 1756 star map of the French astronomer Lacaille, they are designated as le Grand Nuage and le Petit Nuage ("the Large Cloud" and "the Small Cloud"). Herschel in 1847 from Cape Observatory South Africa spent 4 years writing a 400-page report detailing over a thousand of the many stars, nebulae and clusters which constitute the cloud which appeared to be a separate more distant group to the usual stars in the Milky Way, an early indication of separate galaxy.>>

Antonio Pigafetta (c. 1491 – c. 1531) was among the 18 who accompanied Juan Sebastián Elcano on board the Victoria on the return voyage to Spain. Upon reaching port in Sanlúcar de Barrameda in the modern Province of Cadiz in September 1522, three years after his departure, Pigafetta returned to the Republic of Venice. He related his experiences in the "Report on the First Voyage Around the World" (Italian: Relazione del primo viaggio intorno al mondo), which was composed in Italian and was distributed to European monarchs in handwritten form before it was eventually published by Italian historian Giovanni Battista Ramusio in 1550–59. After Magellan and Elcano's voyage, Pigafetta utilized the connections he had made prior to the voyage with the Knights of Rhodes to achieve membership in the order.>>
Art Neuendorffer

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by MarkBour » Wed Apr 18, 2018 10:19 pm

Cousin Ricky wrote:
Wed Apr 18, 2018 6:59 pm
So why are they called the Magellanic Clouds? Lots of people knew they were up there long before Magellan sailed south.
If history and good sense is our guide, then perhaps one day "we" will ask the natives what they call them.
It will probably be difficult to pronounce.
Mark Goldfain

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Pretty Aint It » Thu Apr 19, 2018 1:21 am

A beautiful piece of professional art

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Chris Peterson » Thu Apr 19, 2018 4:55 am

GoshOGeeOGolly wrote:
Wed Apr 18, 2018 5:12 pm

Neufer, this is off topic, but do you think these diamonds are further evidence that the Asteriod Belt was once a planet?
It is quite certain that the Asteroid Belt was never a planet.
Chris

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Thu Apr 19, 2018 12:29 pm

Chris Peterson wrote:
Thu Apr 19, 2018 4:55 am
GoshOGeeOGolly wrote:
Wed Apr 18, 2018 5:12 pm

Neufer, this is off topic, but do you think these diamonds are further evidence that the Asteriod Belt was once a planet?
It is quite certain that the Asteroid Belt was never a planet.
  • If the Asteroid Belt ever contained a planet then most of it's mass has been ejected (by Jupiter):
https://en.wikipedia.org/wiki/Asteroid_belt#Formation wrote:
<<In 1802, shortly after discovering Pallas, Olbers suggested to Herschel that Ceres and Pallas were fragments of a much larger planet that once occupied the Mars–Jupiter region, this planet having suffered an internal explosion or a cometary impact many million years before. Over time, however, this hypothesis has fallen from favor. The large amount of energy required to destroy a planet, combined with the belt's low combined mass, which is only about 4% of the mass of the Moon, do not support the hypothesis. Further, the significant chemical differences between the asteroids become difficult to explain if they come from the same planet. Today, most scientists accept that, rather than fragmenting from a progenitor planet, the asteroids never formed a planet at all.>>
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GoshOGeeOGolly

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by GoshOGeeOGolly » Thu Apr 19, 2018 5:40 pm

Chris Peterson wrote:
Thu Apr 19, 2018 4:55 am
GoshOGeeOGolly wrote:
Wed Apr 18, 2018 5:12 pm

Neufer, this is off topic, but do you think these diamonds are further evidence that the Asteriod Belt was once a planet?
It is quite certain that the Asteroid Belt was never a planet.
The belt is said to contain too little mass to have ever been a planet, but new theories suggest the Asteroid belt once had a LOT more mass, planet size mass, but most was kicked out by gravitational influences of the giant planets as they migrated to different orbits. https://phys.org/news/2017-09-theory-asteroid-belt.html https://phys.org/news/2009-02-scientist ... .html#nRlv

Also, the asterioid's magnetic fields are said to have lasted FAR longer than once thought, and that they were created by the same process as earth's magnetic field, Compositional Convection. https://www.space.com/28319-asteroid-ma ... -core.html

I think the 'quite certain' is not as certain as it once was in this case.

GoshOGeeOGolly

Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by GoshOGeeOGolly » Thu Apr 19, 2018 7:47 pm

neufer wrote:
Thu Apr 19, 2018 12:29 pm

The large amount of energy required to destroy a planet, combined with the belt's low combined mass, which is only about 4% of the mass of the Moon, do not support the hypothesis. Further, the significant chemical differences between the asteroids become difficult to explain if they come from the same planet.

The energy required would be a lot less with a small planet. I can't understand why chemical differences in earth's rocks would not be as varied as the asteroids.

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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by neufer » Thu Apr 19, 2018 11:16 pm

GoshOGeeOGolly wrote:
Thu Apr 19, 2018 7:47 pm
neufer wrote:
Thu Apr 19, 2018 12:29 pm

The large amount of energy required to destroy a planet, combined with the belt's low combined mass, which is only about 4% of the mass of the Moon, do not support the hypothesis. Further, the significant chemical differences between the asteroids become difficult to explain if they come from the same planet.
The energy required would be a lot less with a small planet.
I can't understand why chemical differences in earth's rocks would not be as varied as the asteroids.
Click to play embedded YouTube video.
The one big rocky planet collision that we do know about was the one that created the Moon.

More recently it has been suggested that (a more recent) collision generated Phobos & Deimos.

Perhaps the nanodiamonds come from the planets Earth, Theia or Mars.

:arrow: Theia smashing into Earth
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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by bystander » Fri Apr 20, 2018 3:50 am

neufer wrote:
Thu Apr 19, 2018 12:29 pm

...
More recently it has been suggested that (a more recent) collision generated Phobos & Deimos.
...

viewtopic.php?t=38211
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Re: APOD: Milky Way over Deadvlei in Namibia (2018 Apr 18)

Post by Chris Peterson » Fri Apr 20, 2018 1:15 pm

GoshOGeeOGolly wrote:
Thu Apr 19, 2018 5:40 pm
Chris Peterson wrote:
Thu Apr 19, 2018 4:55 am
GoshOGeeOGolly wrote:
Wed Apr 18, 2018 5:12 pm

Neufer, this is off topic, but do you think these diamonds are further evidence that the Asteriod Belt was once a planet?
It is quite certain that the Asteroid Belt was never a planet.
The belt is said to contain too little mass to have ever been a planet, but new theories suggest the Asteroid belt once had a LOT more mass, planet size mass, but most was kicked out by gravitational influences of the giant planets as they migrated to different orbits. https://phys.org/news/2017-09-theory-asteroid-belt.html https://phys.org/news/2009-02-scientist ... .html#nRlv

Also, the asterioid's magnetic fields are said to have lasted FAR longer than once thought, and that they were created by the same process as earth's magnetic field, Compositional Convection. https://www.space.com/28319-asteroid-ma ... -core.html

I think the 'quite certain' is not as certain as it once was in this case.
Well, no. I think that "quite certain" remains the case. This new theory doesn't change that in the slightest. The material we observe comes from different sources and has different times of origin, and there's nothing to suggest, either theoretically or in terms of actual composition and physical characteristics, that it was ever all combined in a single planetary body.
Chris

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