Psyche could be the stripped-back metallic core left over from collisions in the early planet-forming phase of our Solar System or a remnant \u2018rubble pile\u2019 where metal is only scattered across the surface. Credit: Stocktrek Images \/ Getty Images<\/figcaption><\/figure>Astronomers have speculated that the large chunk of iron and nickel \u2013 if that is indeed what Asteroid 16 Psyche is \u2013 could be the exposed core of a larger proto-planet.<\/p>
During the smash-up and merging of smaller planetesimals (the building blocks of planets), the resulting larger bodies start out completely molten.<\/p>
Heavy metals sink to the core, while lighter rock floats to the top.<\/p>
Psyche may once have been such a \u2018differentiated\u2019 body.<\/p>
After it cooled down, a collision with another asteroid could have stripped the proto-planet of its rocky mantle, leaving a bare metal core.<\/p>
While this scenario would provide a completely unique and unprecedented opportunity for scientists to study the core of a differentiated object, there are other possibilities as to the asteroid\u2019s origin.<\/p>
For example, if a differentiated body is completely shattered by a giant collision, part of the debris could reassemble into a huge \u2018rubble pile\u2019, with many metal-rich fragments ending up on the surface.<\/p>
Or maybe the iron on Psyche\u2019s surface is the result of a hypothesised geological process known as \u2018ferro-volcanism\u2019. <\/p>An artist\u2019s impression of Asteroid 16 Psyche\u2019s nickel-iron mountain peaks. Photos of the asteroid’s true topography could be expected from August 2029. Credit: NASA\/JPL-Caltech\/Arizona State Univ.\/Space Systems Loral\/Peter Rubin<\/figcaption><\/figure>What is asteroid Psyche made of?<\/strong><\/h2>“The most important question we will answer is \u2018what is Psyche?\u2019,” says Lindy Elkins-Tanton of Arizona State University, principal investigator of the Psyche mission.<\/p>
The main reason scientists started to doubt the exposed-core explanation is Psyche\u2019s relatively low density.<\/p>
The asteroid\u2019s dimensions are known from timing observations of stellar occultations and from high-resolution images obtained with the European Southern Observatory\u2019s Very Large Telescope in Chile. <\/p>
Studies of Psyche\u2019s gravitational influence on the orbits of other smaller asteroids carried out by Finnish astronomer Lauri Siltala have revealed the object\u2019s mass.<\/p>
From the known size and mass, Psyche\u2019s mean density turns out to be 3.9g per cubic centimetre.<\/p>
That’s about half the value you would expect for a solid ball of metal.<\/p>Illustration of Asteroid 16 Psyche. Credit: NASA\/JPL-Caltech\/ASU<\/figcaption><\/figure>The density measurements can mean two things.<\/p>
Either Psyche is mainly rock after all, with patches of iron on its surface \u2013 the \u2018lava\u2019 plains mentioned before.<\/p>
Or the asteroid is a porous rubble pile, in which case the iron content could be substantially higher.<\/p>
In 2019, Francis Nimmo and Jacob Abrahams of the University of California Santa Cruz proposed the theory of (ancient) ferro-volcanism <\/p>
This is a process you might expect when a newly formed, molten body is cooling down from the outside in.<\/p>
But a team led by David Cantillo of the University of Arizona carried out laboratory experiments indicating that Psyche\u2019s spectroscopic properties are best explained by a porous body containing up to 82.5% metal, as they wrote in a 2021 paper.<\/p>
Then there\u2019s the riddle about a possible link with iron meteorites.<\/p>
These are assumed to be fragments of disrupted differentiated bodies \u2013 bodies large enough to have ended up with an iron-nickel core.<\/p>
“The problem is that the asteroid belt shows limited evidence that so many bodies with cores actually disrupted,” says Bottke.<\/p>
“This suggests that we are missing something important about Solar System evolution. Our investigation of Psyche may shed light on this mysterious issue.”<\/p>
Given all of these mysteries, it\u2019s not surprising that Solar System researchers look forward to the launch of the Psyche mission on a SpaceX Falcon Heavy rocket from Kennedy Space Center in Florida.<\/p>Asteroid Psyche<\/strong> key facts<\/h2>Date of discovery:<\/strong> 17 March 1852<\/li>Average distance to the Sun:<\/strong> 437 million km<\/li>Orbital period:<\/strong> 4.99 years<\/li>Orbital eccentricity:<\/strong> 0.14<\/li>Orbital inclination:<\/strong> 3.1\u00b0<\/li>Dimensions:<\/strong> 280\u00a0x\u00a0235\u00a0x 175km<\/li>Surface area:<\/strong> 165,800km2<\/sup> (about twice the surface of Ireland)<\/li>Mass:<\/strong> 2.3\u00a0x\u00a01019<\/sup>kg<\/li>Average density:<\/strong> 3.9g\/cm3<\/sup><\/li>Rotational period:<\/strong> 4.2 hours<\/li>Visual brightness:<\/strong> 9.2\u201312.2<\/li>Estimated ore value:<\/strong> $10 quintillion<\/li><\/ul>This guide originally appeared in the October 2023 issue of <\/em>BBC Sky at Night Magazine<\/strong><\/p> <\/body><\/html>\nWhat we know so far about the asteroid set to be studied by NASA’s Psyche mission. <\/p>\n","protected":false},"author":24,"featured_media":49741,"template":"","categories":[1],"acf":{"readingTimeMinutes":"4"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock.jpg",1200,800,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock-300x200.jpg",300,200,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock-768x512.jpg",768,512,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock-1024x683.jpg",800,534,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock.jpg",1200,800,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2023\/10\/asteroid-16-psyche-facts-and-stats-about-the-metal-rich-spacerock.jpg",1200,800,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"What we know so far about the asteroid set to be studied by NASA's Psyche mission.","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/49740"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/49741"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=49740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=49740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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