Oct 30, 2020 11:45 PM
(This post was last modified: Oct 31, 2020 12:02 AM by C C.)
This failed planet is slowly rusting in space
https://www.livescience.com/failed-plane...space.html
EXCERPTS: Roughly two to three times Earth's distance from the sun, in the Asteroid Belt that lies between Mars and Jupiter, 16 Psyche makes its home. [...] Astronomers think that 16 Psyche is the exposed core of a full planet that didn't make it all the way, and we're itching to know more about it. NASA will be sending a probe to check it out in the next few years, and in the meantime, scientists are working to glean what they can from Earth.
Now, for the first time, 16 Psyche has been studied in ultraviolet wavelengths using the Hubble Space Telescope, revealing that, just as we thought, the dense chunk of space rock is remarkably metallic. "We've seen meteorites that are mostly metal, but Psyche could be unique in that it might be an asteroid that is totally made of iron and nickel," said planetary scientist Tracy Becker of the Southwest Research Institute. "Earth has a metal core, a mantle and crust. It's possible that as a Psyche protoplanet was forming, it was struck by another object in our Solar System and lost its mantle and crust."
[...] If 16 Psyche is a protoplanetary core, it's possible such impacts stripped it of its accumulating material. Planets are thought to form when their stars are very young - possibly even in tandem - and are surrounded by a thick cloud of dust and gas. Material in this cloud starts to stick together, first electrostatically, then gravitationally as the object grows more massive.
As these bodies grow, they become hot and a bit molten, allowing material to move around. Core differentiation is the process whereby denser material sinks inwards towards the center of the object, and less dense material rises outwards. For 16 Psyche to be a differentiated core, the protoplanet would once have had to have been much bigger than it is now. Exactly when, and how, its outer mantle was stripped away is a bit of a head-scratcher. But Becker's team's research could be the breadcrumbs that put us on the trail to figuring it out.
[...] “For the first time we were able to determine what we believe to be iron oxide ultraviolet absorption bands in an asteroid,” she said. “This is an indication that an oxidation is taking place on the asteroid, which could be due to the fact that the solar wind hits the surface.” (MORE - details)
‘Fireball’ meteorite that fell to Earth in 2018 reveals its secrets
https://www.ntd.com/fireball-meteorite-t...22726.html
EXCERPTS: A 12-million-year-old meteorite that fell to Earth in January 2018 is covered in more than 2,600 organic compounds, according to new research. Meteorites such as this one likely acted as messengers early in Earth’s history, delivering the building blocks of life, the researchers said. [...] The Hamburg meteorite is largely pristine because it was collected so quickly after falling to Earth.
This means the meteorite didn’t sit still long enough to become weathered, for its metals to begin rusting, for water to seep in through cracks and contaminate it or for its minerals (like olivine) to be altered. [...] Scientists believe the Hamburg meteorite was ejected from its parent asteroid about 12 million years ago, traveling through space until it landed on Earth. An analysis of the meteorite revealed that the rock had been exposed to cosmic rays while zipping through space for 12 million years.
[...] “This meteorite shows a high diversity of organics, in that if somebody was interested in studying organics, this is not normally the type of meteorite that they would ask to look at,” Greer said. “But because there was so much excitement surrounding it, everybody wanted to apply their own technique to it, so we have an unusually comprehensive set of data for a single meteorite.”
Typically, carbonaceous chondrites are a thousand times richer in organics than H4 chondrites, Heck said. Near-Earth asteroid Bennu, which was recently sampled by NASA’s OSIRIS-REx mission, is rich in carbon. “The fact that this ordinary chondrite meteorite was rich in organics provides support of the hypothesis that meteorites played an important role in delivering organic compounds to early Earth,” Heck said. “Meteorites fell to our planet throughout Earth’s history also before life formed and possibly delivered some of the building blocks for life onto Earth.”
The organic matter in the meteorite was originally once heated to up to 1,200 degrees Fahrenheit while it was still part of its parent asteroid. This actually reduced the diversity of the organic compounds in the meteorite from millions to a couple thousand. But Heck was still stunned by how many organic compounds were still in the meteorite despite the heat-induced changes it experienced... (MORE - details)
https://www.livescience.com/failed-plane...space.html
EXCERPTS: Roughly two to three times Earth's distance from the sun, in the Asteroid Belt that lies between Mars and Jupiter, 16 Psyche makes its home. [...] Astronomers think that 16 Psyche is the exposed core of a full planet that didn't make it all the way, and we're itching to know more about it. NASA will be sending a probe to check it out in the next few years, and in the meantime, scientists are working to glean what they can from Earth.
Now, for the first time, 16 Psyche has been studied in ultraviolet wavelengths using the Hubble Space Telescope, revealing that, just as we thought, the dense chunk of space rock is remarkably metallic. "We've seen meteorites that are mostly metal, but Psyche could be unique in that it might be an asteroid that is totally made of iron and nickel," said planetary scientist Tracy Becker of the Southwest Research Institute. "Earth has a metal core, a mantle and crust. It's possible that as a Psyche protoplanet was forming, it was struck by another object in our Solar System and lost its mantle and crust."
[...] If 16 Psyche is a protoplanetary core, it's possible such impacts stripped it of its accumulating material. Planets are thought to form when their stars are very young - possibly even in tandem - and are surrounded by a thick cloud of dust and gas. Material in this cloud starts to stick together, first electrostatically, then gravitationally as the object grows more massive.
As these bodies grow, they become hot and a bit molten, allowing material to move around. Core differentiation is the process whereby denser material sinks inwards towards the center of the object, and less dense material rises outwards. For 16 Psyche to be a differentiated core, the protoplanet would once have had to have been much bigger than it is now. Exactly when, and how, its outer mantle was stripped away is a bit of a head-scratcher. But Becker's team's research could be the breadcrumbs that put us on the trail to figuring it out.
[...] “For the first time we were able to determine what we believe to be iron oxide ultraviolet absorption bands in an asteroid,” she said. “This is an indication that an oxidation is taking place on the asteroid, which could be due to the fact that the solar wind hits the surface.” (MORE - details)
‘Fireball’ meteorite that fell to Earth in 2018 reveals its secrets
https://www.ntd.com/fireball-meteorite-t...22726.html
EXCERPTS: A 12-million-year-old meteorite that fell to Earth in January 2018 is covered in more than 2,600 organic compounds, according to new research. Meteorites such as this one likely acted as messengers early in Earth’s history, delivering the building blocks of life, the researchers said. [...] The Hamburg meteorite is largely pristine because it was collected so quickly after falling to Earth.
This means the meteorite didn’t sit still long enough to become weathered, for its metals to begin rusting, for water to seep in through cracks and contaminate it or for its minerals (like olivine) to be altered. [...] Scientists believe the Hamburg meteorite was ejected from its parent asteroid about 12 million years ago, traveling through space until it landed on Earth. An analysis of the meteorite revealed that the rock had been exposed to cosmic rays while zipping through space for 12 million years.
[...] “This meteorite shows a high diversity of organics, in that if somebody was interested in studying organics, this is not normally the type of meteorite that they would ask to look at,” Greer said. “But because there was so much excitement surrounding it, everybody wanted to apply their own technique to it, so we have an unusually comprehensive set of data for a single meteorite.”
Typically, carbonaceous chondrites are a thousand times richer in organics than H4 chondrites, Heck said. Near-Earth asteroid Bennu, which was recently sampled by NASA’s OSIRIS-REx mission, is rich in carbon. “The fact that this ordinary chondrite meteorite was rich in organics provides support of the hypothesis that meteorites played an important role in delivering organic compounds to early Earth,” Heck said. “Meteorites fell to our planet throughout Earth’s history also before life formed and possibly delivered some of the building blocks for life onto Earth.”
The organic matter in the meteorite was originally once heated to up to 1,200 degrees Fahrenheit while it was still part of its parent asteroid. This actually reduced the diversity of the organic compounds in the meteorite from millions to a couple thousand. But Heck was still stunned by how many organic compounds were still in the meteorite despite the heat-induced changes it experienced... (MORE - details)