by BDanielMayfield » Sun Jun 30, 2019 2:25 pm
orin stepanek wrote: ↑Sun Jun 30, 2019 11:14 am
Since Ceres is A Dwarf; I guess that makes Vesta the Largest Asteroid? I see doing browsing that Ceres is still considered an asteroid!
Quoting NASA, here is why Vesta itself isn't also called a Dwarf planet:
The giant asteroid is almost spherical, and so is nearly classified a dwarf planet. Unlike most known asteroids, Vesta has separated into crust, mantle and core (a characteristic known as being differentiated), much like Earth.
Understanding why this is so was one of the objectives of the Dawn mission. The answer turned out to be that Vesta formed early, within 1 to 2 million years of the birth of the solar system. Short-lived radioactive material that was incorporated into bodies that formed during this epoch heated them to the point where—in cases like Vesta—the objects melted, allowing the denser materials to sink to the asteroid's core and the lower density materials to rise.
Probably the most important short-lived isotope that caused Vesta to internally melt and separate into core, mantle and crust was Aluminum-26, produced abundantly by a SN close to the Sun's birthplace.
26Al has a half-life of only 716,000 years, and it's decay product is stable Magnesium. Some of the essential element Mg in our bodies used to be radioactive Al.
Bruce
[quote="orin stepanek" post_id=293361 time=1561893267 user_id=100812]
Since Ceres is A Dwarf; I guess that makes Vesta the Largest Asteroid? I see doing browsing that Ceres is still considered an asteroid!
[/quote]
Quoting NASA, here is why Vesta itself isn't also called a Dwarf planet:
[quote]The giant asteroid is almost spherical, and so is nearly classified a dwarf planet. Unlike most known asteroids, Vesta has separated into crust, mantle and core (a characteristic known as being differentiated), much like Earth.
Understanding why this is so was one of the objectives of the Dawn mission. The answer turned out to be that Vesta formed early, within 1 to 2 million years of the birth of the solar system. Short-lived radioactive material that was incorporated into bodies that formed during this epoch heated them to the point where—in cases like Vesta—the objects melted, allowing the denser materials to sink to the asteroid's core and the lower density materials to rise.[/quote]
Probably the most important short-lived isotope that caused Vesta to internally melt and separate into core, mantle and crust was Aluminum-26, produced abundantly by a SN close to the Sun's birthplace. [sup]26[/sup]Al has a half-life of only 716,000 years, and it's decay product is stable Magnesium. Some of the essential element Mg in our bodies used to be radioactive Al.
Bruce