Boris Gaensicke, a physics professor at the University of Warwick in England and co-author of the study, (https://www.space.com/shard-shattered-alien-planet-dead-star.html) said in a statement that if the planetesimal
is pure iron, then it could have survived where it is now.
Barbieri et al., "Images of asteroid 21 lutetia: a remnant planetesimal
from the early solar system," Science, vol.
They then proceeded to quantify their ideas and develope a theory based on gravitational interaction between the Sun and a visiting star, in which tidal streamers drawn out from each body condensed into a swarm of small bodies or 'planetesimals
' that eventually coalesced by accretion to form the planets.
For an account of how the Chamberlin-Moulton "planetesimal
hypothesis" temporarily eclipsed the Laplacian "nebular hypothesis" in the early twentieth century, see Ronald L.
The discovery, reported in the journal Science, is the first time that scientists have used spectroscopy to discover a solid body in orbit around a white dwarf, using subtle variations in the emitted light to identify additional gas that the planetesimal
Antarctic Meteorite Program (a collaboration among Cassidy, NASA, the National Science Foundation, and the Smithsonian Institution), as well as current field and curatorial practices, the nebular and planetesimal
history of our solar system through key specimens, the significance of key samples from larger bodies, and much more.
The present consensus is that the Moon formed as the result of a giant impact of an approximately Mars-sized planetesimal
with the proto-Earth.
We cannot rule out the possibility of a Velikovskian extraterrestrial asteroidal or planetesimal
fly-by with an electrical discharge that disrupts the Van Allen Belts and initiates the collapse of Earth's magnetic field.
Among the many explanations scientists have proposed regarding what exactly 'Oumuamua is are comet, asteroid, ripped-up planetesimal
or even alien spacecraft.
Since the star's light exerts radiation pressure that would easily blow such small grains out of orbit, any dust near the star must have arrived there recently, perhaps from a swarm of comets, asteroids, or a dusty planetesimal
. Dust that has been ejected to greater distances might dim the star over longer time scales.
Whether the four inner planets or a migrating Jupiter nudged the planetesimal
toward the asteroid belt is unclear, the team reports.
Chamberlin had advanced the planetesimal
theory (see 1905), which required a near collision that would draw out solar matter by gravitational pull and form the planets.
On New Year's Eve, NASA's New Horizons probe will be flying by the planetesimal
target designated 2014 MU69 in the Kuiper belt far beyond Neptune.
"Dust trapping is one potential solution to a major stumbling block in our theories of how planets form, which predicts that particles should drift into the central star and be destroyed before they have time to grow to planetesimal