Forming the Flora Family: Implications for the Near-Earth Asteroid Population and Large Terrestrial Planet Impactors

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10367582" target="_blank" >RIV/00216208:11320/17:10367582 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.3847/1538-3881/aa64dc" target="_blank" >http://dx.doi.org/10.3847/1538-3881/aa64dc</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-3881/aa64dc" target="_blank" >10.3847/1538-3881/aa64dc</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Forming the Flora Family: Implications for the Near-Earth Asteroid Population and Large Terrestrial Planet Impactors

Popis výsledku v původním jazyce

Formed from a catastrophic collision of a parent body larger than 150 km in diameter, the Flora family is located in the innermost part of the main belt near the v(6) secular resonance. Objects in this region, when pushed onto planet-crossing orbits, tend to have relatively high probabilities of striking the Earth. These factors suggest that Flora may be a primary source of present-day LL chondrite-like NEOs and Earth/Moon impactors. To investigate this possibility, we used collisional and dynamical models to track the evolution of Flora family members. We created an initial Flora family and followed test asteroids 1 and 3 km in diameter using a numerical code that accounted for both planetary perturbations and nongravitational effects. Our Flora family members reproduce the observed semimajor axis, eccentricity, and inclination distributions of the real family after similar or equal to 1 to 1.4 Gyr. A consistency with the surface age inferred from crater spatial densities found on (951). Gaspra may favor the latter age. Our combined collisional and dynamical runs indicate that. the family has lost nearly 90% of its initial kilometer-sized members. At its peak, 100-300 Myr after the family-forming event, Flora family members filled NEO space with nearly 1000 D &gt;= 1 km size bodies before fading to its present contribution of 35-50 such NEOs. Therefore, it is not currently a major source of large NEOs. We also find 700-950 and 35-47 kilometer-sized asteroids struck the Earth and Moon, respectively, most within the first 300 Myr after family formation. These results imply that Flora played a major role in providing impacts to the mid-Proterozoic Earth.

Název v anglickém jazyce

Forming the Flora Family: Implications for the Near-Earth Asteroid Population and Large Terrestrial Planet Impactors

Popis výsledku anglicky

Formed from a catastrophic collision of a parent body larger than 150 km in diameter, the Flora family is located in the innermost part of the main belt near the v(6) secular resonance. Objects in this region, when pushed onto planet-crossing orbits, tend to have relatively high probabilities of striking the Earth. These factors suggest that Flora may be a primary source of present-day LL chondrite-like NEOs and Earth/Moon impactors. To investigate this possibility, we used collisional and dynamical models to track the evolution of Flora family members. We created an initial Flora family and followed test asteroids 1 and 3 km in diameter using a numerical code that accounted for both planetary perturbations and nongravitational effects. Our Flora family members reproduce the observed semimajor axis, eccentricity, and inclination distributions of the real family after similar or equal to 1 to 1.4 Gyr. A consistency with the surface age inferred from crater spatial densities found on (951). Gaspra may favor the latter age. Our combined collisional and dynamical runs indicate that. the family has lost nearly 90% of its initial kilometer-sized members. At its peak, 100-300 Myr after the family-forming event, Flora family members filled NEO space with nearly 1000 D &gt;= 1 km size bodies before fading to its present contribution of 35-50 such NEOs. Therefore, it is not currently a major source of large NEOs. We also find 700-950 and 35-47 kilometer-sized asteroids struck the Earth and Moon, respectively, most within the first 300 Myr after family formation. These results imply that Flora played a major role in providing impacts to the mid-Proterozoic Earth.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA13-01308S" target="_blank" >GA13-01308S: Dynamika malých těles sluneční soustavy</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

The Astronomical Journal

ISSN

0004-6256

e-ISSN

—

Svazek periodika

153

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

23

Strana od-do

—

Kód UT WoS článku

000403658900001

EID výsledku v databázi Scopus

—