The unexpected surface of asteroid (101955) Bennu

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10405380" target="_blank" >RIV/00216208:11320/19:10405380 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=yDKVz91GPt" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=yDKVz91GPt</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s41586-019-1033-6" target="_blank" >10.1038/s41586-019-1033-6</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The unexpected surface of asteroid (101955) Bennu

Popis výsledku v původním jazyce

NASA&apos;S Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer (OSIRIS-REx) spacecraft recently arrived at the near-Earth asteroid (101955) Bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to Earth(1). Bennu is a lowalbedo B-type asteroid(2) that has been linked to organic-rich hydrated carbonaceous chondrites(3). Such meteorites are altered by ejection from their parent body and contaminated by atmospheric entry and terrestrial microbes. Therefore, the primary mission objective is to return a sample of Bennu to Earth that is pristine-that is, not affected by these processes(4). The OSIRIS-REx spacecraft carries a sophisticated suite of instruments to characterize Bennu&apos;s global properties, support the selection of a sampling site and document that site at a sub-centimetre scale(5-11). Here we consider early OSIRIS-REx observations of Bennu to understand how the asteroid&apos;s properties compare to pre-encounter expectations and to assess the prospects for sample return. The bulk composition of Bennu appears to be hydrated and volatile-rich, as expected. However, in contrast to pre-encounter modelling of Bennu&apos;s thermal inertia(12) and radar polarization ratios(13)-which indicated a generally smooth surface covered by centimetre-scale particles-resolved imaging reveals an unexpected surficial diversity. The albedo, texture, particle size and roughness are beyond the spacecraft design specifications. On the basis of our pre-encounter knowledge, we developed a sampling strategy to target 50-metre-diameter patches of loose regolith with grain sizes smaller than two centimetres(4). We observe only a small number of apparently hazard-free regions, of the order of 5 to 20 metres in extent, the sampling of which poses a substantial challenge to mission success.

Název v anglickém jazyce

The unexpected surface of asteroid (101955) Bennu

Popis výsledku anglicky

NASA&apos;S Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer (OSIRIS-REx) spacecraft recently arrived at the near-Earth asteroid (101955) Bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to Earth(1). Bennu is a lowalbedo B-type asteroid(2) that has been linked to organic-rich hydrated carbonaceous chondrites(3). Such meteorites are altered by ejection from their parent body and contaminated by atmospheric entry and terrestrial microbes. Therefore, the primary mission objective is to return a sample of Bennu to Earth that is pristine-that is, not affected by these processes(4). The OSIRIS-REx spacecraft carries a sophisticated suite of instruments to characterize Bennu&apos;s global properties, support the selection of a sampling site and document that site at a sub-centimetre scale(5-11). Here we consider early OSIRIS-REx observations of Bennu to understand how the asteroid&apos;s properties compare to pre-encounter expectations and to assess the prospects for sample return. The bulk composition of Bennu appears to be hydrated and volatile-rich, as expected. However, in contrast to pre-encounter modelling of Bennu&apos;s thermal inertia(12) and radar polarization ratios(13)-which indicated a generally smooth surface covered by centimetre-scale particles-resolved imaging reveals an unexpected surficial diversity. The albedo, texture, particle size and roughness are beyond the spacecraft design specifications. On the basis of our pre-encounter knowledge, we developed a sampling strategy to target 50-metre-diameter patches of loose regolith with grain sizes smaller than two centimetres(4). We observe only a small number of apparently hazard-free regions, of the order of 5 to 20 metres in extent, the sampling of which poses a substantial challenge to mission success.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Nature

ISSN

0028-0836

e-ISSN

—

Svazek periodika

568

Číslo periodika v rámci svazku

7750

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

6

Strana od-do

55-60

Kód UT WoS článku

000463384900038

EID výsledku v databázi Scopus

2-s2.0-85063187846