Un mondo che assomiglia ad una pallina da golf
Un nuovo studio condotto da Pierre Vernazza (Laboratoire d'Astrophysique di Marsiglia, Francia), utilizzando le strutture dell'ESO, ha osservato per la prima volta l'asteroide Pallade con una risoluzione angolare estremamente elevata. Si è potuto osservare l'asteroide in modo così dettagliato grazie allo strumento SPHERE con ottica adattiva sul Very Large Telescope (VLT).
L'astronomo tedesco Heinrich Wilhelm Matthäus Olbers scoprì per la prima volta Pallade il 28 marzo 1802. Così chiamato in onore della dea greca Pallade Atena, l'asteroide - insieme a molti altri asteroidi scoperti nel 19o secolo - fu inizialmente classificato come pianeta. Con il passare del tempo e il miglioramento della tecnologia, Pallade fu in seguito riclassificato come asteroide. Oggi è famoso per essere il terzo asteroide più grande del sistema solare, con un diametro medio di 512 km.
Sebbene Pallade sia il più grande asteroide conosciuto nel sistema solare dopo Cerere e Vesta, è l'unico di questi grandi asteroidi che non è stato visitato da un veicolo spaziale. Ciò è dovuto alla sua orbita, che ha un'inclinazione insolitamente alta rispetto al piano dell'orbita terrestre, il che significa che è particolarmente difficile atterrarci con un veicolo spaziale.
Queste nuove immagini mostrano che la superficie di Pallade possiede caratteristiche topografiche molto interessanti che suggeriscono una violenta storia di collisioni. Numerosi grandi crateri si trovano in entrambi gli emisferi di Pallade, formando una superficie simile a una pallina da golf. I due grandi bacini di impatto distinti sulla sua superficie potrebbero anche essere legati ad un impatto che ha causato la frattura di un oggetto originale in diversi corpi separati. Il punto luminoso che appare nell'emisfero meridionale di Pallade (immagine a destra) ricorda anche molto i depositi di sale su Cerere.
Crediti:ESO/M. Marsset et al./MISTRAL algorithm (ONERA/CNRS)
Riguardo l'immagine
| Identificazione: | potw2008a |
| Lingua: | it-ch |
| Tipo: | Collage |
| Data di rilascio: | Lunedì 24 Febbraio 2020 06:00 |
| Grandezza: | 1540 x 768 px |
Riguardo all'oggetto
| Nome: | 2 Pallas |
| Tipo: | Solar System : Interplanetary Body : Asteroid |
Formati delle immagini
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