Skip navigation
  • INAF logo
  • Home
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects
  • Explore by
    • Research outputs
    • Researchers
    • Organization units
    • Projects
  • Login:
    • My DSpace
    • Receive email
      updates
    • Edit Account details
  • Italian
  • English

  1. OA@INAF
  2. PRODOTTI RICERCA INAF
  3. 1 CONTRIBUTI IN RIVISTE (Journal articles)
  4. 1.01 Articoli in rivista
Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12386/26097
Title: Size-frequency distribution of boulders ≥10 m on comet 103P/Hartley 2
Authors: PAJOLA, MAURIZIO 
LUCCHETTI, ALICE 
BERTINI, IVANO
MARZARI, FRANCESCO
A'Hearn, Michael F.
La Forgia, Fiorangela
Lazzarin, Monica
Naletto, Giampiero
Barbieri, Cesare
Issue Date: 2016
Journal: ASTRONOMY & ASTROPHYSICS 
Number: 585
First Page: A85
Abstract: Aims: We derive the size-frequency distribution of boulders on comet 103P/Hartley 2, which are computed from the images taken by the Deep Impact/HRI-V imaging system. We indicate the possible physical processes that lead to these boulder size distributions. <BR /> Methods: We used images acquired by the High Resolution Imager-Visible CCD camera on 4 November 2010. Boulders ≥10 m were identified and manually extracted from the datasets with the software ArcGIS. We derived the global size-frequency distribution of the illuminated side of the comet (~50%) and identified the power-law indexes characterizing the two lobes of 103P. The three-pixel sampling detection, together with the shadowing of the surface, enables unequivocally detection of boulders scattered all over the illuminated surface. <BR /> Results: We identify 332 boulders ≥10 m on the imaged surface of the comet, with a global number density of nearly 140/km<SUP>2</SUP> and a cumulative size-frequency distribution represented by a power law with index of -2.7 ± 0.2. The two lobes of 103P show similar indexes, I.e., -2.7 ± 0.2 for the bigger lobe (called L1) and -2.6+ 0.2/-0.5 for the smaller lobe (called L2). The similar power-law indexes and similar maximum boulder sizes derived for the two lobes both point toward a similar fracturing/disintegration phenomena of the boulders as well as similar lifting processes that may occur in L1 and L2. The difference in the number of boulders per km<SUP>2</SUP> between L1 and L2 suggests that the more diffuse H<SUB>2</SUB>O sublimation on L1 produce twice the boulders per km<SUP>2</SUP> with respect to those produced on L2 (primary activity CO<SUB>2</SUB> driven). The 103P comet has a lower global power-law index (-2.7 vs. -3.6) with respect to 67P. The global differences between the two comets' activities, coupled with a completely different surface geomorphology, make 103P hardly comparable to 67P. A shape distribution analysis of boulders ≥30 m performed on 103P suggests that the cometary boulders show more elongated shapes when compared to collisional laboratory fragments as well as to the boulders present on the surfaces of 25 143 Itokawa and 433 Eros asteroids. Consequently, this supports the interpretation that cometary boulders have different origins with respect to the impact-related asteroidal boulders.
URI: http://hdl.handle.net/20.500.12386/26097
URL: https://www.aanda.org/articles/aa/abs/2016/01/aa26834-15/aa26834-15.html
ISSN: 0004-6361
DOI: 10.1051/0004-6361/201526834
Bibcode ADS: 2016A&A...585A..85P
Fulltext: open
Appears in Collections:1.01 Articoli in rivista

Files in This Item:
File Description SizeFormat 
Pajola_Boulders_103P_Final_23_Dec_2015.pdfPdf editoriale1.25 MBAdobe PDFView/Open
Show full item record

Page view(s)

15
checked on Jan 18, 2021

Download(s)

5
checked on Jan 18, 2021

Google ScholarTM

Check

Altmetric


Items in DSpace are published in Open Access, unless otherwise indicated.


Explore by
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects

Informazioni e guide per autori

https://openaccess-info.inaf.it: tutte le informazioni sull'accesso aperto in INAF

Come si inserisce un prodotto: le guide a OA@INAF

La Policy INAF sull'accesso aperto

Documenti e modelli scaricabili

Feedback
Built with DSpace-CRIS - Extension maintained and optimized by Logo 4SCIENCE