Searching for parent bodies of differentiated meteorites in the main-belt using visible and near-infrared spectroscopy
Authors: Galinier Marjorie , Delbo Marco , Galluccio Laurent , Marrocchi Yves 
Published: September 2022

&lt;p&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;Finding a link between meteorites and asteroids thanks to spectroscopy gives a great insight of the composition of &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;the bodies in the asteroid population. Meteorites such as the Howardite-Ensatites-Diogenites (HEDs) have been &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;successfully linked to the asteroid Vesta (McCord et al. (1970), summary by McSween Jr. et al. (2013)), and the&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt; ordinary chondrite meteorite population has been connected to a subtype of S-type asteroids, after having taken into &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;account space weathering processes (Binzel et al. 2001). These processes alter the surface of asteroids and modify&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt; their reflectance spectra with respect to that of the fresher meteorites, hence they need to be taken into account&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt; prior to comparing asteroids with meteorites spectra (Hapke 2001). Other meteorite types have been studied and &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;linked to asteroid types, but some objects still do not show convincing connections (DeMeo et al. 2022).&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt; Linking meteorites to the primordial population of objects would give information about the formation and &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;evolution of bodies in the Solar System. Indeed, the planetesimals that formed earliest in the Solar System are &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;thought to have been fully differentiated, due to the melting induced by the heating produced by the radioactive &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;decay of&lt;/span&gt; &lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;26&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;Al isotopes. This should have resulted in planetesimals presenting a basaltic crust, an olivine-dominated&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt; mantle and an iron-rich core (DeMeo et al. 2019). However most of these primitive objects have evolved, have &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;been disrupted or integrated to other bodies (such as planets) and their formation processes and the composition of &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;their primordial crusts is not well known.&lt;/span&gt;&lt;br role=&quot;presentation&quot; /&gt;&lt;br role=&quot;presentation&quot; /&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;We will report about searching for potential parents bodies of meteorites coming from differentiated planetesimals, &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;using literature data and the new dataset of reflectance spectra that will be released in the Gaia Data Release 3 &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;(DR3) in June 2022. This dataset will present low resolution mean reflectance spectrum of 60 518 Solar System &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;objects, acquired by Gaia&amp;#8217;s blue and red spectrophotometers (BP and RP) between August 2014 and May 2017. &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;Each spectrum will consist of 16 discrete wavelength bands that spans the visible wavelength range from 374 to &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;1034 nm (Gaia collaboration, Galluccio, Delbo et al. 2022). &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;These data should allow to look inside asteroid collisional families and search for hints of differentiation, &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;looking for members corresponding to the crust, mantle or core of a disrupted planetesimal. We intend to use these &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;data to try to link meteorites that are known to have been produced by differentiation (e.g. metallic or andesitic &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;bodies) to the primordial population of asteroids. Finding the parent body of differentiated meteorites would allow &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;to understand better the formation and differentiation of planetesimals in our Solar System.&lt;/span&gt;&lt;br role=&quot;presentation&quot; /&gt;&lt;br role=&quot;presentation&quot; /&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;To compare the reflectance spectra of meteorites with Gaia&amp;#8217;s asteroids, we will first use a curve matching method. &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;Curve matching consists in determining whether any given spectrum is similar to a reference spectrum, by the &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;means of a coefficient that has to be minimized (such as the&lt;/span&gt; &lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;&amp;#967;&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;2&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;) or maximized (correlation coefficient for example)&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt; (Popescu et al. 2012). We will as well study the features of the spectra in order to better characterize the asteroids &lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;and validate the matches (Gaffey 2011). Space weathering processes will be taken into account.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;Acknowledgements&lt;br role=&quot;presentation&quot; /&gt;The authors acknowledge the financial support of CNES and OCA, which make this study possible. M. Delbo thanks financial support from the ANR ORIGINS (ANR-18-CE31-13-0014).&lt;br /&gt;&lt;br /&gt;References&lt;br /&gt;Binzel, R. P., Rivkin, A. S., Bus, S. J., Sunshine, J. M., &amp; Burbine, T. H. 2001, Meteoritics &amp; Planetary Science, 36, 36&lt;br role=&quot;presentation&quot; /&gt;DeMeo, F. E., Burt, B. J., Marsset, M., et al. 2022, Icarus, 380, 114971&lt;br role=&quot;presentation&quot; /&gt;DeMeo, F. E., Polishook, D., Carry, B., et al. 2019, Icarus, 322, 13&lt;br role=&quot;presentation&quot; /&gt;Gaffey, M. J. 2011, AIP Conference Proceedings, 1386, 1386&lt;br /&gt;Gaia collaboration, Galluccio, Delbo et al. 2022 Gaia Data Release 3: Reflectance spectra of Solar System Small Bodies. A&amp;A under review.&lt;br /&gt;&lt;/span&gt;&lt;span dir=&quot;ltr&quot; role=&quot;presentation&quot;&gt;Hapke, B. 2001, J. Geophys. Res., 106, 10039&lt;br role=&quot;presentation&quot; /&gt;McCord, T. B., Adams, J. B., &amp; Johnson, T. V. 1970, Science, 168, 1445&lt;br role=&quot;presentation&quot; /&gt;McSween Jr., H. Y., Binzel, R. P., De Sanctis, M. C., et al. 2013, Meteoritics &amp; Planetary Science, 48, 48&lt;br role=&quot;presentation&quot; /&gt;Popescu, M., Birlan, M., &amp; Nedelcu, D. M. 2012, A&amp;A, 544, 544&lt;br /&gt;&lt;/span&gt;&lt;/p&gt;