AVDELLIDOU , Chrysa

Near-Earth asteroids Ryugu and Bennu, were visited, characterised, and sampled by the Hayabusa2 and OSIRIS-REx missions: remote sensing data and sample return analysis showed that both asteroids have primitive, hydrated and organic-rich compositions. The dark families of the inner main belt (IMB) that belong to the spectroscopic C-complex have...

In this paper, we present masses of 103 asteroids deduced from their perturbations on the orbits of the inner planets, in particular Mars and the Earth. These determinations and the INPOP19a planetary ephemerides are improved by the recent Mars orbiter navigation data and the updated orbit of Jupiter based on the Juno mission data. More...

Aims. The near-Earth asteroid population suggests the existence of an inner main belt source of asteroids that belongs to the spectroscopic X complex and has moderate albedos. The identification of such a source has been lacking so far. We argue that the most probable source is one or more collisional asteroid families that have escaped...

The wavelength dependence and temporal evolution of the hypervelocity impact self-luminous plume (or "flash") from CO 2 ice, water ice, and frozen Martian and lunar regolith simulant targets have been investigated using the Kent two-stage light-gas gun. An array of 10 band-pass filtered photodiodes and a digital camera monitored changes in the...

ABSTRACT In the last 20 yr, over 600 impact flashes have been documented on the lunar surface. This wealth of data presents a unique opportunity to study the meteoroid flux of the Earth–Moon environment, and in recent years the physical properties of the impactors. However, other than through serendipitous events, there has not been yet a...

On-going space missions NASA's OSIRIS-REx and JAXA's Hayabusa2 are gathering more and more information on asteroid regolith. In order to better understand how regolith respond to processes occurring in space (particularly micro-meteoroid impacts and thermal cracking), we have developed asteroid analog materials. In the present paper we focus on...

The two on-going sample return space missions, Hayabusa2 and OSIRIS-REx are going to return to Earth asteroid regolith from the carbonaceous near-Earth asteroids Ryugu and Bennu. The two main processes that lead to regolith production are the micrometeorite bombardment and the thermal cracking. Here we report the production of a weak simulant...

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Two on-going sample return space missions, Hayabusa2 and OSIRIS-REx are orbiting and characterising two near-Earth asteroids, (162173) Ryugu and (101955) Bennu respectively. Initial ground-based observations and preliminary mission data indicate that the composition of these small objects is similar to the CM or CI meteorites [1-4]. However,...

The identification of meteorite parent bodies provides the context for understanding planetesimal formation and evolution as well as the key Solar System events they have witnessed. However, identifying such links has proven challenging and some appear ambiguous. Here, we identify that the family of asteroid fragments whose largest member is...

In this paper, we report the results of a campaign of measurements on four fragments of the CM Aguas Zarcas (AZ) meteorite, combining X-ray computed tomography analysis and Fourier-transform infrared (FT-IR) spectroscopy. We estimated a petrologic type for our sampled CM lithology using the two independent techniques, and obtained a type CM2.5,...

Rubble pile asteroids are widely understood to be composed of reaccumulated debris following a catastrophic collision between asteroids in the main asteroid belt, where each disruption can make a family of new asteroids. Near-Earth asteroids Ryugu and Bennu have been linked to collisional families in the main asteroid belt, but surface age...

On asteroids, fractures develop due to stresses driven by diurnal temperature variations at spatial scales ranging from sub-millimetres to metres. However, the timescales of such rock fracturing by thermal fatigue are poorly constrained by observations. Here we analyse images of the asteroid (101955) Bennu obtained by the Origins, Spectral...

Abstract The surfaces of airless bodies like asteroids in the solar system are known to be affected by space weathering. Experiments simulating space weathering are essential for studying the effects of this process on meteorite samples, but the problem is that the time spent to reproduce space weathering in these experiments is billions of...

We found mini-craters on Bennu's boulders. We measure their sizes. We then use scaling laws to derive the strength and collisional lifetimes of C-type objects.

When the OSIRIS-REx spacecraft pressed its sample collection mechanism into the surface of Bennu, it provided a direct test of the poorly understood near-subsurface physical properties of rubble-pile asteroids, which consist of rock fragments at rest in microgravity. Here, we find that the forces measured by the spacecraft are best modeled as a...

Context. Families of asteroids generated by the collisional fragmentation of a common parent body have been identified using clustering methods of asteroids in their proper orbital element space. However, there is growing evidence that some of the real families are larger than the corresponding cluster of objects in orbital elements, and there...

When rubble-pile asteroid 2008 TC3 impacted Earth on October 7, 2008, the recovered rockfragments indicated that such asteroids can contain exogenic material [1,2]. However,spacecraft missions to date have only observed exogenous contamination on large,monolithic asteroids that are impervious to collisional disruption [3, 4]. Here we report...