EU-ESA Workshop on Size Determination of Potentially Hazardous Near-Earth Objects

Session

Polarimetric observations

12 Nov 2024, 11:50

Rooms H.IV, H.V and H.VI (ESOC)

14. The Calern Asteroid Polarimetric Survey version 2.0

Philippe Bendjoya (Université de la côte d'Azur, Observatoire de la Côte d’Azur, CNRS UMR 7293, Laboratoire Lagrange, France)

12/11/2024, 11:50

Polarimetric observations of NEOs are important for a number of reasons:
• Determination of the geometric albedo and hence possible derivation of diameter
• Determination of some surface regolith properties
• For taxonomic classification purposes
• Because it is useful to identify special classes of objects having anomalous compositions
• Because it is useful to identify objects...

13. Study of near-Earth asteroids by polarimetric technique (REMOTE)

Irina Belskaya (Institute of Astronomy, V. N. Karazin Kharkiv National University, Sumska Str. 35, Kharkiv 61022, Ukraine)

12/11/2024, 16:50

Polarimetry is an effective tool for remote sensing of asteroid surfaces, mainly for assessing their albedo and surface texture, and searching for surface peculiarities. The main advantage of the polarimetric method of albedo determination is that albedo can be derived directly from polarimetric measurements using simple empirical relationships between polarimetric parameters and albedos....

28. Capability of the FoReRo2 instrument and the 2m RCC Telescope at the Bulgarian National Astronomical Observatory Rozhen for polarimetric observations of small solar system bodies

Galin Biserov Borisov (Institute of Astronomy and National Astronomical Observatory)

12/11/2024, 17:15

The Two-Channel-Focal-Reducer Rozhen (FoReRo2) was delivered to the Bulgarian National Astronomical Observatory (BNAO) Rozhen based on a contract between the Max-Planck Institute for Solar System Research and the Institute of Astronomy and National Astronomical Observatory (IA and NAO) in 2004. Since then, the FoReRo2 has been used at the f/8 Ritchey-Chrétien focus of the 2m...

26. Double Trouble: Polarimetric Insights into the Didymos- Dimorphos post-DART Evolution

Zuri Gray

13/11/2024, 09:00

On September 26, 2022, the NASA DART (Double Asteroid Redirection Test) spacecraft
struck Dimorphos, the moonlet of Didymos, to test near-Earth object deflection via impact for planetary defence [1]. As well as causing a change in Dimorphos’ orbital period [2], the impact caused a massive dust cloud to be ejected from the surface, e.g. [3,4]. By studying the characteristics and behaviour of...

25. Polarimetry as a tool for physical characterization of potentially hazardous NEOs

Maxime Devogele (ESA NEOCC)

13/11/2024, 09:25

The degree of linear polarization of sunlight scattered by an asteroid contains valuable information for rapid characterization of the surface properties of Near-Earth objects (NEOs). In the case of atmosphereless bodies the state of linear polarization varies as a function of the phase angle (α) and is described using the so-called Pr parameter.

The properties of the phase-polarization...

15. Cross validation of albedo determination for 1627 Ivar from three different techniques

Elena Selmi

13/11/2024, 09:50

Near Earth Objects, with their perihelia < 1.3 AU, represent both a potential hazard and a valuable asset for the foreseeable in-space resource utilization, and are hence of great interest to the scientific community. Their physical parameters, such as diameter, albedo and thermal inertia, can be constrained by a number of techniques, with different types of input requirements and levels of...

6. Rapid-Defender: A New Polarimeter for Planetary Defense

Estela Fernández-Valenzuela (Florida Space Institute, UCF)

13/11/2024, 10:35

Polarization observations are a key tool for swiftly determining the size of a NEO, and consequently, their potential threat to Earth. The degree of linear polarization is inversely proportional to the albedo of the scattering surface of an asteroid. This relation is better constrained at high phase angles at which NEOs are usually observed and where polarization is more significant. This...

21. Asteroid polarization at near-infrared wavelengths

Joseph Masiero (Caltech/IPAC)

13/11/2024, 11:00

The polarization of light reflected by asteroids can be used to constrain the albedo of the asteroid's surface, and probe mineralogical surface properties such as grain size and index of refraction. Depending on the specific mineral components of the body these surface properties are expected to change with wavelength, and so observations of the polarization beyond the visible provide...