Celestial mechanics and polarization optics of the Kordylewski dust cloud in the Earth–Moon Lagrange point L5 – Part II. Imaging polarimetric observation: new evidence for the existence of Kordylewski dust cloud

Abstract

Telescopes mounted with polarizers can study the neutral points of the Earths atmosphere, the solar corona, the surface of planets/moons of the Solar System, distant stars, galaxies and nebulae. These examples demonstrate well that polarimetry is a useful technique to gather astronomical information from spatially extended phenomena. There are two enigmatic celestial objects that can also effectively be studied with imaging polarimetry, namely the Kordylewski dust clouds (KDCs) positioned around the L4 and L5 triangular Lagrangian libration points of the Earth-Moon system. Although in 1961 the Polish astronomer, Kazimierz Kordylewski had observed two bright patches near the L5 point with photography, many astronomers assume that these dust clouds do not exist, because the gravitational perturbation of the Sun, solar wind and other planets may disrupt the stabilizing effect of the L4 and L5 Lagrange points of the Earth and Moon. Using ground-born imaging polarimetry, we present here new observational evidence for the existence of the KDC around the L5 point of the Earth-Moon system. Excluding artefacts induced by the telescope, cirrus clouds or condensation trails of airplanes, the only explanation remains the polarized scattering of sunlight on the particles collected around the L5 point. By our polarimetric detection of the KDC we think it is appropriate to reconsider the pioneering photometric observation of Kordylewski. Our polarimetric evidence is supported by the results of simulation of dust cloud formation in the L5 point of the Earth-Moon system presented in the first part of this paper.

Ground- and Space-Based Observation of Kordylewski Clouds

“…In 1989, the clouds were again photographed by Winiarski [13]. On the other hand, many scholars are strongly skeptical about the existence of the KDCs (Roosen, Harrington & Jeffreys 1967; Bruman 1969; Valdes & Freitas 1983; Igenbergs et al 2012) [14]. According to these scholars, the KDCs cannot exist around the EML4 and EML5 points for long due to the gravitational perturbation from the Sun, solar wind, and other planets [14].…”

“…Although the KDCs cannot exist for a long time, they still have the chance of short-term survival. From June to October in 2017, Slíz-Balogh et al [14] made successful observations by using ground-based polarized light photography technology. Through a series of innovative methods, the important indirect evidence of dynamic stability of the KDCs is 3 Space: Science & Technology obtained [14].…”

“…From June to October in 2017, Slíz-Balogh et al [14] made successful observations by using ground-based polarized light photography technology. Through a series of innovative methods, the important indirect evidence of dynamic stability of the KDCs is 3 Space: Science & Technology obtained [14]. Table 1 shows the ground observation results in recent 70 years [15].…”

A Dedicated Lunar Trojan Asteroid Survey with Small Ground-Based Telescopes

“…These so called Kordylewski dust clouds are so faint that proving their existence has been rather difficult. Slíz-Balogh et al (2018) concluded -on the basis of polarimetric observations-that they do exist despite the Japanese Hiten space probe not finding an increase in the concentration of dust compared to the surrounding space when passing through the Earth-Moon L4 and L5 points (Igenbergs et al 1991).…”

Scaling-Based Two-Step Reconstruction in Full Polarization-Compressed Hyperspectral Imaging

“…Due to reflecting the rich spectral and spatial characteristics, hyperspectral imaging is widely used in agricultural detection [ 1 , 2 ], food production [ 3 , 4 ], biomedical identification [ 5 , 6 ] and other fields. Polarization imaging plays an indispensable role in environmental monitoring [ 7 , 8 ], astronomical observation [ 9 , 10 ], tumorigenesis detection [ 11 , 12 ] and other aspects. Meanwhile, polarization hyperspectral imaging naturally shows multiple applications in non-destructive quality evaluation [ 13 , 14 ].…”