Thermal inertia of main belt asteroids smaller than 100km from IRAS data

Context. Thanks to the Gaia mission, it will be possible to determine the masses of approximately hundreds of large main belt asteroids with very good precision. We currently have diameter estimates for all of them that can be used to compute their volume and hence their density. However, some of those diameters are still based on simple thermal models, which can occasionally lead to volume uncertainties as high as 20–30%. Aims. The aim of this paper is to determine the 3D shape models and compute the volumes for 13 main belt asteroids that were selected from those targets for which Gaia will provide the mass with an accuracy of better than 10%. Methods. We used the genetic Shaping Asteroids with Genetic Evolution (SAGE) algorithm to fit disk-integrated, dense photometric lightcurves and obtain detailed asteroid shape models. These models were scaled by fitting them to available stellar occultation and/or thermal infrared observations. Results. We determine the spin and shape models for 13 main belt asteroids using the SAGE algorithm. Occultation fitting enables us to confirm main shape features and the spin state, while thermophysical modeling leads to more precise diameters as well as estimates of thermal inertia values. Conclusions. We calculated the volume of our sample of main-belt asteroids for which the Gaia satellite will provide precise mass determinations. From our volumes, it will then be possible to more accurately compute the bulk density, which is a fundamental physical property needed to understand the formation and evolution processes of small Solar System bodies.

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Thermal properties of large main-belt asteroids observed by Herschel PACS

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037718 ◽

2020 ◽

Vol 638 ◽

pp. A84

Author(s):

V. Alí-Lagoa ◽

T. G. Müller ◽

C. Kiss ◽

R. Szakáts ◽

G. Marton ◽

...

Keyword(s):

Adaptive Optics ◽

Thermal Inertia ◽

Physical Models ◽

Absolute Calibration ◽

Calibration Error ◽

Main Belt ◽

Infrared Observations ◽

Fine Grained ◽

Shape Models ◽

First Time

Non-resolved thermal infrared observations enable studies of thermal and physical properties of asteroids via thermo-physical models provided the shape and rotational properties of the target are well determined. We used calibration-programme Herschel PACS data (70, 100, 160 μm) and state-of-the-art shape models derived from adaptive-optics observations and/or optical light curves to constrain for the first time the thermal inertia of twelve large main-belt asteroids. We also modelled previously well-characterised targets such as (1) Ceres or (4) Vesta as they constitute important benchmarks. Using the scale as a free parameter, most targets required a re-scaling ~5% consistent with what would be expected given the absolute calibration error bars. This constitutes a good cross-validation of the scaled shape models, although some targets required larger re-scaling to reproduce the IR data. We obtained low thermal inertias typical of large main belt asteroids studied before, which continues to give support to the notion that these surfaces are covered by fine-grained insulating regolith. Although the wavelengths at which PACS observed are longwards of the emission peak for main-belt asteroids, they proved to be extremely valuable to constrain size and thermal inertia and not too sensitive to surface roughness. Finally, we also propose a graphical approach to help examine how different values of the exponent used for scaling the thermal inertia as a function of heliocentric distance (i.e. temperature) affect our interpretation of the results.

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Near-Earth objects as principal impactors of the Earth: Physical properties and sources of origin

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307003304 ◽

2006 ◽

Vol 2 (S236) ◽

pp. 251-260

Author(s):

Dimitrij F. Lupishko ◽

Mario Di Martino ◽

Richard P. Binzel

Keyword(s):

Physical Properties ◽

Binary Systems ◽

Raw Materials ◽

Thermal Inertia ◽

Point Of View ◽

Main Belt ◽

Asteroid Hazard ◽

Axis Rotation ◽

Near Earth Objects ◽

Cometary Origin

AbstractNear-Earth objects (NEOs) are objects of a special interest from the point of view not only of cosmogonic problems of the Solar system, but of the applied problems as well (the problem of asteroid hazard, NEOs as the potential sources of raw materials, etc.). They are much smaller in sizes than main-belt asteroids (MBAs), very irregular in shape and covered with a great number of craters of different sizes. Most of NEOs are covered by regolith of low thermal inertia and different thickness. Objects with complex non-principal axis rotation (tumbling bodies) and with super-fast rotational periods have been detected among them. The new data, based on photometric and radar observations, evidence that about 15-20 %; of NEOs could be binary systems. Most of the classified NEOs fragments of differentiated assemblages of S-and Q-types. Analysis of physical properties of NEOs clearly indicates that the asteroid main-belt is the principal source of their origin and only about 10 % of NEOs have a cometary origin.

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Size-dependent modification of asteroid family Yarkovsky V-shapes

Astronomy and Astrophysics ◽

10.1051/0004-6361/201732079 ◽

2018 ◽

Vol 611 ◽

pp. A82 ◽

Cited By ~ 5

Author(s):

B. T. Bolin ◽

A. Morbidelli ◽

K. J. Walsh

Keyword(s):

Size Dependence ◽

Drift Rate ◽

Thermal Inertia ◽

Major Axis ◽

Main Belt ◽

Semi Major Axis ◽

Size Dependent ◽

Dependent Modification ◽

The Relationship ◽

Asteroid Families

Context. The thermal properties of the surfaces of asteroids determine the magnitude of the drift rate cause by the Yarkovsky force. In the general case of Main Belt asteroids, the Yarkovsky force is indirectly proportional to the thermal inertia, Γ. Aims. Following the proposed relationship between Γ and asteroid diameter D, we find that asteroids’ Yarkovsky drift rates might have a more complex size dependence than previous thought, leading to a curved family V -shape boundary in semi-major axis, a, vs. 1/D space. This implies that asteroids are drifting faster at larger sizes than previously considered decreasing on average the known ages of asteroid families. Methods. The V-Shape curvature is determined for >25 families located throughout the Main Belt to quantify the Yarkovsky size-dependent drift rate. Results. We find that there is no correlation between family age and V -shape curvature. In addition, the V -shape curvature decreases for asteroid families with larger heliocentric distances suggesting that the relationship between Γ and D is weaker in the outer MB possibly due to homogenous surface roughness among family members.

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Brief summary of Kleť photographic search programme for minor planets

International Astronomical Union Colloquium ◽

10.1017/s0252921100031419 ◽

1999 ◽

Vol 173 ◽

pp. 189-192

Author(s):

J. Tichá ◽

M. Tichý ◽

Z. Moravec

Keyword(s):

Ccd Camera ◽

Minor Planet ◽

Minor Planets ◽

Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

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FEASIBILITY OF USING THERMAL INERTIA TO SHIFT THE PEAK ENERGY DEMAND OF BUILDINGS

10.1615/ihtc16.ecs.023992 ◽

2018 ◽

Author(s):

Xiaoqing Chen ◽

Hailong Li ◽

Xueqiang Li ◽

Yabo Wang ◽

Kai Zhu

Keyword(s):

Energy Demand ◽

Thermal Inertia ◽

Peak Energy

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Thematic maps in the scientific studies of the moon

Geodesy and Cartography ◽

10.22389/0016-7126-2019-943-1-68-75 ◽

2019 ◽

Vol 943 (1) ◽

pp. 68-75

Author(s):

S.G. Pugacheva ◽

E.A. Feoktistova ◽

V.V. Shevchenko

Keyword(s):

Natural Resources ◽

Thermal Inertia ◽

High Growth ◽

Lunar Soil ◽

Nature Management ◽

The Moon ◽

Surface Cooling ◽

Laser Altimeters ◽

Space Infrastructure ◽

The Impact

The article presents the results of astrophysical studies of the Moon’s reflected and intrinsic radiation. We studied the intensity of the Moon’s infrared radiation and, thus, carried out a detailed research of the brightness temperature of the Moon’s visible disc, estimated the thermal inertia of the coating substance by the rate of its surface cooling, and the degree of the lunar soil fragmentation. Polarimetric, colorimetric and spectrophotometric measurements of the reflected radiation intensity were carried out at different wavelengths. In the article, we present maps prepared based on our measurement results. We conducted theresearch of the unique South Pole – Aitken basin (SPA). The altitude profiles of the Apollo-11 and Zond-8 spacecrafts and the data of laser altimeters of the Apollo-16 and Apollo-15 spacecrafts were used as the main material. Basing upon this data we prepared a hypsometric map of SPA-basing global relief structure. A surface topography map of the Moon’s Southern Hemisphere is given in the article. The topography model of the SPA topography surface shows displacement centers of the altitude topographic rims from the central rim. Basing upon the detailed study of the basin’s topography as well as its “depth-diameter” ratio we suggest that the basin originated from the impact of a giant cometary body from the Orta Cloud. In our works, we consider the Moon as a part of the Earth’s space infrastructure. High growth rates of the Earth’s population, irrational nature management will cause deterioration of scarce natural resources in the near future. In our article, we present maps of the natural resources on the Moon pointing out the most promising regions of thorium, iron, and titanium. Probably in 20 or 40 years a critical mining level of gold, diamonds, zinc, platinum and other vital rocks and metals will be missing on the Earth.

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