Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 128 for “"asteroids"”.
-
Surface properties of asteroids.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1972.
-
Detecting surface inhomogeneity of asteroids
… of surface composition inhomogeneity on asteroids using time-series spectroscopy and photometry. Observations were conducted on three test cases—Pluto, asteroid 2005 EK70, and the weather satellite Meteosat-11 using the Mookodi instrument on the Lesedi telescope. For Pluto, time-resolved …
-
Solar-wind heating of asteroids.
Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.
-
Adaptive-Optimal Control of Spacecraft near Asteroids
<p>Spacecraft dynamics and control in the vicinity of an asteroid is a challenging and exciting problem. Currently, trajectory tracking near asteroid requires extensive knowledge about the asteroid and constant human intervention to successfully plan and execute proximity operation. This work aims …
-
Spin-axis alignment of Koronis family asteroids
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1995.
-
Characterisation of small, close-approaching near-earth asteroids
Near-Earth Asteroids (NEAs) are a population of asteroids in a steady state, constantly being replenished with asteroids from the main belt. NEAs have orbits that come close to or cross the Earth's orbit and therefore some could have impacting trajectories and pose a threat. Small NEAs (diameter < …
-
Effects of space weathering on the Trojan asteroids
Trojan asteroids orbit at Jupiter's L4 and L5 points. They are included in the D-class of asteroids because of their steep spectral slope. According to spectra of other asteroid classes, the larger the diameter is of a D-class asteroid, the redder the asteroid should be in the visible spectrum. We …
-
Observation and Modelling of Meter-Class Earth impacting Asteroids
Earth is constantly bombarded by solar system objects of a wide variety of sizes, from micron-sized meteoroid stream and sporadic meteor dust, to meter-sized and larger meteoroids observed as fireballs. Fireball event characteristics directly point to the properties and structure of the parent body …
-
A near-ultraviolet spectroscopic survey of B-type asteroids
… presence of spectral slope variations of B-type asteroids in the near-ultraviolet wavelength range and further compare variations to those found in the near-infrared (de Leon et al., 2012) and infrared (All-Lagoa et al., 2013). New observations of 19 B-type asteroids were obtained using the …
-
DeMeo taxonomy : categorization of asteroids in the near-infrared
… become available in the near-infrared for asteroids down to relatively faint (V= 17) limiting magnitudes. (Rayner et al. 2003) With a larger data range, which includes important absorption features at one and two microns suggesting the presence of minerals, there is a need for an extended …
-
CCD photometry and spectroscopy and small main-belt asteroids
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1994.
-
Lagrangian Points and Jacobi Constants for a Class of Asteroids
<p>Asteroid Gravitational Potentials are difficult to model owing to their irregularity in shape. This thesis focuses on two approaches to model asteroid gravity fields, namely, multiple-body and spherical harmonics modeling. Computation of gravity potential serves as a first step to determine …
-
Spectral Study of Asteroids and Laboratory Simulation of Asteroid Organics
We investigate the spectra of asteroids at near- and mid-infrared wavelengths. In 2010 and 2011 we reported the detection of 3 ?m and 3.2-3.6 ?m signatures on (24) Themis and (65) Cybele indicative of water-ice and complex organics [1] [2] [3]. We further probed other primitive asteroids in the …
-
Relating size and spectral reflectance properties of S-type asteroids
The spectral slopes of 701 S-type asteroids have been statistically shown to depend on asteroid size. The spectral reflectance data were taken during the second phase of the Small Main-belt Asteroid Spectroscopic Survey. It was concluded that larger S-type asteroids have a higher spectral slope …
-
On stress, strength, and failure in asteroids during planetary entry
Efforts to characterize the danger posed by asteroids have motivated an effort to model their entry and breakup in Earth’s atmosphere. These models, crucial to planetary defense efforts, necessitate an understanding of the physics underlying fragmentation — including knowledge of key governing …
-
Adaptive Control Combined with Integral Concurrent Learning for Trajectory Tracking Near Asteroids
… operations in the vicinity of Near-Earth Asteroids (NEAs) are essential for scientific studies and possible future planetary-defense missions. Unlike motion around large celestial bodies, spacecraft dynamics near small, rotating asteroids are dominated by weak, highly irregular gravity …
-
Design and modeling of kinetic impact missions for deflecting near-earth asteroids
The solar system is full of small bodies such as asteroids and comets that are thought to be remnants of early planetary formation. As of June 2025, there are more than 1.4 million known small bodies in the solar system, more than 4,000 of which are classified as comets. These objects routinely …
-
Killer asteroids : feasibility of using the IRTF to track near-earth objects
The possibility of an asteroid or comet impact necessitates the tracking and cataloging of all such objects which could potentially impact Earth. Currently, no comprehensive catalog of Near Earth Objects (NEOs) exists which contains information on the physical properties of the objects. …
Page 1 of 7