Results 1 to 10 of about 60,993 (224)
IEEE Access, 2019 An adaptive control law is proposed in this paper for body-fixed hovering over an asteroid with an unknown gravity field and an unknown rotation rate. The unknown parameters and irregular shape of an asteroid make the hovering problem challenging.
Bo Zhang, Yuanli Cai
doaj +1 more source
Erosion Rate Measurements for DART Spacecraft Ion Propulsion System
Applied Sciences, 2022 The Double Asteroid Redirection Test (DART) spacecraft was developed to provide the first measurement for orbital deflection of an asteroid upon intentional impact. The NEXT ion engine is part of the mission, on its maiden voyage.
Mark W. Crofton +3 more
doaj +1 more source
Pyroxene and Hydroxyl Signatures in Vesta Newly Calibrated Data from Dawn Mission
Universe, 2023 Thanks to the VIR spectrometer onboard NASA’s Dawn spacecraft, which orbited Vesta in 2011–2012, thousands of hyperspectral images of its surface have been collected.
Giuseppe Massa +9 more
doaj +1 more source
A Post‐Launch Summary of the Science of NASA's Psyche Mission
AGU AdvancesAstronomical observations indicate that asteroid (16) Psyche is a large, high‐density (likely >3,400 kg·m−3), metal‐rich (30–55 vol. %) asteroid. Psyche may be remnant core material or it could be a primordial, undifferentiated metal‐rich object.
Steven D. Dibb +15 more
doaj +1 more source
Thermochemical equilibrium calculations of high-temperature O2 generation on the early Earth: Giant asteroid impact on land [PDF]
Journal of the Serbian Chemical Society, 2003 Earth’s atmosphere is composed primarily of N2 and O2. The origin of free O2 in the early Earth’s atmosphere is still subject of considerable debate.1 Theoretical models suggest that the initial form of free O2 in the atmosphere has been oceanic H2O ...
Premović Pavle I.
doaj +1 more source
Оптимальное управление движением космического аппарата в поле притяжения астероида Эрос 433
Вестник Самарского университета: Аэрокосмическая техника, технологии и машиностроение, 2019 Рассматривается алгоритм оптимизации управляемого движения космического аппарата с двигателями малой тяги в поле притяжения астероида Эрос 433. Гравитационное поле астероида имеет сложную конфигурацию.
А. Ю. Шорников
doaj +1 more source
Holocene impact craters on Earth
Miscellanea Geographica: Regional Studies on Development, 2023 Impact craters are formed by collisions of cosmic bodies moving with hypervelocity. The formation of these features is not restricted to the distant geological past; new structures are constantly being created and at least 13 confirmed impact craters and
Losiak Anna
doaj +1 more source
IEEE Journal of Selected Topics in Applied Earth Observations and Remote SensingIn China's Tianwen-2 mission, a dual-frequency radar will be carried out to detect the asteroid 2016 HO3. The dual-frequency radar can acquire the information of the asteroid's surface and internal structure. There are few studies about the
Niutao Liu, Ya-Qiu Jin, Feng Xu
doaj +1 more source
Post-Cataract Surgery Visual Disturbance in a Retinitis Pigmentosa Patient with Asteroid Hyalosis
Case Reports in Ophthalmology, 2011 A patient with retinitis pigmentosa showed visual disturbances following successful cataract surgery. He had a dense asteroid hyalosis in the eye before cataract surgery. After the surgery he noticed that his vision became worse.
Yoko Jingami +4 more
doaj +1 more source
Applied SciencesFor the convenience of comparison with previous literature, the gravity calculations are revisited for the Asteroid 4769 Castalia, but with extensions on its surface and on intersecting planes and spheres around it, using the polyhedron and harmonic ...
Weiduo Hu, Tao Fu, Chang Liu
doaj +1 more source