相关论文: Geological Mapping and Chronology of Lunar Landing…
All future lunar missions require a definition of the lunar reference system and a realization in the form of the lunar reference frame to ensure consistent products for positioning, navigation, cartography, and timing. This paper defines…
We present data from the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) covering the 15-year span from April 2006 through the end of 2020. APOLLO measures the earth-moon separation by recording the round-trip travel time of…
Lunar Laser Ranging (LLR) measurements are crucial for advanced exploration of the laws of fundamental gravitational physics and geophysics. Current LLR technology allows us to measure distances to the Moon with a precision approaching 1…
Pluto and its satellites will be the most distant objects ever reconnoitered when NASA's New Horizons spacecraft conducts its intensive flyby of this system in 2015. The size-frequency distribution (SFD) of craters on the surfaces in the…
Small scale jet-induced erosion experiments are useful for identifying the scaling of erosion with respect to the various physical parameters (gravity, grain size, gas velocity, gas density, grain density, etc.), and because they provide a…
This paper reviews improved calibration methods for the Lunar Reconnaissance Orbiter Lunar Exploration Neutron Detector. We cross calibrated the set of LEND observations and models of its detectors physical geometry and composition against…
Like many airless planetary surfaces, the surface of the Moon is scattered by populations of blocks and smaller boulders. These features decrease in abundance with increasing exposure time due to comminution by impact bombardment and…
The lifetime of free neutrons measured in the lab has a long standing disparity of $\sim$9~s. A space-based technique has recently been proposed to independently measure the neutron lifetime using interactions between the galactic cosmic…
In this paper we analyse different chronometers based on the models of chemical evolution developed in Chamcham, Pitts \& Tayler (1993; hereafter CPT) and Chamcham \& Tayler (1994; hereafter CT). In those papers we discussed the ability of…
Ever since the Apollo era, a question has remained as to the origin of the lunar swirls (high albedo regions coincident with the regions of surface magnetization). Different processes have been proposed for their origin. In this work we…
The analysis of the surface texture from the particle (grain size, shape and internal structure) to its organization (surface roughness) provides information on the geological processes. CRISM multi-angular observations (varied emission…
Recent lunar crater studies have revealed an asymmetric distribution of rayed craters on the lunar surface. The asymmetry is related to the synchronous rotation of the Moon: there is a higher density of rayed craters on the leading…
Context. Among options for definition of the lunar reference time, the option taking Lunar Coordinate Time (O1) has its simplicity but cannot be realized by any clock without steering, while another option adopting the lunar geoid…
The timing of the Moon's formation is fundamental to understanding the early Earth-Moon system. Ages of lunar magma ocean (LMO) crystallization have long been regarded as a key proxy for that event. Yet returned lunar sample ages cluster…
The automatic identification of planetary feature names in astronomy publications presents numerous challenges. These features include craters, defined as roughly circular depressions resulting from impact or volcanic activity; dorsas,…
The extinct p-process nuclide 146Sm serves as an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its alpha-decay daughter 142Nd. Based on analyses of 146Sm/147Sm alpha-activity and atom ratios, we…
The timescales of accretion, core formation, and magmatic differentiation in planetary bodies can be constrained using extinct radionuclide systems. Experiments have shown that Ni becomes more siderophile with decreasing pressure, which is…
Giant impacts by comets and asteroids have probably had an important influence on terrestrial biological evolution. We know of around 180 high velocity impact craters on the Earth with ages up to 2400Myr and diameters up to 300km. Some…
Crater count equilibrium occurs when new craters form at the same rate that old craters are erased, such that the total number of observable impacts remains constant. Despite substantial efforts to understand this process, there remain many…
The impact flux over the last 3 Ga in the inner Solar System is commonly assumed to be constant through time. However, asteroid break-up events in the main belt may have been responsible for cratering spikes over the last ~2 Ga on the…