相关论文: A Mixture of Ancient and Modern Understanding Conc…

On January 20th, 2019, a total lunar eclipse was possible to be observed in Santiago, Chile. Using a smartphone attached to a telescope, photographs of the phenomenon were taken. With Earth's shadow on those images, and using textbook…

The search of a rational explanation of eclipses pervades the beginnings of philosophical and scientific thought. Within this intellectual frame, the knowledge of the "saros cycle" (a cycle of 18 years, 10 or 11 days and 1/3 of a day that…

A time-dependent gravitational constant or mass would correctly describe the suspected increasing of both: the Astronomical unit and the eccentricity of the Lunar orbit around the Earth.

This work deals with the comparison of different parameters (French/IMCCE and US/JPL ephemerides) used to calculate the extension of the umbral shadow and the location of the centre line in the total solar eclipse that took place on March,…

Reports from the 2nd and 3rd Century AD attribute the first measurement of the angular size of the Sun to Thales of Miletus, in the 6th Century BC. Cleomedes, also in the 2nd Century AD, described a method to perform the measurement, based…

The variation of a planet's obliquity is influenced by the existence of satellites with a high mass ratio. For instance, the Earth's obliquity is stabilized by the Moon, and would undergo chaotic variations in the Moon's absence. In turn,…

A new technique has been devised for the analysis of extensive air shower data in observing the effect of the moon on this data. In this technique the number of EAS events with arrival directions falling in error circles centered about the…

Following a technique of Galileo we compute the height on a mountain on the Moon. It is based on a simple observation that precisely on a half Moon day, the Earth, the Moon, and the Sun form the vertices of a right triangle with the Moon at…

We have studied long period, 206 and 412 day, variations in tidal sea level corresponding to various moon phases collected from five observatories in the Northern and Southern hemispheres. Variations in sea level in the Bay of Fundy, on the…

The lifetime of a satellite is limited, and its calibration may be not stable, it is necessary to continue ground-based measures of the solar diameter with methods less affected by atmospheric turbulence, and optical aberrations: planetary…

We have proposed a model to obtain the length of the day and month at any geologic time. The day is found to increase by 0.002 sec/century since the seventeenth century. The lengthening of the day is attributed entirely to the increasing…

Although they are sometimes considered problematic to grasp by students, the concepts behind non-Euclidean geometry can be taught using astronomical images. By using photographs of the Moon taken with a smartphone through a simple…

Various theories have been proposed to explain the Moon's current inclined orbit. We test the viability of these theories by reconstructing the thermal-orbital history of the Moon. We build on past thermal-orbital models and incorporate the…

Why does the Sun have a radius around 696000~km? We will see in this article that dimensional arguments can be used to understand the size of the Sun and of a few other things along the way. These arguments are not new and can be found…

We obtained two astronomical values, the Earth-Venus distance and Venus diameter, by means of a geometrical treatment of photos taken of Venus transit in June of 2012. Here we presented the static and translational modelsthat were…

The applicability of the linear theory of elasticity to the Moon has been studied. As a criterion was taken the smallness of the strain tensor. The elastic moduli are obtained from the data of the project "Apollo". The pressure was…

Lunar Laser Ranging (LLR) measurements are crucial for advanced exploration of the evolutionary history of the lunar orbit, the laws of fundamental gravitational physics, selenophysics and geophysics as well as for future human missions to…

For a hypothetical planet on a highly eccentric orbit, we have calculated the osculating orbital parameters and its closest approaches to Earth and Moon over a period of 750 kyr. The approaches which are close enough to influence the…

The paper proposes an alternative to the Foucault pendulum for detecting various movements of rotation of the Earth. Calculations suggest that if the duration of a "free" fall becomes longer the eastward deflection will be amplified in…

The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of time scales. Most prominent is the 11-year solar cycle, which is significantly modulated on…