Related papers: Does the Lunar Surface Still Offer Value As a Site…
Lunar Laser Ranging (LLR), which has been carried out for more than 35 years, is used to determine many parameters within the Earth-Moon system. This includes coordinates of terrestrial ranging stations and that of lunar retro-reflectors,…
This paper presents the first structured evaluation of Solar System bodies hypothetically relocated to Earth orbit (1 AU) to assess their potential as alternative habitats. Using comparative criteria, planetary size and gravity, atmospheric…
Radio telescopes observe extremely faint emission from astronomical objects, ranging from compact sources to large scale structures that can be seen across the whole sky. Satellites actively transmit at radio frequencies (particularly at…
The intense activity of cratering on the Moon and in the inner regions of the solar system was accomplished during the first 10^9 years [1]. Occasionally, some impact events occur even nowadays. In Section 1, we treat, from a historical…
This is a presentation of the purpose of astronomy in the context of modern society. After exposing two misconceptions about astronomy, I detail its role in five domains, certified knowledge, incorporated abilities, innovations, collective…
Adaptive Optics is a prime example of how progress in observational astronomy can be driven by technological developments. At many observatories it is now considered to be part of a standard instrumentation suite, enabling ground-based…
Three possible applications of lunar laser ranging to space geodesy are studied. First, the determination of daily Earth orientation parameters (UT0 and variation of latitude), which is rarely used nowadays in presence of all-year VLBI,…
In this paper, we present a physical modeling activity whose objective is to allow students to determine the differences between a disk and a sphere using pure scientific criteria. Thereunto, we reproduce the Sun-Earth-Moon system with…
The gravitational field of the sun will focus light from a distant source to a focal point at a minimal distance of 550 Astronomical Units from the sun. A proposed mission to this gravitational focus could use the sun as a very large lens,…
Laser pulses fired at retroreflectors on the Moon provide very accurate ranges. Analysis yields information on Earth, Moon, and orbit. The highly accurate retroreflector positions have uncertainties less than a meter. Tides on the Moon show…
The moon illusion, in which the moon appears larger at the horizon than at higher altitudes, has been investigated since antiquity, yet it remains not fully explained. Our method of investigating the phenomenon is based on that attributed…
The Hubble Space Telescope has produced astonishing science over the past thirty years. Hubble's productivity can continue to soar for years to come provided some worn out components get upgraded. While powerful new ground-based and space…
After decades of relative neglect, interest in Venus surges anew in the planetary science community and the public. New missions are planned and selected, and will pave the way to the decade of Venus, as new observations allow us to uncover…
Mars provides a critical analog to once habitable exoplanets that have since lost their surface liquid water. The current atmospheric state of Mars retains the chemical fingerprints of that transition, including isotopic signatures of…
The Antarctic plateau contains the best sites on earth for many forms of astronomy, but none of the existing bases was selected with astronomy as the primary motivation. In this article, we try to systematically compare the merits of…
The "Airships: A New Horizon for Science" study at the Keck Institute for Space Studies investigated the potential of a variety of airships currently operable or under development to serve as observatories and science instrumentation…
Humanity has the knowledge to solve its problems but lacks the moral insight to implement these ideas on a global scale. New moral insight can be obtained through transformative experiences that allow us to examine and refine our underlying…
Spectroscopy is one of the most important tools that an astronomer has for studying the universe. This chapter begins by discussing the basics, including the different types of optical spectrographs, with extension to the ultraviolet and…
Surface chemistry of airless bodies in the solar system can be derived from remote x-ray spectral measurements from an orbiting spacecraft. X- rays from planetary surfaces are excited primarily by solar x-rays. Several experiments in the…
Terrestrial exoplanets are on the verge of joining the ranks of astronomically accessible objects. Interpreting their observable characteristics, and informing decisions on instrument design and use, will hinge on the ability to model these…