Ensuring a Sustainable World
We are on the cusp of a 21st century Age of Discovery - about the Earth, about the solar system, about ourselves and our place in the cosmos - with new opportunities to address age-old challenges, as well as to meet emerging ones. While advancing into space is not the answer to these challenges, it can be a significant and vital part of an answer, providing benefits that other answers cannot.
With a thoughtful program of space activities we can ensure a sustainable world with abundant energy and resources, a high standard of living, and unprecedented opportunity for all. However, to become a widely held vision that we must pursue now, rather than just interesting ideas for some distant time, we need to see space as integral to addressing societal issues. This book shows a way to do that.
There are abundant opportunities in space, but the only way to utilize them is to go there. As our ancestors crossed thresholds to inhabit the Earth, we can cross the threshold to become a space-faring civilization, and realize the benefits of those efforts. Space is only 100 km (62 miles) away, you just need to look up.
What people are saying:
"Crossing the Threshold is a carefully considered, insightful narrative that should interest anyone and everyone who cares about the future of spaceflight." - Homer Hickam, author of Rocket Boys/October Sky
"Crossing the Threshold is a NASA veteran's thoughtful and considered look at the value of space travel and exploration, not only for satisfying humanity's seemingly unquenchable thirst for adventure and knowledge but also for preparing and positioning us technically to begin to solve some of the greatest problems facing us on Earth." - Henry Petroski, Aleksandar S. Vesic Professor of Civil Engineering and Professor of History, Duke University, author of The Essential Engineer: Why Science Alone Will Not Solve Our Global Problems
Crossing the Threshold "is very impressive for the range of ideas and technical specifics." - Felix Godwin, author of The Exploration of the Solar System.

This book addresses a variety of topics within the growing discipline of Archaeoastronomy, focusing especially on Archaeoastronomy in Sicily and the Mediterranean and Cultural Astronomy. A further priority is discussion of the astronomical and statistical methods used today to ascertain the degree of reliability of the chronological and cultural definition of sites and artifacts of archaeoastronomical interest. The contributions were all delivered at the XVth Congress of the Italian Society of Archaeoastronomy (SIA), held under the rubric "The Light, the Stones and the Sacred" - a theme inspired by the International Year of Light 2015, organized by UNESCO. The full meaning of many ancient monuments can only be understood by examining their relation to light, given the effects that light radiation produces in "interacting" with lithic structures. Moreover, in addition to manifestations of the sacred through the medium of light (hierophanies), there are many ties between temples, tombs, megalithic structures, and the architecture of almost all ages and cultures and our star, the Sun. Readers will find the book to be a source of fascinating insights based on synergies between the disciplines of archaeology and astronomy.

A Survey of the Status of the Determination of the General Perturbations of the Minor Planets (Asteroids).

How is it possible to imagine what is unknown and therefore unimaginable? How can the unimaginable be represented? On what materials do such representations rely? These questions lie at the heart of this book. Copernican theory redefined the role and importance of the imagination even as it implied the moment of its crisis. Based on this claim, Ladina Bezzola Lambert analyzes seventeenth-century astronomical texts - particularly descriptions of the moon and treatises written in support of the theory of the plurality of worlds - to show how early modern astronomers questioned the role of the imagination as a tool to visualize the unknown, but also how, pressed by the need to support their theories with convincing descriptions of other potential worlds, they sought to overcome the limitations of the imagination with a sophisticated rhetoric and techniques more commonly associated with poetic writing. The limitations of the imagination are at once a problem that all of the texts discussed struggle with and their recurrent theme. In the first and last chapter, the focus shifts to a more explicitly literary context: Ariosto's Orlando furioso and the work of Italo Calvino. The change of focus from science to literature and from the narratives of the past to contemporary ones serves to emphasize that the issues relating to the imagination, its limitations and creative means, are basically the same both in science and literature and that they are still relevant today.

This book on space geodesy presents pioneering geometrical approaches in the modelling of satellite orbits and gravity field of the Earth, based on the gravity field missions CHAMP, GRACE and GOCE in the LEO orbit. Geometrical approach is also extended to precise positioning in space using multi-GNSS constellations and space geodesy techniques in the realization of the terrestrial and celestial reference frame of the Earth. This book addresses major new developments that were taking place in space geodesy in the last decade, namely the availability of GPS receivers onboard LEO satellites, the multitude of the new GNSS satellite navigation systems, the huge improvement in the accuracy of satellite clocks and the revolution in the determination of the Earth's gravity field with dedicated satellite missions.

Robert Grosseteste (1168/75-1253), Bishop of Lincoln from 1235-1253, is widely recognized as one of the key intellectual figures of medieval England and as a trailblazer in the history of scientific methodology. Few of his numerous philosophical and scientific writings circulated as widely as the Compotus, a treatise on time reckoning and calendrical astronomy apparently written during a period of study in Paris in the 1220s. Besides its strong and long-lasting influence on later writers, Grossteste's Compotus is particularly noteworthy for its innovatory approach to the theory and practice of the ecclesiastical calendar-a subject of essential importance to the life of the Latin Church. Confronting traditional computistical doctrines with the lessons learned from Graeco-Arabic astronomy, Grosseteste offered his readers a critical and reform-oriented take on the discipline, in which he proposed a specific version of the Islamic lunar as a substitute for the failing nineteen-year cycle the Church still employed to calculate the date of Easter. This new critical edition of Grosseteste's Compotus contains the Latin text with an en-face English translation. It is flanked by an extensive introduction and chapter commentary, which will provide valuable new insights into the text's purpose and disciplinary background, its date and biographical context, its sources, as well as its reception in later centuries.

A contemporary of Galileo and a forerunner of Isaac Newton, Johannes Kepler (1571-1630) was a pioneering German scientist and a pivotal figure in the history of astronomy. This colorful, well-researched biography brings the man and his scientific discoveries to life, showing how his contributions were every bit as important as those of Copernicus, Galileo, and Newton. It was Kepler who first advocated the completely new concept of a physical force emanating from the sun that controls the motion of the planets--today we call this gravity and take it for granted. He also established that the orbits of the planets were elliptical in shape and not circular. And his three laws of planetary motion are still used by contemporary astronomers and space scientists. The author focuses not just on these and other momentous breakthroughs but also on Kepler's arduous life, punctuated by frequent tragedy and hardships. His first wife died young, and eight of the twelve children he fathered succumbed to disease in infancy or childhood. He was frequently caught up in the religious persecutions of the day. His mother narrowly escaped death when she was accused of being a witch. Intermingling historical and personal details of Kepler's life with lucid explanations of his scientific research, this book presents a sympathetic portrait of the man and underscores the critical importance of Kepler's discoveries in the history of astronomy.

Pulsar timing is a promising method for detecting gravitational waves in the nano-Hertz band. In his prize winning Ph.D. thesis Rutger van Haasteren deals with how one takes thousands of seemingly random timing residuals which are measured by pulsar observers, and extracts information about the presence and character of the gravitational waves in the nano-Hertz band that are washing over our Galaxy. The author presents a sophisticated mathematical algorithm that deals with this issue. His algorithm is probably the most well-developed of those that are currently in use in the Pulsar Timing Array community. In chapter 3, the gravitational-wave memory effect is described. This is one of the first descriptions of this interesting effect in relation with pulsar timing, which may become observable in future Pulsar Timing Array projects. The last part of the work is dedicated to an effort to combine the European pulsar timing data sets in order to search for gravitational waves. This study has placed the most stringent limit to date on the intensity of gravitational waves that are produced by pairs of supermassive black holes dancing around each other in distant galaxies, as well as those that may be produced by vibrating cosmic strings. Rutger van Haasteren has won the 2011 GWIC Thesis Prize of the Gravitational Wave International Community for his innovative work in various directions of the search for gravitational waves by pulsar timing. The work is presented in this Ph.D. thesis.

This book offers review chapters written by invited speakers of the 3rd Session of the Sant Cugat Forum on Astrophysics - Gravitational Waves Astrophysics. All chapters have been peer reviewed. The book goes beyond normal conference proceedings in that it provides a wide panorama of the astrophysics of gravitational waves and serves as a reference work for researchers in the field.

In this thesis, ultimate sensitive measurement for weak force imposed on a suspended mirror is performed with the help of a laser and an optical cavity for the development of gravitational-wave detectors. According to the Heisenberg uncertainty principle, such measurements are subject to a fundamental noise called quantum noise, which arises from the quantum nature of a probe (light) and a measured object (mirror). One of the sources of quantum noise is the quantum back-action, which arises from the vacuum fluctuation of the light. It sways the mirror via the momentum transferred to the mirror upon its reflection for the measurement. The author discusses a fundamental trade-off between sensitivity and stability in the macroscopic system, and suggests using a triangular cavity that can avoid this trade-off. The development of an optical triangular cavity is described and its characterization of the optomechanical effect in the triangular cavity is demonstrated. As a result, for the first time in the world the quantum back-action imposed on the 5-mg suspended mirror is significantly evaluated. This work contributes to overcoming the standard quantum limit in the future.

This thesis describes the essential features of Moon-plasma interactions with a particular emphasis on the Earth's magnetotail plasma regime from both observational and theoretical standpoints. The Moon lacks a dense atmosphere as well as a strong intrinsic magnetic field. As a result, its interactions with the ambient plasma are drastically different from solar-wind interactions with magnetized planets such as Earth. The Moon encounters a wide range of plasma regime from the relatively dense, cold, supersonic solar-wind plasma to the low-density, hot, subsonic plasma in the geomagnetic tail. In this book, the author presents a series of new observations from recent lunar missions (i.e., Kaguya, ARTEMIS, and Chandrayaan-1), demonstrating the importance of the electron gyro-scale dynamics, plasma of lunar origin, and hot plasma interactions with lunar magnetic anomalies. The similarity and difference between the Moon-plasma interactions in the geomagnetic tail and those in the solar wind are discussed throughout the thesis. The basic knowledge presented in this book can be applied to plasma interactions with airless bodies throughout the solar system and beyond.

This thesis develops new and powerful methods for identifying planetary signals in the presence of "noise" generated by stellar activity, and explores the physical origin of stellar intrinsic variability, using unique observations of the Sun seen as a star. In particular, it establishes that the intrinsic stellar radial-velocity variations mainly arise from suppression of photospheric convection by magnetic fields. With the advent of powerful telescopes and instruments we are now on the verge of discovering real Earth twins in orbit around other stars. The intrinsic variability of the host stars themselves, however, currently remains the main obstacle to determining the masses of such small planets. The methods developed here combine Gaussian-process regression for modeling the correlated signals arising from evolving active regions on a rotating star, and Bayesian model selection methods for distinguishing genuine planetary signals from false positives produced by stellar magnetic activity. The findings of this thesis represent a significant step towards determining the masses of potentially habitable planets orbiting Sun-like stars.