Chasing Nomadic Worlds: A New Class of Deep Space Missions (original) (raw)

Nomadic Planets Near the Solar System

Gravitational microlensing has revealed an extensive population of “nomadic” planets not orbiting any star, with Jupiter-mass nomads being more populous than main sequence stars. Except for distant objects discovered through microlensing, and hot, young nomads found near star formation regions, to date only a small number of nomad candidates have been discovered. Here I show that there should be significant numbers of mature nomadic exoplanets close enough to be discovered with existing or planned astronomical resources, including possibly dozens of massive planets closer than the nearest star. Observational data are used to derive models relating mass, radius, heat flux and magnetic dipole moment; these are used to show the observability of nomads in the IR, due to thermal emissions, and at radio frequencies, due to cyclotron maser instabilities. These neighboring nomadic planets will provide a new exoplanet population for astronomical research and, eventually, direct exploration by spacecraft.

Dark Earths: Initial Goals for Interstellar Exploration

Recent research has revealed the existence of a large population of ``nomadic planets,'' planets not in orbit around any star, and these nomadic planets have been shown to be potentially capable of supporting biospheres. The density of Interstellar nomadic planets is large enough that some such planets should be considerably closer to the Sun than even the closest stars. If such close nomadic planets can be found, they would offer compelling destinations for initial interstellar missions.

Interstellar Planets

Comments Astrophys., 1990

The presence of unseen mass in the solar neighbourhood has prompted modelling of, and searches for, a population of cool, low mass stars to make up the deficit. Such brown dwarfs are thought to exist within a mass range of 0.01 M⊙ < M < 0.08 M⊙. In this paper the possibility of the existence of interstellar planets (ISPs) of mass range 5x10^-9 M⊙ < M < 0.01 M⊙ is examined. Six potential modes of formation of ISPs are identified, although some are mutually exclusive, depending of different cosmogonic hypotheses. ISPs are of two basic types: those formed solitary within molecular clouds and those formed within, and subsequently unbound from, planetary systems. While the existence of the former is uncertain, interstellar planets of the unbound variety almost definitely exist, although not in sufficient quantity to account for the unseen mass. The number density of unbound planets in the solar neighbourhood may be of a similar, or greater, order of magnitude to that of stars, the majority of them being massive planetesimals ejected from planetary systems in formation. The nearest extra-solar planet may thus be closer to the solar system than the nearest star.

On A Hypothetical Mechanism of Interstellar Life Transfer Trough Nomadic Objects

Origins of Life and Evolution of Biospheres

Lethal radiation, low vacuum pressure and low temperatures – this is how space welcomes organisms. Crossing of immense interstellar distances inflates the exposure time of biological material to harmful space conditions. This paper discusses the intriguing possibility of a life-bearing exoplanet being ejected from its planetary system and carrying life across interstellar distances (nomadic = free floating = rogue planet). The proposed interstellar panspermia mechanism reduces the exposure time to space conditions and provides multiple chances for interactions between microbes-bearing rock debris and exoplanets within system the nomadic object encountered on its way. The testing strategy is outlined and discussed in the paper, including testable predictions the proposed hypothesis makes.

The Astronomical, Astrobiological and Planetary Science Case for Interstellar Spaceflight

Jbis Journal of the British Interplanetary Society 62 415 421, 2009

A review is presented of the scientific benefits of rapid (v 0.1 c) interstellar spaceflight. Significant benefits are identified in the fields of interstellar medium studies, stellar astrophysics, planetary science and astrobiology. In the latter three areas the benefits would be considerably enhanced if the interstellar vehicle is able to decelerate from its interstellar cruise velocity to rest relative to the target system. Although this will greatly complicate the mission architecture, and extend the overall travel time, the scientific benefits are such that this option should be considered seriously in future studies.

Interstellar Probes: The Benefits to Astronomy & Astrophysics

arXiv: Popular Physics, 2019

Long range observations in the field of astronomy have opened up our understanding of the Solar System, the Galaxy and the wider Universe. In this paper we discuss the idea of direct in-situ reconnaissance of nearby stellar systems, using robotic probes. In particular, we consider what additional knowledge can be learned that can only be obtained by such close encounters. This may include calibration of existing measurements, detailed observations of stellar winds, astrometry measurements of stellar parallax, refinement of our understanding of physics through the use of long baseline interferometers. In addition, getting close to an exoplanet will enable detailed knowledge of planetary interiors, surface processes, geological evolution, atmospheric composition and climate, internal seismology, detailed surface morphology and even the speculative possibility of detecting the presence of microbial life, detailed palaeontology or even indigenous life-forms. We argue that astronomical r...

The hitchhiker’s guide to the outer solar system

2015

We propose a novel deep space propulsion method called the Comet Hitchhiker. The concept is to perform momentum exchange with small bodies (i.e., asteroid and comet) using an extendable/retrievable tether and a harpoon. Unlike previously proposed tethered fly-by, the use of extendable tether enables to change the relative speed with a target. Hence Hitchhiker would be a prospective means of providing orbit insertion deltaV, particularly for rendezvous missions to small bodies in the outer Solar System such as Kuiper belt objects and Centaurs, which are not easily manageable with chemical propulsion or solar electric propulsion. Furthermore, by applying regenerative brake during a hitchhike maneuver, a Hitchhiker can harvest energy. The stored energy can be used to make a departure from the target by quickly retrieving the tether, which we call a inverse hitchhike maneuver. By repeating hitchhike and inverse Hitchhike maneuvers, a Hitchhiker could perform a mission to rendezvous with...

Problems and Perspectives in Interstellar Exploration

JBIS, 1999

This paper is the continuation of an effort started by a previous paper [1], that included major aspects issued up to September 1998 relevant to the feasibility of the problem known as The Interstellar Flight (TIF) - as far as present human knowledge with reasonable extrapolation is concerned. The present work represents (1) a significant revision also including comments and questions from many distinguished investigators on different areas/fields of space flight & exploration, (2) a focus on new meaningful concepts that are reported and discussed.