scholarly journals Evaluating the Microbial Habitability of Rogue Planets and Proposing Speculative Scenarios on How They Might Act as Vectors for Panspermia

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 833
Author(s):  
Dirk Schulze-Makuch ◽  
Alberto G. Fairén
Keyword(s):  
Direct Evidence ◽  
Planetary Systems ◽  
Brown Dwarfs ◽  
Energy Sources ◽  
The Poor ◽  
The Galaxy ◽  
Unicellular Organisms ◽  
Host Life

There are two types of rogue planets, sub-brown dwarfs and “rocky” rogue planets. Sub-brown dwarfs are unlikely to be habitable or even host life, but rocky rogue planets may have a liquid ocean under a thick atmosphere or an ice layer. If they are overlain by an insulating ice layer, they are also referred to as Steppenwolf planets. However, given the poor detectability of rocky rogue planets, there is still no direct evidence of the presence of water or ice on them. Here we discuss the possibility that these types of rogue planets could harbor unicellular organisms, conceivably based on a variety of different energy sources, including chemical, osmotic, thermal, and luminous energy. Further, given the theoretically predicted high number of rogue planets in the galaxy, we speculate that rogue planets could serve as a source for galactic panspermia, transferring life to other planetary systems.

The Long View of Planetary Systems

2018 ◽  
Author(s):  
Karel Schrijver
Keyword(s):  
Solar System ◽  
Milky Way ◽  
Planetary Systems ◽  
Giant Planets ◽  
Milky Way Galaxy ◽  
Population Statistics ◽  
The Past ◽  
General Terms ◽  
The Galaxy ◽  
The Universe

How many planetary systems formed before our’s did, and how many will form after? How old is the average exoplanet in the Galaxy? When did the earliest planets start forming? How different are the ages of terrestrial and giant planets? And, ultimately, what will the fate be of our Solar System, of the Milky Way Galaxy, and of the Universe around us? We cannot know the fate of individual exoplanets with great certainty, but based on population statistics this chapter sketches the past, present, and future of exoworlds and of our Earth in general terms.

Epilogue: Paradigms, Problems, and Predictions

2017 ◽  
Author(s):  
John Chambers ◽  
Jacqueline Mitton
Keyword(s):  
Solar System ◽  
Planetary Systems ◽  
Planetary Science ◽  
Good Time ◽  
Science Program ◽  
The Galaxy ◽  
Recent Developments ◽  
Powerful Stimulus ◽  
Rapid Pace ◽  
Over Time

This concluding chapter talks about how astronomers and space agencies in dozens of countries are helping to see the solar system as never before, transforming points of light into real worlds, and even bringing samples of those worlds back to Earth. At the same time, the stunning discovery of hundreds of other planetary systems in the galaxy has provided a powerful stimulus to understand how planetary systems form and evolve, and to find out what makes one system different from another. Moreover, in 2010, NASA announced its latest science plan. One of the key goals for NASA's future planetary science program is to learn how the Sun's family began and how it has changed over time. The chapter argues that the rapid pace of recent developments makes now a good time to take stock of what scholars know, even though the story is still incomplete.

scholarly journals Turning solar systems into extrasolar planetary systems in stellar clusters

2010 ◽  
Vol 6 (S276) ◽  
pp. 304-307
Author(s):  
Melvyn B. Davies
Keyword(s):  
Solar System ◽  
Planetary System ◽  
Large Fraction ◽  
Planetary Systems ◽  
Single Star ◽  
Solar Systems ◽  
Close Encounters ◽  
Eccentric Orbits ◽  
The Galaxy ◽  
Hostile Environments

AbstractMany stars are formed in some form of cluster or association. These environments can have a much higher number density of stars than the field of the galaxy. Such crowded places are hostile environments: a large fraction of initially single stars will undergo close encounters with other stars or exchange into binaries. We describe how such close encounters and exchange encounters will affect the properties of a planetary system around a single star. We define singletons as single stars which have never suffered close encounters with other stars or spent time within a binary system. It may be that planetary systems similar to our own solar system can only survive around singletons. Close encounters or the presence of a stellar companion will perturb the planetary system, leading to strong planet-planet interactions, often leaving planets on tighter and more eccentric orbits. Thus, planetary systems which initially resembled our own solar system may later more closely resemble the observed extrasolar planetary systems.

scholarly journals Evidence for jet driven outflows: the case of 3C293

2014 ◽  
Vol 10 (S313) ◽  
pp. 289-293
Author(s):  
E. K. Mahony ◽  
J. B. R. Oonk ◽  
R. Morganti ◽  
T. A. Oosterloo ◽  
B. H. C. Emonts ◽  
...  
Keyword(s):  
Black Hole ◽  
Galaxy Evolution ◽  
Direct Evidence ◽  
Host Galaxy ◽  
Central Black Hole ◽  
Radio Jets ◽  
Neutral Gas ◽  
The Galaxy ◽  
Mass Outflow ◽  
Gas Quenching

AbstractThe tight correlations observed between galaxies and their SMBH provides compelling evidence that the evolution of the galaxy and its central black hole are strongly linked. This is generally attributed to feedback mechanisms which, according to simulations, often take the form of outflows of gas, quenching star formation in the host galaxy and halting accretion onto the central black hole. While there are a number of plausible ways that outflows could be produced, recent results have shown that in some cases radio jets could be responsible for driving fast outflows of gas. One such example is seen in the nearby radio galaxy 3C293. In this talk I will present results from JVLA radio observations where we detect fast outflows (~1200 km/s) of neutral gas which are being driven by the radio-jet approximately 0.5 kpc from the central core, providing direct evidence for jet-ISM interaction. This is accompanied with recent IFU observations showing that ionised gas outflows are also being driven by the radio jet. Pinpointing the location of these outflows enables us to derive crucial parameters, such as the mass outflow rates and kinetic energy involved, which we can compare to predictions from galaxy evolution simulations.

Drought throws spotlight on Chile’s water stewardship

2020 ◽  
Keyword(s):  
Climate Change ◽  
Drinking Water ◽  
Water Scarcity ◽  
Energy Sources ◽  
Energy Matrix ◽  
Content Type ◽  
The North ◽  
The Poor ◽  
Precious Resource ◽  
Desalination Plants

Significance The poor, and small farmers, are the worst hit. Conflicts over the precious resource are impacting the mining and agricultural sectors. Agriculture represents 72% of water use, followed by drinking water (12%), industry (7%) and mining (4%). Consumption is expected to grow by 4.5% by 2030. Impacts Hydropower represents about 30% of Chile’s energy matrix, but backup from other energy sources should avoid outages. A further 20 desalination plants are in the pipeline, mainly implemented by the mining sector to resolve water scarcity in the north. A bill creating an institutional framework on climate change, sent to Congress in January, is in its first legislative stage in the Senate.

scholarly journals CHARACTERIZING THE COOL KOIs. IV. KEPLER-32 AS A PROTOTYPE FOR THE FORMATION OF COMPACT PLANETARY SYSTEMS THROUGHOUT THE GALAXY

2013 ◽  
Vol 764 (1) ◽  
pp. 105 ◽  
Author(s):  
Jonathan J. Swift ◽  
John Asher Johnson ◽  
Timothy D. Morton ◽  
Justin R. Crepp ◽  
Benjamin T. Montet ◽  
...  
Keyword(s):  
Planetary Systems ◽  
The Galaxy

scholarly journals Longslit Optical Spectroscopy of Powerful Far-Infrared Galaxies

1989 ◽  
Vol 134 ◽  
pp. 414-415
Author(s):  
Lee Armus ◽  
Timothy M. Heckman ◽  
George K. Miley
Keyword(s):  
Direct Evidence ◽  
Thermal Emission ◽  
Large Range ◽  
Far Infrared ◽  
Spectral Energy ◽  
Infrared Galaxies ◽  
Energy Distributions ◽  
Hii Region ◽  
The Galaxy ◽  
Infrared Spectral

It has been known since the IRAS mission that there exist galaxies with far-infrared luminosities of 1011–1012Lo, and LFTR/LB = 10–100. Through extensive modelling and observations of HII-region/molecular cloud complexes in the Galaxy, this infrared radiation is believed to be thermal emission from heated dust grains (c.f. review by Stein and Soifer 1983). While starburst models are consistent with the data over a large range in wavelength, direct evidence for sizeable populations of young stars is scarce, and in many cases the presence of an active nucleus either cannot be ruled out, or is required on the basis of energy considerations. In order to better understand the energy source responsible for heating the dust, we have undertaken a spectroscopic survey of galaxies chosen to have far-infrared spectral energy distributions similar to the prototypical class members Arp 220, NGC 6240, NGC 3690, and Mrk 231. It was required that between 25μ and 60μ, α ≤ −1.5, and that between 60μ and 100μ, α ≥ −0.5, where Sv α vα.

scholarly journals Star formation at the Galactic Centre: coevolution of multiple young stellar discs

2019 ◽  
Vol 490 (4) ◽  
pp. 5820-5831 ◽  
Author(s):  
Alessandra Mastrobuono-Battisti ◽  
Hagai B Perets ◽  
Alessia Gualandris ◽  
Nadine Neumayer ◽  
Anna C Sippel
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Direct Evidence ◽  
Galactic Nuclei ◽  
Galactic Centre ◽  
Stellar Clusters ◽  
Stellar Disc ◽  
The Galaxy ◽  
Kinematic Properties

ABSTRACT Studies of the Galactic Centre suggest that in situ star formation may have given rise to the observed stellar population near the central supermassive black hole (SMBH). Direct evidence for a recent starburst is provided by the currently observed young stellar disc (2–7 Myr) in the central 0.5 pc of the Galaxy. This result suggests that star formation in galactic nuclei may occur close to the SMBH and produce initially flattened stellar discs. Here, we explore the possible build-up and evolution of nuclear stellar clusters near SMBHs through in situ star formation producing stellar discs similar to those observed in the Galactic Centre and other nuclei. We use N-body simulations to model the evolution of multiple young stellar discs and explore the potential observable signatures imprinted by such processes. Each of the five simulated discs is evolved for 100 Myr before the next one is introduced in the system. We find that populations born at different epochs show different morphologies and kinematics. Older and presumably more metal-poor populations are more relaxed and extended, while younger populations show a larger amount of rotation and flattening. We conclude that star formation in central discs can reproduce the observed properties of multiple stellar populations in galactic nuclei differing in age, metallicity, and kinematic properties.

Energy use, poverty and development in the SADC

2007 ◽  
Vol 18 (3) ◽  
pp. 10-17 ◽  
Author(s):  
J.C. Nkomo
Keyword(s):  
Economic Growth ◽  
Energy Consumption ◽  
Poverty Alleviation ◽  
Energy Use ◽  
Significant Proportion ◽  
Reducing Power ◽  
Energy Sources ◽  
The Poor ◽  
Growth Energy ◽  
Essential Prerequisite

The purpose of this paper is to investigate the rela-tionship between economic growth, energy use, poverty alleviation and development in the Sou-thern African Development Community (SADC) countries. Association is drawn between human development indices and energy consumption, eco-nomic growth and poverty. It turns out that poverty has a bearing on the types of energy consumed, which in turn, affects health, education and income earning opportunities. Access to reliable and afford-able energy remains an essential prerequisite for combating poverty, and available evidence shows that a significant proportion of the population in SADC countries lack access even to the most basic energy supplies and services. Furthermore, inequal-ities penalize the poor by leaving them with a small-er share of income thus limiting their energy sources and weakening the poverty-reducing power of growth.

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