1. Current Advances in Biosciences:
Astrobiology – Discovering the Planetary Mechanisms and
Molecular Foundations of a Living Universe
Name: Matthew Langdale
Email: M.L.Research1990@Gmail.com

2. Contents
ABSTRACT 1
I: INTRODUCTION 1
ASTROBIOLOGY:THE NEXT FRONTIER IN BIOLOGICAL RESEARCH
ON OUR DEFINITION OF ‘LIFE’
DEFINING SCOPE IN A HIGHLY MULTI-DISCIPLINARY FIELD
II: RESEARCHING FAVOURABLE CONDITIONS THROUGHOUT THE SOL SYSTEM 3
METHANEON MARS: METHANOGENSOR GEOLOGICAL PROCESSES?
THE IMPLICATIONSOF RECENT ENCELEDEAN DISCOVERIES
TITAN:LIQUID HYDROCARBONSAND THE AZOTOSOME
III: INTERSTELLAR ORGANIC CHEMISTRY AND THE RNA WORLD 6
STELLAR EJECTIONS: THE ORIGIN OF COMPLEX ORGANIC COMPOUNDS
FORMAMIDE AND THEORIGIN OF NUCLEOBASES
IV: DISCUSSIONS AND CONCLUSIONS 8
COMPLEX INTERACTIONS:WHAT CAN WE INFER FROM CURRENT RESEARCH?
THE FUTUREOF BIOLOGY: AT THE THRESHOLD OF A BRAVE NEW UNIVERSE
REVIEW SUMMARY AND FUTURE ISSUES 10
FIGURES AND TABLES 11
LITERATURE CITED 12
GLOSSARY 15

3. 1
Abstract
The investigation into life beyond Earth has
been progressing for almost half a century,
though speculation on its nature is a discussion
nearly as old as mankind itself. While it is
quite unlikely that we will find intelligent life
in the near future – serendipitous
breakthroughs in probing technology and
spaceflight not withstanding – much of our
lack of evidence rests on our definition of
‘life’.
The conditions needed to sustain simple
life beyond Earth are fairly common – both at
the planetary level, and the molecular level.
Discoveries relating to the common
occurrence of volatile organic molecules are
beginning to occur much more frequently; this
is alongside mounting evidence of abundant,
complex organic compounds. An argument,
that we must reassess our commonly held view
of life if we are to make further progress, is
put forward. Until we make the next great
discovery, our plans to search further continue
to grow in scope.
Keywords
Geophysics, molecular biology, astrophysics,
cosmology, microbiology, organic chemistry
I: Introduction
Astrobiology: The Next Frontier in
Biological Research
NASA defines the field of astrobiology as
“…the study of the origins, evolution,
distribution, and future of life in the universe.”
(Fletcher, 2015) – A concise description of the
field. While astrobiology does primarily
concern itself with possibilities beyond
terrestrial life, we must also take care not to
forget life here on Earth. Often, it is our
understanding of ‘life as we know it’ which
guides research into ‘life as we do not know
it’; or rather,‘life as we may not quite
understand it’.
The known universe is thought to host
close to 3x1023
stars (Dokkum & Conroy,
2010), and of those, it has recently been
proposed that as many as 5x1022
could be
considered ‘Earth-like’ and habitable (Abe et
al., 2013). The probability of only a single one
of these habitable exoplanets harbouring life is
highly probable. However,much of our
understanding of life is based on how much we
have discovered about ourselves; our own
evolution, biology, and ecology – There is no
guarantee that life elsewhere would adapt the
same form as our own, or even be based on the
same fundamental chemistry.
In order for us to investigate the existence
of life beyond Earth, a broadening of the mind
– of the concept of life – must first take place.

4. 2
On our definition of ‘life’
Since the moment we gained the ability to
comprehend our surroundings with abstract
reasoning, humanity has pondered the
existence of life in the heavens. Celestial
objects, similar in form to Earth, are now
known to be in abundance. Not only this, but
our own sun – the energy of all life on Earth –
appeared to be lost amongst an endless ocean
of close brothers and sisters.
And yet we still seemed to be the only life
capable of observing the sheer scope of the
universe around us. However,while we might
so far be the only life capable of observing and
comprehending, this does not exclude the
possibility of other forms of life.
As a brief example; life on Earth exhibits
severalmechanisms of stimulus interaction
with its surrounding environment, in the form
of distinct taxes. Could we consider such
response mechanisms to be defining factors of
living organisms? Can something be
considered ‘alive’ if it has no means of
defining, navigating, and utilizing the
surrounding environment?
On the same note, could we consider the
key molecule found in all life on Earth, DNA,
to be an indicator of life? While it may appear
to be nothing more than a complex molecular
compound, it has self-sustained innate
replication functions and tendencies; traits
considered to be key defining indicators of
complex life. While it would be a significant
discovery if we were to discover evidence of
DNA-like molecular structures outside of
Earth, would we consider this evidence of life,
or merely of complex organic chemistry?
This poses further ethical questions
regarding whether we should intrusively
observe and interact with such processes if we
were to discover them elsewhere. It also leads
to significant questions about where we place
the starting line in our own evolutionary
history.
Defining ‘scope’ in a highly
multidisciplinary field
Of course, these questions all pertain to our
own biology, and it is this understanding of
ourselves that can help narrow the search for
life elsewhere. Using our knowledge of
evolutionary developments, our understanding
of early Earth conditions, and even planetary
sciences,we can begin to form a picture of
how and where life might occur. Not only does
this lead to a greater understanding of the
universe and its primitive biological systems,
it also helps us better understand how we came
to be.
It is within these fields this review is
focused. Planetary sciences can help us
determine whether a celestial body holds the
geophysical system requirements needed to
sustain life; early molecular developments in
our own evolution can help us focus our
search; and research into the prevalence of
organic compounds beyond Earth allows us a
glimpse at just how common the potential
seeds of life could be.

5. 3
II: Researching Favourable Conditions
throughout the Sol System
Life finding missions have been
continuously ongoing since the early 1960’s,
ever since the USSR successfully obtained
lunar soil samples for investigation
(Vinogradov, 1971). Since these initial steps,
our understanding of both our own planet, and
the planets/moons surrounding us, has
increased exponentially. This greater
understanding has led to many breakthroughs
in our comprehension of how life on Earth
came to be. Using this deeper level of insight,
we are now capable of gauging the
geophysical processes and chemical conditions
of the worlds surrounding us; allowing us to
narrow the search for possible habitable
conditions.
Methane on Mars: Methanogens or
Geological Processes?
When humanity ponders extra-terrestrial
life, Mars is typically the first place the mind
envisions. This would appear to be with good
reason, as recent advances in the field of
planetary research have shown its geological
processes were once highly similar (Yin,
2012). Research has also shown that Mars may
have once held an oxygen rich atmosphere
(Tuff, Wade, & Wood, 2013).
The Mars Science Laboratory (MSL) has
also detected methane presence utilizing their
Tunable Laser Spectrometer (TLS) instrument
(Webster et al, 2015). What is intriguing about
this discovery is not so much the background
presence,but the presence of regular interval
pulses of methane into the atmosphere (Fig 1).
As the data shows, NASA’s curiosity rover
recorded nearly a tenfold increase in the
surrounding Martian atmosphere. Naturally,
the explanations put forward have varied
greatly - however, severalpossible ideas by
Yung and Chen (2015) discuss the potentiality
of life-bearing origins.
Their rationale posits that Methanogens are
responsible for the intermittent release of
methane into the atmosphere, using Earth
microbiota as analogous models. Methanogens
on Earth are known to produce methane using
CO2 and H2 as nutrient sources (Bapteste,
Brochier, & Boucher, 2005) by way of the
following redox reaction:
CO2 + H2 = CH4 + 2H2O
Where CO2 and H2, CH4 and H2O represent
carbon dioxide, hydrogen gas, methane, and
water respectively. The methane produced
then goes on to facilitate ATP production via
an active transport diffusion gradient. This is
in contrast to plants and algae, which use
water as their reducing agent.
Yung and Chen’s argument - that
methanogens could exist within the potential
deep subsurface ice deposits on Mars - is
based on the ecology of similar organisms here
on Earth (Tung, Bramall, & Price 2005). This
hypothesis is not without evidence to the
contrary, however - There are other ways in
which methane could be produced on the
surface of the rocky planet. The most likely
explanation is the production of methane

6. 4
through a collection of processes known as
Fischer-Tropsch reactions,which can
sometimes create methane gas as a natural by-
product (Dry 2002) (Etiope, Schoell, &
Hosgörmez, 2011). Recording the same pulse
in a constant pattern, with minimal deviation,
over a set period of time would lend much
greater credence to this hypothesis.
The Implications of Recent Enceledean
Discoveries
Moving away from Mars,the next
discovery originates within the icy meteor
rings of Saturn.
Recent research undertaken by Hsu et al
(2015) using the Cassini space probe has
shown that there is ongoing hydrothermal
activity on Enceladus (evidenced by icy
geysers spewing froth from Enceladus’
southern face) (Fig. 2). This builds upon
recent discoveries favouring the existence of a
warm, sub-surface ocean (Parkinson, Liang,
Yung, & Kirschivnk 2008) (Crockett, 2015).
Samples analysed from deep within the plumes
of water vapour show the presence of volatile
chemicals such as CH4,CO2, NH3, and H4
(Bouquet, Mousis, Waite, & Picaud, 2015).
Explanations for the presence of methane
vary, with the most reasonable being that these
compounds originate from the core of
Enceladus, and are carried to the surface by
the geyser.
Much like with Mars, researchers have
posited explanations using Earth as an
analogous comparison subject (Mousis,
Lunine, waite et al, 2009): On Earth, methane
largely takes on the form of methane clathrate;
crystal water lattices which store methane
within chambers1
. This form of methane gas is
either stored within the continental rocks of
the Polar Regions, or in ocean sediments at
depths greater than three-hundred metres.
The process of methanogenesis by
microbial methanogens drives methane
production within Earth’s oceans. Much like
speculation of Methane presence in the
martian atmosphere, similar arguments have
been made regarding Enceladus (Taubner,
Schleper, Firneis, & Rittman, 2015). Though
we must inspect the CH4 carbon isotope count
further if we are to make further claims on its
origin. Life as we know it has a tendency to
favour lighter isotopes, therefore a greater
ratio of carbon-12 to carbon-13 would give us
further reason to probe even deeper below the
surface.
On further note, Enceladus is known to
maintain a 2:1 mean motion orbital resonance
with dione (Hurford, Bills, Helfenstein,
Greenberg, Hoppa, & Hamilton, 2009). This
resonance maintains Enceladus’ non-zero
orbital eccentricity, the heat dissipation from
which results in tidal deformation. This tidal
deformation is the primary source of heat
energy driving the moon’s geological activity.
Methane Clathrate Composition
The chemical formula for methane
clathrate is (CH4)4(H2O)23 – Containing
1mol of methane for every 5.75mol of water;
a methane mass of ~13.4%. The actual
amount varies by the amount of methane
molecules held within the ice-water
lattice structure.

7. 5
Much like with Earth, this dissipation of
heat energy can possibly occur through
subsurface hydrothermal vents. This process
could help organisms such as methanogens
survive in much more ‘Earth-like’ conditions;
giving methane in the plume of Enceladus a
possible biological origin.
Further studies would need to pierce the
surface and investigate the depths below.
Much of this is still speculative, and more
research will need to be undertaken in order to
investigate Enceladus’ subsurface environment
– and life bearing conditions - definitively.
Titan: Liquid Hydrocarbons and the
Azotosome
Methane appears to be fairly abundant
throughout the solar system, as both Mars and
Enceladus have shown. The one place where it
becomes a much more unique occurrence,
however, is the Saturnian moon Titan.
Titan has recently been found to hold vast
lakes and oceans composed of liquid
hydrocarbons (Fig. 3); specifically, methane
and ethane (Stofan, Elachi, Lunine et al.,
2007). It also holds a dense, hydrocarbon rich
atmosphere, abundant with nitrogen (98.4%),
methane (1.4%) and hydrogen (0.1%) – other
trace elements are also noted, though
negligible (Niemann, Atreya, Bauer et al.,
2005). As Titan only receives roughly 1% of
the amount of sunlight Earth receives,Titan’s
conditions are incredibly frigid. These
conditions lead to methane taking the place of
water in the hydrological cycle or precipitation
and evaporation.
This is an important discovery for
researchers of exobiology, as it makes Titan
the only place in the Sol system, besides Earth,
that holds vast quantities of standing and
flowing liquids.
Researchers (Gilliam & Lerman, 2014)
have also presented findings which
demonstrate a varying abundance of ammonia,
dispensed by cryovolcanoes, within the
atmosphere. These conditions mean Titan
could be of a highly similar atmospheric
composition to Earth at the time we believe
life first emerged,albeit much colder.
With all of this evidence put forward, it is
tempting to dismiss the possibility of life on
Titan; the atmosphere is right, but the moon is
below freezing, and the seas are composed of
methane and ethane. Life as we know it could
not possibly survive here.
The azotosome,however,could survive
here.
The azotosome (Fig. 4) is a novel and
hypothetical cell membrane structure,posited
by chemical engineers Stevenson, Lunine, and
Clancy (2015) of Cornell University. It is
composed entirely of molecules found in
Titan’s atmosphere and oceans – namely
nitrogen, carbon and hydrogen – and has the
same flexibility as the liposome vesicles of
terrestrial biology. These hypothetical vesicles
are capable of completely repelling methane,
separating the outer environment from the
vesicle’s inner environment.
After selecting for the methane-based
compounds most capable of spontaneous self-
assembly, acrylonitrile was decided upon. The
most significant part of this discovery is the

8. 6
likely presence of acrylonitrile in Titan’s lower
atmosphere (McEwan,Fairley, Scott, Anicich
1996). The possibility of an acrylonitrile
azotosome,analogous to the terrestrial
phospholipid membrane, becomes much more
credible.
Of course, this research is groundbreaking.
Not only does it prove that life could
hypothetically form from a universally
abundant molecule, but it could also harbor
membrane bound structures much like our
own. However,while we have simulated the
existence of vesicle-like structures, we are still
lacking in data on how they might behave. We
are also lacking in data based on what it might
encapsulate, as we have no hypothetical
models of acrylonitrile-azotosome-bound
organelles. We also lack insight into what
these organelles may be constructed from, or
how they would work. Perhaps this could be
our next objective?
Prior experimental models of Titan (Pasek,
Mousis, Lunine, 2011) have delivered
evidence that phosphine could be taking part
in the moon’s hydrocarbon cycle. As
phosphorous chemistry is key to the function
of terrestrial life, further research could
concentrate on studying the interaction
between phosphine and the acrylonitrile
azotosome.
III: Interstellar Organic Chemistry and the
RNA World
Early organic compounds – alongside water
molecules – are thought to have been delivered
to the surface of Earth through comet and
asteroid impacts. These comets and asteroids
often carry fundamental organic compounds, a
trace amount of which are capable of
withstanding the descent through Earth’s
atmosphere. Once they had been delivered to
Earth, the conditions of our planet are said to
have been just right, leading to synthesis of
more complex compounds – a process known
as exogenesis.
Even today, we continue to gather evidence
of organic payload delivery to Earth through
this process. Due to the oxygen composition of
present Earth’s highly-reactive atmosphere
(caused by photosynthesis), however, many of
these compounds are oxidized shortly after, or
before, synthesis.
While present Earth can be considered
hostile to these volatile compounds, there are
many places beyond Earth where they have
also been observed.
Stellar Ejections: The Origin of Organic
Compounds
Research recently undertaken by Kwok
(2015) has demonstrated that intricate organic
matter is prevalent throughout the universe.
With respect to the Solar System, it can be
found in meteorites, interplanetary dust
particles, and on the various moons.
Spectroscopic signatures of organics with
aromatic structures – such as polycyclic
aromatic hydrocarbons – can be found in the
ejection contents of stars,diffuse interstellar
medium, and even external galaxies
(Ehrenfreund, Spaans,& Holm, 2011) (Fig. 5).

9. 7
Past research and discussion also
undertaken by Kwok (2011) has shown that
the universe could have been saturated by
complex organic compounds, since the earlier
stages of its history. These organic compounds
are created via the process of stellar
nucleosynthesis within red giant, low-medium-
mass stars of the asymptotic giant branch –
specifically carbon stars.
Chyba and Sagan (1992) estimated the total
amount of carbonaceous dust and material
delivered to Earth exogenously to be between
1016
and 1018
kg since its formation. This is a
significantly constant bombardment and load
capacity. Could we truly consider it out of the
bounds of possibility that other ‘earth-likes’
would also harbor the right conditions, simply
waiting for these materials to arrive and
undergo molecular synthesis?
These observations also pose several
further exciting questions:
 Might it be that the fundamental
requirements for life, within a
system, are primarily dependent on
the nuclear structure of its host
star?
 Is the genesis of complex life
simply a case of ‘organic
compounds finding the right
environmental conditions, at just
the right time?’
 If stellar ejections are a key source
of organic building blocks, does
this mean that carbon-based ‘life’
throughout the universe could be
more common than we initially
thought?
Prior studies have also shown that red
dwarf systems could both be ideal for
habitable worlds (Yang, Liu, Hu, & Abbot,
2014; Yang, Cowan, & Abbot, 2013), and not
so ideal (Barnes,Mullins, & Goldblatt et al.,
2012). However,given the sheer abundance of
habitable red dwarf systems throughout the
Milky Way (Delfosse,Bonfils, Forveille, et
al., 2012) an argument for placing our
spectroscopic focus on these systems much
more actively can be made.
Further research into stellar ejection
content would benefit from focusing on m-star
and c-star systems with prior-suspected
habitable bodies.
FORMAMIDE AND THE ORIGIN OF
NUCLEOBASES
Leading on from the discussion of organics
and asteroids, between 3.9 billion and 4.2
billion years ago, the late heavy bombardment
period saturated our system with asteroids
(Nature Geoscience,2013). It is during this
period that the earliest potential evidence of
life has first been recorded (Bell, Boehnke,
Harrison, & Mao, 2015). While the current
evidence of life first emerging during this
period has been widely accepted,what has not
yet been revealed is the events which first led
to its emergence. Recent research on the

10. 8
chemistry of formamide, however, has brought
a potential new hypothesis to light.
Formamide is a derivative of formic acid,
created through the process of treating said
formic acid with ammonia, producing
ammonium formamate,which becomes
formamide when heated. The interesting thing
about formamide is that research (Barks,
Buckley, Grieves, et al., 2010) has shown it to
be important in the formation of nucleobases
guanine and adenine – two of life’s five
fundamental building blocks.
Building on this discovery is research
undertaken by Ferus et al. (2015). Their
investigation involved simulating high-energy
synthesis of a hypothetical asteroid impact by
inducing dielectric breakdown of plasma.
During this process,they discovered the
dissociative state of formamide could lead to
highly reactive cyano and amino radicals.
These could then react with formamide
molecules to produce all the accepted building
blocks of DNA and RNA – adenine, guanine,
cytosine, thymine and uracil.
These reactions lend credence to the
hypothetical ‘RNA world’ posited by
numerous prominent researchers throughout
the course of history (Crick 1968; Orgel 1968;
Gesteland, Cech,& Atkins, 2005), lending a
significant boost to the already widely
accepted credibility of the hypothesis.
The research undertaken by both Ferus et al
and Barks et al are large steps towards
understanding the initial reactions of life.
However,there is still research be undertaken
regarding the sustained requirements needed
for these reactions to continuously occur over
many millennia.
Research on interactions between common
building blocks, ultraviolet light, and hydrogen
sulfide (Patel,Percivalle, Ritson, Duffy, &
Sutherland, 2015) offer promising glimpses
into the formation of complex metabolisms.
Now we have a clearer understanding of how
nucleobases may have come to be, identifying
early metabolic reactions is the logical next
step. Past this, studying interactions between
these primitive metabolic actions and early
nucleobases could yield even greater insights.
IV: DISCUSSIONS AND CONCLUSIONS
Many advances across severalscientific
fields have been discussed throughout the
length of this review. From the importance of
planetary forces,to possible exogenic origins
of life, it is clear that astrobiology is a field
teeming with untapped potential for new
discoveries; not only with regards to extre-
terrestrial life, but with regards to our own
evolution, also.
Creating Formamide
The exact chemical reaction yielding
formamide is as follows:
1. HCOOH + NH3  HCOONH4
2. HCOONH4 → HCONH2 + H2O

11. 9
COMPLEX INTERACTIONS: WHAT CAN WE
INFER FROM CURRENT RESEARCH?
With regards to life on Earth, the research
undertaken on asteroid impacts, as well as
results from the recent Rosetta mission
(Goesmann, Rosenbauer, Cabane et al., 2015),
have begun suggesting potential exogenic
origins of our own molecular building blocks.
If not an entirely exogenic origin, then we
could at least reasonably argue that outside
forces may have played a vital part in our
evolution.
Life is highly dependent on conditions not
just on a planetary level, but an astrophysical
level too. Enceledus’ interaction with both its
neighbouring moon, and its host planet, prove
to be vital to the potential existence of life in
its oceans. We can utilize many processes
found on Earth to narrow our search for
exobiological life, leading to hypothetical
explanations for processes on other planets.
Our knowledge of the molecular content of
stars is beginning to help narrow our search for
habitable planets, though these hypothetically
life-bearing planets are not without
challenging atmospheric and environmental
conditions.
Life as we know it is incredibly delicate,
and clearly requires absolute perfect
conditions to emerge and thrive. However,as
hypothetical models of methane-based life on
Titan have shown, life elsewhere could be
chemically diverse, and radically different to
our own.
Research has pointed towards the origin of
organic molecules being within the stars
themselves. This leads to intriguing questions
regarding the possibility of life within systems.
Could life be pre-determined during the
formation of a system’s star? Could it be that
the requirements for life are not universal, but
pre-scripted during the initial formation of a
system? Perhaps only certain systems carry the
unique chemical composition needed for life to
thrive?
The Future of Biology: Lurking at the
threshold of a brave new universe
While biological research may appear to
have come quite far in the last century, we still
have a lot to discover if we are to crack the
evolutionary code. The field of astrobiology is
still young, and these initial steps towards
understanding ourselves and how we came to
be are merely infantile. Advancements have
shown that we need to begin taking the entire
universe into account if we are to fully
understand ourselves. As Sagan (1983) once
said;
“The nitrogen in our DNA,the calcium in our
teeth, the iron in our blood, the carbon in our
apple pies were made in the interiors of
collapsing stars. We are made of starstuff.”
In light of his words, it could be argued that
we must begin to view the entire universe as
our ecosystem, not just the planet we evolved
upon. By treating the stars as a part of our
immediate environment, we may come to
understand more about the origin and
existence of life itself.

12. 10
Summary
 When searching for life beyond Earth, we may need to expand our definition in
order to make new breakthrough discoveries.
 Planets and stars are intricately interwoven systems. Their underlying
mechanisms may guide us in our search for life.
 Evidence points in the direction of both exogenous and endogenous processes
playing apart in terrestrial evolution.
 Stars can offer us a wealth of information in terms of the origin of organic
compounds.
 Methane is abundant throughout the solar system, which could mean methanogen
analogues might be too.
Future Issues
 There must be serious consideration regarding future probes sent to the lakes of
Titan
 We must further study the azotosome and build new models of methane-based
life, as it is a highly abundant molecule.
 Further investigations of red dwarf systems could yield interesting results.

13. 11
Figures and Tables
Fig. 1 – Graph showing intermittent methane
peaks in Mars’ Gale Crater
(Webster CR, Mahaffy PR, Atreya SK, Flesch
GJ, Mischna MA, et al. 2015)
Fig. 2 – Images depicting Enceladus’ icy
plumes. A and C are images taken by Cassini.
B and D are computer generated enhancements
(NASA, 2015)
Fig. 3 - An aerial view of methane lakes on
Titan (NASA-JPL, 2015)
Fig. 4 - Computer generated model of the
9-nanometer acrylonitrile-azotosome
(Stevenson, 2015)
Fig. 5 – Spectrographic analysis of organic
compounds superimposed above the Orion
nebula (NASA, O’Dell, & Wong, 2011)

14. 12
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17. 15
Glossary
Asymptotic Giant Branch
The region of the Hertzsprung-Russell
diagram populated by low-medium mass
stars.
Dielectric Breakdown
The rapid reduction in resistance of an
electrical insulator when the applied voltage
exceeds the material’s breakdown voltage.
Exogenic/Exogenously
An action or object coming from outside of a
system
Fischer-Tropsch Reactions
A set of chemical reactions that convert a
mixture of carbon-monoxide gas and
hydrogen gas into liquid hydrocarbons.
Hydrocarbon
An organic compounds consisting entirely of
hydrogen and carbon.
Nucleobases
An information-carrying molecule
fundamental to all life on Earth.
Orbital Resonance
When two orbiting bodies exert a consistent
gravitational influence on eachother.
Radicals (Cyano/Amino)
An atom, molecule, or ion with unpaired
valence electrons, which may take part in
reactions. ‘Cyano-’ are radicals with
molecular formula CN. ‘Amino-’ are radicals
with molecular formula NH2.
Red Dwarf
Small, cool star of low to medium mass.
Stellar Nucleosynthesis
The creation of new atomic nuclei from pre-
existing nucleons – protons and neutrons -
within a star.
Tidal Deformation
Displacement of solids due to regular
movement of surface liquid.