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Composition
The particles studied in cosmic and heliospheric science are atoms or pieces of atoms. Atoms are composed of three major building blocks: protons (with a positive charge), neutrons (with no charge), and electrons (with a negative charge). The nucleus of an atom contains the protons and neutrons, while the electrons orbit the nucleus. The number of protons determines to which element the atom belongs: hydrogen has one proton, carbon has six, etc.
The Particle Adventure (by the Particle Data Group) introduces the theory of fundamental particles and forces, called the Standard Model. It explores the experimental evidence and the reasons physicists want to go beyond this theory. In addition, it provides information on particle decay and a brief history section.
The Science of Matter, Space, and Time (by the Fermilab) contains another good particle physics "tour".
![Hydrogen, deuterium, and tritium models](hdt.gif)
New elements are created in stars by a process called nucleosynthesis. (More about nucleosynthesis...)
The number of neutrons tells us which isotope of the element is present. The isotope number is the total of the number of protons plus the neutrons. Take carbon, for example, which is a very common element necessary for life, and is found in nature as diamonds and graphite. We find several different isotopes of carbon in nature. Carbon-12 has an equal number of protons and neutrons, six of each. Carbon-14 contains two more neutrons (eight) than carbon-12, but still has only six protons. This makes carbon-14 an isotope of carbon, but it is different from carbon-12. While carbon-12 is a stable isotope, carbon-14 is unstable, or radioactive. It is much less common in nature but is found where carbon-12 is found. Because of its radioactive nature, carbon-14 is used to date archaeological artifacts.
Shown in this figure, deuterium and tritium are isotopes of hydrogen.
This image is from the Princeton
Plasma Physics Laboratory, which also offers a good interactive tour of matter.
The periodic table of the elements provides some information about each of the different elements. Each element has distinctive properties, and those with similar properties are grouped into families, shown by the different colors. Follow the link on the periodic table here to learn more about it and the different elements.
In an atom, the number of electrons that orbit the nucleus equals the number of protons in the nucleus, thus making an atom electrically neutral. When bombarded by ultraviolet (UV) radiation or after being struck by energetic particles, atoms can lose one or more of their electrons. The positively charged remains of these atoms are called ions. The number of electrons lost determines the charge state of the particle. For example, alpha particles are helium nuclei with a double positive charge; they have two protons and two neutrons, but no electrons.
Together with their freed electrons, the ions form a plasma. Plasma is a fourth state of matter, not a liquid, solid, or gas. Matter in the Sun is in a plasma state. Plasma is the most common state of matter in the Universe. More than 99% of all matter is plasma, so what we see on Earth is the exception. Since plasmas consist of electrically-charged particles, electric and magnetic forces affect a plasma.
When we measure the elemental, isotopic, and charge composition of ions, it helps us to understand how nature selected the particles and accelerated them to the energies at which we find them. The "composition" of electrons is not interesting, since all electrons look the same. But their number, energy, and direction of travel are important.
Back to Basics
May 1, 2012: "Beautiful"
new particle found at LHC -- National Geographic
April 24, 2012: Gamma
rays hint at dark matter -- Physics World
April 21, 2012: New
study finds no evidence for dark matter in the Milky Way --
Astrobiology
April 18, 2012: Not-quite-so
elementary, my dear electron -- Nature
April 13, 2012: On
the border between matter and anti-matter -- Science Daily
April 4, 2012: Handheld
plasma flashlight rids skin of notorious pathogens -- Science
Daily
March 29, 2012: Cassiopeia A: A
star explodes and turns inside out -- Chandra X-ray Observatory
March 27, 2012: Lightning
strikes produce free neutrons, and we're not sure how -- Ars
Technica
March 19, 2012: Neutrinos
not faster than light -- Nature
March 8, 2012: Experiment
observes elusive neutrino transformation -- Caltech
March 7, 2012: Internal
structure of antihydrogen probed for the first time -- Physics
World
February 25, 2012: Tellurium
in ancient stars -- Astrobiology
January 31, 2012: IBEX:
Glmpses of the interstellar material beyond our solar system --
NASA
January 9, 2012: A
guide to the dark side -- Science
December 23, 2011: Shell galaxy
NGC 7600 -- APOD
December 22, 2011: LHC
reports discovery of its first new particle -- BBC
December 22, 2011: How
to build a gamma-ray laser with antimatter hybrid -- New Scientist
December 21, 2011: What
Higgs result means for dark matter conspiracy -- New Scientist
December 18, 2011: Hints of Higgs from the
Large Hadron Collider -- APOD
December 16, 2011: Revealing
how the elements were forged -- Astrobiology
December 14, 2011: More clues in the
hunt for the Higgs -- Caltech
December 13, 2011: ATLAS
and CMS experiments present Higgs search status -- Max Planck
Institute
December 5, 2011: The
return of energetic 3He in the inner heliosphere -- ACE News
November 24, 2011: Caught in the
afterglow -- APOD
November 23, 2011: Physicists
set strongest limit on mass of dark matter -- Brown University
November 23, 2011: LHC antimatter anomaly hints at new physics
-- New Scientist
November 17, 2011: World's
most difficult chemical experiment: The struggle to discover the
secret of super-heavy elements -- Science Daily
November 17, 2011: Racing
to be the first to create the world's heaviest element -- Science
Daily
November 16, 2011: NGC 7822 in Cepheus
-- APOD
November 10, 2011: Pristine relics
of the Big Bang spotted -- Physics World
November 9, 2011: Three
new elements named -- Astrobiology
November 9, 2011: Physicists
chip away at mystery of antimatter imbalance -- Science Daily
November 6, 2011: Ancient
galaxies are rich in elements -- Astrobiology
October 18, 2011: Dark
matter mystery deepens -- Astronomy
October 4, 2011: Isotope
ranking reveals leading labs -- Nature
October 3, 2011: Dark matter movie from
the Bolshoi simulation -- APOD
September 30, 2011: The
Pulled Groin Extrapolation -- Big Blog Theory
September 22, 2011: The
Skank Reflex Analysis & the Infestation Hypothesis -- Big Blog
Theory
September 13, 2011: Shedding
light on the mystery of dark matter -- Nature
September 8, 2011: CRESST uncovers
hint of dark matter -- Physics World
September 7, 2011: SDSS J102915+172927: A
star that should not exist -- APOD
August 28, 2011: Don't
panic about the missing Higgs -- for now -- New Scientist
August 25, 2011: Using
ionic charge states as a thermometer in the solar corona --
Caltech
August 25, 2011: Surprise
difference in neutrino and antineutrino mass lessening with new
measurements from a Fermilab experiment -- Science Daily
August 18, 2011: Cubic neutrons
might find it hip to be square -- Physics World
August 17, 2011: Cosmological
evolution of dark matter is similar to that of visible matter --
Science Daily
August 10, 2011: Antimatter
found orbiting Earth -- a first -- National Geographic
August 3, 2011: Half
of Earth's heat from radioactive decay -- Astrobiology
July 25, 2011: New laser
technique makes cold positronium -- Physics World
July 23, 2011: Asymmetric
quarks defy standard model of physics -- Nature
July 22, 2011: Surprise
LHC blip hints at Higgs -- again -- New Scientist
July 21, 2011: Particle
discovery fills a gap -- Science News
July 19, 2011: Radioactive decay
accounts for half of Earth's heat -- Physics World
July 14, 2011: New
spin revealed on mysterious antimatter -- Space.com
June 29, 2011: Dark
matter may solve 'radio filaments' mystery -- BBC
June 27, 2011: Four-way
stop sign -- HEAPOW
June 25, 2011: The
breath of the solar system's birth -- Astrobiology
June 23, 2011: NASA
mission suggests sun and planets constructed differently -- NASA
June 23, 2011: Proton
somersault study could explain why matter still exists -- Wired
June 20, 2011: A
neutrino-flavored universe -- Astrobiology
June 15, 2011: Evidence mounts
for previously unseen neutrino oscillation -- Physics World
June 14, 2011: 'Hidden'
galaxies of the universe have lower amounts of heavier elements --
Science Daily
June 10, 2011: Tevatron
teams clash over new physics -- Nature
June 6, 2011: Two
ultra-heavy elements added to the periodic table -- Wired
June 5, 2011: CERN
experiment traps antimatter atoms for 1000 seconds -- CERN
May 28, 2011: Physicists
explain the long, useful lifetime of carbon-14 -- Science Daily
May 25, 2011: Rounding
the electron -- Nature
May 24, 2011: Universe's
not-so-missing mass -- Science Daily
May 16, 2011: Cosmic ray
detector blasts off on space shuttle -- Physics World
May 10, 2011: The
collider that cried 'Higgs' -- Nature
May 6, 2011: WIMP
wars -- Scientific American
May 4, 2011: Antiuniverse
here we come -- Nature
May 3, 2011: Signs
of dark matter from Minnesota mine -- Science News
April 28, 2011: Antimatter
detector ready for launch -- Nature
April 27, 2011: "We
hope to detect the largest proportion of the matter in space" --
Max Planck Institute
April 27, 2011: The dark side of the universe -- Science News
April 24, 2011: RHIC
physicists nab new record for heaviest antimatter -- Brookhaven
National Laboratory
April 7, 2011: Tevatron
accelerator yields hints of new particle -- BBC
April 1, 2011: The
strong force -- Astrobiology
March 31, 2011: Neutral
atoms made to act like electrically charged particles -- Science
Daily
March 28, 2011: The
fringes of Perseus -- HEAPOW
March 22, 2011: Physicists
create heaviest form of antimatter ever seen -- New Scientist
March 17, 2011: LHC
could be the first time machine -- Astrobiology
March 7, 2011: Silent
superball -- HEAPOW
March 5, 2011: Cooling neutron
star -- APOD
February 28, 2011: Beautiful
theory collides with smashing particle data -- Nature
February 25, 2011: Radioactivity
challenges dark-matter detector -- Nature
February 24, 2011: The
Toast Derivation -- Big Blog Theory
February 23, 2011: 'Weird
science' uncovered inside neutron star -- Eurekalert
February 17, 2011: Musical
chairs around the periodic table -- Astrobiology
February 16, 2011: Herschel
measures dark matter for star-forming galaxies -- NASA
February 13, 2011: Ice fishing for cosmic
neutrinos -- APOD
January 31, 2011: Hunt
for dark matter closes in at Large Hadron Collider -- Eurekalert
January 26, 2011: Neutrino
detector starts measurement -- Max Planck Institute
January 24, 2011: Periodic
table gets some flex -- Science News
January 20, 2011: No
direct link between black holes and dark matter, scientists find
-- Science Daily
January 20, 2011: The
Love Car Displacement -- Big Blog Theory
January 19, 2011: Tevatron
to shut down in September -- Science News
January 18, 2011: NASA's
Fermi catches thunderstorms hurling antimatter into space --
Imagine the Universe!
January 14, 2011: Dark-matter
galaxy detected: Hidden dwarf lurks nearby? -- National Geographic
January 14, 2011: A
twisted way to take pictures -- Science News
January 10, 2011: Spacecraft
catches thunderstorms hurling antimatter into space -- AGU
January 10, 2011: How
do you make lithium melt in the cold? -- Eurekalert
January 10, 2011: NASA's
Fermi catches thunderstorms hurling antimatter into space -- NASA
January 6, 2011: New
subatomic particle could help explain the mystery of dark matter --
Scientific American
December 23, 2011: World's
largest neutrino detector completed at South Pole -- Scientific
American
December 20, 2011: Physics
World reveals its top 10 breakthroughs for 2010 (see #1) --
Physics World
December 16, 2011: The
Justice League Recombination -- Big Blog Theory
December 15, 2011: Atomic
weights of 10 elements on periodic table about to make an historic
change -- Eurekalert
December 1, 2011: Solar
observation mission celebrates 15 years -- NASA
December 1, 2011: Mercury
serves up a nuclear surprise -- Nature
November 29, 2011: New particle
links dark matter with missing antimatter -- Physics World
November 26, 2011: Flame nebula
close-up -- APOD
November 17, 2011: Antimatter
held for questioning -- Nature
November 11, 2011: LHC sees its
first ZZ event -- Physics World
November 5, 2010: Neutral
positronium scatters like a charged particle -- Physics World
November 2, 2010: What
is quantum mechanics good for? -- Scientific American
October 31, 2010: Isotope
near 'doubly magic' tin-100 flouts conventional wisdom -- Science
Daily
October 29, 2010: 'Best evidence
yet' for dark matter comes from Milky Way centre -- Physics World
October 22, 2010: NGC 7822 in
Cepheus -- APOD
October 21, 2010: Sailing
toward the island of stability -- Science News
October 8, 2010: Black
hole blasts superheated early universe -- National Geographic
October 1, 2010: Just
how small is the proton? -- Scientific American
September 23, 2010: Equinox and the
iron sun -- APOD
September 12, 2010: Oklo: Ancient
African nuclear reactors -- APOD
September 10, 2010: Searching the
sun for dark matter -- Physics World
September 9, 2010: How
can we use neutrinos to probe dark matter in the sun? --
Eurekalert
August 28, 2010: A
strange solar flare connection -- Astrobiology
August 28, 2010: Mining
for missing matter -- Science News
August 17, 2010: Lasers could make virtual particles real -- New Scientist
July 7, 2010: How
Planck's pain could be the LHC's gain -- New Scientist
July 7, 2010: The
proton shrinks in size -- Nature
July 7, 2010: Incredible
shrinking proton raises eyebrows -- New Scientist
July 2, 2010: The coolest antiprotons
-- Physical Review Focus
July 1, 2010: Ultra-precise
test confirms photons are bosons -- Physics World
June 22, 2010: God
particle signal is simulated as sound -- BBC
June 18, 2010: Neutrino
surprise emerges from MINOS -- Physics World
June 16, 2010: "God
particle" may be five distinct particles, new evidence shows --
National Geographic
June 8, 2010: Does dark matter
come in two types? -- Physics World
May 26, 2010: Muon
whose army? A tiny particle's big moment -- New Scientist
May 26, 2010: Why
I love neutrinos -- Scientific American
May 23, 2010: Evidence
for why we exist -- Astrobiology
May 17, 2010: Missing
no more? -- HEAPOW
May 6, 2010: Dark matter 'no
result' comes under fire -- Physics World
April 23, 2010: Decaying
beauty spied for first time by LHC -- New Scientist
April 21, 2010: Wide angle: The
Cat's Paw nebula -- APOD
April 17, 2010: What's
the (dark) matter? -- Scientific American
April 15, 2010: Enceladus
leaves plasma bubbles in its wake -- Astronomy
April 9, 2010: Exploring the island of
superheavy elements -- Physics
April 2, 2010: Mass
of the common quark finally nailed down -- Science
March 23, 2010: Black
holes may hint at the nature of dark matter -- Astronomy
March 23, 2010: New
method could revolutionize dating of ancient treasures --
Eurekalert
March 23, 2010: Dark
energy: The biggest mystery in the Universe -- Smithsonian
March 22, 2010: Helium
rain on Jupiter explains lack of neon in atmosphere -- Eurekalert
March 22, 2010: Process
in big-screen plasma TVs can produce ultra-clean fuel --
Eurekalert
March 17, 2010: Fake
dark matter could show what real stuff is like -- New Scientist
March 17, 2010: Scientists
supersize quantum mechanics -- Nature
March 17, 2010: Hunt
for the sterile neutrino heats up -- Nature
March 15, 2010: Seeking
dark matter on a desktop -- SLAC
March 15, 2010: For
kids: Heaviest named element is official -- Science News
March 12, 2010: Borexino bags
geoneutrinos -- Physics World
March 5, 2010: Liquid metal stirs
itself -- Physical Review Focus
March 4, 2010: Exotic
antimatter detected at Relativistic Heavy Ion Collider --
Brookhaven National Lab
March 2, 2010: NASA's
Fermi probes "dragons" of the gamma-ray sky -- NASA
March 1, 2010: Astornomically
large lenses measure the age and size of the Universe -- SLAC
February 28, 2010: Pauli Exclusion
Principle: Why you don't implode -- APOD
February 26, 2010: A
CoGeNT result in the hunt for dark matter -- Nature
February 25, 2010: Naming
an atomic heavyweight -- Science News
February 22, 2010: Making use of
neutrons -- Chemical & Engineering News
February 9, 2010: A new 3D map
of the interstellar gas within 300 parsecs from the Sun --
Astronomy & Astrophysics
January 31, 2010: Plasma
experiments aboard International Space Station yielding better picture
of liquids and solids -- Science Daily
January 27, 2010: Helium sell-off
risks future supply -- Physics World
January 22, 2010: Millennium
annular solar eclipse -- APOD
January 19, 2009: Painless
plasma jets could replace dentist's drill -- Eurekalert
January 9, 2009: Dark matter
and dark energy update -- Sky & Telescope
January 7, 2009: Why
won't the supernova explode? -- Science@NASA
January 7, 2009: Astronomers
map dark matter 'beach ball' -- NPR
January 2, 2009: Experiment
detects particles of dark matter, maybe -- Science News
December 28, 2009: "Superatoms"
mimic elements: Research reveals new perspective of periodic table
-- Penn State
December 28, 2009: Atomic
dogs: The making of an internet sensation -- New Scientist
December 18, 2009: Dark
matter detected for first time? -- National Geographic
December 10, 2009: The colors of IC
1795 -- APOD
December 9, 2009: HUDF infrared:
Dawn of the galaxies -- APOD
December 8, 2009: Suzaku
spies treasure trove of intergalactic metal -- NASA's Imagine the
Universe!
December 7, 2009: Heavy
metal mine -- HEAPOW
December 2, 2009: Dust sculptures
in the Rosette nebula -- APOD
December 2, 2009: Suzaku
spies treasure trove of intergalactic metal -- NASA
November 26, 2009: Plasmas have
healing powers -- Physics World
November 24, 2009: Neutrino
experiment starts its search for the unknown -- Astronomy.com
November 20, 2009: Quarks influenced by their
neighborhood -- Physical Review Focus
November 13, 2009: New
experiment could reveal make-up of the Universe -- Science Daily
November 11, 2009: Exoplanets
clue to Sun's curious chemistry -- Eurekalert
November 6, 2009: Signature
of antimatter detected in lightning -- Science News
November 2, 2009: Ropes
of plasma: Onset and stagnation of 3-D magnetic reconnection --
Eurekalert
October 19, 2009: Bright
light hints at a dark centre to the Galaxy -- Nature
October 16, 2009: So close,yet so far --
Physical Review Focus
October 7, 2009: Dirty
stars are popular hosts -- Astrobiology Magazine
September, 30, 2009: Galaxy
study hints at cracks in dark matter theories -- New Scientist
September 21, 2009: Is dark matter
mostly 'dark atoms'? -- Physics World
September 11, 2009: Aage Niels Bohr:
1922-2009 -- Physics World
September 8, 2009: Laser
cooling may create "exotic" states of matter -- National
Geographic
September 2, 2009: Researcher
uses 100,000 degree heat to study plasma, what happens to matter
around black holes -- Science Daily
September 2, 2009: Antimatter
mystery -- New Scientist
September 2, 2009: The
lithium problem -- New Scientist
August 26, 2009: Particle
imbalance may upset the apple cart -- Science News
August 14, 2009: In search of antimatter galaxies -- Science@NASA
August 14, 2009: Isotope
crisis threatens medical care -- Science News
August 11, 2009: New
laser technique may help find supernova -- Eurekalert
August 10, 2009: Exploring
the standard model of physics without the high-energy collider --
Eurekalert
August 6, 2009: New
experiment could reveal make-up of the universe -- Eurekalert
July 24, 2009: Ray
of hope in dark-matter hunt -- Nature
July 14, 2009: 'Copernicium'
proposed as name for newly discovered element 112 -- Eurekalert
July 13, 2009: Dark
matter helped early galaxies survive "massacre" -- National
Geographic
July 8, 2009: Astrophysicists
solve mystery in Milky Way galaxy -- UCSD
July 1, 2009: Mass
mismatch makes mystery for proton's strange cousin -- Science News
June 30, 2009: Solar
ghosts may haunt Earth's radioactive atoms -- New Scientist
June 29, 2009: NuTeV
anomaly helps shed light on physics of the nucleus -- Science
Daily
June 26, 2009: Magnetic
'superatoms' promise tuneable materials -- New Scientist
June 19, 2009: Quirky
supernova could be something new -- New Scientist
June 19, 2009: A Higgs boson without
the mess -- Physical Review Focus
June 15, 2009: First
new element for five years makes periodic table -- New Scientist
June 15, 2009: Magnetic
super-atoms discovered -- Science Daily
May 29, 2009: Dark-energy
particle spotted? -- Nature
May 28, 2009: Great
moments in GRIStory -- NASA
May 28, 2009: Particle physics
-- it matters, say UK policy makers -- Physics World
April 14, 2009: 13
things that do not make sense (#5 Dark matter, #7 Tetraneutrons) -- New Scientist
March 31, 2009: Spooky
mirror tricks -- Max Planck Institute
March 29, 2009: Signals of a
strange universe -- APOD
March 23, 2009: SPICE
will measure Sun's plasma properties -- Astronomy.com
March 18, 2009: Particle
oddball surprises CDF physicists at Fermilab -- Fermilab
March 13, 2009: Lasers provide antimatter
bonanza -- Physical Review Focus
March 9, 2009: Fermilab
collider experiments discover rare single top quark -- Fermilab
February 20, 2009: Dark
matter as a source of antiparticles -- APS Physics
February 10, 2009: Chameleon
particle blends into the background -- Physics World
February 9, 2009: New
forces in the dark sector -- APS Physics
February 5, 2009: PAMELA paper
dampens dark-matter claim -- Physics World
February 4, 2009: High
pressure yields novel single-element boron 'compound' -- Science
Daily
January 31, 2009: Simeis 147:
Supernova remnant -- APOD
January 15, 2009: Does
dark matter encircle Earth? -- Scientific American
January 7, 2009: European
boost for particle therapy -- Nature
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