Everything in the universe is made up of protons, neutrons
and electrons. Material composed of
protons, neutrons and electrons is what astronomers call baryonic matter
(ordinary atoms). [2] Until recent discoveries, astronomers thought almost the
entire composition of the universe was baryonic matter until evidence suggested
there is something more that we cannot see. [3] According to NASA, our universe
is roughly made up of 68% dark energy,
27% dark matter, and about 5% normal matter. What exactly are these? [4]
Dark energy is a form of energy that
permeates all of space, producing a repulsive force that accelerates the
expansion of the universe. Dark matter
is matter that does not emit or absorb electromagnetic radiation. It is thought
to constitute most of the mass in the universe. Normal matter is matter in galaxies-including stars, gas, and
dust-that emits electromagnetic radiation. Dark
energy was discovered when two separate teams of astronomers studied a Type
Ia supernovae in 1998. They both independently found that the distances to the
galaxies which had the supernovae they were observing were farther than when
they had been found using other methods. There is so much that is a mystery
about dark energy, forming more questions everyday about the universe.
Composition Pie Chart
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/DMPie_2013.svg/250px-DMPie_2013.svg.png
References:
1.
“The Composition of the Universe”, Hubble News, https://www.spacetelescope.org/science/composition_of_universe/
2.
Webmaster: Britt Griswold, NASA Official: Dr.
David T. Chuss, Friday, 01-24-2014, wmap.gsfc.nasa.gov/universe/uni_matter.html
3.
“Dark Energy, Dark Matter”, NASA Official: Ruth
Netting, April 30, 2013, science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/
4.
“21st Century Astronomy: Stars and
Galaxies fourth edition, Norton & Company, Inc., 500 Fifth Avenue, New
York, N.Y. 10110
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