SCIENCE
Space Science
NASA missions
Travel to Mars
Origin of Life
Space Science
NASA missions
Travel to Mars
Origin of Life
| ORIGIN OF LIFE - COMETS BROUGHT THE RAW MATERIALS |
Asteroids or minor planets are small, rocky bodies that
orbit the Sun. There about ten thousand asteroids
orbit the Sun between Mars and Jupiter. Asteroids are
dangerous to Earth, one large-room size asteroid hit
north Arizona 50 thousand years ago.
Comets are different from asteroids.
Comet has three basic parts: coma, nucleus and trail.
Coma is a spherical envelop of gas and dust, which
develops around a nucleus. Nucleus is the solid part of
a comet; its diameter is about a few to a few dozen
kilometers. It consists of ices and dust grains. Trail
consists of dust particles and debris, which follows the
comet's orbit.
Comets might bring the raw materials for
the pageant of life on Earth.
When the Earth was first formed, its surface was so
hot resulting in a loss of virtually all of the volatile
organic chemicals. Thus, Earth was not a satisfactory
source for lifeÂ’s building blocks.
Comets are the source of organic materials and cooling
agents. They delivered packs of raw materials to Earth
for the pageant of life and cooled the Earth surface to
allow some organic molecules to stay.
At early stages, condensations of some simple
molecules occurred to form more complex molecules
such as amino acids, and then, later nucleic acids. Over
a long period of time, DNAs were formed. In the late
1990s, Nobel Prize winner, Stanley B. Prsiner,
discovered self-replicating proteins - prions!! Though
they do not have respiration, they can replicate.
Probably, they are one of the simplest 'living
molecules'.
SOURCES David H. Levy, Comets Creators and Destroyers,
Touchstone. 1998. Jacques Crovisier and Therese Encrenaz, Comet
Science: the study of remnants from the Birth of the Solar System,
Cambridge University Press, 2000.
orbit the Sun. There about ten thousand asteroids
orbit the Sun between Mars and Jupiter. Asteroids are
dangerous to Earth, one large-room size asteroid hit
north Arizona 50 thousand years ago.
Comets are different from asteroids.
Comet has three basic parts: coma, nucleus and trail.
Coma is a spherical envelop of gas and dust, which
develops around a nucleus. Nucleus is the solid part of
a comet; its diameter is about a few to a few dozen
kilometers. It consists of ices and dust grains. Trail
consists of dust particles and debris, which follows the
comet's orbit.
Comets might bring the raw materials for
the pageant of life on Earth.
When the Earth was first formed, its surface was so
hot resulting in a loss of virtually all of the volatile
organic chemicals. Thus, Earth was not a satisfactory
source for lifeÂ’s building blocks.
Comets are the source of organic materials and cooling
agents. They delivered packs of raw materials to Earth
for the pageant of life and cooled the Earth surface to
allow some organic molecules to stay.
At early stages, condensations of some simple
molecules occurred to form more complex molecules
such as amino acids, and then, later nucleic acids. Over
a long period of time, DNAs were formed. In the late
1990s, Nobel Prize winner, Stanley B. Prsiner,
discovered self-replicating proteins - prions!! Though
they do not have respiration, they can replicate.
Probably, they are one of the simplest 'living
molecules'.
SOURCES David H. Levy, Comets Creators and Destroyers,
Touchstone. 1998. Jacques Crovisier and Therese Encrenaz, Comet
Science: the study of remnants from the Birth of the Solar System,
Cambridge University Press, 2000.