Transcript a solar system is born

A SOLAR SYSTEM IS
BORN
Chapter 16 – 1
part 2
The Birth of a Star
• As the planets are
forming, gas and dust near
the center of the solar
nebula grow dense.
• In the center the
hydrogen atoms begin to
fuse.
• Fusion creates energy
that pushes outward. The
star begins to shine.
• A star is born and a new
solar system is formed.
Energy Production in the Sun
• The sun has been shining for about 4.6
billion years.
• Tiny amounts of matter can produce a
huge amount of energy.
Nuclear Fusion
• Nuclear fusion is
the process by
which two or more
low-mass nuclei
fuse to form
another nucleus.
• When hydrogen
nuclei fuse they
form helium and
ignition begins.
Conditions Required for Fusion
• Under normal conditions, hydrogen
atoms never get close enough to join.
• In center of the sun, the temp. and
pressure are very high.
• This forces the atoms together, so
hydrogen can fuse.
Measuring Interplanetary
Distances
• One way scientists measure distances in
space is by using the astronomical unit.
• One AU is the average distance
between the Earth and the sun which is
150,000,000 km.
Another Way
• Another way to measure distances is by
using the speed of light.
• A light-minute is how far light travels in
one minute, 18,000,000 km.
• Distance in the solar system is also
measured in light-hours and light-years.
THE END