Space & Earth Science Chapter 4: The Sun
proto-star
a huge, dark ball of gas that eventually accumulates enough mass that the crushing gravitational force at the center it is able to ignite the fusion process within the star; Eagle Nebula; "stellar nursery"
photons
a packet of electromagnetic energy containing an amount of energy related to its wavelength
the sun's location
a spiral arm of the galaxy, about three-fifths of the distance from the center to the edge
bright-line spectrum
a unique pattern of spectrum lines produced directly by light emitted by an object
Milky Way galaxy
a vast, disk-shaped assemblage of stars that slowly turn like a giant pinwheel
how long it takes the sun to rotate at the equator
about 25 days
the sun's diameter
approximately 1.4 million kilometers (868,000 miles)
in what form is about 93% of the sun's energy emitted
electromagnetic waves
convective zone
extends from roughly seven-tenths of the sun's radius to the surface; heats plasma that rises to the surface of the photosphere as granules
thermonuclear reactions
generate the sun's energy
neutrinos
how the other 7% of the sun's energy is emitted; tiny particles that apparently travel at the speed of light and can easily penetrate ordinary matter light-years in thickness
"the greater light to rule the day"
name for the sun in Genesis 1:16
how many degrees is the sun's tilt
7 degrees from the ecliptic plane
penumbra
a brighter, outer portion of a sunspot
plages
"clouds" of plasma that emit light in a single or just a few wavelengths (located in the chromosphere)
the sun's distance from earth
150 million kilometers (93 million miles)
umbra
a dark, inner portion of a sunspot
solar wind
a flow of mostly protons and electrons from the sun; a continuation of the corona into space well beyond the orbit of Pluto
continuous spectrum
a full spectrum of colors that can be seen because the lines are so close together
spectrum
all the wavelengths that make up light; the wavelengths that compose the light from an object
coronal mas ejection (CME)
an extremely large mass of particles that can be discharged in a CME; are the most damaging solar flares to satellites and systems on Earth
spectroscope
an instrument used to identify specific colors (wavelengths) in light; separates the light coming from stars by recording the object's spectrum; allows astronomers to determine what elements are present and also indicates how much of an element is present in the star
eruptive prominences
are apparently caused by changes in the local magnetic fields and last for only a few hours
why is nearly all matter in the solar system in a plasma state
because the sun is over 99% of the solar system's matter, and the sun is mostly made up of plasma
why sunspots appear dark
because they are cooler than the surrounding photosphere
solar energy
can be especially useful for hearing water and for heating and cooling homes; has been most successfully applied to heating buildings
dark-line spectrum
can be seen when particular wavelengths are absorbed by gaseous elements between the source and the spectroscope
photovoltaic, or PV cells
can convert light directly to electricity; a flat wafer like device that can be manufactured in a variety of sizes
advantages of solar energy
can never be depleted as long as the sun shines; freely available to all (even though equipment is expensive); high- quality energy; has no polluting waste products; safe to use
aurora borealis (northern lights) and aurora australis (southern lights)
caused by particles from the solar flare weakening the earth's magnetic field and colliding with atoms in the earth's atmosphere
why does the sun appear yellow
colors toward the middle of the spectrum are more intense than those toward the ends of the spectrum, the human eye is most sensitive toward the middle of the spectrum- so yellow is the color that we see best, and visible light, especially yellow, is the light our atmosphere allows to pass most easily
the sun and all the other stars
created on the fourth day of creation
problems with the evolutionary theory of star origins
gasses naturally tend to disperse, not concentrate into a dense mass; the likelihood of such a convenient supernova occurring is extremely unlikely; evolutionists have a problem explaining where the first stars came from, since there were no preexisting stars to from supernovas in order to start the proto-star evolution
diffraction grating
how wavelengths are separated in most modern spectroscopes; a thin plate of glass or plastic containing thousands of microscopic lines ruled or molded onto the transparent surface (separates light into its different wavelengths)
disadvantages of solar energy
it is diffuse (not concentrated); collectors of solar energy must have large surface areas; must be sunny- not cloudy; not available at night
ionosphere
layer of ionized gas particles that have one or more electrons removed from their atoms following collisions with high-energy particles from space (mostly from the sun); effective in reflecting shortwave radio signals transmitted from Earth back toward earth's surface
semiconductor materials
materials that conduct electricity under certain conditions; elements from which computer microprocessor and memory chips are fabricated
what have been identified in the sun
more than 60 naturally occurring elements
spicules
numerous pointed jets of plasma
Johannes Fabricius
observed sunspots around AD 1611 using a telescope and a camera obscure
how much of the solar system's matter is in the sun
over 99% of all the matter in the entire solar system
faculae
plages that emit light in enough different wavelengths to appear white in photographs
coronagraph
produces a artificial eclipse (a total solar eclipse) in order to observe either part of the sun's atmosphere
particles that accompany solar flares
protons (positively charges atoms) and electrons (negatively charged atoms)
nuclear fusion
releases tremendous amounts of energy
magnetic energy
seems to be specifically associated with or could even be the cause of sunspot activity
solar flares
severe storms on the sun; a sudden energetic outburst of the sun's matter that emits both rays and particles
what two things on earth are most likely to be affected by sunspot activity
shortwave radio transmissions and weather
sunspots
small, dark areas that appear on the sun's surface; they move from west to east; the observation that sunspots disappear at the western limb (edge) reappears the eastern limb in about two weeks- this observation shows that the sun is rotating
quiescent prominences
smaller and seem to hang in the corona for up to several days, supported by magnetic loops
prominence
streams of material that appear to rise into the corona from the chromosphere and then gradually fall back
complete sunspot cycle
takes 22 years
line spectra
the "signature", or pattern of lines that each pure substance has
wavelength
the distance from the crest (top) of one wave to the crest of the next
core
the innermost part of the sun; where thermonuclear reactions occur
chromosphere (thin) (invisible)
the middle layer of the sun's atmosphere (immediately above the photosphere)
why the moon appears to be the same size of the sun
the moon is 400 times closer to earth than the sun
hydrogen
the most abundant element in the sun
corona (extensive) (invisible)
the outermost layer of the sun's atmosphere (begins at the top of the chromosphere and continues outward from the sun for millions of kilometers in all directions)
helium
the second most abundant element in the sun; was discovered on the sun before it was discovered on earth
what proves that the sun is degenerating
the sun loses about 6 million tons of matter per second
what is the sun's atmosphere compared to the sun's surface
the sun's atmosphere is hotter than the sun's surface
sunspot cycle
the time between years of maximum sunspots (11 years)
pressure
the total amount of force (a push) exerted over a standard area
photosphere
the visible surface of the sun; divided into small cells called granules
hydrogen and helium
they make up about 98% of the sun's mass
granules
what the sun's surface is divided into; typically 700 to 1000 km. in diameter and lasts for about 8 minutes; hot masses of plasma rising from the sun's interior to the surface
plasma
what the sun's surface is made up of; superheated ionized matter than cannot be classified as a solid, liquid, or gas
radiative zone
where fusion energy travels outward through electromagnetic waves
radiation (from solar flares)
x-rays and extreme ultraviolet rays that temporarily destroy portions of the ionosphere and disrupt a variety of ground-based radio communications