Download 1 Josh Machado Science Section C. Language Arts Section E. 5/15

Josh Machado
Science Section C.
Language Arts Section E.
5/15/12
Space Research Paper
Stars: The Key to the Cosmos
Stars may appear as distant, ordinary specks of light in the night sky, but they are extraordinary
on the inside. Every natural element in the universe, with the exception of hydrogen, is forged inside
the core of a star. Stars scatter these elements throughout the universe in stellar explosions of
astronomical proportions. These elements create the building blocks for life. But, along with the
power to create life, stars also have the power to destroy it. They are born in cold clouds of dust and
gas, but can end their lives in fiery explosions. Yet long ago, humans knew practically nothing about
these strange stellar bodies. Stars have been pondered about since the dawn of human
civilization. Although humans have wondered about them for thousands of years, most of what we
know about these massive celestial bodies, has been discovered in the past 150 years. Our closest star
in the vast cosmos is our sun. Our sun provides the conditions for life here on Earth. Without that star,
burning bright, 93 million miles away, Earth would be a cold, dark, and lifeless ball of rock. Most of
what we know about stars has come from our sun. However, scientists still study stars far from Earth,
in fact, too far to even affect life here. But in doing so, our understanding of the universe, how life
began, and one day, how it might end, have been revolutionized. The stars may truly be our key to
unlocking the secrets of the vast and puzzling cosmos that surrounds us.
Stars have been studied for thousands of years. Ancient civilizations marked and tracked the
movement of the stars. They named the constellations, and charted them too. Long ago, astronomers
didn’t have many tools. They relied on their eyes for observation, and their minds for predictions. In
the 1600’s astronomer Galileo Galilei gazed up at the sky with his telescope. Compared to the power
of today's telescopes, Galileo’s strongest telescope was only a few times stronger than the average pair
1 of binoculars today. But the skies had been studied before, long before Galileo’s time. The ancient
Mayan civilization examined the stars, and used them to create one of the most accurate calendars of
the time. Ancient Chinese astronomers in the year 1054 AD, witnessed a supernova so bright that it
was visible by day. Astronomers today now know that it was that very supernova that created the Crab
Nebula. Stars have been studied for thousands of years. Mankind has always longed for a deeper
understanding of the world around us, which includes all the mysteries beyond our home
planet. Learning about stars helps us in our understanding of the universe. Stars, believe it or not, help
explain everything from how elements are created, how atoms work, and even how life began on
Earth. Human civilizations have always wondered about the stars, and continue to do so today.
The life of a star is a very complex, and lengthy process. A young star begins its life inside of a
dense cloud of gas and dust, which can stretch for light years across, called a nebula. Nebulae are
often bright and colorful, perhaps one of the most breathtaking sights in all of the cosmos. But despite
all the beautiful colors, the most interesting things take place in the darker regions of a nebula, where
the gas and dust are more tightly packed. Inside those dark areas, clouds of hydrogen swirl around a
dense center, which will later become the core of the star. As more and more material is drawn to the
core, it becomes more densely packed, and therefore, it heats up. Pressure builds to mind boggling
levels, and two jets of pure energy shoot out of the soon to be born star, also known as a protostar. At
a blazing 10 to 15 million Kelvins (20 million to 27 million degrees fahrenheit), the star ignites. At
this temperature, hydrogen atoms can fuse to form helium, which takes us to our next important stage
in the life of a star, the main sequence.
A star can burn bright for billions of years during this stage of its life. One might wonder how
anything can survive for that long. Stars are incredibly powerful nuclear power plants, in a sense, that
generate more energy than you could imagine. But in order to access this immense amount of energy,
a star must be able to tap into the energy inside of an atom. To do so, stars fuse hydrogen atoms to
create helium. When two hydrogen atoms smash into each other, they create one helium atom, along
2 with a photon. Photons are the smallest “packets” of light. When a photon is created, its goal is to
escape the star. However, this goal is not as simple as it sounds. On its journey to escape the massive
celestial body, the photon is literally stuck inside the star for thousands, even millions of years. In the
process of escaping, the photon bounces around inside the star, crashing into atoms, and other particles
alike. Photons escaping the surface is actually what heats up the outer layers. However, photons
aren’t the only thing that fusion creates. When two atoms fuse together, a small amount of mass is
“lost”. It hasn’t actually disappeared, rather it has been converted into pure energy. This energy
surges outward, and balances out with the incredible force of gravity pressing inwards. Since the star
is so massive, the amount of gravity attempting to crush it, is enormous. Luckily, fusion prevents this
from happening. Throughout the entire life of the star, fusion and gravity are locked in an intense
battle. Fusion wants to blow the star to pieces, while gravity wants to crush in on it. Our sun
experiences these same forces, and fortunately for us, just like with all stars, they balance each other
out. Well, until the end of the stars life, that is.
When our sun comes to the end of its roughly 10 billion year lifespan, it will become a red
giant. Just like theoretical physicist Lawrence Krauss says, “The sunlight from our sun that bathes us
and warms us everyday is nothing but starlight, because our sun is nothing but a star like all the rest”
(How The Universe). And just like every star, it will eventually die. Imagine if we could fast forward
5 billion years into the future, around the time when astronomers predict our sun will die. Picture
yourself with a front row seat to the death of our sun. Once our sun runs out of hydrogen, fusion
begins to slow. The force of fusion pushing outwards weakens, and gravity begins to press
inwards. In response, the star heats up, and begins to swell. The sun will swell from one million miles
in diameter, to 100 million miles. When this happens, the sun will literally expand so far, it will
swallow up our planet, and incinerate it. It would now officially be a red giant. Our sun will one day
run out of hydrogen, and when that happens, it will begin to fuse helium into beryllium. When this
occurs, more energy is created than when two hydrogen atoms fuse. This excess energy surges
3 outward and eventually blows away the outer layers of the star, leaving behind a hot dense core, a
stellar corpse known as a white dwarf.
When a star comes to the end of its life, there are a number of ways it can die, as well as
numerous varieties of stellar corpses that can be left behind. When stars around the size of our sun die,
they become red giants, and eventually white dwarfs. A white dwarf is a small, dense leftover core
from a red giant, that can burn for billions of years. Larger stars, more than eight times the mass of our
sun, will become a supernova. These massive stars burn through their fuel very fast. Unlike smaller
stars, the larger stars create more elements. Instead of dying after they fuse helium into carbon, they
go on to forge heavier elements, such as oxygen and silicon. But the instant the star creates iron, it is
doomed. The star puts energy into the iron atoms in an attempt to make them fuse together. However,
iron absorbs energy, therefore it will not fuse. Since the star has no fusion to provide energy to push
outward, gravity crushes the star. The outer layers of the star slam into the core, and the inner layers
are thrown outwards in an explosion of galactic proportions. A supernova. After a massive explosion
like a supernova, one would think that nothing would be left. Until recently, astronomers thought the
same thing. In 1965 Antony Hewish and Samuel Okoye discovered the first neutron star, which
proved that despite the intensity of a supernova, there was actually something left. When a star
explodes there is a variety of stellar corpses that can be left behind. Among these possibilities are
neutron stars, pulsars, magnetars, and in the most extreme cases, black holes. Although not much is
known about these “dead” stars, there are plans to gain more knowledge in the future.
It’s true that there is a lot we don’t know about stellar corpses, but believe it or not, there is also
a lot that astronomers don’t know about living stars too. NASA is currently constructing the James
Webb Space Telescope, which, in 2018, will be launched to study the first moments in the creation of a
star. Since stars form in the dense areas of nebulae, NASA needs another way of observing this, other
than with visible light. The Hubble Telescope uses infrared light to gaze into the pillars of dust and
gas. However, there are certain areas of extreme density that not even the Hubble can observe, hence
4 the need for a new telescope. The James Webb
Telescope. This telescope contains a massive mirror to gain
immense amount of light. In fact, this mirror is more than
twice the size of the Hubble Space Telescope’s mirror. In
addition, the telescope is also created for the purpose of
observing infrared light. “Webb is designed to look deeper
into space to see the earliest stars and galaxies that formed in the
universe and to look deep into nearby dust clouds to study the formation
of stars and planets.” (Frequently Asked Questions”). And best yet, the
James Webb Space Telescope
Seen above is a model of the James
Web Space Telescope. The large piece
made up of smaller hexagons is the
telescope’s primary mirror that
gathers light.
telescope will have sharper, more accurate images than the Hubble
Space Telescope. When this telescope is finally orbiting our earth, it could, and without a doubt will,
revolutionize our understanding of how stars are formed.
Understanding precisely how stars form would revolutionize the field of astronomy. But
finding life on another planet would revolutionize mankind. One might be curious as to what stars
have to do with finding life on other planets. Well, frankly, it has everything to do with it. A star
needs to provide the proper conditions in order for life to form on a planet. A planet cannot be too
close, nor too far from its host star. There are many specific qualifications a star must meet in order to
possibly contain life within one of its planets. And there is one specific classification of stars that
stand out to astronomers. G stars. These stars interest astronomers in the hunt for extraterrestrial life
because of a number of properties. For instance, G stars have a stable energy output throughout most
of their lifespan, which means that the amount of heat and radiation the star emits, is roughly the same
throughout the star’s main sequence. Also, these stars have long lives (up to 15 billion years) which
gives an adequate amount of time for life to develop. Unfortunately, only approximately 2.5% of stars
in the Milky Way are G stars. However, fortunately for us, our very own sun happens to be one of
those few. The search for life may seem to be all about finding earth-like planets, but in actuality, it
5 depends on the star.
Without the existence of stars, neither you or I would exist at this very moment. Not Earth, the
moon, Mars, practically nothing. If the first stars had never formed, the universe would be nothing but
a vast, empty cloud of hydrogen gas. Our closest star, the sun, provides heat, light, and energy for us
here on Earth. We are dependent on our sun. Without it, we would not be able to survive on this
planet. The world we have come to know and love, with thriving life, and deep blue oceans, would not
exist. Stars create the materials to create life, but also have the apocalyptic power to destroy
it. Understanding stars helps astronomers and physicists better understand the universe. It turns out,
that those simple, ordinary little specks of light we see in the night sky, could truly be the keys to the
cosmos.
6