Exploring our closest star, the Sun, its makeup, evolution, its place in the universe, and its significance to life on earth.

1. By
Amita Vadlamudi

2. Our Closest Star

3.  The sun – the center of our universe – is a
sphere of hot plasma around which the Earth
and all other planets revolve. It is a dominant
body of the solar system and constitutes
approximately 99 percent of its entire mass.
Not only is the Sun a significant source of
energy, but it also provides sufficient light and
heat needed on the Earth’s surface.

4.  Located at the center of the solar system, the
Sun is approximately 99.3 million miles away
from the Earth. It lies to the inner rim of the
Milky Way galaxy’s Orion Arm. The exact
location is known as the Local Interstellar
Cloud or Gould Belt, approximately 7.5 to 8.5
kiloparsecs away from the Galactic Center – the
rotational center of the Milky Way galaxy.

5. The diameter of the sun is approximately 864,000
miles or 109 times more than the Earth. Its mass is
330,000 times than that of the Earth

6.  Sun consists mostly of hydrogen. The rest of the
components are helium and other elements,
including oxygen, carbon, neon, and iron.
 In the process of fusion consistently occurring, the
Sun fuses approximately 600 million tons of
hydrogen into helium every second, including
which 4 million is converted to the energy needed
for planets such as the Earth. In a state where
hydrogen fusion in the Sun’s core has diminished,
there will be a significant increase in temperature
and density with its outer layer expanding and
transforming into a red giant.

7.  The Sun’s chemical composition is gained from
an interstellar medium which has evolved over
the past 4.6 billion years. Within the core, the
amount of helium has altered from 24 percent
to 60 percent due to the process of fusion.
Moreover, gravity has also allowed helium and
some of the other elements to settle from the
Sun’s photosphere towards the center.

8.  The photosphere is a star’s outer shell. It is also
the visible surface of the Sun that is marked by
bright granules of plasma. The chemical
composition of this sphere is usually
considered as a representation of the
primordial Solar System. The elements
comprising the Sun are usually measured by
studying the spectroscopy of the photosphere
and the meteorites that haven’t heated fully to
melting temperatures as yet.

9.  The Sun has eight planets as part of the
Planetary System. It includes the four
terrestrial planets i.e., Mercury, Venus, Mars,
and Earth, two gas planets i.e., Jupiter and
Saturn, and two ice planets i.e., Uranus and
Neptune. There are several other comets, dwarf
planets, and icy bodies that lie within the same
Solar System as well.

10.  Some of the first satellites designed for the
observation of the Sun were NASA Pioneers 6,
7, 8, and 9 which launched between the years
1959 and 1968. They orbited the sun at a similar
distance to which the Earth is currently at, and
made measurements on the solar wind and
solar magnetic field. As times progressed and
newer innovations emerged, discoveries were
made on the coronal mass ejections, coronal
transients, and coronal holes – all that played a
significant impact in understanding solar wind.

11.  The Sun plays a scientific, symbolic and
religious role across various cultures. Without
the intense energy provided by the Sun, there
would be no life on Earth.

12.  Amita Vadlamudi