Just because you can’t see something it doesn’t
means it’s not there. Sometimes you looked closer
this is where telescope comes in handy.
A telescope is an instrument that allows people
to see distant objects. Telescopes are important
tools in astronomy, or the study of planets, stars,
and other objects in outer space.
In fact, Telescope comes from Greek work
Teleskopos which means far- seeing.
People generally use
telescope to look at an
object in outer space like
planets, stars and comets.
Sometimes telescope is
used here on Earth to see
interesting wild life from a
distance.
Telescopes were first invented in 1600 are used to
look for ships they were far away.
In fact, Italian scientist Galileo pointed telescope
towards sky that it became a tool in astronomy.
Two things came out of Galileo doing this, one good
and one not so good. The good thing that happened
the austronomers and the scientist who studing
outer space began to discover objects in space such
as the moons craters,the milky way and the Jupiters
moon.
The bad thing that happened is that he pointed the
telescope directly towards the Sun that damage his
eyes.
Telescopes on the sun don’t match.
In the late 1600s, Isaac Newton developed the
reflecting telescope. By using mirrors instead of
lenses, Newton was able to make an improved
telescope that did not suffer from some of the issues
with the refractor.
Types of Telescope:
There are several different types of telescopes. Some,
called light telescopes-gather light from objects.
Other telescopes gather different kinds of
information about the object being viewed.
There are two basic types of light telescopes:
refracting telescopes and reflecting telescopes.
A refracting telescope uses lenses. A lens is a
curved piece of glass that refracts, or bends, light. A
reflecting telescope uses mirrors. Some telescopes
use both lenses and mirrors.
A refracting telescope is a tube with one or more
lenses at each end. Light
from a far-off object enters
the far end of the tube. The
lens or lenses at that end,
called objective lenses,
bend the light. They focus
it at a point near the other
end of the tube. The light
forms an image, or picture
of the object, at this point. The lens or lenses at this
end, called the eyepiece, magnify the image.
Reflecting telescopes are much more powerful than
refracting telescopes. A
reflecting telescope has
a curved mirror at the
bottom of the tube.
Light from an object
reflects, or bounces, off
the mirror. The mirror
focuses the light at a
point in the tube. A
second mirror sits in the way of this focused light. It
sends the light out the side of the tube, through an
eyepiece. A lens in the eyepiece magnifies the image
formed by the light.
In some reflecting telescopes light passes through a
lens before hitting the curved mirror. The lens helps
to make the image sharper.
Some light telescopes are fairly small tubes that sit
on a stand and can be carried around easily.
Buildings called observatories house much larger,
more powerful light telescopes. Spacecraft may also
carry light telescopes.
The Hubble Space Telescope, which orbits Earth on
a spacecraft, is a type of reflecting telescope. Being
outside the Earth's atmosphere allows the Hubble to
view outer space without background light. This has
enabled it to take some amazing pictures of far away
stars and galaxies.
Hubble Space Telescope
was the first space-based telescope.
Source: NASA.
Other Telescopes
Some types of telescopes do not collect light. These
telescopes collect other forms of energy from
space—for example, radio waves, infrared radiation
(a type of heat), and X-rays. Planets, stars, gas, and
other things in space give off these types of energy.
Radio telescopes look like huge bowls. They collect
radio waves that travel to Earth’s surface. Infrared,
X-ray, and other similar telescopes are mounted on
spacecraft.
All these telescopes allow scientists to gather
information about things in space that cannot
necessarily be seen. For example, they have shown
that there is water vapor in other parts of the Milky
Way galaxy. They have also helped scientists
understand how stars and planets form and how
stars die.
Fun Facts about Telescopes
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The successor to the Hubble Telescope is the
James Webb Space Telescope. It is planned to be
launched in 2021.
The first telescopes were used by sea merchants
and the military.
Most observatories are built on mountaintops
where the air is thinner and cleaner.
A lot of astronomers today work remotely from
the actual telescope. They control the telescope
using computers over the internet.
The largest refracting telescope in the world is
located at Yerkes Observatory in Wisconsin.
Kitt Peak National Observatory—outside of Tucson,
Arizona—is the site of the world's largest collection of
optical telescopes as well as the world's largest solar
telescope.