We witness different events happening in space. We get an image of celestial bodies, which gave a boost to understand the universe better. These were possible due to the invention of telescopes and by using the telescope to monitor space. A telescope is an optical device that allows lenses, circular mirrors, or a mixture of both to view distant objects or various instruments that use electromagnetic radiation to observe the emission, absorption, or reflection of electromagnetic waves in space. In the 17th century, our ancestors invented the first refracting telescopes, which used glass lenses.
For the past centuries, telescopes evolve from a simple magnifier to view celestial bodies to a tool that we can detect activities in the universe. The astronomical telescope, to be specific, provided our generation with what lies in the vast universe. We saw how a black hole devours stars and planets and how it sucks up celestial bodies in close vicinity. Galileo Galilei, a famous physicist, astronomer, and engineer, was the first to point out the telescope skyward to observe space. He spearheaded the scientific revolution between the 16th and 17th centuries. During this time, he effectively disproved Aristotelian physics and cosmology, which had historically influenced European science.
The Hubble Space Telescope as seen from the departing Space Shuttle Atlantis.
Astronomers before Galileo only explained what they see but did not elaborate on what activities happen in space. Without the telescope, it was arduous to give accurate observations. It contributed to the delay in astronomy and space exploration discovery for years to come. Until the year 1609 came, where Galileo built his telescope to observe the celestial bodies. Galileo's telescope was not as good as the telescopes we have at this time, but it was enough to provide Galileo a good sight of the natural surface of the moon. In his first sketches, the moon has craters and was rugged, which rejected the idea of heavenly perfection of the Aristotelian view of the universe.
In 1610, Galileo discovered four new stars that orbit Jupiter, which the largest moons it has. These orbiting moons disprove the Aristotelian view of the universe's geocentric notion, which stated that the heavens revolve around the earth. These observations support the vital role of telescopes but show us that not everything we believe in will always be true. Galileo’s discoveries with the telescope added weight to the heat he is having with the catholic church. Soon after releasing books regarding his discoveries with the telescope and the beliefs he had in mind, he struck a plea bargain and sentenced to house arrest. He remained here until he died in 1642, working and writing the concept that changes the world.
The Swiss 1.2-m Leonhard Euler Telescope in its dome at La Silla.
After the discoveries that Galileo Galilei made, scientists began to improve the telescope in different ways. Johannes Kepler studied optics and constructed a telescope with two convex lenses that flipped the images. From the papers of Kepler, Isaac Newton reasoned that a telescope made of mirrors rather than lenses would be more efficient. In 1668, he designed a reflecting telescope. The reflecting telescope would become the dominant astronomical instrument centuries later.
Between 1850 to 1900, people encountered a problem with reflectors, specifically those with speculum metal mirrors. They redesigned large reflectors with apertures ranging from 60 centimeters to 1 meter. It resulted in the Yerkes Observatory refractor in 1897. In the early 1900s, they developed a series of larger reflectors with glass mirrors. It included the 1.5-meters in Mount Wilson, the 2.5-meters in Hooker Telescope (1917), and the 5-meters meters of Hale Telescope (1948). These are the major research telescopes in 1900, and all are reflectors.
The Hooker reflecting telescope at Mount Wilson Observatory.
Credit: Andre Dunn
With the development of the radio, scientists could start to study not just light but other electromagnetic radiation in space. In 1931, Karl Jansky, an American inventor, was the first to observe radio emissions from space. He discovered a source of radio interference coming from the center of the Milky Way galaxy. Since then, radio telescopes have mapped the shape of galaxies and the existence of background microwave radiation that confirmed a prediction in the Big Bang Theory.
In the 1970s, the European Space Agency and the National Aeronautics and Space Administration began designing and building the Hubble Space Telescope. The telescope tasked is to explore the solar system. It measured the age and size of the universe. It searched for our cosmic roots and charted the evolution of the universe. It helped us unlock the mysteries of galaxies, stars, planets, and life itself. Since the time we launched it in 1990, It was able to determine the age of our universe with more precision. It was able to found more moons near Pluto. Besides, they used Hubble Space Telescope to observe the galaxies in the young universe and monitored the space weather on the outer planets. It was even able to observe exoplanets by the mid-1990s.
he primary mirror assembly of James Webb Space Telescope under construction.
In 2009, we started planet-hunting using the Kepler telescope. So far, we have found out 4000 potential planets as of the moment. We focused its observation on a section of the Cygnus constellation to discover more planets in the universe. In 2013, they created a new mission in which Kepler moves between different regions of the sky instead of pointing at the same section. Hopefully, we will be able to launch the James Webb Space Telescope on October 31, 2021. it is of the Hubble space telescope. It will be placed farther to earth than the Hubble and focus its science on the history of creation, the origins of the universe at first light, the formation of the first galaxies and stars, and the origins of life (including exoplanets).
Astronomers discover more and more planets in far galaxies with the sophisticated telescope we have. It speeds up space exploration and gives us a better insight into the big questions in astronomy. With James Webb Space Telescope, we can closely observe a curious subset of orbs that are free-floating in the outskirts of the universe (at the peak of what our telescope can reach). Astronomers discovered these orbs in 2003 but not observed them due to the difficulty of detecting them using existing ground telescopes. Some of which are gassy, Jupiter-sized, and few resemble rockier planets like the Earth.
With the telescope, we are able to see back to the earliest scene of the universe, which about 13.8 billion years old. In the future and with good technology, we can even further see to when the stars and galaxies formed, somewhat the Cosmic dawn. We can give much of the credit for space telescopes, it studied the deep Universe from orbit for decades, especially the Hubble space observatory. With the telescope, we still continue to discover and answer the big questions in science. It only a matter of time before we can see how the Universe began, and debunk or approve the theories we had for so long. It unlocks the mysteries of Dark Matter and Dark energy and locates habitable zones and worlds. As we look further, we may be able to find life beyond Earth and our Solar System. It will happen with the telescope.
Note: The cover image is created by the author in Canva.
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