These Space Telescopes Were Built to See the Unseen

 

When you gaze up into the night sky the stars may appear to twinkle back at you but is the old nursery rhyme true do stars actually twinkle we know for a fact that the sun our own star doesn't twinkle but how come the other stars at night do the truth is the stars appear to be twinkling because of their light being distorted by the earth's atmosphere before reaching us this is also why earth-based telescopes don't always give us the clearest picture as they too have to see through earth's muddling atmosphere and thus arose the need for eyes in space to see it as it is welcome to Science Reads and today let's peer into the history of space telescopes and what these eyes in the sky have revealed to us about the vast expanse of space In July 1958 Arthur "Art" Code received a telegram from the fledgling space science board of the national academy of sciences the agency was asking Arthur an astronomer at the university of Wisconsin-Madison commonly known as art among his peers to help them launch an instrument of about a hundred pounds into the earth's orbit Arthur Code's department in the university was already well known for pioneering a technique for measuring the light emitted by celestial objects called photoelectric photometry Arthur took the opportunity to propose a launch of a small telescope equipped with a photoelectric photometer designed to measure the ultraviolet or uv energy output of stars a task impossible from earth's surface a decade later on December 7th 1968 that idea culminated in nasa's launch of the first successful space-based observatory the orbiting astronomical observatory or OAO-2 thus began the age of space telescopes as OAO-2 was followed by revolutionary projects such as Hubble, Spitzer, Chandra and Compton further expanding our knowledge of the cosmos but the history of telescopes goes even further into history astronomer lyman spitzer who is considered the father of the Hubble space telescope first suggested the idea of a space-based observatory in a 1946 rand corporation study that was 12 years before Arthur code was offered the opportunity that culminated in the first ever space telescope OAO-2 data yielded many scientific firsts including a modern understanding of stellar physics surprising insights into stellar explosions called novae and exploration of a comet that had far-reaching implications for theories of planet formation and evolution it played a key role in inventing space astronomy notes Rich Townsen chair of the UW astronomy department it paved the way for the Hubble space telescope and everything beyond that launched in 1990 and still operational Hubble has completed three decades in space and is expected to survive at least one more before it will start decaying nasa's most famous space observatory is well known for revolutionizing astronomy helping us see space like never before with its breathtaking imagery and reaching with its bold gaze to where no man has appeared before the Hubble deep field and ultra deep field have helped us to scale the observable universe calculate the life cycle of the stars understand black holes and estimate how primordial galaxies must have formed Hubble received its final makeover at the end of the first decade of the 21st century and will now be working alongside its successor the James Webb space telescope and we can't wait to find out

 what these two can do together

 Compton gamma-ray observatory was the second of the four great observatories of nasa and was launched a year after Hubble the astronomical satellite transformed our

 knowledge of the high-energy sky over its nine-year lifetime Compton produced the first ever all-sky survey in gamma rays the most energetic and penetrating form of light discovered hundreds of new sources and unveiled a universe that was inexplicably dynamic and diverse weighing 17 tons Compton was the heaviest astrophysical payload ever flown at the time of its launch on April 5th 1991 aboard the space shuttle Atlantis com then managed to collect data on some of the most violent physical processes in the universe including the surprising detection of gamma rays from thunderstorms on earth and the most persuasive evidence to date that gamma-ray bursts were the most distant and powerful explosions in the cosmos Compton also managed to discover an entirely new class of galaxies that are powered by supermassive black holes and the milky way being part of this new class Compton was followed by the Chandra x-ray observatory in 1999 and the infrared sensitive Spitzer space telescope in 2003 all of them remain operational today except Compton which was deliberately and safely deorbited in 2000 as astronomers were so excited by the initial results they felt that better equipment was required to research compton's discoveries this led to the inception of nasa's fermi gamma-ray space telescope

 Named after Indian-American physicist Subrahmanyan Chandrasekhar, Chandra is the third of NASA's great observatories and is the world's most powerful x-ray telescope examining x-rays emitted by the universe's strangest objects built to study cosmic entities like quasars gas clouds black holes and neutron stars Chandra has worked in tandem with different telescopes including its predecessor Hubble to take composite images of galaxies and other occupants of the cosmos Chandra has played a pivotal role in

 the discovery of hidden black holes

 providing insightful observations of our own galaxy's supermassive black hole sagittarius Chandra is also responsible for x-ray images of everyone's favorite red planet Mars

 without space telescopes we cannot observe infrared radiation coming from outer space because our earth's atmosphere absorbs the majority of it don't worry for it's a good thing otherwise we would all die of skin cancer as ir radiation reduces dna repair efficiency in our body and thus promotes chances of getting skin cancer but it is also why we needed an ir radiation gathering telescope above the earth's atmosphere and that became Spitzer the fourth great observatory in space launched by nasa Spitzer gathered ir radiation emanating from cosmic objects including faraway galaxies black holes and even comets in our own solar system moreover Spitzer was the first telescope to see light from an exoplanet and it did so on pure accident the Spitzer telescope charted the first weather map of an exoplanet and discovered the planetary system of Trappist-1 the largest batch of Earth-like planets ever discovered in a single system scientists observed the Trappist-1 system for over 500 hours with Spitzer to identify five of the seven planets of the star system and found three of them were in the habitable zone the telescope also detected one of the most remote planets ever known which is about 13,000 light years away from the earth using the microlensing technique using this technique Spitzer and the Korea Microlensing Telescope Network were able to identify multiple exoplanets which we would have never found otherwise Spitzer also used its infrared vision to observe the dust of six dead white dwarf stars that helped us to understand the death of stars and the birth of planets better after more than 16 years of studying the universe Spitzer's journey came to an end in 2020 NASA's planet hunting telescope was

 launched in 2009 and was tasked to

 find earth-like planets in the milky way that are in the habitable zone of their star system and have a possibility of teeming with life to do so it was tasked with searching for characteristic variations in the light from a pre-select target group of a hundred thousand stars using the light dipping method Kepler studied far corners of the galaxy and was able to discern that there are more planets in the galaxy than stars and they come in all sizes what's even more surprising is that the most common size it found was somewhere between earth and Neptune which surprisingly doesn't exist in our solar system thanks to Kepler's observation we discovered many small planets and the telescope proved that planets of smaller size are more common than we thought of before also most star systems have a large number of planets orbiting close to their parent stars than our solar system the existence of these compact system raises questions about how solar systems form

 are these planets born close to their parent star or do they form farther out and migrate in thanks to the kepler telescope we are now in the golden age of discovering exoplanets as it discovered just over 2600 exoplanets on its own before it ran out of fuel in 2018 and was sadly retired formerly known as GLAST Fermi Telescope was conceptualized to take over Compton's research as it was better equipped to do the

 job launched in 2009 fermi has been

 scanning the skies every three hours and has observed more than 5,000 individual gamma-ray sources including

 an explosion called GRB130427a

 the most powerful gamma-ray burst scientists have detected fermi's all-sky map produced by the large area telescope or lat has revealed two massive structures extending above and below the plane of the milky way these two bubbles span 50,000 light years and were probably produced by the supermassive black hole at the center of the galaxy only a few million years ago The Gamma-ray Burst Monitor (GBM), Fermi’s secondary instrument can see the entire sky at an instant except the portion blocked by earth the satellite has observed over 2,300 gamma-ray bursts the most luminous events in the universe gamma-ray bursts occur when massive stars collapse or neutron stars or black holes merge and drive jets of particles at nearly the speed of light in those jets matter travels at different speeds and collides emitting gamma rays fermi has fundamentally improved our understanding of how the universe operates and will continue to do so in the future as well this spacecraft has both provided evidence for long cherished theories and has also forced the scientific community to re-evaluate some of its assumptions there have been many more telescopes and observatories launched into space by other space organizations across the world but nothing even comes close to what the James Webb space telescope will be able to achieve and we cannot wait to explore a whole

 new part of the universe with you all

 here's to a bright future and a great year of space exploration tell us in the comments what you are most excited about for 2022