How Were Exoplanets Found?

As mentioned earlier, the efforts of exploring the abandoned and hidden planets in the galaxy were started way before. Scientific history states that the era early of early exploration, and sophisticated telescopes accompanied exoplanet detection both in space and around. Some were designed to measure the sizes and types of these planets, and others were deployed to take a closer view of them.

One of the vital steps involved in getting to know more about exoplanets was direct imaging of exoplanets. There were two main methods that scientists relied on, wobble and shadows. The wobble method, also known as radial velocity, detects the telltale jitters of the stars when they are pulled with the gravitation of the orbiting planet. The wobble method is used to measure the mass of the planet.

Both of these methods were used to develop the initial images of the first exoplanet, i.e., 51 Peg back in 1995. It was the combined efforts of Michael Mayor and Didier Queloz. The radical velocity methods using the ground telescopes have found around 700 planets so far. A large number of exoplanets were found by searching for shadows.

Shadows are caused by the dip in starlight when a planet crosses its way. The such crossing is called a transit. These shadows reveal how big the star is. Searching for the planetary shadows is called the transit method that scientists generally use to check up on the planets. NASA’s Kepler space telescope invented in 2009 has discovered 2,600 confirmed exoplanets. In the K2 mission, the telescope is all set to explore new and undiscovered planets soon. Both the methods, wobbles and shadows are being upgraded to get closer insights into the exoplanets real more quickly.

About The Founder of Exoplanet

If you have been updated with the news regarding Nobel prize awards, you would know that the coveted Nobel Prize in Physics has been shared by three scientists who have given their immense contribution to unraveling and making the history of the universe. They are responsible for the discovery of some of the greatest mysteries of the world. For the “Theoretical Discoveries in Physical Cosmology,” Canadian-American James Peebles from Princeton University received one-half of the prize.

The remaining half was shared by Michel Mayor and Didier Queloz, the Swiss scientist who brought the concept of exoplanets to the mainstream and discovered the first-ever exoplanet, 51 Pegasi b. Their discovery sprouted a wave of revolution in astronomy, after which around 4,000 exoplanets have been found.

The Quest to Finding the First Exoplanet

The discovery of the first exoplanet orbiting its star was a benchmark discovery in astronomic science. Two significant facts were revealed after Mayor’s and Queloz’s discovery; first, that sun is not the only star playing a host to planets, and second, that universe is full of secrets that are yet to be discovered. Over the years, humans had struggled to find whether life existed beyond the Earth and its solar system. Around 24 years ago, the mystery was unraveled when Mayor and Queloz, two Swiss scientists, came forward with their discoveries of the first exoplanet, named 51 Pegasi b. Back in 1995, with their constant efforts and persistence, both the scientists were able to find an exoplanet that was orbiting a star called 51 Pegasi, later the planet was given the name 51 Peg b. It is said that the planet’s mass is similar to that of Jupiter and is 100 times closer to its star, which makes its temperature shoot over 10000° C.

Planets from our solar system like Saturn and Jupiter are giant in masses and are ten times further from the sun and have temperatures below – 100° C. It is deemed that Saturn and Jupiter were formed through gaseous discs around the sun due to the accumulation of gas and ice. The discovery of the hot exoplanets gave a hint to scientists that planets can be formed in extremely diverse conditions outside Earth’s solar system. The development of 51 Peg b was the result of technological prowess and dedication. Both scientists have indulged in finding planets outside our solar system when everyone believed that it was a lost hope. 

No one was actively searching for such exoplanets. Still, Mayor and Queloz were determined to discover what they intended to do when they started a long-term program, which ended up in finding the first exoplanet. They used a radial velocity method to identify 51 Pegasis b orbiting its star. When a planet revolves around its star, the star also starts moving in a similar yet smaller orbit. Due to the planet’s gravitational pull, the star tends to wobble around. 

The movements of the star can be seen from the Earth which is known as the Doppler shift. The wavelength of the light changes according to the actions of the star. This method was also used to measure the speed at which the planet was moving. The rate of the planet was also influenced by the location of the other planets as well.

When both scientists found the signs of their first exoplanet having a short orbit, they were determined to make further observations to analyze its properties. The radical discovery of Mayor and Queloz’s 51 Peg b triggered an avalanche of astronomical observation for the next two decades. Their discovery compelled every other scientist to delve deep into the development of exoplanets. After 51 Peg b, more than 4000 other exoplanets were discovered. Ranging from Jupiter to Earth-sized planets, there were plenty of exoplanets that came into the mainstream space studies. Mayor and Queloz’s discovery proved that there are other cosmo bodies in space that are yet to be discovered, and adequate technology has to be deployed to unravel the mystery.

The discovery of an exoplanet was a breakthrough in the space world. The groundwork was laid by Michel Mayor and Didier Queloz. Their radical discovery of the exoplanets and related studies have bagged the Nobel Prize for Physics. Both the Swiss scientists have given so many space studies that have compelled space scientists to steer their concentration and technologies towards finding the hidden planets that might be orbiting some abandoned star in the galaxy. If you are keen to know more about their discovery, then don’t stop and read on…

Learn more about their journey towards the common goal of finding exoplanets and bringing their existence to mainstream space studies.

It All Started With A Pulsar

Though Mayor and Queloz discovered the first widely accepted exoplanet in 1995, their search was triggered by Aleksander Wolazczan and Dale Frail, who have been exploring the two other planets orbiting the same star since 1992. But they soon withdrew from the program and left the study midway. Afterwhich, Mayor and Queolz took the scene and started their research. Unlike the sun, the star was completely different, and it was a pulsar, a dense core corpse of a giant star rotating rapidly. At regular intervals, the pulsar would leave a beam of radiation on the Earth, similar to the light from a distant lighthouse. When the exoplanets orbit around their host star, they tend to exert a gravitational tug on the pulsar, making it wobble. Such wiggles would make subtle transformations in the frequencies. 

Though Mayor and Queloz were able to find the transformations in the pulsar’s frequencies, which were significant findings in astronomy, they needed something more. They had to put in some more work and research into the matter to make their discovery more authentic and bring the concept to the mainstream. The idea of planets other than the ones in our solar system surviving a supernova orbiting around the pulsars was still a mystery to be solved.

Bringing the Doppler Shift to the Mainstream

The wiggling of the stars longed for quite a while until astronomers found the perfect technology to gauge the measurement. It was a spectrometer that astronomers relied on for its size. It is a device that broke up the light from a distance into a multitude of elements. With the help of the spectrometer, Mayor and Queloz were able to get a close view of the planets and detect the presence of hydrogen and carbon. They used to monitor the star day and night and observe the change in the spectrum. The changes in the movement that were seen from the Earth were called the Doppler shift.

Doppler shift was not a new technique that astronomers were using; it was discovered almost two hundred years ago. It was Mayor and Queloz that took the method to another level by tweaking it to some extent. 

They were determined to prove the existence of an exoplanet in the universe. When a planet orbits a star, the gravitational pull of the planet will pull the star just like a leash on a dog. Though there won’t be some significant movement as the star overweighs the world, there will be a slight change. In 1995, the Nobel award winner duo proved the detectable movement or wobble in star 51 Pegasi’s spectrum. They confirmed that such wobble could only be caused by a small or unseen companion, probably an exoplanet.

Pegasi: A Boring Star

There’s nothing remarkable and significant about the star 51 Pegasi. Maybe that’s what something that made the discovery of an exoplanet so special and brought a radical revolution in astronomy. Pegasi is a general-looking star residing 50 light-years away with 10% more mass than our sun and is around 6 billion years old. It’s just a regular star, living an ordinary life with a single planet orbiting around it. It was the discovery of the mayor and Queloz that brought 51 Pegasi into the limelight.

The Swiss scientists ushered a new path of exploration that resulted in the development of hundreds and thousands of other exoplanets. It’s only a matter of a few technological advancements and research, and we are just one long-term program away from discovering Earth’s twin galaxy.

Hot Like Jupiter

After the discovery of an exoplanet, there were many speculations and anticipations in the astrophysics field. The discovery of Mayor and Queloz has already brought a wave of advancements, and scientists were looking to take a piece of the pie. After the discovery, scientists started comparing the specifications of the 51 Pegasi b with the planets of our solar system. The planet that was orbiting 51 Pegasi was nothing like what we have in our solar system. It is surprising to know that the early discovery of the exoplanet was tossed as junk in 1992. 

It was Mayor and Queloz’s undisputable findings that confirmed the reality of exoplanet and their existence in our universe. The International Astronomical Union gave the planet orbiting around 51 Pegasi a name. It was named Dimidium, and its informal name was Bellerophon. It is basically a gas giant with a mass similar to that of Jupiter and 150 times the mass of Earth. Dimidium orbits 5 million miles from its host star, which is actually seven times closer than Mercury is presently closer to the sun. 

Everyone has been deeming Dimidium as hot Jupiter because it has the same mass of Jupiter, but it is way hotter than the giant planet of our solar system. Apart from the temperature, there are many things common between Jupiter and Dimidium. For instance, the mass, the gaseous state.

How Can You Spot Exoplanets?

With the discovery of an exoplanet, Mayor and Quloz have brought exoplanets to mainstream astronomy. Now people are closer to the fact that our solar system is not the only cosmic body in the solar system, and there are plenty of other planets and stars which accompany us. It is quite easy to spot the existence of an exoplanet. One of the common ways to look for exoplanets is to search for wobbly stars in the night sky. A star that is host to one or two planets will not orbit perfectly on its axis due to the gravitational tug from the planet. 

This irregular movement/orbiting looks like wobbling from a distance, and we can know that the star has planet/s orbiting around it. This is one of the proven methods of finding the existence of exoplanets as hundreds and thousands of planets have been already found through this method. However, only massive planets like Jupiter can be discovered through this method as it is quite challenging to monitor the wobble of small planets like the Earth. Next time, when you spot the stars in the night sky twinkling in an irregular, you can confirm that the star must be hosting an exoplanet. 

How Can We Find Earth-Like Planets?

It has become pretty necessary to find Earth-like planets and detect whether life sustainability is possible there. Climate change and global warming have put humankind in danger, and we are daily facing threats. Hence, scientists have been continuously working towards finding earth-like planets. The main motive behind the discovery of exoplanets was to discover whether there were any life sustainability elements present in its atmosphere. 

NASA launched a spacecraft called Kepler in 2009 that was primarily designed to look for exoplanets. Kepler was sent into the dark space to look for planets of all sizes and masses. It generally targeted the bodies that orbited around the stars. Some of the planets that were discovered by Kepler were rocky and very distant from their parent stars. There was a sweet spot between the planet, and the star called the habitable zone where life can be sustained.

Kepler used the transit method to detect the existence of the exoplanets. The light of the star changes when Kepler passes its way which helped them figure out the size, temperature, and atmosphere of the planet. Examining the time between the transit, scientists can find the distance between the planet and the star. As mentioned at the beginning of the article, Kepler is getting an up-gradation with TESS, and with this, more exoplanets are waiting to be discovered.

Why Should We Care About Exoplanets?

Exoplanets are those neighbors that were once hidden in mystery. Thanks to Mayor and Queloz, who took the initiative and decided to bring these exoplanets into mainstream astronomy. Their discovery has brought a radical change in the way we perceive the universe.

Now that you have learned so much about exoplanets so far, you might have been thinking about why exoplanets need to be discovered in the first place. Some NASA scientists have given their views on why these exoplanets should be observed. Take a look at the five primary reasons why humans should be acquainted with exoplanets.

A Quest to Discover More

Space is a hidden treasure trove that has some incredible mysteries in it that are ushering to unravel. Exoplanets are one such hidden gems in space that must be discovered to add up to the universe. It is essential to identify exoplanets that people have never seen before. And it is always good to find some co-existing planets in the universe. 

It is quite evident that Earth’s ecosystem is something mysterious about the Earth. Be it the proper distance from the sun or the perfect combination of atmospheric elements, life is sustainable on Earth. One of the significant and significant reasons to go and look for exoplanets is to discover whether there are any more Earth-like planets where life can be sustained. It has become quite daunting to account that Earth will have the same favorable situation for survival. Hence, it has become more than essential to look out for exoplanets and search for life signs in them. 

Many scientists have quoted that they love the adrenaline rush of researching exoplanets. They find it exciting to delve deep in search of exoplanets in the universe. Out of pure zest and zeal, scientists have been contributing to the exploration of exoplanets. It is always different to work on different exoplanets as every other planet is distinctive from others.

They Prove the Co-Existence

Whether you are dealing with astronomy or not, one of the most thought-provoking questions of humanity is, “Are we the only cosmic body in the universe?” Space is an open door to the infinite hidden heavenly bodies. Philosophers and all curious minds have always been searching for answers to this question. But, our generation is the first to have to deploy the tools and technologies to find the co-existing planets in the universe.

Searching for exoplanets is necessary to discover the co-existing bodies in the universe. Today, not only we are aware that there are thousands and millions of stars other than the sun that are host to the planets, but we are also continually searching for a wide array of more planets already. Who knows, we can discover more solar systems in the universe. 

Know More About The Universe

Exoplanets are the greatest way to learn about the universe. They tell us a lot about the surroundings of the universe and their parent stars. Without the discovery of 51 Pegasi b, it would not have been possible to know the existence of exoplanets, and these neighboring planets would have been mysteries to us. Some notable Exoplanets are:

1. 51 Pegasi b: The very first exoplanet was discovered in 1995. It was found orbiting around a sun-like star. Similar to the mass of Jupiter, it revolves around its parent sun five times closer than Mercury.

2. HD 209458 b: Technically, it was the first exoplanet that was discovered in 1992, but there was no specific evidence of its existence. Later, with the help of proper technology in the subsequent years, it was confirmed as an existing planet. Another notable thing about this planet is that it has a different atmosphere and temperature profile.

3. 55 Cancri e: This planet is also deemed as the Super-Earth that orbits its parent star. It is bright enough to spot with the naked eye. A year on this planet only lasts up to 17 hours and 41 minutes. The planet is speculated to have a diamond core and is super rich in carbon. 

4. HD 80606 b: Holding the record of the most eccentric exoplanet, this planet was discovered in 2001. The orbit of this planet is quite similar to Halley’s Comet around the sun, which makes it quite a peculiar planet.

5. WASP – 33 b: Discovered in 2011, this planet has a sunscreen-type layer of the stratosphere that instantly absorbs the ultraviolet rays from its parent star. It orbits the star in a backward direction and causes slight vibrations in the star as well. 

What Innovation Awaits Us?

The next-gen space telescopes are already gearing up for innovative discoveries. The first in line is the launch of TESS (Transiting Exoplanet Survey Satellite). TESS claims to get a full-sky survey of the stars and their transiting planets. Kepler will be assisting TESS by handing over the “torch of discovery.” TESS is designed to get a closer and broader look at the exoplanets and discover more of them. With the help of the James Webb Space Telescope which is scheduled to launch in 2020, TESS will be shedding light on the undiscovered exoplanets in space. 

Webb Telescope will deploy a giant, light-collecting mirror that will be capturing all the light coming from the planets directly. The light will be then split into a multi-colored spectrum, displaying the gases existing in the planet’s atmosphere. Webb’s targets majorly include the Super earth and planets more substantial than the Earth and smaller than Neptune. Its main motive is to find rocky planets just like Earth, where life can be sustained. If humans are lucky, Webb may see signs of carbon dioxide, oxygen, and methane in the atmosphere of these planets. We would probably have to wait a little longer to get acquainted with planets having Earth-like atmospheres.