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Finding a second earth

“Finding a second earth is not a matter of ‘if’, but of ‘when’,” says Thomas Zurbuchen of NASA. But, is it really so inevitable?

In recent times, not many intergalactic discoveries have received the amount of attention and craze as the TRAPPIST-1 system. The widespread fanfare of sorts was led by scientists who stated that the new solar system could be our best (and closest) bet to find life beyond planet Earth. This solar system had seven planets orbiting a tiny star in orbits in the ‘habitable zone’. Quite understandably, everyone’s excited, and also scared, mystified and keen to know if there really are more of us present in the expanding universe.

The question is, are we channelling our rationale rather blindly? In this issue, we look deeper into the discovery of the TRAPPIST-1 solar system, and try to reason crucial answers to niggling questions that have lingered at the back of our minds.

What is the TRAPPIST-1 discovery?

Using the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) placed in La Silla Observatory, Chile, a team of scientists spotted three planets orbiting a dwarf star about 39 light years from Earth. This effort was led by astrophysicist Michael Gillion at the University of Liege, Belgium. The star itself was discovered by the Two Micron All-Sky Survey (2MASS) back in 1999, and finally, on February 22, 2017, four more planets were discovered in the system, bringing the total number of planets up to seven.

In terms of the TRAPPIST star’s composition, it was observed and classified to be an “ultra cool” dwarf star with metallic constituency. Interestingly, all the planets that have been discovered in this solar system fall in a unique spatial distribution, and are much closer to each other than any of the planets in our solar system. This, as the discovery revealed, has significant consequences.

For one, this solar system is much younger than that of ours, aged about 500 million years. In contrast, our solar system is calculated to be 4.6 billion years old, and the very first signs of life appeared approximately 3.8 billion years ago. Interestingly, the TRAPPIST-1 solar system is younger than the 800 million years it took for us to support life.

trappist1The headlining discovery, however, is that three out of the seven discovered planets lie in the habitable zone. A solar system’s habitable zone is a belt where rocky planets may exist with optimum heat, light and atmospheric conditions, all of which would lead to the planets being able to support forms of life as we know them. This is what made its discovery so celebrated, because we’ve never come across a solar system that has three Earth-like planets. It is also only 39 light years away from Earth, much closer than a number of other Earth-like exoplanets that have been discovered previously.

Gauging its significance

Seeing that the TRAPPIST star is significantly cooler than other stars (even our Sun), each of these exoplanets orbit very close to it, and each other.

This has led to NASA initiating further studies on how the forces interact among planets in this solar system. The planets are so close that if one looked up at the sky from one planet, they would spot the other planets as massive orbs on the night sky. While this sounds fantastic for aesthetic and romantic appeal, the main significance of this discovery is that the planetary forces would react with each other, because of the proximity.

Because of the forces interlocking, the planets, they may not exhibit rotation on their individual axes. This is a hindrance in our hopeful calculations of spotting life in the TRAPPIST-1 system. It is quite possible that without rotational movement, the planets in the habitable zone may experience day on one half and night on the other for eternity. This would further lead to vicious winds and devastating tidal waves (if these planets contain water) on the night half of the planet, making it unsuitable for supporting life as we know it.

Other significances of the TRAPPIST discovery also lies in the nature of the solar system. An ongoing study by researchers at Harvard University has claimed that the proximity of all the planets mean interplanetary panspermia is highly probable, or maybe even possible. Interplanetary panspermia is the hypothesis that life can exist across wider zones of the universe, spread by agents like meteoroids and comets. When it comes to the TRAPPIST-1 system, panspermia seems even more possible because of how the planets are lined up, and this further increases the chance for more planets to support life.

How are these planets discovered?

The first peg in the discovery of the TRAPPIST-1 system was the discovery of the star back in 1999 by 2MASS, one of the most ambitious space research projects. 2MASS surveyed the entire sky in the infrared spectrum. Subsequent studies were taken up by Prof. Gillon and his team at the University of Liege, who used the Chile-based TRAPPIST to make observations in 2015 based on the 2MASS J23062928-0502285 star discovered in 1999.

Subsequent studies and observations also involved the Spitzer Space Telescope and the Very Large Telescope, both belonging to NASA, following which the announcement was made in February 2017. Data from the Spitzer telescope also relayed planetary sizes of those in the TRAPPIST-1 system, which have given astronauts a first estimate of the mass of each of these planets. Six of the seven discovered planets are being said to be rocky in composition, and the last one may be gaseous, falling on the outer edge of the system.

Further observations and studies are being made to make more confirmed calculations on these planets, and NASA’s Hubble Space Telescope has initiated observation of the planets to study the atmospheric compositions. Most of these discoveries follow a similar path of discovery with the Kepler telescope being particularly prolific in the discovery of the planets. Until now, about 15 rocky exoplanets have been spotted orbiting stars in the habitable zone, the most notable of which till date was the Kepler-452b.

Discovered in 2015, the planet orbits a Sun-like star nearly 1,400 light years away, and is presently being studied by observatories and researchers.

Is mankind really a multi-planetary species?

Dangers surrounding the longevity of Earth has been at the back of our minds for a long time now, and that has brought out the all-important question – is mankind a multi-planetary species?

Thousands of science fiction novels and movies have suggested the presence of intelligent humanoid entities in faraway solar systems, who somehow muster the ability to understand human speech, context, compassion and more such specifics. Wishful thinking aside, it may be highly improbable to think of life forms existing in different stellar systems in a similar way as it exists here.

Mankind, however, has lately set its sight on Mars, with some of the greatest minds in the world targeting to set up colonies in the red planet in the near future. There is a need for mankind to be a multi-planetary species, and that primarily spawns from the fact that our universe grows on complexity. From our perception of the universe, and not the other way round, complexity is a way of evolution that ensures greater heights to be reached in future generations.

Here’s how our present home compares to possible future ones

As a result, converting mankind into a multi-planetary species is crucial to ensure that our branch of evolution can continue even in the incident of a gargantuan calamity that can threaten life on Earth. This would ensure that evolution continues for mankind, and much time and devotion is to be spent on ensuring the survival of all branches of mankind for as long as possible. As celebrated astrophysicist Carl Sagan once stated, “We are a way for the cosmos to know itself.”

Mankind is what defines the meaning and significance of interstellar discoveries, and it is this, apart from evolutionary needs, that make mankind the perfect fit for being a multi-planetary species.
Incidentally, at a nearby distance and with seemingly optimum conditions upon first impressions, the TRAPPIST-1 system could not have been more ideal in mankind’s galactic colonisation plans.

Are we asking the right questions?

Every wrong question asked would mean that somewhere, a right question remained unanswered. It’s true that the TRAPPIST-1 discovery is indeed unique in nature, and no such systems have been discovered before. It is also important to consider complex details before simply being fascinated by the details of the latest system.

Should we really be asking whether there is life on these planets, or should we first look into the finer details that may prohibit life, and move ahead accordingly? Space research is expensive, without having given much concrete outcome to significantly alter the course of life. As such it is important for us to know that we need to ask the right questions, and choose them very carefully.

The entire solar system spans lesser than the distance between the Sun and Mercury

Alongside this lies the all-important discussion on how will extraterrestrial life actually look like, if we actually stumble upon it in the future? Are we narrowed down upon our perception of life and life forms in order to discover what is unknown? Even if we do find life somewhere outside our Solar system, how would we communicate? Would it lead to any good, or are we hunting down our own nemesis?

The TRAPPIST-1 system is being seen as an optimistic ground for researching on extraterrestrial life, and answering a lot of questions for which mankind has been searching answers.

Extraterrestrials; Fermi Paradox

The prospect of discovering extraterrestrial life in TRAPPIST-1 brings us back to the Fermi paradox. It states the contradictions presented by high probability estimates and clear lack of evidences in our hunt for intelligent life forms.

The Fermi paradox states the clear observation of billions of stars in the universe, along with the probability that a few billions of them are similar to the Sun in terms of composition. This further generates very high probability that at least a few millions of the Sun-like stars would have planets that lie in the habitable zone, exhibiting Earth-like qualities. In turn, at least some of them would run high probabilities of developing intelligent life forms.

What mysteries would these planets behold?

This would place our Solar system as one of the many intelligent life-supporting systems, and leave TRAPPIST-1 with the prospect of being able to support life, subject to further discoveries. The Fermi paradox further states that many of these intelligent life forms may have set out on interstellar explorations. This means establishing contact with extraterrestrial life should prove fruitful at some point of time or the other.

The question, though, remains. Whether such extraterrestrial life would have the means to receive our message or not. This has remained a major thorn in our quest for extraterrestrial life, leading to questioning whether the TRAPPIST-1 system is too young, or maybe too old in accordance to its star, to support intelligent life forms.

A beautiful sight to behold, this

“Mankind was born on Earth, it was never meant to die here”

Taking a leaf out of Christopher Nolan’s screenplay, it is not too wrong to be optimistic on the TRAPPIST-1 system. It is, after all, the most striking discovery of Earth-like planets.

Much work and studies still remain, and so do a number of questions surrounding our sudden flux of interest in discovering extraterrestrial life. The likes of Elon Musk are taking to the skies to begin space tourism, and even aiming for Mars to spread out mankind’s arm of evolution. Will we stumble upon intelligent life in our near future, or are we actually all alone in the vast universe?

Much of these answers may lie within the confines of TRAPPIST-1.

Mankind was certainly born on Earth, but was it really not meant to die here?

This article was first published in the April 2017 issue of Digit magazine. To read Digit’s articles first, subscribe here or download the Digit app for Android and iOS. You could also buy Digit’s previous issues here.

Souvik Das

Souvik Das