Discovering FIRST Signs of Life On TRAPPIST-1 | James Webb Space Telescope

 

The TRAPPIST-1 planetary system is unique among star systems known so far having seven earth-sized exoplanets could any of them have life according to our new toy in space the James Webb telescope they are ideal candidates for it but how can Webb find life there welcome to Science Reads and today let's discuss how the James Webb telescope will search for life on seven earth-sized planets last year when the James Webb space telescope was launched in december it took over the mantle as the world's premier space telescope from the legendary Hubble this new and flashy telescope is aiming to provide key insights into our own solar system as well as distant worlds around other stars one of its primary objectives is TRAPPISTt-1 an exoplanet system of seven earth-sized rocky planets around an ultra-cool dwarf star now when we say ultra-cool we do not mean you can go skiing on this star's surface an ultra-cool dwarf star is still a star with an effective temperature of less than 2,700 kelvin and that's approximately 4,400 degrees fahrenheit yeah it's still blazing hot by our standards but the exoplanets this dwarf star offers are different prospects as three of them are within the habitable zone of this system's star that's the goldilocks zone within which planetary surface temperatures are capable of sustaining liquid water trappist-1 is located only 39 light years from earth cosmically speaking that's like being right around the corner all of its seven planets are intriguing and have been the subject of many studies since their discovery but just because three of these planets are in the habitable zone doesn't guarantee that these planets are capable of sustaining life the habitable zone is just one of many conditions that need to be met to make a planet subject to our next real estate boom these conditions or indicators are known as biosignatures the most important of these biosignatures is the composition of their atmosphere an exoplanet needs to have significant quantities of methane oxygen water vapor carbon dioxide and many other important gases in somewhat similar proportions to those observed on earth until now we didn't have any way to determine these details of any exoplanet but according to a study the james webb space telescope might just be the game changer we were desperately searching for astronomers believe that the webb telescope will be powerful enough to detect signs of life at the distance of these earth-sized planets by analyzing their atmosphere for biosignatures in fact the webb telescope is trying to accomplish this task right now as you're reading this article but how can webb telescope be successful in achieving something no other telescope could accomplish in the past the answer lies in the stars literally these closest potentially habitable planets are still tens of light years away from us even

 from where jwst is orbiting at l2

 but this new telescope has got some new tricks up its sleeves you see when a planet is between our observation point and the exoplanet system's host star we can use sensitive telescopes to detect how much of the star's light is

 blocked by the planet in its atmosphere

 before it reaches us the proportion by which the light dips is called the transit depth and will differ in wavelength since gaseous elements each selectively absorb certain wavelengths of light more than others using a specialized telescope called a spectrometer telescope we can analyze light by wavelength to see which signals are lacking compared to when the star is not being transited therefore we can tell which gases are most likely prevalent in the atmosphere this technique is called transit spectroscopy to be fair this is not a new technique exclusive to the webb telescope transit spectroscopy was first used with hubble in 2002 and has been in common use for well over a decade so then why couldn't hubble accomplish the same objective why haven't we already found life-sustaining planets among the stars what's so special about jwst that only it can analyze the atmospheres of obvious candidates for habitability like trappist-1 while certain steps of transit spectroscopy were available with existing technology the most important measurement in identifying biosignatures the shift in transit depth was out of our reach with other telescopes with telescopes that predate webb we were able to determine the size of the star planet and separate the star angularly and spectrally from the light emitted from the multitude of other extrasolar objects but because planets are considerably smaller than their host stars the dip in brightness or the transit depth observed when a planet transits the surface of a star dozens of light years away is also quite small and that's where the previous telescopes were lacking they were unable to measure the minuscule shifts in a transit depth's wavelength

 at this distance telescopes like hubble were able to detect the atmospheric composition of exoplanets in categories like hot jupiters and hot neptunes or in other words planets much much larger than our earth and nowhere close to being habitable the combination of its location and advanced instruments grants jwst an

 infrared sensitivity greater than any previous telescope which will allow it to characterize the atmospheres of earth-sized exoplanet systems like trappist-1 for the first time researchers suggest that the webb telescope should be able to detect and analyze any atmosphere fairly quickly pretty much in a year or so since the planets are all close to their star that means their transit times are relatively short for those who don't know transit time is the time it takes for a planet to cross in front of its star from our viewpoint webb should be able to confirm the atmosphere or lack of it within 10 transits or less transit spectroscopy poses an additional challenge it's that the light we receive may be partially blocked by objects in space between our telescope and the star a prime example of such obstacles is the huge clouds of gases like hydrogen carrying tiny solid particles known as interstellar dust this dust fills much of the space between stars distorting most wavelengths of light as they travel from around the universe through space towards our telescopes infrared light is a key exception to this rule as with its long wavelengths it can penetrate through most dust unfiltered but infrared light comes with its own catch-22 every object including the telescope machinery emits infrared radiation if its temperature is above freezing which makes analyzing it not that easy this is another reason space telescopes are better at exploring space it's possible to maintain such a temperature in the vacuum of space rather efficiently jwst has also been equipped with specialized equipment for detecting and analyzing radiation in the near and mid infrared range such as the near infrared spectrometer and the mid infrared instrument the webb telescope is the largest astrophysical space observatory and the most technically complex science mission nasa has ever built and it's just the beginning future space telescopes are already being designed with these capabilities firmly in mind

 the james webb space telescope's capability of detecting the atmospheres of small rocky planets is exciting since other telescopes haven't been able to do this yet there's a big question in the field right now whether these planets even have atmospheres especially the innermost planets if and when we've confirmed that there are atmospheres then what can we learn about each planet's atmosphere and the molecules that make it up we're expecting a result within a year but there's a possibility that might not be the case as it might depend if the planet's atmosphere has clouds if a planet has

 a thick cloudy atmosphere like venus

 it could take up to 30 transits to confirm it so the webb telescope can still do it it would just take longer but that is still an achievable goal one of the other possibilities is that webb will find evidence of water that the planets lost when the system was much younger and the star was much hotter in such cases an atmosphere could contain abiotic oxygen which means not created by life which might be a false positive signal of active biology scientists would need to determine if the oxygen is biotic or abiotic the james webb space telescope will be absolutely invaluable for studying rocky planets like earth and many more of these rocky worlds are being discovered all the time in the vast space of our milky way galaxy it's estimated that there are billions of such worlds in our galaxy alone and the web might provide the first compelling evidence for life on one or more of them there's one thing for sure there can't be a better star system for webb's telescope to start its search for extraterrestrial life than trappist-1. tell us in the comments what are your expectations from this star system  you