One of the TRAPPIST-1 Planets Has an Iron Core

In February of 2017, a team of European astronomers announced the discovery of a seven-planet system orbiting the nearby star TRAPPIST-1. Aside from the fact that all seven planets were rocky, there was the added bonus of three of them orbiting within TRAPPIST-1’s habitable zone. Since that time, multiple studies have been conducted to determine whether or not any of these planets could be habitable.

In accordance with this goal, these studies have focused on whether or not these planets have atmospheres, their compositions and their interiors. One of the latest studies was conducted by two researchers from Columbia University’s Cool Worlds Laboratory, who determined that one of the TRAPPIST-1 planets (TRAPPIST-1e) has a large iron core – a finding which could have implications for this planet’s habitability.

The study – titled “TRAPPIST-1e Has a Large Iron Core“, which recently appeared online – was conducted by Gabrielle Englemenn-Suissa and David Kipping, a senior undergraduate student and an Assistant Professor of Astronomy at Columbia University, respectively. For the sake of their study, Englemenn-Suissa and Kipping took advantage of recent studies that have placed constraints on the masses and radii of the TRAPPIST-1 planets.

These and other studies have benefited from the fact that TRAPPIST-1 is a seven planet system, which makes it ideally suited for exoplanet studies. As Professor Kipping told Universe Today via email:

“It’s a wonderful laboratory for exoplanetary science for three reasons. First, the system has a whopping seven transiting planets. The depth of the transits dictates the size of each planet so we can measure they sizes quite precisely. Second, the planets gravitationally interact with one another leading to variations in the times of the transits and these have been used to infer the masses of each planet, again to impressive precision. Third, the star is very small being a late M-dwarf, about an eighth the size of the Sun, and that means transits appear 8^2 = 64 times deeper than they would if the star were Sun-sized. So we have lots of things working in our favor here.”

Together, Englemann-Suissa and Kipping used mass and radius measurements of the TRAPPIST-1 planets to infer the minimum and maximum Core Radius Fraction (CRF) of each planet. This built on a study they had previously conducted (along with Jingjing Chen, a PhD candidate at Columbia University and a member of the Cool Worlds Lab) in which they developed their method for determining a planet’s CRF. As Kipping described the method:

“If you know the mass and radius very precisely, like the TRAPPIST-1 system, you can compare them to that predicted from theoretical interior structure models. The problem is that these models generally comprise of possible four layers, an iron core, a silicate mantle, a water layer and an light volatile envelope (Earth only has the first two, its atmosphere contributes negligible to mass and radius). So four unknowns and two measured quantities is in principle an unconstrained, unsolvable problem.”

This artist’s concept shows what each of the TRAPPIST-1 planets may look like, based on available data about their sizes, masses and orbital distances.Credits: NASA/JPL-Caltech

Their study also took into account previous work by other scientists who have attempted to place constraints on the chemical composition of the TRAPPIST-1 system. In these studies, the authors assumed that the planets’ chemical compositions were connected to that of the star, which can be measured. However, Englemann-Suissa and Kipping took a more “agnostic” approach and simply considered the boundary conditions of the problem.

“We essentially say that given the mass and radius, there are no models with cores smaller than X that can possibly explain the observed mass and radius,” he said. “The core might be bigger than X but has to be at least X since no theoretical models could explain it otherwise. Here, X would therefore correspond to what we could call the minimum core radius fraction. We then play the same game for the maximum limit.”

What they determined was that the minimum core size of six of the TRAPPIST-1 planets was essentially zero. This means that their compositions could be explained without necessarily having an iron core – for instance, a pure silicate mantle could be all that’s there. But in the case of TRAPPIST-1e, they found that its core must comprise at least 50% of the planet by radius, and at most, 78%.

Compare this to Earth, where the solid inner core of iron and nickel and a liquid outer core of a molten iron-nickel alloy comprise 55% of the planet’s radius. Between the upper and lower limit of TRAPPIST-1e’s CRF, they concluded that it must have a dense core, one which is likely comparable to Earth. This finding could mean that of all the TRAPPIST-1 planets, e is the most “Earth-like” and likely to have a protective magnetosphere.

As Kipping indicated, this could have immense implications when it comes to the hunt for habitable exoplanets, and might push TRAPPIST-1e to the top of the list:

“This gets me more excited about TRAPPIST-1e in particular. That planet is a tad smaller than the Earth, sits right in the habitable-zone and now we know has a large iron core like the Earth. We also know it does not possess a light volatile envelope thanks to other measurements. Further, TRAPPIST-1 appears to be a quieter star than Proxima so I’m much more optimistic about TRAPPIST-1e as potential biosphere than Proxima b right now.”

This is certainly good news in light of recent studies that have indicated that Proxima b is not likely to be habitable. Between its star emitting powerful flares that can be seen by the naked eye to the likelihood that an atmosphere and liquid water would not survive long on its surface, the closest exoplanet to our Solar System is currently not considered a good candidate for finding a habitable world or extra-terrestrial life.

In recent years, Kipping and his colleagues have also dedicated themselves and the Cool Worlds Laboratory to the study of possible exoplanets around Proxima Centauri. Using the Canadian Space Agency’s Microvariability and Oscillation of Stars (MOST) satellite, Kipping and his colleagues monitored Proxima Centauri in May of 2014 and again in May of 2015 to look for signs of transiting planets.

While the discovery of Proxima b was ultimately made by astronomers at the ESO using the Radial Velocity Method, this campaign was significant in drawing attention to the likelihood of finding terrestrial, potentially-habitable planets around nearby M-type (red dwarf) stars. In the future, Kipping and his team also hope to conduct studies of Proxima b to determine if it has an atmosphere and determine what its CRF could be.

Once again, it appears that one of the many rocky planets orbiting a red dwarf star (and which is closer to Earth) might just be a prime candidate for habitability studies! Future surveys, which will benefit from the introduction of next-generation telescopes (like the James Webb Space Telescope) will no doubt reveal more about this  system and any potentially habitable worlds it has.

Further Reading: arXiv

TRAPPIST-1 Planets Might Actually Have Too Much Water to be Habitable

In February of 2017, the world was astounded to learn that astronomers – using data from the TRAPPIST telescope in Chile and the Spitzer Space Telescope – had identified a system of seven rocky exoplanets in the TRAPPIST-1 system. As if this wasn’t encouraging enough for exoplanet-enthusiasts, it was also indicated that three of the seven planets orbited within the stars’ circumstellar habitable zone (aka. “Goldilocks Zone”).

Since that time, this system has been the focus of considerable research and follow-up surveys to determine whether or not any of its planets could be habitable. Intrinsic to these studies has been the question whether or not the planets have liquid water on their surfaces. But according to a new study by a team of American astronomers, the TRAPPIST planets may actually have too much water to support life.

The study, titled “Inward Migration of the TRAPPIST-1 Planets as Inferred From Their Water-Rich Compositions“, recently appeared in the journal Nature Astronomy. The study was led by Cayman T. Unterborn, a geologist with the School of Earth and Space Exploration (SESE), and included Steven J. Desch, Alejandro Lorenzo (also from the SESE) and Natalie R. Hinkel – an astrophysicists from Vanderbilt University, Nashville.

As noted, multiple studies have been conducted that have sought to determine if any of the TRAPPIST-1 planets could be habitable. And while some have stressed that they would not be able to hold onto their atmospheres for long due to the fact that they orbit a star that is variable and prone to flaring (like all red dwarfs), others studies have found evidence that the system could be rich in water and ideal for life-swapping.

For the sake of their study, the team used data from prior surveys that attempted to place constraints on the mass and diameter of the TRAPPIST-1 planets in order to calculate their densities. Much of this came from a dataset called the Hypatia Catalog (developed by contributing author Hinkel), which merges data from over 150 literary sources to determine the stellar abundances of stars near to our Sun.

Using this data, the team constructed mass-radius-composition models to determine the volatile contents of each of the TRAPPIST-1 planets. What they noticed is that the TRAPPIST planets are traditionally light for rocky bodies, indicating a high content of volatile elements (such as water). On similarly low-density worlds, the volatile component is usually thought to take the form of atmospheric gases.

But as Unterborn explained in a recent SESE news article, the TRAPPIST-1 planets are a different matter:

“[T]he TRAPPIST-1 planets are too small in mass to hold onto enough gas to make up the density deficit. Even if they were able to hold onto the gas, the amount needed to make up the density deficit would make the planet much puffier than we see.”

Artist’s impression of some of the planets orbiting the ultra-cool red dwarf star TRAPPIST-1. Credit: ESO

Because of this, Unterborn and his colleagues determined that the low-density component in this planetary system had to be water. To determine just how much water was there, the team used a unique software package developed known as ExoPlex. This software uses state-of-the-art mineral physics calculators that allowed the team to combine all of the available information about the TRAPPIST-1 system – not just the mass and radius of individual planets.

What they found was that the inner planets (b and c) were “drier” – having less than 15% water by mass – while the outer planets (f and g) had more than 50% water by mass. By comparison, Earth has only 0.02% water by mass, which means that these worlds have the equivalent of hundreds of Earth-sized oceans in their volume. Basically, this means that the TRAPPIST-1 planets may have too much water to support life. As Hinkel explained:

“We typically think having liquid water on a planet as a way to start life, since life, as we know it on Earth, is composed mostly of water and requires it to live. However, a planet that is a water world, or one that doesn’t have any surface above the water, does not have the important geochemical or elemental cycles that are absolutely necessary for life.”

These findings do not bode well for those who believe that M-type stars are the most likely place to have habitable planets in our galaxy. Not only are red dwarfs the most common type of star in the Universe, accounting for 75% of stars in the Milky Way Galaxy alone, several that are relatively close to our Solar System have been found to have one or more rocky planets orbiting them.

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

Aside from TRAPPIST-1, these include the super-Earths discovered around LHS 1140 and GJ 625, the three rocky planets discovered around Gliese 667, and Proxima b – the closest exoplanet to our Solar System. In addition, a survey conducted using the HARPS spectrograph at the ESO’s La Silla Observatory in 2012 indicated that there could be billions of rocky planets orbiting within the habitable zones of red dwarf stars in the Milky Way.

Unfortunately, these latest findings indicate that the planets of the TRAPPIST-1 system are not favorable for life. What’s more, there would probably not be enough life on them to produce biosignatures that would be observable in their atmospheres. In addition, the team also concluded that the TRAPPIST-1 planets must have formed father away from their star and migrated inward over time.

This was based on the fact that the ice-rich TRAPPIST-1 planets were far closer to their star’s respective “ice line” than the drier ones. In any solar system, planets that lie within this line will be rockier since their water will vaporize, or condense to form oceans on their surfaces (if a sufficient atmosphere is present). Beyond this line, water will take the form of ice and can be accreted to form planets.

From their analyses, the team determined that the TRAPPIST-1 planets must have formed beyond the ice line and migrated towards their host star to assume their current orbits. However, since M-type (red dwarf) stars are known to be brightest after the first form and dim over time, the ice line would have also moved inward. As co-author Steven Desch explained, how far the planets migrated would therefore depend on when they had formed.

Artist’s impression of how the surface of a planet orbiting a red dwarf star may appear. The planet is in the habitable zone so liquid water exists. Credit: M. Weiss/CfA

“The earlier the planets formed, the farther away from the star they needed to have formed to have so much ice,” he said. Based on how long it takes for rocky planets to form, the team estimated that the planets must have originally been twice as far from their star as they are now. While there are other indications that the planets in this system migrated over time, this study is the first to quantify the migration and use composition data to show it.

This study is not the first to indicate that planets orbiting red dwarf stars may in fact be “water worlds“, which would mean that rocky planets with continents on their surfaces are a relatively rare thing. At the same time, other studies have been conducted that indicate that such planets are likely to have a hard time holding onto their atmospheres, indicating that they would not remain water worlds for very long.

However, until we can get a better look at these planets – which will be possible with the deployment of next-generation instruments (like the James Webb Space Telescope) – we will be forced to theorize about what we don’t know based what we do. By slowly learning more about these and other exoplanets, our ability to determine where we should be looking for life beyond our Solar System will be refined.

Further Reading: SESE, Nature Astronomy

Good News For The Search For Life, The Trappist System Might Be Rich In Water

When we finally find life somewhere out there beyond Earth, it’ll be at the end of a long search. Life probably won’t announce its presence to us, we’ll have to follow a long chain of clues to find it. Like scientists keep telling us, at the start of that chain of clues is water.

The discovery of the TRAPPIST-1 system last year generated a lot of excitement. 7 planets orbiting the star TRAPPIST-1, only 40 light years from Earth. At the time, astronomers thought at least some of them were Earth-like. But now a new study shows that some of the planets could hold more water than Earth. About 250 times more.

This new study focuses on the density of the 7 TRAPPIST-1 planets. Trying to determine that density is a challenging task, and it involved some of the powerhouses in the world of telescopes. The Spitzer Space Telescope, the Kepler Space Telescope, and the SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) facility at ESO’s Paranal Observatory were all used in the study.

This artist’s impression shows several of the planets orbiting the ultra-cool red dwarf star TRAPPIST-1. New observations, when combined with very sophisticated analysis, have now yielded good estimates of the densities of all seven of the Earth-sized planets and suggest that they are rich in volatile materials, probably water. Image: ESO/M. Kornmesser

In this study, the observations from the three telescopes were subjected to complex computer modelling to determine the densities of the 7 TRAPPIST planets. As a result, we now know that they are all mostly made of rock, and that some of them could be 5% water by mass. (Earth is only about 0.02% water by mass.)

Finding the densities of these planets was not easy. To do so, scientists had to determine both the mass and the size. The TRAPPIST-1 planets were found using the transit method, where the light of the host star dips as the planets pass between their star and us. The transit method gives us a pretty good idea of the size of the planets, but that’s it.

It’s a lot harder to find the mass, because planets with different masses can have the same orbits and we can’t tell them apart. But in multi-planet systems like TRAPPIST-1, there is a way.

As the planets orbit the TRAPPIST-1 star, more massive planets disturb the orbits of the other planets more than lighter ones. This changes the timing of the transits. These effects are “complicated and very subtle” according to the team, and it took a lot of observation and measurement of the transit timing—and very complex computer modelling—to determine their densities.

Lead author Simon Grimm explains how it was done: “The TRAPPIST-1 planets are so close together that they interfere with each other gravitationally, so the times when they pass in front of the star shift slightly. These shifts depend on the planets’ masses, their distances and other orbital parameters. With a computer model, we simulate the planets’ orbits until the calculated transits agree with the observed values, and hence derive the planetary masses.”

So, what about the water?

First of all, this study didn’t detect water. It detected volatile material which is probably water.

Whether or not they’ve confirmed the presence of water, these are still very important results. We’re getting good at finding exoplanets, and the next step is to determine the properties of any atmospheres that exoplanets have.

Team member Eric Agol comments on the significance: “A goal of exoplanet studies for some time has been to probe the composition of planets that are Earth-like in size and temperature. The discovery of TRAPPIST-1 and the capabilities of ESO’s facilities in Chile and the NASA Spitzer Space Telescope in orbit have made this possible — giving us our first glimpse of what Earth-sized exoplanets are made of!”

This diagram compares the sizes, masses and estimated temperatures of the TRAPPIST-1 planets with Solar System planets. The colours indicate temperatures and the black line matches the densities and composition of the terrestrial planets in the Solar System. Planets above the line are less dense and planets below are more dense. Image: EXO/S.Grimm et. al.

This study doesn’t tell us if any of the TRAPPIST planets have life on them, or even if they’re habitable. It’s just one more step on the path to hopefully, maybe, one day, finding life somewhere. Study co-author Brice-Olivier Demory, at the University of Bern, said as much: “Densities, while important clues to the planets’ compositions, do not say anything about habitability. However, our study is an important step forward as we continue to explore whether these planets could support life.”

This diagram compares the masses and energy input of the seven TRAPPIST-1 planets, along with the properties of the four innermost Solar System planets. Image: NASA/JPL-Caltech

This is what the study determined about the different planets in the TRAPPIST system:

  • TRAPPIST 1-b and 1c are the two innermost planets and are likely to have rocky cores and be surrounded by atmospheres much thicker than Earth’s.
  • TRAPPIST-1d is the lightest of the planets at about 30 percent the mass of Earth. We’re uncertain whether it has a large atmosphere, an ocean or an ice layer.
  • TRAPPIST-1e is a bit of a surprise. It’s the only planet in the system slightly denser than Earth. It may have a denser iron core, and it does not necessarily have a thick atmosphere, ocean or ice layer. TRAPPIST-1e is a mystery because it appears to be so much rockier than the rest of the planets. It’s the most similar to Earth, in size, density and the amount of radiation it receives from its star.
  • TRAPPIST-1f, g and h might have frozen surfaces. If they have thin atmospheres, they would be unlikely to contain the heavy molecules that we find on Earth, such as carbon dioxide.

The TRAPPIST-1 system is going to be studied for a very long time. It promises to be one of the first targets for the James Webb Space Telescope (we hope.) It’s a very intriguing system, and whether or not any of the planets are deemed habitable, studying them will teach us a lot about our search for water, habitability, and life.

New Study Claims that TRAPPIST-1 Could Also Have Gas Giants

Most exoplanets orbit red dwarf stars because they're the most plentiful stars. This is an artist's illustration of what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right). Credits: NASA/JPL-Caltech

In February of 2017, NASA scientists announced the existence of seven terrestrial (i.e. rocky) planets within the TRAPPIST-1 star system. Since that time, the system has been the focal point of intense research to determine whether or not any of these planets could be habitable. At the same time, astronomers have been wondering if all of the system’s planets are actually accounted for.

For instance, could this system have gas giants lurking in its outer reaches, as many other systems with rocky planets (for instance, ours) do? That was the question that a team of scientists, led by researchers from the Carnegie Institute of Science, sought to address in a recent study. According to their findings, TRAPPIST-1 may be orbited by gas giants at a much-greater distance than its seven rocky planets.

The study, titled “Astrometric Constraints on the Masses of Long-Period Gas Giant Planets in the TRAPPIST-1 Planetary System“, recently appeared in The Astronomical Journal. As they indicate in their study, the team relied on follow-up observations made of TRAPPIST-1 over a period of five years (from 2011 to 2016) using the du Pont telescope at the Las Campanas Observatory in Chile.

Using these observations, they sought to determine if TRAPPIST-1 could have previously-undetected gas giants orbiting within the outer reaches of the system. As Dr. Alan Boss – an astrophysicist and planetary scientist with the Carnegie Institute’s Department of Terrestrial Magnetism and the lead author on the paper – explained in a Carnegie press statement:

“A number of other star systems that include Earth-sized planets and super-Earths are also home to at least one gas giant. So, asking whether these seven planets have gas giant siblings with longer-period orbits is an important question.”

For years, Boss has conducted an exoplanet-hunting survey with the co-authors of the study – Alycia J. Weinberger, Ian B. Thompson, et al. – known as the Carnegie Astrometric Planet Search. This survey relies on the Carnegie Astrometric Planet Search Camera (CAPSCam), an instrument on the du Pont telecope that searches for extrasolar planets using the astrometric method.

This indirect method of exoplanet-hunting determines the presence of planets around a star by measuring the wobble of this host star around the system’s center of mass (aka. its barycenter). Using CAPSCam, Boss and his colleagues relied on several years of observations of TRAPPIST-1 to determine the upper mass limits for any potential gas giants orbiting in the system.

From this, they concluded that planets that were up to 4.6 Jupiter Masses could orbit the star with a period of a year. In addition, they found that planets up to 1.6 Jupiter Masses could orbit the star with 5-year periods. In other words, it is possible that TRAPPIST-1 has some long-period gas giants orbiting its outer reaches, much in the same way that long-period gas giants exists beyond the orbit of Mars in the Solar System.

Three of the TRAPPIST-1 planets – TRAPPIST-1e, f and g – dwell in their star’s so-called “habitable zone. CreditL NASA/JPL

If true, the existence of these giant planets could resolve an ongoing debate about the formation of the Solar System’s gas giants. According to the most-widely accepted theory about the Solar System’s formation (i.e. Nebular Hypothesis), the Sun and planets were born of a nebula of gas and dust. After this cloud experienced gravitational collapse at the center, forming the Sun, the remaining dust and gas flattened out into a disk surrounding it.

Earth and the other terrestrial planets (Mercury, Venus and Mars) all formed closer to the Sun from the accretion of silicate minerals and metals. As for the gas giants, there are some competing theories as to how they formed. In one scenario, known as the Core Accretion theory, the gas giants also began accreting from solid materials (forming a solid core) which became large enough to attract an envelop of surrounding gas.

A competing explanation – known as the Disk Instability theory – claims that they formed when the disk of gas and dust took on a spiral arm formation (similar to a galaxy). These arms then began to increase in mass and density, forming clumps that rapidly coalesced to form baby gas giants. Using computational models, Boss and his colleagues considered both theories to see if gas giants could form around a low-mass star like TRAPPIST-1.

Whereas Core Accretion was not likely, the Disk Instability theory indicated that gas giants could form around TRAPPIST-1 and other low-mass red dwarf stars. As such, this study provides a theoretical framework for the existence of gas giants in red dwarf star systems that are already known to have rocky planets. This is certainly encouraging news for exoplanet-hunters given the spate of rocky planets have been found orbiting red dwarfs of late.

Aside from TRAPPIST-1, these include the closest exoplanet to the Solar System (Proxima b), as well as LHS 1140b, Gliese 581g, Gliese 625b, and Gliese 682c. But as Boss also noted, this research is still in its infancy, and much more research and discussion needs to take place before anything can be said conclusively. Luckily, studies such as this one are helping to open to the door to such studies and discussions.

“Gas giant planets found on long-period orbits around TRAPPIST-1 could challenge the core accretion theory, but not necessarily the disk instability theory,” said Boss. “There is a lot of space for further investigation between the longer-period orbits we studied here and the very short orbits of the seven known TRAPPIST-1 planets.”

Boss and his team also assert that continued observations with the CAPSCam and further refinements in its data analysis pipeline will either detect any long-period planets, or put an even tighter constraint on their upper mass limits. And of course, the deployment of next-generation infrared telescopes, such as the James Webb Space Telescope, will assist in the hunt for gas giants around red dwarf stars.

Further Reading: Carnegie Institute of ScienceThe Astronomical Journal

Hubble Spots First Indications of Water on TRAPPIST-1s Planets

This artist’s impression shows the view from the surface of one of the planets in the TRAPPIST-1 system. A powerful laser beacon using current and near-future technology could send a signal strong enough to be detected by any alien astronomers here. Credit: NASA/ESA/HST

In February of 2017, astronomers from the European Southern Observatory (ESO) announced the discovery of seven rocky planets around the nearby star of TRAPPIST-1. Not only was this the largest number of Earth-like planets discovered in a single star system to date, the news was also bolstered by the fact that three of these planets were found to orbit within the star’s habitable zone.

Since that time, multiple studies have been conducted to ascertain the likelihood that these planets are actually habitable. Thanks to an international team of scientists who used the Hubble Space Telescope to study the system’s planets, we now have the first clues as to whether or not water (a key ingredient to life as we know it) exists on any of TRAPPIST-1s rocky worlds.

The team’s study, titled “Temporal Evolution of the High-Energy Irradiation and Water Content of TRAPPIST-1 Exoplanets“, recently appeared on the Hubble site. Led by Swiss astronomer Vincent Bourrier from the Observatoire de l’Université de Genève, the team relied on Hubble’s Space Telescope Imaging Spectrograph (STIS) to study the amount of ultraviolet radiation each of the TRAPPIST-1 planets receives.

Artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth. Credit: NASA/JPL

As Bourrier explained in a Hubble press release, this helped them to determine the water content of the system’s seven planets:

“Ultraviolet radiation is an important factor in the atmospheric evolution of planets. As in our own atmosphere, where ultraviolet sunlight breaks molecules apart, ultraviolet starlight can break water vapor in the atmospheres of exoplanets into hydrogen and oxygen.”

How ultraviolet radiation interacts with a planet’s atmosphere is important when it comes to assessing the potential habitability of a planet. Whereas lower-energy UV radiation causes photodissociation, a process where water molecules break down into oxygen and hydrogen, extreme ultraviolet rays (XUV radiation) and x-rays cause the upper atmosphere of a planet to heat up – which causes the hydrogen and oxygen to escape.

Since hydrogen is lighter than oxygen, it is more easily lost to space where its spectra can be observed. This is precisely what Bourrier and his team did. By monitoring the TRAPPIST-1 planets spectra for signs of hydrogen loss, the team was effectively able to gauge their water content. What they found was that the UV radiation emitted by TRAPPIST-1 suggests that its planets could have lost quite a lot of water during their history.

The losses were most severe for the innermost planets – TRAPPIST-1b and 1c – which receive the most UV radiation from their star. In fact, the team estimates that these planets could have lost more than 20 Earth-oceans worth of water in the course of the system’s history – which is estimated to be between 5.4 and 9.8 billion years old. In other words, these inner planets would be bone dry and most definitely sterile.

This illustration shows the seven TRAPPIST-1 planets as they might look as viewed from Earth using a fictional, incredibly powerful telescope. Credit: NASA/JPL-Caltech

However, these same findings also suggest that the outer planets of the system have lost significantly less water over time, which could mean that they still possess abundant amounts on their surfaces. This includes the three planets that are within the star’s habitable zone – TRAPPIST-1e, f and g – which indicates that these planets could be habitable after all.

These findings are bolstered by the calculated water loss and geophysical water release rates, which also favor the idea that the more-massive and outermost planets have retained most of their water over time. These findings are very significant, in that they further demonstrate that atmospheric escape and evolution are closely linked on the planets of the TRAPPIST-1 system.

The findings are also encouraging, since previous studies that considered atmospheric loss in this system painted a rather grim picture. These include those that indicated that TRAPPIST-1 experiences too much flare, that even calm red dwarfs subject their planets to intense radiation over time, and that the distance between TRAPPIST-1 and its respective planets would mean that solar wind would be deposited directly onto their atmospheres.

In other words, these studies cast doubt on whether or not stars that orbit M-type (red dwarf) stars would be able to retain their atmospheres over time – even if they had an Earth-like atmosphere and magnetosphere. Like Mars, this research indicated that atmospheric stripping caused by solar wind would inevitably render their surfaces cold, desiccated, and lifeless.

Artist’s illustration showing the difference  TRAPPIST-1 in relation to our Sun. Credit: ESO

In short, this is one of the few pieces of good news we’ve received since the existence of seven planets in the TRAPPIST-1 system (and three potentially habitable ones) was first announced. It’s also a positive indication as far as the habitability of red dwarf star systems go. In recent years, many of those impressive exoplanet finds have taken place around red dwarf stars – i.e. Proxima b, LHS 1140b, Gliese 581g, Gliese 625b, and Gliese 682c.

Given the number of rocky planets that have been detected orbiting this type of star – and the fact that they are the most common in in the Universe (accounting for 70% of stars in the Milky Way alone) – knowing that they could support habitable planets is certainly welcome! But of course, Bourrier and his colleagues emphasize that the study is not conclusive, and further research is needed to determine if any of the TRAPPIST-1 planets are actually watery.

As Bourieer indicated, this will most likely involve next-generation telescopes:

“While our results suggest that the outer planets are the best candidates to search for water with the upcoming James Webb Space Telescope, they also highlight the need for theoretical studies and complementary observations at all wavelengths to determine the nature of the TRAPPIST-1 planets and their potential habitability.”

Rocky planets around the most common type of star, the potential to retain water, and 1oo billion potential planets in the Milky Way Galaxy alone. One thing is for sure: the James Webb Space Telescope is going to have its hands full once it is deployed in October of 2018!

And be sure to check out this animation of the TRAPPIST-1 system as well, courtesy of L. Calçada and the ESO:

Further Reading: Hubble Space Telescope, HST (2)

Scientists Discover TRAPPIST-1 is Older Than Our Solar System

Most exoplanets orbit red dwarf stars because they're the most plentiful stars. This is an artist's illustration of what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right). Credits: NASA/JPL-Caltech

In February of 2017, a team of European astronomers announced the discovery of a seven-planet system orbiting the nearby star TRAPPIST-1. Aside from the fact that all seven planets were rocky, there was the added bonus of three of them orbiting within TRAPPIST-1’s habitable zone. As such, multiple studies have been conducted that have sought to determine whether or not any planets in the system could be habitable.

When it comes to habitability studies, one of the key factors to consider is the age of the star system. Basically, young stars have a tendency to flare up and release harmful bursts of radiation while planets that orbit older stars have been subject to radiation for longer periods of time. Thanks to a new study by a pair of astronomers, it is now known that the TRAPPIST-1 system is twice as old as the Solar System.

The study, which will be published in The Astrophysical Journal under the title “On The Age Of The TRAPPIST-1 System“, was led by Adam Burgasser, an astronomer at the University of California San Diego (UCSD). He was joined by Eric Mamajek, the deputy program scientist for NASA’s Exoplanet Exploration Program (EEP) at the Jet Propulsion Laboratory.

Together, they consulted data on TRAPPIST-1s kinematics (i.e. the speed at which it orbits the center of the galaxy), its age, magnetic activity, density, absorption lines, surface gravity, metallicity, and the rate at which it experiences stellar flares. From all this, they determined that TRAPPIST-1 is quite old, somewhere between 5.4 and 9.8 billion years of age. This is up to twice as old as our own Solar System, which formed some 4.5 billion years ago.

These results contradict previously-held estimates, which were that the TRAPPIST-1 system was about 500 millions yeas old. This was based on the fact that it would have taken this long for a low-mass star like TRAPPIST-1 (which has roughly 8% the mass of our Sun) to contract to its minimum size. But with an upper age limit that is just under 10 billion years, this star system could be almost as old as the Universe itself!

As Dr. Burgasser explained in a recent NASA press statement:

“Our results really help constrain the evolution of the TRAPPIST-1 system, because the system has to have persisted for billions of years. This means the planets had to evolve together, otherwise the system would have fallen apart long ago.”

The implications of this could be very significant as far as habitability studies are concerned. For one, older stars experience less in the way of flareups compared to younger ones. From their study, Burgasser and Mamajek confirmed that TRAPPIST-1 is relatively quiet compared to other ultra-cool dwarf stars. However, since the planets around TRAPPIST-1 orbit so close to their star, they have been exposed to billions of years of radiation at this point.

An artist’s depiction of planets transiting a red dwarf star in the TRAPPIST-1 System. Credit: NASA/ESA/STScl

As such, it is possible that most of the planets which orbit TRAPPIST-1 – expect for the outermost two, g and h – would probably have had their atmospheres stripped away – similar to what happened to Mars billions of years ago when it lost its protective magnetic field. This is certainly consistent with many recent studies, which concluded that TRAPPIST-1’s solar activity would not be conducive to life on any of its planets.

Whereas some of these studies addressed TRAPPIST-1s level of stellar flare, others examined the role magnetic fields would play. In the end, they concluded that TRAPPIST-1 was too variable, and that its own magnetic field would likely be connected to the fields of its planets, allowing particles from the star to flow directly  onto the planets atmospheres (thus allowing them to be more easily stripped away).

However, the results were not entirely bad news. Since the TRAPPIST-1 planets have estimated densities that are lower than that of Earth, it is possible that they have large amounts of volatile elements (i.e. water, carbon dioxide, ammonia, methane, etc). These could have led to the formation of thick atmospheres that protected the surfaces from a lot of harmful radiation and redistributed heat across the tidally-locked planets.

Then again, a thick atmosphere could also have an effect akin to Venus, creating a runaway greenhouse effect that would have resulted in incredibly thick atmospheres and extremely hot surfaces. Under the circumstances, then, any life that emerged on these planets would have had to be extremely hardy in order to survive for billions of years.

Artist’s impression of the view from the most distant exoplanet discovered around the red dwarf star TRAPPIST-1. Credit: ESO/M. Kornmesser.

Another positive thing to consider is TRAPPIST-1’s constant brightness and temperature, which are also typical of M-class (red dwarf) stars. Stars like our Sun have an estimated lifespan of 10 billion years (which it is almost halfway through) and grow steadily brighter and hotter with time. Red dwarfs, on the other hand, are believed to exist for as much as 10 trillion years – far longer than the Universe has existed – and do not change much in intensity.

Given the amount of time it took for complex life to have emerged on Earth (over 4.5 billion years), this longevity and consistency could make red dwarf star systems the best long-term bet for habitability. Such was the conclusion of one recent study, which was conducted by Prof. Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA). And as Mamajek explained:

“Stars much more massive than the Sun consume their fuel quickly, brightening over millions of years and exploding as supernovae. But TRAPPIST-1 is like a slow-burning candle that will shine for about 900 times longer than the current age of the universe.”

NASA has also expressed excitement over these findings. “These new results provide useful context for future observations of the TRAPPIST-1 planets, which could give us great insight into how planetary atmospheres form and evolve, and persist or not,” said Tiffany Kataria, an exoplanet scientist at JPL. At the moment, habitability studies of TRAPPIST-1 and other nearby star systems are confined to indirect methods.

However, in the near future, next-generation missions like the James Webb Space Telescope are expected to reveal additional information – such as whether or not these planets have atmospheres and what their compositions are. Future observations with the Hubble Space Telescope and the Spitzer Space Telescope are also expected to improve our understanding of these planets and possible conditions on their surface.

Further Reading: NASA, arXiv

Even Though Red Dwarfs Have Long Lasting Habitable Zones, They’d be Brutal to Life

Artist's concept of the TRAPPIST-1 star system, an ultra-cool dwarf that has seven Earth-size planets orbiting it. We're going to keep finding more and more solar systemsl like this, but we need observatories like WFIRST, with starshades, to understand the planets better. Credits: NASA/JPL-Caltech

Ever since scientists confirmed the existence of seven terrestrial planets orbiting TRAPPIST-1, this system has been a focal point of interest for astronomers. Given its proximity to Earth (just 39.5 light-years light-years away), and the fact that three of its planets orbit within the star’s “Goldilocks Zone“, this system has been an ideal location for learning more about the potential habitability of red dwarf stars systems.

This is especially important since the majority of stars in our galaxy are red dwarfs (aka. M-type dwarf stars). Unfortunately, not all of the research has been reassuring. For example, two recent studies performed by two separate teams from Harvard-Smithsonian Center for Astrophysics (CfA) indicate that the odds finding life in this system are less likely than generally thought.

The first study, titled “Physical Constraints on the Likelihood of Life on Exoplanets“, sought to address how radiation and stellar wind would affect any planets located within TRAPPIST-1s habitable zone. Towards this end, the study’s authors – Professors Manasvi Lingam and Avi Loeb – constructed a model that considered how certain factors would affect conditions on the surface of these planets.

This artist’s concept shows what each of the TRAPPIST-1 planets may look like, based on available data about their sizes, masses and orbital distances. Credits: NASA/JPL-Caltech

This model took into account how the planets distance from their star would affect surface temperatures and atmospheric loss, and how this might affect the changes life would have to emerge over time. As Dr. Loeb told Universe Today via email:

“We considered the erosion of the atmosphere of the planets due to the stellar wind and the role of temperature on ecological and evolutionary processes. The habitable zone around the faint dwarf star TRAPPIST-1 is several tens of times closer in than for the Sun, hence the pressure of the stellar wind is several orders of magnitude higher than on Earth. Since life as we know it requires liquid water and liquid water requires an atmosphere, it is less likely that life exists around TRAPPIST-1 than in the solar system.”

Essentially, Dr. Lingam and Dr, Loeb found that planets in the TRAPPIST-1 system would be barraged by UV radiation with an intensity far greater than that experienced by Earth. This is a well-known hazard when it comes to red dwarf stars, which are variable and unstable when compared to our own Sun. They concluded that compared to Earth, the chances of complex life existing on planets within TRAPPIST-1’s habitable zone were less than 1%.

“We showed that Earth-sized exoplanets in the habitable zone around M-dwarfs display much lower prospects of being habitable relative to Earth, owing to the higher incident ultraviolet fluxes and closer distances to the host star,” said Loeb. “This applies to the recently discovered exoplanets in the vicinity of the Sun, Proxima b (the nearest star four light years away) and TRAPPIST-1 (ten times farther), which we find to be several orders of magnitude smaller than that of Earth.”

Three of the TRAPPIST-1 planets – TRAPPIST-1e, f and g – dwell in their star’s so-called “habitable zone. CreditL NASA/JPL

The second study – “The Threatening Environment of the TRAPPIST-1 Planets“, which was recently published in The Astrophysical Journal Letters – was produced by a team from the CfA and the Lowell Center for Space Science and Technology at the University of Massachusetts. Led by Dr. Cecilia Garraffo of the CfA, the team considered another potential threat to life in this system.

Essentially, the team found that TRAPPIST-1, like our Sun, sends streams of charged particles outwards into space – i.e. stellar wind. Within the Solar System, this wind exerts force on the planets and can have the effect of stripping away their atmospheres. Whereas Earth’s atmosphere is protected by its magnetic field, planets like Mars are not – hence why it lost the majority of its atmosphere to space over the course of hundreds of million of years.

As the research team found, when it comes to TRAPPIST-1, this stream exerts a force on its planets that is between 1,000 to 100,000 times greater than what Earth experiences from solar wind. Furthermore, they argue that TRAPPIST-1’s magnetic field is likely connected to the magnetic fields of the planets that orbit around it, which would allow particles from the star to directly flow onto the planet’s atmosphere.

Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech
Illustration showing the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Credits: NASA/JPL-Caltech

In other words, if TRAPPIST-1’s planets do have magnetic fields, they will not afford them any protection. So if the flow of charged particles is strong enough, it could strip these planets’ atmospheres away, thus rendering them uninhabitable. As Garraffo put it:

“The Earth’s magnetic field acts like a shield against the potentially damaging effects of the solar wind. If Earth were much closer to the Sun and subjected to the onslaught of particles like the TRAPPIST-1 star delivers, our planetary shield would fail pretty quickly.”

As you can imagine, this is not exactly good news for those who were hoping that the TRAPPIST-1 system would hold the first evidence of life beyond our Solar System. Between the fact that its planets orbit a star that emits varying degrees of intense radiation, and the proximity its seven planets have to the star itself, the odds of life emerging on any planet within it’s “habitable zone” are not significant.

The findings of the second study are particularly significant in light of other recent studies. In the past, Prof. Loeb and a team from the University of Chicago have both addressed the possibility that the TRAPPIST-1 system’s seven planets – which are relatively close together – are well-suited to lithopanspermia. In short, they determined that given their close proximity to each other, bacteria could be transferred from one planet to the next via asteroids.

An artist’s depiction of planets transiting a red dwarf star in the TRAPPIST-1 System. Credit: NASA/ESA/STScl

But if the proximity of these planets also means that they are unlikely to retain their atmospheres in the face of stellar wind, the likelihood of lithopanspermia may be a moot point. However, before anyone gets to thinking that this is bad news as far as the hunt for life goes, it is important to note that this study does not rule out the possibility of life emerging in all red dwarf star systems.

As Dr. Jeremy Drake – a senior astrophysicist from the CfA and one of Garraffo’s co-authors – indicated, the results of their study simply mean that we need to cast a wide net when searching for life in the Universe.  “We’re definitely not saying people should give up searching for life around red dwarf stars,” he said. “But our work and the work of our colleagues shows we should also target as many stars as possible that are more like the Sun.”

And as Dr. Loeb himself has indicated in the past, red dwarf stars are still the most statistically-likely place to find habitable worlds:

“By surveying the habitability of the Universe throughout cosmic history from the birth of the first stars 30 million years after the Big Bang to the death of the last stars in 10 trillion years, one reaches the conclusion that unless habitability around low-mass stars is suppressed, life is most likely to exist near red dwarf stars like Proxima Centauri or TRAPPIST-1 trillions of years from now.”

If there is one takeaway from these studies, it is that the existence of life within a star system does not simply require planets orbiting within the circumstellar habitable zones. The nature of the stars themselves and the role played by solar wind and magnetic fields also have to be taken into account, since they can mean the difference between a life-bearing planet and a sterile ball of rock!

Further Reading: CfA, International Journal of Astrobiology, The Astrophysical Journal Letters.

We Have More Details on the Outermost Trappist-1 Planet!

The announcement of a seven-planet system around the star TRAPPIST-1 earlier this year set off a flurry of scientific interest. Not only was this one of the largest batches of planets to be discovered around a single star, the fact that all seven were shown to be terrestrial (rocky) in nature was highly encouraging. Even more encouraging was the fact that three of these planets were found to be orbiting with the star’s habitable zone.

Since that time, astronomers have been seeking to learn all they can about this system of planets. Aside from whether or not they have atmospheres, astronomers are also looking to learn more about their orbits and surface conditions. Thanks to the efforts of a University of Washington-led international team of astronomers, we now have an accurate idea of what conditions might be like on its outermost planet – TRAPPIST-1h.

According to the team’s study – “A seven-planet resonant chain in TRAPPIST-1“, which was recently published in the journal Nature Astronomy – they relied on data from the Kepler mission to determine the planet’s orbital period. Specifically, they consulted data obtained during Campaign 12 of the K2 mission, a 79-day observation period that ran from December 15th, 2016 to March 4th, 2017.

This artist’s concept shows what each of the TRAPPIST-1 planets may look like, based on available data about their sizes, masses and orbital distances. Credits: NASA/JPL-Caltech

Led by Rodrigo Luger, a graduate student at the University of Washington, the team was already aware of pattern in the orbits of the system’s six inner planets. This was based on prior data provided by the Spitzer Space Telescope, which indicated that these planets are in an orbital resonance – i.e. their respective orbital periods are mathematically related and influence one other.

From this data, the team had already calculated that TRAPPIST-1h would have an orbital period of just less than 19 days. Once they consulted the K2 data, they noticed that during the 79-day observation period, TRAPPIST-1h made four transit of the star – which worked out to an orbital period of 18.77 days. In other words, the team found that their observations were consistent with their calculations.

This finding was a welcome relief to Luger and his colleagues. As he stated in a UW press release:

“TRAPPIST-1h was exactly where our team predicted it to be. It had me worried for a while that we were seeing what we wanted to see. Things are almost never exactly as you expect in this field – there are usually surprises around every corner, but theory and observation matched perfectly in this case.”

The discovery of this resonance means that TRAPPIST-1 has set another record. For starters, it is already renowned from being one of only two star systems to host seven extra-solar planets – the other being the HR 8832 star system, a main-sequence K3V-type variable star located 21 light years away. Second, it has the most confirmed terrestrial planets to be discovered in a single star system to date.

Three of the TRAPPIST-1 planets – TRAPPIST-1e, f and g – dwell in their star’s so-called “habitable zone. CreditL NASA/JPL

But with this latest data, TRAPPIST-1 now holds the record for having the most planets in an orbital resonance as well. The previous place holders were Kepler-80 and Kepler-223, both of which have four planets in an orbital resonance. According to Luger, this resonance was likely established when the TRAPPIST-1 system was still young and the planets were still in the process of formation. As Luger explained:

“The resonant structure is no coincidence, and points to an interesting dynamical history in which the planets likely migrated inward in lock-step. This makes the system a great testbed for planet formation and migration theories. We could therefore be looking at a planet that was once habitable and has since frozen over, which is amazing to contemplate and great for follow-up studies.”

The possibility that the planets achieved their current orbital dance early in the system’s history could also mean that TRAPPIST-1h was once habitable. While three planets orbit with the star’s habitable zone (TRAPPIST-1 d, e, and f), TRAPPIST-1h orbits the star at a distance of about 10 million km (6 million mi), which places it well beyond the reach of the star’s habitable zone.

In fact, at this distance, TRAPPIST-1h gets about as much energy from the Sun as the dwarf planet Ceres (located in our Solar System in Main Asteroid Belt, between Mars and Jupiter), which results in an average surface temperature of 173 K (-100 °C; -148 °F). But in the past, when its star was brighter and hotter, the planet may have received enough energy that its surface would have been warm enough to support liquid water.

Artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth. Credit: NASA/JPL

“We could therefore be looking at a planet that was once habitable and has since frozen over, which is amazing to contemplate and great for follow-up studies,” said Luger. TRAPPIST-1 is also a prime candidate for follow-up study given its proximity. Located just 39.5 light years from Earth, this star and its system of planets present some exceptional opportunities for the study of exoplanets and M-type star habitability.

Beyond that, this study also demonstrated that despite the failure of two reaction wheels, the Kepler mission is still extremely useful when it comes to the study of exoplanets. Despite the fact that maintaining a steady eye on the TRAPPIST-1 system presented instrumental challenges, Kepler still managed to produce reliable information that was consistent with the team’s calculations.

Besides determining TRAPPIST-1h’s orbital period, the team used the K2 data to further characterize the orbits of the other six planets, rule out the possibility of there being more planets in the system, and learn more about the star itself (such as its rotation period and level of activity). This information will also be crucial in determining whether or not any of the planets located within the star’s habitable zone could in fact be habitable.

The discovery of the TRAPPIST-1’s system was an event that was many years in the making. But the rate at which new discoveries have turned up has been very impressive. In the coming years, with the deployment of next-generation planet-hunters – like the James Webb Telescope and the Transitting Exoplanet Survey Satellite (TESS) – we will be able to dig deeper and learn even more.

And be sure to enjoy this video of TRAPPIST-1’s orbital resonance, courtesy of Assistant Professor Daniel Fabrycky of the University of Chicago:

Further Reading: UW Today, Nature Astronomy


NASA Brings Trappist-1 Into Focus… Kinda Sorta

TRAPPIST-1 is probably the most well-known ultra-cool, or red dwarf, star. It is host to several rocky, roughly Earth-sized planets. Astronomers think it's no accident that ultra-cool stars and red dwarfs are host to so many smaller, rocky planets, and they hope that SPECULOOS will find them. Credit: NASA/JPL-Caltech

On February 22nd, 2017, NASA announced the discovery of a seven-planet system around the red dwarf star known as TRAPPIST-1. Since that time, a number of interesting revelations have been made. For starters, the Search for Extra-Terrestrial Intelligence (SETI) recently announced that it was already monitoring this system for signs of advanced life (sadly, the results were not encouraging).

In their latest news release about this nearby star system, NASA announced the release of the first images taken of this system by the Kepler mission. As humanity’s premier planet-hunting mission, Kepler has been observing this system since December 2016, a few months after the existence of the first three of its exoplanets were announced.

These observations took place between December 15th, 2016 and March 4th, 2017, as part of Kepler’s extended mission (known as K2). During this 74-day period, K2 collected data on minuscule changes in the star’s brightness, which were caused by transits made by the star’s exoplanets. And as of Wednesday, March. 8th, this information is now available to the scientific community.

Artist’s impression of of the exoplanets orbiting the ultracool dwarf star TRAPPIST-1. Credit: ESO/M. Kornmesser/N. Risinger (

These observations constituted the longest continuous set of observations of the star system to date. But in truth, the initial coordinates designated for this observation (known as Campaign 12) were set back in Oct. 2015, and did not focus on TRAPPIST-1. But as of May 2016, when the system’s first three planets were announced, the science teams adjusted their focus to observe them.

As Michael Haas, the science office director for the Kepler and K2 missions at NASA’s Ames Research Center, explained:

“We were lucky that the K2 mission was able to observe TRAPPIST-1. The observing field for Campaign 12 was set when the discovery of the first planets orbiting TRAPPIST-1 was announced, and the science community had already submitted proposals for specific targets of interest in that field. The unexpected opportunity to further study the TRAPPIST-1 system was quickly reconized and the agility of the K2 team and science community prevailed once again.”

While the data is raw and uncalibrated, it is expected to help astronomers learn more about this system of planets. In particular, it could help astronomers to place constraints on the seventh planet’s orbital period and mass (which are currently unknown). Additional information about the other six planets, particularly their size and mass, could also help astronomers make more accurate assessments about their composition.

Raw data from the K2 Category 12 survey. Credit: NASA/Kepler/K2 Campaign12

The magnetic activity of the host star, which is important in determining if any of its planets could be habitable, is also something that astronomers would like to learn more about. Last, but not least, the new data will help astronomers to prepare proposals for the use Earth-based telescopes next winter to further investigate TRAPPIST-1.

These proposals are due this month, and the timely arrival of this data ought to help research teams to refine their research objectives for next year. Any refinements made using this data will also help astronomer plan for follow-up studies using next-generations telescopes like the James Webb Space Telescope. As Geert Barentsen, a K2 research scientist at NASA’s Ames Research Center, explained:

“Scientists and enthusiasts around the world are invested in learning everything they can about these Earth-size worlds. Providing the K2 raw data as quickly as possible was a priority to give investigators an early look so they could best define their follow-up research plans. We’re thrilled that this will also allow the public to witness the process of discovery.

By the end of May 2017, the data will be fully processed and calibrated, which will also be made available to the public. As you can see from the images above, it was a little on the pixelated side! Still, we can expect some interesting finds to come out of this crowded star system in the coming months. Hopefully, some of that information will help us to determine if there’s any real chance of life forming there.

Further Reading: NASA, Kepler and K2