It is “only” 49 light years from Earth exoplanet LHS 1140 bwhich has attracted much attention in the scientific arena due to its supposed habitability. Discovered in 2017, the planet outside our solar system is the star of a new study that points to the presence of oceans on its surface.
The new findings, led by researchers from the University of Montreal, are based on observations using NASA’s powerful James Webb telescope. The exoplanet has a number of characteristics that are as intriguing as they are interesting. According to scientists from the Canadian institute, Not only will there be water; it also contains a large amount of nitrogen.They also point out that it is a “super-Earth”: it is 1.73 times larger than our planet, with a mass 5.6 times greater.
Is the exoplanet LHS 1140 ba potential candidate for human existence in space? Also, is it likely that alien beings live here? What are the next steps of the investigation to uncover the secrets of that world? To answer these and other questions, Hypertext spoke exclusively with the study’s authors.
5 Facts About Exoplanet LHS 1140 b: What Variables Indicate It’s Habitable?
- It is important to emphasize that this is an exoplanet. That is, it is located outside our solar system. According to NASA, it was discovered 49 light years from the surface of the Earth. In particular, his house This is the constellation Cetus, also known as the Whale.
- It is considered a rocky planet, although it is estimated that 10% to 20% of its mass is water. Experts note that in the temperate region exoplanet may contain liquid waterfundamental resource for life. This surface would be about 4,000 kilometers long. The frozen oceans, for their part, would be on their “dark side.”
- It is classified as a “super-Earth”. Its mass is 5.6 times greater than our planet. In addition, its diameter is 1.73 times greater.
- LHS 1140 b orbits its star, the red dwarf LHS 1140, every 24.7 days. The exoplanet is locked to its star and its rotation is synchronous. This means that one of its faces is constantly receiving light.
- New research suggests the possible presence of oxygen-rich secondary atmospheresimilar to what we have here on Earth.
“It is not possible to even remotely send people to any of these worlds.”
“Rather than leaving Earth, exoplanet researchers hope to place our planet in the broader context of all the types of worlds that exist in the universe. We are also interested in studying which of these worlds might host life,” he says. Hypertext Natalie OuelletteAn astrophysicist and science communicator at the University of Montreal. He is also the liaison between the Canadian Space Agency (CSA) and the teams that operate the James Webb Space Telescope.
Based on this, does the study of exoplanet LHS 1140 b point to the search for a potentially habitable world for humans? Are you trying to find extraterrestrial life? Maybe both?
In fact, the entire field of exoplanet research is aimed at characterizing them. This helps us understand how they formed and evolved, and how they fit into the broader diversity of exoplanets. We also aim to search for life beyond our solar system.
Given our current space exploration technology, sending humans to any of these worlds is even remotely impossible. Even the closest exoplanet to our solar system, Proxima Centauri b, is more than 4 light years away. The journey would take more than 7,000 years using the fastest ship ever built, the Parker Solar Probe, which is not even designed to carry humans.
We know they used the James Webb power. Is there some kind of rotation system that allows the telescope to be used? I mean, given that this instrument is used for a lot of observations, how is it being asked to aim at this exoplanet LHS 1140 b?
Most James Webb observations are conducted through so-called General Observer (GO) programs. These programs are selected annually through a highly competitive process in which researchers must submit proposals. A selection committee then distributes the available time among the highest-ranked participants.
We have just begun the third cycle of this process, and only one out of nine proposals has received time! There are other special ways to access the telescope, including what is called Discrete Director Time (DDT). Very important and/or urgent observing programs can be submitted at any time to quickly receive DDT at JWST. This is much more competitive than receiving GO time, and is reserved for only the most valuable and promising studies.
Our team received DDT in December 2023 for the latest study of the exoplanet LHS 1140 b. In the future, we hope that some combination of GO time, DDT time, and perhaps other programs can help the LHS 1140 b team continue their exploration.
Since Mars and other planets in our solar system are (for now) inaccessible to us, why is 49 light years considered a “short” distance? Will it be possible to travel this distance in the future?
As I mentioned, there is currently no way to travel the distances that separate us from exoplanets. This includes those that are relatively close to us, such as the exoplanet LHS 1140 b. There are some initiatives, such as Breakthrough Starshot, which talk about sending a microchip on a light sail at a fraction (10%) of the speed of light, in the hopes of reaching Proxima Centauri b within a few decades. But this is still very speculative and does not involve human spaceflight. In the meantime, we have to do all this wonderful research remotely!
“The most likely scenario is a water world with a nitrogen-rich atmosphere.”
Charles Cadieux is a student at the Trottier Institute for the Study of Exoplanets (iREx) and one of the lead authors of the study, which was led by Professor René Doyon. The specialist explains that although the presence of water is not a definitive sign of life on LHS 1140 b, it is tempting to consider the possibility.
The exoplanet was discovered in 2017. What are the main results of your research? What new information did you find about the exoplanet LHS 1140 b?
It is one of the most studied exoplanets, observed by many facilities and instruments, including the TESS telescope, Hubble, Spitzer, the ESPRESSO spectrograph on ESO’s Very Large Telescope, and others. Earlier this year, our team reanalysed almost all existing observations of this system for the first time in a collaborative study to update and obtain more precise parameters of the planet, such as its radius and mass.
We found that the density of the exoplanet LHS 1140 b is inconsistent with the interior of Earth. In fact, a hydrogen envelope or layer of water above a rocky, metal-rich core is the most likely scenario for its nature. We then used the NIRISS instrument on James Webb to distinguish between these scenarios, since a large, hydrogen-rich atmosphere would be detectable in just one or two visits. We found that LHS 1140 b’s atmosphere is not dominated by hydrogen. And the most likely scenario is a water world with a nitrogen-rich atmosphere.
What were the main challenges and obstacles you encountered during this research?
Because exoplanet LHS 1140 b orbits a star smaller and cooler than our Sun, our observations of James Webb’s atmosphere are more susceptible to stellar pollution. Star spots on the surface of the M dwarf star are cool enough to form water-like molecules that could be misinterpreted as a planetary signal. The biggest challenge was to conduct this careful analysis to correct our stellar pollution data.
Returning to your conclusions, what does the presence of nitrogen and frozen water mean? Are they signs that allow us to think about the possible existence of life there?
The presence of nitrogen and water, either liquid or frozen, does not imply or suggest life on LHS 1140 b. However, we know that life began in liquid water on Earth. So an important step in the search for life beyond the solar system is to look for exoplanets with surface conditions (temperature and pressure) that allow liquid water to exist.
In this study, we reject the mini-Neptune (hydrogen-rich) scenario for this temperate exoplanet, which would be inhospitable to life. Our climate modeling of LHS 1140 b for a water world scenario with a nitrogen-rich atmosphere predicts the formation of an ocean if the planet has sufficient levels of CO2 greenhouse effect. Detecting CO2 would require many more observations of the system with JWST, but would consist of a strong proxy detection of liquid water on LHS 1140 b.
Your study indicates that the region that points to the star LHS 1140 has an average temperature of 20 degrees Celsius. Would that mean that part of your oceans are liquid?
Because LHS 1140 b is ten times closer to its star than Earth is to the Sun, the tidal force on the planet is strong enough to synchronize the planet’s rotation (day) with its revolution (year) around its star (24.7 days). This is analogous to the Earth-Moon system, in which the satellite always shows the same face. LHS 1140 b has a permanent day side and a permanent night side. And the temperature is high enough to melt the frozen surface only in the region that receives the most radiation from the star.
What are the next steps in studying the exoplanet LHS 1140 b?
Next, we need to repeat our observations with the James Webb Telescope to confirm the preliminary detection of a nitrogen-rich atmosphere. This will take about a year of observations. The current set was made with the NIRISS instrument, but we also plan to use NIRSpec on JWST, which extends further into the infrared and allows us to probe the CO2 content of the atmosphere. As mentioned above, the CO2 greenhouse effect controls the surface temperature and the size of the liquid water ocean. A clear detection of CO2 will require 2-3 years of observations with JWST and should provide definitive proof that LHS 1140 b is a super-Earth planet with a large supply of water.
The peer-reviewed findings of the study were published in Letters from the Astrophysical Journal.
Source: Hiper Textual
