00:00We have found evidence for possible biological activity on an exoplanet.
00:08We have found signs of biosignature molecules, either DMS or DMDS or both,
00:16both of which are produced uniquely by life here on Earth
00:20and have been predicted to be biosignatures on planets around other stars as well.
00:26And we found the strongest evidence to date on a biosignature molecule,
00:33in this case a combination, potentially around another star outside the solar system.
00:39And that is a major breakthrough in our search for life beyond the solar system.
00:49Not only that there is a chance that the planet can actually be habitable,
00:55but what we are finding is that we are demonstrating that it is possible to detect biosignatures
01:03in atmospheres of such planets around nearby stars with existing facilities.
01:09And that's a big breakthrough.
01:11Currently, the only scenario that explains all the observations, in other words,
01:15detections of methane and carbon dioxide, non-detection of ammonia and carbon monoxide,
01:20and now possible detection of these molecules means that based on our current understanding,
01:25the only scenario that explains all of this is one where it's a Haitian world that is teeming with life.
01:31And what is a Haitian world? It's an ocean-covered surface with a thin hydrogen-rich atmosphere,
01:37and the ocean being habitable.
01:39So that is the only scenario which can currently explain all the observations together.
01:44However, we want to remain open to other alternatives one might come up with in the future.
01:56This moment in history of science will be viewed as a paradigm shift in our search for life,
02:00and the reason for that is that we have breached the level where we are demonstrating that if there is life out there,
02:09if there are Haitian worlds out there, there is ocean worlds with hydrogen atmospheres with life on them,
02:15we are basically establishing here that we can detect that kind of signature,
02:21those kinds of planets and biosignatures in them.
02:25So that is a paradigm shift in our understanding.
02:28This is a monumental discovery.
02:31It is very important, but we also have to be extremely cautious.
02:35The reason is that this is one of the biggest questions we have asked as a species in all of science,
02:41and we have to deal with it very carefully in that we want to be really, really robust in establishing
02:46whether this is actually life that we are seeing.
02:49We want two things.
02:50We want more observations to confirm that this signal is robust.
02:53We are seeing it at a three sigma level.
02:56We still have three in a thousand chance of it being a fluke.
02:59So we want to observe more to get it to a five sigma level, less than a chance in a million,
03:03a part in a million of a fluke.
03:06But we also want to do more theoretical and observational studies to make sure that there is absolutely no other way we can make this molecule without life.
03:15I think it is our responsibility as scientists and as part of a society that we want to answer this very deep question in a very careful and robust manner.
03:24But the excitement is still there nevertheless that we've got the capability to do it now.
03:29We'll be right back to the next session.
03:30We'll see you later.
03:31And we'll see you later.
03:32We'll see you later.
03:33Bye-bye.
03:59You
Comments