K2-18b: did JWST really find evidence of life on this exoplanet?

00:00 - Introduction
02:45 - What do we know about K2-18b so far?
05:21 - Madhusudhan et al. (2023) - K2-18b is a hydrogen atmosphere with a liquid water ocean with dimethyl sulphide
09:33 - Shorttle et al. (2024) - K2-18b has hydrogen atmosphere with a magma ocean
11:05 - Wogan et al. (2024) - K2-18b is just a mini-Neptune
13:19 - What data do we need to figure this out?
16:37 - Bloopers

Video filmed on a Sony ⍺7 IV

---

---

---

---

---

🔔 Don't forget to subscribe and click the little bell icon to be notified when I post a new video!

---

👩🏽‍💻 I'm Dr. Becky Smethurst, an astrophysicist at the University of Oxford (Christ Church). I love making videos about science with an unnatural level of enthusiasm. I like to focus on how we know things, not just what we know. And especially, the things we still don't know. If you've ever wondered about something in space and couldn't find an answer online - you can ask me! My day job is to do research into how supermassive black holes can affect the galaxies that they live in. In particular, I look at whether the energy output from the disk of material orbiting around a growing supermassive black hole can stop a galaxy from forming stars.

[gleedads]

Awesome summary: "Promise me you'll bear all of this in mind...just because one model fits the data doesn't mean there aren't other models..." This is such a good summary of the essence of science that I will probably point my students at this video, whether we are studying anything to do with exoplanets or not.

[mastick]

"Well, this kind of confusion, of not knowing what the actual right answer is, is science in action and it's wonderful to see."

This attitude is honestly the main reason I subscribed to your channel. I love it.

[bujin]

One thing that blows my mind is that I went to university to study astrophysics not very long after the first exoplanet was discovered. I found it fascinating back then that we had the ability to detect planets around other stars. And now we're able to analyse the light passing through the atmospheres of these planets. I wonder where we'll be in another 30 years time.

[SazzleCam]

1st rule of media: Don't let data & scientific analysis get in the way of selling a good story.

[jacobhald]

Just want to point out that magma means underground molten rock, where lava means topside molten rock. So a magma ocean would mean an underground ocean of molten rock. I guess that's sort of what we have right here at home in our own planet. In other words, we got K2-18b at home! :D

[tf]

Dr. Becky videos are just pure gems. Thank you again.

[RaeanneNichol]

I simply love your channel because you illustrate quite well how same data can be interpreted in many different ways. And which is why we need to keep asking questions and obtaining more data to better understand our universe just a little more clearly.

[luudest]

Ok, we need to build a bigger telescope right now.

[mikeoitzman]

Awesome analysis. You break it down nicely for the layman. Appreciate you! Keep up the great work.

[kayleescruggs]

I was in high school when discovery of the first exoplanet was announced. And now, we might soon have evidence of life on them. It almost feels like science fiction.

[GamingDemiurge]

As a physicist myself I believe that is impossible to find life outside earth by astronomical means. The reason is that there is a bias (yes, a bias not scientific skepticism or Occam razor as I will explain) for which a "natural" explanation will always be accepted over an "alien" explanation.

The base for this bias is the sentence "extraordinary claims require extraordinary proof" which I pretty much agree, but not in this case. In order to stablish that an occurrence is extraordinary one needs to know what ordinary is, i.e. one needs to have knowledge of the probability of such thing to happen. We don't have that data.

You can always make a theory to explain any astronomical data with "natural" assumptions. Therefore never ever we will be able to find life using it.

[JeffLearman]

THANKS! I saw the headlines but didn't even bother to read, hoping it'd be covered here, especially if it wasn't the usual news hype.

[LeftCoastStephen]

I listen to this and am reminded of the old saying:

Lies, damned lies and STATISTICS.

Excellent explanation of something that goes so far over my head it could be in orbit

😊

[UnknownUser-rbpd]

I really hope the media interest continues because that's how we inspire new people and hopefully encourage Governments to continue funding research into things that have no real current practical benefit at a time of pressing budget issues.
The Chinese landing on the moon again and a likely cold war developing between China and Western democracies will hopefully encourage the US and other Western nations to put more resources into space exploration similar to what happened in the 1950s and 1960s where we went from the first satellite to landing on the moon in 12 years because each side was scared of being left behind.
When I was growing up I fully expected that progress to continue and that interplanetary spaceflight would be routine nowadays but sadly, despite some impressive unmanned missions and telescopes like Hubble and JWST, we've mostly tread water as far as human exploration is concerned.

[seliasthemage]

I really like the way you cover this by talking through each of the papers.

[highlandrc]

Another great video... Thanks Dr. Becky <3 from Scotland

[frankvanderpool]

Your excitement about hat you do is invigorating and I enjoy listening to you explain plausible possibilities of complex scenarios is mesmerizing. I'm a retired Industrial teacher and I know when someone is doing a great job. I do share your astronomical interest. Have a sunny day and a clear night!

[d_mosimann]

Call me back when found an earth-sized planet arround a G-Star with life signs on it.

[zriraum]

Always excited when a new becky video drops! Space videos at night is the vibe🤩

[StEvEn-dpri]

As a non-scientist, but an armchair science enthusiast, it drives me crazy to see the claims that some of these "scientists" make using such imperfect data. The ambiguity in the data leaves way too much room for interpretation to make a claim this important.