I would think
this would be a dream moment for
any astronomer.
This is what...
this is what we look forward to,
to be making major discoveries
about the universe
and our place in the universe in general.
What we have found
in this present discovery is
that for the first time,
we have detected carbon bearing molecules
in the atmosphere of a habitable zone planet.
Now, this has never happened before.
This is the first time in history that
this has been possible,
thanks to the James Webb Space Telescope
and the fact that we are able to do that
in a habitable zone planet
is already a major technological achievement
and now as far as what that means scientifically
we have several key advancements,
scientific advancements that come out of it.
First is that...
the molecule methane, for example,
has been sought after for a long time,
a little over a decade now.
We have been as a field,
trying to look for hydrocarbons and methane,
in particular in various low temperature planets, but never found it.
This is actually called the 'missing methane' problem
and for the first time, we are seeing it.
And then secondly,
the combination of methane and our detection of carbon dioxide
and non-detections of other important molecules
like ammonia, for example, or carbon monoxide,
that atmospheric composition
tells us
that of all the possible ways to explain it,
the most plausible way is
that there is an ocean underneath.
It's very hard to get that sort of composition otherwise,
so this is what leads us to think that
this is
a very possible
Hycean world,
which are basically planets with
planet wide oceans and hydrogen rich atmospheres
which have just the right conditions
on the surface to be able to host life
under conditions similar to what we see on Earth.
Now, it comes with its caveats.
Obviously, we know that there should be
a surface water layer,
but we don't know exactly what the temperature
of that water is
so we can't say for sure if it's definitely habitable,
but it's got
all the indications of being so
and we need more observations
to establish that more firmly.
So a common question
that gets asked is
'Could this planet support life?'
Currently,
we can't say that for sure.
We need more observations.
We did detect a molecule at a tentative level
called dimethyl sulfide.
This molecule is unique
to life on Earth.
There is no other way this molecule is produced on Earth.
So it has been predicted
to be a very good biosignature
in exoplanets and habitable exoplanets
including Hycean worlds.
So we want over the next few years
to look at
several of these Hycean-candidate Hycean worlds
with the James Webb Space Telescope
and map out
in as much detail as we can.
If they do support the presence of an ocean,
especially a habitable ocean
underneath the hydrogen rich atmosphere
and if they do,
do they show any signs
of the presence of any biomarkers in their atmospheres?
And if we do find biomarkers,
we want to also do theoretical work alongside to establish
if those biomarkers can be uniquely tied
to the presence of biological activity on the planet
and we hope that our present discovery
presents like the stepping stone
to that new era
of exoplanet characterisation that we are entering.
This particular discovery is
as important to the scientific community
as it is...
to anyone really
because this...
hints at the core
of the questions that we have asked as a species
for thousands of years.
Why are we here? Are we alone?
These are questions
everyone, almost everyone
can be found asking at some point in their life.
You go into the night sky,
you wonder...
are we alone?