Since the unveiling of the first images from the fully deployed and calibrated James Webb
Space telescope, it has literally been off and running performing multiple observations per day.
In fact, there are so many that some of the images are unprocessed,
just posted data waiting for a scientist to come along and interpret, including another deep
field image that we simply haven’t seen yet. Also recently released have been pictures of Jupiter,
look at Jupiter in Infrared, and also the asteroid 6481 Tenzing, named after Tenzing
Norgay, the Nepalese mountaineer that first summited Mount Everest with Edmund Hillary.
But also posted are JWST’s current targets and while not a comprehensive list,
the examples showcased here give a good feeling for what science this telescope is doing
and what we can expect as the data are interpreted.
One object that we already have an image for is particularly breathtaking. This is a Spizter
space telescope image of the galaxy NGC 628 in infrared. And here is how JWST sees it.
This galaxy is perhaps better known as M-74 or the Phantom Galaxy. At 32 million light-years distant,
it’s a truly classic spiral galaxy of a class known as a grand design spiral galaxy. This name
comes from its very well defined spiral arms. This can differ in spiral galaxies, some being
more complex and less defined as opposed to this one. Being included in Charles Messier’s catalog
in the 18th century, we’ve known of this galaxy for some time but only just so as it’s actually
a really difficult target to spot in amateur telescopes, one of the hardest on Messier’s list
for the amateur astronomer. But it’s of great interest scientifically for several reasons.
The first is that this galaxy gives a face-on opportunity for astronomers studying galactic
spiral structures, it contains roughly the same amount of stars that our own galaxy hosts,
and gives insight on just why spiral galaxies display this structure and how it evolves
and behaves. This galaxy is also known to have exhibited several relatively recent supernovae,
one in 2002, 2003 and 2013, with the 2013ej supernova being unusually bright for its distance.
The aftermath of the 2003 supernova shows a rare instance of a light echo, where the
supernova’s light is echoed as it hits dust in the foreground as it propagates at the speed of light,
allowing scientists to probe the composition of the dust of another galaxy entirely.
Moreover, there is evidence for a somewhat peculiar black hole in this galaxy that comes in
as intermediate mass, unlike the supermassive black holes at the centers of galaxies,
and stellar black holes. It’s not clear how a black hole of this mass forms,
but it may be that it forms from a group of smaller stellar type black holes coalescing, with
the scarcity of the type simply being a result of that situation not happening very commonly.
Two more recently targeted objects were NGC 3603 and NGC 346. The latter is an open star
cluster and nebula located in the small magellanic cloud, a satellite galaxy of the Milky Way.
This object is of interest because it’s actively forming high mass stars,
with a number of giant stars that were formed in the cluster surrounding it.
These types of stars like to explode as supernovas and live very short lives, but when
they do go supernova they can populate areas of galaxies like this with heavier elements,
which in the case of our solar system resulted in the resource rich planets we enjoy today.
It may be that clusters like this are the first step towards eventual planets that can host life.
NGC 3603 is a similar kind of object known as a reflection nebula
and also has an associated star cluster, where the individual stars within the cluster are
illuminating the nebula. This is not unlike clouds illuminated at night by city lights below them.
Studying objects like this can give insight on the chemical composition of this nebula
and those like it, basically showing the evolution of the building blocks of stars.
Another target shows the dynamic schedule of JWST and how targets are chosen. Suggested just
ten days before the observation, the object SGAS 1723-IFU represents a lensed object.
This is a phenomena of the gravitational lensing effect shown so prominently in the
first James Webb image. This astounding trick, perhaps you could call it a hack,
of the universe allows you to see very distant objects, some of which are some of the most
distant individual objects we’ve ever seen, naturally magnified by gravitational sources
bending light. This could in principle allow us to make observations of things
like the very earliest stars in the universe that in every other respect are now long gone.
Yet another early target for Webb is the supernova remnant SN-1987 A. This is the remains of a type
II supernova that occurred in another satellite galaxy of the Milky way, the Large magellanic
cloud in 1987. The blue supergiant star Sanduleak 69-202 exploded before modern astronomer’s very
eyes and allowed them to characterize a relatively close supernova in real time. There were initially
a couple of mysteries involved with this event, the first is that the models at the time for
supernova events were flat wrong, it had been predicted that blue supergiant stars such as this
one did not undergo supernovas. That was until this one did it, forcing a revision of the models.
Another mystery was that for many years there was no indication of
a surviving neutron star leftover from this event.
This was eventually solved when indirect evidence of its presence was recently uncovered.
This supernova goes down in history as the first observable naked eye supernova since the invention
of the telescope, and remains an active target of interest for astronomers and now James Webb.
Also targeted was SPT 0311, which is one of a pair of galaxies that are probably in the process of
merging. We’ve only known about this target since 2017, but it has proven to be of great interest,
and perfect initial targets for Webb’s infrared capabilities. The objects are very high redshift
galaxies, indicating that they are extremely distant, and we’re seeing them as they were
when the universe was only 780 million years old. The galaxies are also very actively forming stars
from our far future perspective, and studies of them show a surprising chemical composition,
despite being so early, both water and carbon monoxide are seen. That means that carbon and
oxygen were present in the universe very early on, two very important components needed for life.
This only deepens the Fermi Paradox. If the basic chemical stuff of life was present that early,
less than a billion years after the big bang,
then the universe has been able in principle to have spawned life for a very large
chunk of its history. We may be newcomers to a galaxy that’s been capable of producing life for
most of its history. So why don’t we see evidence of alien civilizations everywhere?
And that leads us to perhaps the most interesting recent target of James Webb, Trappist -1,
which consisted of an observation of about 5 hours. The results of this are not yet out there,
but the system is amongst the most interesting we’ve found to date in regards to exoplanets.
This system consists of seven terrestrial planets, four of which are within the habitable zone of
the red dwarf they orbit, and could host liquid water, and possibly even life. But that really
depends on what these planets are actually like, and step one in figuring that out is the question
of whether any of them have atmospheres, which is needed for liquid water on their surfaces.
Whether they have life past the temperature conditions for simply water is a matter of debate.
On the pro side, the best candidate is Trappist 1e, which is a rocky planet on the order of about
90 percent the mass of earth. Some work has been done on models of atmospheric stability that show
that even though this is the best candidate in the system for a potential biosphere, its chances
of having one under the conditions of what we know about it are lower than earth. Another pro
though is that these planets orbit so closely to each other that rapid panspermia is likely,
if you have life on one member, it’s more likely to be on all members where it’s possible on
worlds above and beyond one that can spawn life. Other lesser examples may be able to sustain it,
but not spawn it. Rapid Panspermia is actually more likely in that star system in principle
than it is here in our own, where it still remains a very real possibility.
There are some rough aspects of this world that have come to light recently.
One is just how the planets of the system interact,
they are in a very tight resonance that may go back to their formation and they pass very close
to each other. This would create very pronounced tidal effects, and if Trappist 1e has an ocean,
it’s certainly being affected more than what earth’s tides see. What this means for the genesis
of life remains unknown, but if tidal pools were indeed important to abiogenesis on earth
as some suspect, this equation could be altered on a planet like Trappist 1e. You might see periodic
flooding replaced by a long period of arid dryness on the coasts of a planet like this,
and that might prevent the chemical reactions needed to get life going.
And you could also wonder that since all of the planets in this system are tidally locked,
what does that do to define how life functions? There’s no day-night cycle in this situation,
which is important for life on earth. Another recent discovery
is that because Trappist-1 itself is a small red dwarf, if you could somehow
transport earth’s photosynthesizing life to any of the habitable zone planets,
it would die due to a lack of sufficient energy from the star to sustain photosynthesis. But
at the same time, our photosynthesis evolved here under the light of a strong G type star,
so it may be able to take some other pathway at lower energies elsewhere in the universe.
And then there is the atmospheric makeup of these worlds, should they prove to have atmospheres.
And this is probably what JWST is interested in doing,
taking a profile of measurements of transits in order to try to spot any atmospheres during a
transit and trying to characterize what we can about them. Atmospheres are wildcards,
especially in regards to how they interact with ultraviolet light from the star.
If you get too much, you can kill any life there, we use UV for that here on earth. If you
have too little however, you change the possible chemistry in the planet’s atmosphere and you can
build up chemicals not conducive to life, such as carbon monoxide. On the other hand, hypothetical
forms of microbial life that use ultraviolet light as an energy source have been proposed.
As a result, Trappist 1’s proximity to earth at about 40 light years and ease of observation
of transits made it a prime target for JWST to stretch its wings in the search
of exoplanet atmospheres, even terrestrial ones like the Trappist system. As an aside,
SETI for good measure has also taken a look at this system for radio signals, but found none.
But one really interesting aspect of this system is that if there is technological life there,
in a few thousand years earth will begin to transit the sun from their perspective,
and if they have a JWST of their own, this world would absolutely scream its
biosignature atmospheric gasses, and by that time, maybe even a far flung space
faring human civilization emitting techno signatures into space.
Thanks for listening! I am Futurist and science fiction author John Michael Godier
currently worried about the JWST. At this rate, it’s going to get tired and then the
data will be in question. We’ll tell it to look at proxima centauri, and then we’ll get
a message back that says it's too sleepy and to send a cheese pizza to L2, which would be beyond
costly. Though I guess it could probably bake a frozen pizza pretty quickly on the sun shield
side, hmm freeze dried space pizza hmm, anyway be sure to check out my books at your favorite
online book retailer and subscribe to channels for regular, in-depth explorations into the
interesting, weird and unknown aspects of this amazing universe in which we live.