We know more about the universe in which we live right now than we’ve ever known in
the entire history of humanity.
Discoveries are coming at breakneck speed expanding our knowledge base of existence,
and nowhere is this more prominent than in space science.
So here are ten mind blowing recent space discoveries.
Number 10.
Intergalactic Supernova SETI Searches
SETI searches are hard.
From astounding amounts of earth interference to the fact that radio signals from space
are incredibly weak, you are also faced with always taking shots at the dark.
When you turn the telescope to a distant star system, you can only listen for a short time,
usually only a few hours.
This means that you have every chance to miss a signal, and only a very slim chance as far
as timing is concerned to see one.
And to boot, you don’t know what frequency aliens would be transmitting at, it could
be any of billions.
As a result, thinking within SETI is moving in a different direction because the one thing
we do know is that scientifically minded aliens would know of these problems as well as we
do.
So if they wanted to make their presence known and say hello to the universe, there might
be more efficient ways to do that through finding universal sign posts where you could
put a signal, and expect anyone else with science to see it.
One such method are supernovae.
If you time your SETI contact signal with a supernova, which presumably all species
in your nearby group of galaxies would see with their telescopes, then you might just
find such a signpost and see success, though it might be millions of years before you know
you were successful.
This question led researchers in SETI to recently observe the effects of a supernova, known
as SN2023ixf, in the Pinwheel galaxy 21 million light years away to see if there might be
signals of alien origin associated with it.
This is actually the closest supernova in a decade, even being extremely distant in
another galaxy, but it also happened 21 million years ago very distantly, meaning that any
signals sent around the pinwheel galaxy are not likely to be visible to us.
But the researchers at the University of Washington had a different idea.
So we saw the supernova in the pinwheel galaxy.
But stars further from it in our local neighborhood haven’t seen it yet.
This means that if they send out hello signals every time they see a supernova, it might
be a good time to turn our radio telescopes to those stars and see if we catch any signals.
So the team has been observing stars within about 300 light years of earth that have just
seen the supernova to see if anyone is saying hello.
One wonders if someday we will be the ones pulsing out hello signals every time we see
a distant supernova, perhaps as one might see a huge, distant fireworks display and
decide to set off a firecracker of their own in a galactic wide analogue of a 4th of July,
or similar holiday barbecue.
Number 9.
Saturn’s Rings May Be Young
Using data from the Cassini spacecraft, researchers studying the micrometeoroid environment around
Saturn were recently able to estimate the age of Saturn’s rings.
How this was done, the researchers looked at how dark saturn’s icy ring matter is.
Given that the material started out as bare ice, the accumulation of dust on the surface
of the material would cause it to gradually darken.
At the shade it is today, they were able to work out that the rings can’t be more than
about 400 million years old.
Determining the age of Saturn’s rings has been contentious, and continues to be.
In response to the study, it’s been pointed our that if the rings lose dust over time
through some other process, the dating could be wrong and they could be far more ancient.
This might be the case if the rings were created by the shredding of a small moon early in
Saturn’s history billions of years ago.
That’s assuming however that they weren’t originally formed from the destruction of
a captured object.
In any case the formation, origin and age of Saturn’s rings remains unknown.
Number 8.
Keep the Magnets Away From the Meteorites
The study of meteorites is really an exercise in studying the history of the solar system.
They can show the earliest, most pristine material from the solar nebula, to highly
shocked and altered material showing the violence of impacts in space.
They can also tell us much about the history of Mars particularly, in that the only material
from the red planet on earth today is from meteorites blasted off its surface.
Meteorite hunters have long relied on magnets in what they do, as meteorite material has
a tendency to strongly attract magnets.
If a magnet sticks to a rock, it’s the first step in identifying if it is indeed of meteorite
origin.
But there’s a problem.
By doing that, the magnet can erase the magnetic past of that rock.
This is particularly important with Martian meteorites.
If in a pristine state, they retain a kind of magnetic memory of Mars and how it’s
magnetic field was when the rocks first formed.
This is important, because Mars no longer has a magnetic field, after having collapsed
3.7 billion years ago.
Unfortunately the vast majority of Martian meteorites have been exposed to magnets since
their recovery and no longer preserve this information.
Only a handful still do, so its hoped that for future finds of meteorites of Martian
origin the collectors will keep this in mind, or if its a multiple stone fall, only test
one and leave the rest pristine.
Number 7.
Stars from Andromeda
The Milky Way and the Andromeda galaxy are on a collision course.
Recent work has shown that the outer fringes of the two galaxies may already be interacting,
but there’s another possibility here that there may be stars in the Milky Way that originated
in Andromeda that could be far closer.
The idea goes like this.
Stars can get ejected at high speed from their parent galaxy, typically through an interaction
with a black hole.
They can be tossed out of their parent galaxy at escape velocity only to wander intergalactic
space.
The Milky Way does this, and so does Andromeda.
The question is, how many stars in the milky way could be from Andromeda originally.
The answer is between 12 on the very lowest end, and nearly four thousand on the upper
end estimate.
If these exist, they should be identifiable with the GAIA data set as very rapidly moving
stars coming from the direction of Andromeda, and might even bear chemical signatures in
their spectra atypical for the Milky Way.
Number 6.
The Background Gravitational Rumble
One interesting use for pulsars that’s come available in recent years is to use them to
probe gravitational waves, known as pulsar timing arrays.
These allow the study of the cosmic background of gravitational waves, in a kind of galaxy
wide detector.
What they found is that a background of gravitational waves does indeed exist, using tiny variations
in the time the individual pulsar’s signals took to reach earth.
The findings still need confirmation, but the evidence for the background is at this
point growing especially when a prediction of general relativity was observed within
them.
The question is, what’s causing them.
The leading hypothesis is that it’s merging supermassive blackholes at the centers of
galaxies across the universe creating it.
The problem is that this doesn’t exactly match current models in that these kinds of
black hole events would need to be more common than we understand.
There is however another option, in that the background may have been created by the big
bang itself during the period of cosmic inflation, offering a possible probe into that enigmatic
event.
Yet another is that they originated as defects in the early universe as it changed phases.
The data does not yet make it clear which option it is, but it does seem that there
is a way forward to collect more data in a collaborative effort and at least learn more
about whatever causes this background.
Number 5.
Ring Wormholes
Typically wormholes are thought of in the classic sense, tunnels through spacetime linking
two different points in space, or perhaps black holes performing that function.
But there is another option for wormholes that’s being talked about within science
as of late.
Known as ring wormholes, these would not be three dimensional per se, but flat in a sense.
As usual, for this type of wormhole to exist, you have two uphill battles.
The first is that it requires a string of negative matter, a circle, that could act
as a flat wormhole.
We don’t know that negative matter can exist, it’s just not expressly prohibited by physics.
We have no idea how to make it.
The second is the ever present problem that whenever you do something like this, it ends
up being a time machine.
A backwards one, that could deposit you on the other side, and if you went back through
you could end up before you left, limited by the age of the wormhole being a hard stop
on just how far back you could go.
A third issue are quantum effects that would obliterate any such wormhole, which are not
yet well understood.
All three taken together, we’ll probably find that these kinds of wormholes are not
possible.
But fun to think about at any rate.
Number 4.
Gamma Ray Burst Supernovae
Gamma ray bursts remain one of the most mysterious phenomena in astronomy today.
These are the most luminous events in the electromagnetic spectrum since the big bang
itself, coming ias a flash in gamma rays, followed by an after glow in longer wavelengths.
There appear to be different classes of gamma ray burst, right now with some associated
with binary star mergers, and others exploding stars.
But until recently, the origins of them have been difficult to pin down.
In October of 2022, the brightest gamma ray burst yet observed occurred that seems to
confirm a supernova origin.
This event, known as GRB 221009A was known as a long gamma ray burst, and seems to have
preceded a supernova event by about 10 or 20 days.
The indications for the supernova was teased out of the data as an extra brightening of
sorts, but remains in question and difficult to confirm.
Still, the best model we have points to supernovae as the origin of this kind of signal, but
it would be interesting if a burst of this type in a distant galaxy produced no signal
at all and sent the whole origin theory for this type of gamma ray burst back to the drawing
board.
Number 3.
Yet Another Outer Solar System Planet Possibility
In recent years, there has been talk of two possible planets beyond the orbit of neptune.
Setting the debate aside of whether Pluto is a ninth planet, the first of this is the
infamous planet 9 which has been invoked as a possibility to explain peculiar orbits of
some trans-neptunian objects, which if it exists is likely to be a protoplanetary core
or super earth about 5 times the mass of earth that was ejected into a far orbit after the
formation the solar system.
Evidence continues to mount for the existence of this planet, but as of yet it has not been
directly detected.
Lesser known is the possibility of planet 10.
Here there is a strange feature of the Kuiper Belt known as the cliff, where material abruptly
drops off which may represent either a cut off of material during the formation of the
Kuiper belt, or a large gap.
One possibility to explain this would be the existence of a Mars sized planet in the area
clearing the local neighborhood.
Now we have the possibility of a planet 11 much more distant than the aforementioned.
This would be a Neptune sized world deep out in the Oort cloud.
Modeling showed that the dynamics of planetary ejection from the inner solar system would
place up to ten percent of objects originally forming originally in the inner solar system
actually in the oort cloud as opposed to being ejected entirely from the solar system.
This would leave such a planet in a highly eccentric orbit that would place it very distant
of the sun for most of its orbit, but dramatically closer during a relatively short period.
Interestingly, if this object is Neptune or Uranus sized, it might be discoverable with
future telescopes, but if it’s smaller than that, it may never be discoverable until we
actually go out there, which is far future.
But the idea of large planets in the Oort cloud is interesting, because percentages
can be placed on it, with a Uranus sized world having about a 7 percent chance of existing.
Number 2.
The Milky Way’s Filaments
Recently, strange horizontal filaments have been detected by instruments such as Meerkat
emanating from the environment of Sagittarius A star, the supermassive black hole at the
center of the Milky Way.
There are two types of filaments, longer vertical ones discovered in the 80’s that align towards
the black hole, and are aligned overall with the galaxy’s magnetic field in the area,
and are probably made of high energy electrons stretching about 150 light years out.
But the horizontal filaments, which should be random but aren’t, are made of gas only
stretch about 5 to 10 light years.
This points to some kind of outburst from the environment of Sagittarius A star around
6 million years ago, and there is some evidence for previous outbursts, but the actual mechanism
for creating the two phenomena remains unknown.
It might however lead to a better understanding of the black hole’s spin, and even give
clues to the early history of the formation of the galaxy.
Number 1.
Cosmological Time Dilation
Few attributes of the universe are as strange as time dilation, an effect of special and
general relativity depending on circumstance.
Fundamentally, this means that time does not tick at the same rate everywhere in the universe,
an assumption Newton once made that turned out to be incorrect.
Time dilation is well proven, if you put a clock in a gravity well, such as earth, or
you put an atomic clock on a fighter jet doing mach 2, time will tick at a different rate
than a control clock not in that environment.
Indeed, certain satellites have to be corrected for this for them to even work, particularly
the GPS system.
But there is another lesser known aspect to time dilation.
Known as cosmological time dilation, the most distant objects in the universe that we can
see, light dating from the early days of the universe has the effect of appearing as though
time were slowed down.
This means that looking at those distant objects, they appear to evolve slower than what we
see today.
This is a product of the expansion of the universe, as it expands, light must travel
increasingly further distances to reach us, thus takes more time to get here.
We see this as dilation.
But it’s an illusion, if you were present near those objects when the light left them,
time would appear to tick normally.
This effect has been well studied for 30 years in very distant supernovae which unfold much
slower than nearby ones.
More recently however Geraint Lewis and Brendon Brewer have looked at quasars, among the oldest
objects in the universe that we can see.
They studied 190 quasars, paying attention to the level of redshift they showed, a marker
of their distance, showing that the most distant ones, about a billion years after the big
bang, appear to be running from our perspective five times slower in time.
Thanks for listening!
I am futurist and science fiction author John Michael Godier and be sure to check out my
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in-depth explorations into the interesting, weird and unknown aspects of this amazing
universe in which we live.