an interstellar meteorite could be hiding in the ocean. Why
doesn't Jupiter have rings like Saturn, when the Earth's
magnetic field almost collapsed the shortest day on Earth, and
Planet Nine is running out of places to hide all this and more
space news in this week's episode of Space bites. Hi,
everyone.
I'm Fraser Cain. I'm the publisher of Universe Today,
I've been a space and astronomy news journalist for over 20
years. This is our space bites, a weekly roundup of all of the
big space and astronomy news that we're reporting on Universe
Today. Now, this is a short version of the much longer email
newsletter that I write every week, but still, we understand
some of you would prefer to have it in video form. So let's get
into the news. Why doesn't Jupiter have rings? Then you
might not know but all of the giant planets in the Solar
System have rings, Jupiter, Saturn, Uranus, and Neptune. Now
for Jupiter, Uranus and Neptune. The rings are made of dust while
the rings for Saturn are these beautiful, sweeping, icy rings.
And you would think with the amount of gravity that Jupiter
has, it should be able to have icy rings just like Saturn and
Jupiter has Icy Moons like Saturn think about Europa and
Ganymede. Now, astronomers think that the rings of Saturn might
have come from comets that came in from the outer solar system,
they got too close to the planet, and they were broken up.
And once again, Jupiter probably experienced comets getting too
close. In the past we've seen comets crashed into Jupiter. So
we know this happens. So once again, why doesn't Jupiter have
rings. Astronomers did a simulation where they looked at
the gravitational interactions of the environment around
Jupiter and the environment around Saturn. And what they
found was that because Jupiter has the giant Jovian moons,
these four moons, Io, Europa, Callisto and Ganymede, that
interact with each other. It makes large rings like Saturn
just impossible to be stable for any long period of time. Saturn
does have a very large moon with Titan, but it's just the one
moon and it accounts for almost all of the mass in the Saturn
system apart from the planet itself. And so with only one
moon, it can't really disrupt these rings. So Saturn has
rings, while Jupiter just can't have stable long term giant icy
rings. But it makes you wonder like if Jupiter didn't have all
of those moons, would it have an even more impressive ring system
just makes you wonder. There could be an interstellar
meteorite here on Earth. The US Department of Defense recently
declassified information on fireballs and meteors that they
had been tracking. These are the really bright meteors that
struck the atmosphere, in most cases burned up, but in some
cases, actually made it through the atmosphere and landed
somewhere on Earth. So these are happening all of the time. It's
just there mostly happening over the ocean, over places where
there just aren't any population and so people don't notice them
happening. But the Department of Defense has satellites designed
I guess, to detect nuclear weapon launches, and so they're
able to also detect these meteors as they impact the
atmosphere. And what's interesting is that one of these
meteors seemed to have a trajectory that was
Interstellar. So think about like Oumuamua or comet Borisov.
This was an object that was on a trajectory that must have come
from outside of the Solar System. And the department of
defense actually confirmed this trajectory. This object exploded
in the upper atmosphere off the coast of Papua New Guinea. And
it's believed that it was large enough that fragments went into
the ocean in that area. Now, we don't know exactly where it
happened, but it's probably like a 10 kilometer by 10 kilometer
grid. And now some astronomers are proposing to go look for it.
Although it's a really large search area. Because these
objects are magnetic, they could be easier to find and think
about it. There could be objects that came from another solar
system, hear on the bottom of our ocean next almost inevitable
when you think about the amount of material that's probably
flying through the Solar System at all times. Could you imagine
how much astronomers could learn by studying an object that was
formed in another star system. Last week, I reported that a
Chinese long march booster was going to be returning
uncontrolled back to the Earth and it happened on July 30. The
booster reentered the Earth's atmosphere and crashed off the
coast of Borneo. Fortunately, into the ocean, nobody was hurt.
And it's believed that some people on Borneo were able to
actually capture a video of the booster as it was returning
through the atmosphere. NASA was not pleased by both the
uncontrolled entry and the total lack of notice by the Chinese
This was going to be happening and wrote a sternly worded
letter. And hopefully, this is the last time that we see one of
these giant boosters returning without any thought about where
it's going to land and who it might hit. These things should
be dumped into the ocean safely. We just had the shortest day in
history, the Earth takes approximately 24 hours for the
Sun to return to the same spot in the sky. I probably need to
explain this briefly the difference between a sidereal
day and a solar day so a tent sidereal day, that's the amount
of time it takes for the Earth to rotate once on its axis for
the stars to return to the same spot. And you might be surprised
to learn that it takes 23 hours and 56 minutes for the Earth to
turn once on its axis, it then takes an additional four minutes
for the Sun to return to the same spot in the sky. And that's
why we say that a day is 24 hours long. But it turns out on
June 29, we had the shortest day of the day was shorter by 1.59
milliseconds, which is the shortest day in recorded
history. So why is this happening, it's believed has
something to do with the Chandler wobble, which is how
the Earth shape can change because of ocean variation of
atmospheric variation, there can be changes with the Earth's
crust as mantle and material is moving around, and it can
slightly change the spin rate of planet Earth. But at the largest
scale, the Earth's rotation is actually slowing down. That's
because the Earth and the Moon are in a title interaction. As
the Moon is slowly drifting away from the Earth, the length of
the day on Earth gets slower and slower, and over time, the Earth
and the Moon will be tidally locked. So this is the shortest
day but don't expect shorter and shorter days, the Earth is not
spinning up. But this is a bit of a problem because so much of
our modern technology is based on clocks on atomic clocks down
here on Earth. And out in space, the whole GPS system relies on
these clocks, and as the length of day changes, that can cause
some of these clocks to be slightly inaccurate, and so the
clocks will have to be updated. To account for the actual length
of a day. A black hole can tear a neutron star apart in the
blink of an eye, astronomers have detected dozens of
collisions between black holes, because of the gravitational
waves that they admit they've been using the LIGO and Virgo
observatories. And we also know of three collisions between a
black hole and a neutron star. Probably the problem is, is that
black holes and neutron stars can be fairly similar masses.
And so it's hard to know exactly which two objects collide with
each other. And so astronomers have simulated what would happen
when a neutron star gets too close to the black hole. And
what happens, and I'm sure you're not surprised, is the
neutron star is torn into fragments in a shockingly short
amount of time, takes about two seconds to go from a neutron
star, a object that is compressed matter the mass many
times the mass of a star, compact it down to the size of a
city to be completely torn apart into a stream of atoms and
blasted out into space and also added to the mass of the black
hole. But as this process is happening, it will give off a
very specific signature that astronomers should be able to
detect in their gravitational waves. And so with more and more
of these models and simulation, we should get a much better
sense of what were the two objects that collided together
was it two black holes, was it a black hole and a neutron star,
two neutron stars, a white dwarf and neutron star. Over time,
stars will be able to map out all of the gravitational wave
signals of all of these objects. But still, just like the
imagination boggles to think about these objects, which have
many times the mass of our Sun colliding together, and
wrenching each other apart in that short amount of time. Space
is really terrifying. Planet Nine is running out of places to
hide. It's been several years since Mike Brown and Constantine
Madigan predicted the existence of Planet Nine to some large
object probably with five times the mass of the Earth, out in
the outer solar system somewhere between 101,000 astronomical
units. And they made this prediction because of the motion
of the objects in the Kuiper Belt. There seems to be some
kind of clustering of these objects as if some much heavier
object is farther out and is shepherding these dwarf planets
and icy capability objects into very specific orbits. And of
course, astronomers have gone looking for this Planet Nine.
They've looked in the places you would expect to Find it along
the plane of the ecliptic in certain regions. And so far, it
hasn't turned up. And so astronomers wanted to try a
fairly bold idea. They started with an infrared survey of the
outer solar system. And they mapped out all of the objects
that could roughly be a dwarf planet or some kind of ice
object like Planet Nine. And then they looked at another
infrared survey 20 years later, and mapped anything which seemed
to have moved in that time period that could be this
mysterious planet nine. And they found about 500 candidate
objects, which is kind of exciting, it's more than they
were anticipating. But then as they looked through each one of
these objects, they had to disqualify them. And it turns
out that these infrared signals that they were detecting, were
actually a type of nebula that was shifting in its temperature
and, and caused a signal that made them think that it was
actually something that was planet sized, as opposed to just
a diffuse gas. So by the time they were finished, they weren't
able to find any objects that match the Planet Nine. And so we
still don't know if Planet Nine is out there. But this further
constrains the places where it might be around in the Solar
System. But really, we're gonna have to wait until the Vera
Rubin observatory comes online later this year, to have our
best shot of finding this object if it's out there. And if not,
that, we need an explanation for why all of these objects in the
Kuiper Belt are moving in the way that they do. A time when
the Earth's magnetosphere almost collapsed. The Earth's
magnetosphere is incredibly important for life on Earth,
like we would not be alive without the magnetosphere. And
we know that it is generated by an internal Dynamo inside the
Earth, we've got various layers inside the Earth of iron and
nickel, molten metal that are rotating around. And as they
turn, they generate this very powerful magnetic field that
extends out from the Earth and protects the planet in this
magnetic bubble. And we know throughout history that this
magnetic field can flip every few 100,000 years. And the way
that scientists have figured this out is kind of amazing.
They map the magnetic field line in flows of lava. And then
they're able to detect the orientation of the Earth's
magnetic field. And then they find a place where the lab is
older. And they can see that the magnetic field lines were going
in the opposite direction, they can measure each time these
magnetic field lines flip. And what they found was that about
500 million years ago, the magnetic field turned off
completely. Why? Well, what it seems to be is that the Earth
earlier than 500 million years ago, didn't have a fully formed
inner core, we think about the structure of the Earth, you've
got the outer crust where we live, you've got the mantle,
where lava can flow out from the inside of the Earth, you've got
the outer core, and then you've got the inner core, which is
thought to be a solid iron nickel ball inside the the
Earth. And it's believed that this inner core didn't fully
formed until about 500 billion years ago. And when it did, as
it was forming, it actually shut off the planet's magnetic field.
And then it reformed it again. And we've had it ever since. And
so it will be pretty interesting to think about what it might be
like if that magnetic field had never fully formed. And it also
makes you wonder, then what would it look like on other
planets? Is this a situation that happened on Mars, and maybe
because its inner core never fully formed, because it's so
much smaller and cooled down, that it wasn't able to get that
full planet wide magnetic field for a longer period of time. But
still good thing that the magnetic field did return, we
wouldn't be having this conversation if it hadn't. Even
citizen scientists get time on James Webb. Now, one of the cool
things about James Webb and the Hubble Space Telescope, is that
these telescopes are freely available to anyone around the
world. So you can be living in any country and you're able to
get access to James Webb and Hubble for free, you just have
to make the science case. And that's the tricky part is
convincing the team that the observations that you want to
make are important that are going to be contributing to
science. But you don't have to be a member of a research
institution or a university or a government you can just be an
amateur citizen scientist. And so citizen scientists were
participating in a project from the Zooniverse called backyard
world's Planet Nine study. And they were looking for cooler
objects in the outer solar system, maybe more dwarf
planets, maybe a nearby brown dwarf, something like that. And
they found enough interesting objects that they were able to
write about 20 papers FROM ALL OF THIS citizen science
research, and some of these objects are considered so
interesting that they've been able to get follow up time on
the James Webb Space Telescope. And so at some point in the next
few months, they're going to be able to observe these cooler
brown dwarf objects and report their findings. And so just
shows you, if you are interested in space, and astronomy, and you
want to get involved in some of these projects, there are lots
of people that will be glad to get your help. And you can get
your name on a scientific paper, and maybe even get time on James
Webb to make further observations. I'm sure you're
getting sick of cool pictures from James Webb Space Telescope.
And so I thought we just put this to the end. This is your
dessert for listening to all of this interesting space news. And
this is a really cool picture of the cartwheel galaxy, imaged by
James Webb.
And what's cool about this object is it is a clear result
of a collision between galaxies. You see this amazing shape, it
kind of looks like a ring like a bullseye. And what happened was,
at some point about 400 million years ago, a smaller Galaxy
punched right through the middle of this larger galaxy, and
caused all kinds of damage to the galaxies, inner regions. And
so when you look at this galaxy in other wavelengths, thanks to
the near camera instrument, on James Webb, you can see where
all of the dust and gas has piled up as the result of this
collision, you can actually see where new star formation is
happening both in this outer ring and bits near the core as
this galaxy is just blasting off into space. Very cool. We're
gonna get like I said, a lot more amazing images every time
we find them. We will show more of them off to you here on our
video. Now, if you want more information on any of the
stories we talked about here this week, you can find them in
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right, those are all the stories that we had this week. I hope
you enjoyed them. We'll see you next week.