This is Spacetime Series twenty six, episode fifty nine, for broadcast in the
seventeenth of May twenty twenty three. Coming up on Spacetime, The mysterious Moons
of Uranus, the magic key to getting satellite navigation to work, and early
problems for EU abstuse mission on its swear to the Jovian System. All that
and more coming up on Spacetime Welcome to Spacetime with Stewart Garry. Astronomers reanalyzing
dead from Ness's voyage of spacecraft and then comparing to new computer modeling say that
four of Uranus's largest moons may contain liquid water oceans under their icy crust.
If confirmed, it adds to a growing list of objects in the art of
Solar System now thought to be ocean worlds. The findings are reported in the
Journal of Geophysical Research. Planets provides the first detailed study of the evolution of
the interior makeup and structure of all five of Uranus's large moons Arial Umbreo,
Titania, Oberna, Miranda. The work suggests that four of these moons old
oceans that could be dozens of kilometers deep. Citists know of twenty seven moons
currently orbiting the ice giant wall of Uranus, with the four largest ranging from
Titania, which is one thousand, five hundred and eighty kilometers wide, to
Ril, which is one thousand, one hundred and sixty kilometers across. Sitists
have long thought that Titania, given its size, will be the most likely
to retain internal heat caused by radioactive decay. The other moons that all previously
be considered too small to retain enough heat to keep an internal ocean from freezing.
That's especially important because heating provided by the gravitational pull of Uranus would only
be a minor source of heat. Astronomers who have listed Uranus for priority exploration
have now begun focusing their attention to the planet in preparation for a potential mission.
The studies lead author, Julie Castello Rogues from nash's Jet Propulsional Laboratory in
Pasadena, California, says the new work could inform how a future mission might
investigate the moons, but it also has implications that go far beyond Uranus.
She says that when it comes to small bodies in our Solar system, that
is dwarf planets and moons, planetary scientists had previously found evidence of osions in
several unlikely places, including the Dwarf Planet series and Pluto, as well as
Satins small moon Mimus. This paper investigates what those could be and how they're
relevant to the many bodies in the Solar System that could be rich in water
but have limited internal heat. So the author's revisited findings from NASA's voyture Too
flybys of Uranus back in the nineteen eighties and from ground based observations. They
then developed computer models and infuse them with additional findings from NASA's Galileo, Cassini,
Dawn, and New Horizons missions, each of which discovered ocean worlds,
including special insights in the chemistry and geology of Saturn's ice moon and Solidus,
as well as Pluto and its moons, Sharon and the Dwarf Planet series,
all icy bodies around the same size as the Uranian and yes, that's how
you say it, moons. The authors use that modeling to gauge how porous
the Uranian moon's surfaces are, finding that they're all likely to be insulated enough
to retain enough internal heat needed to host an ocean, and they also found
what could be a potential heat source in the Moon's rocky mantles, which release
hot liquid and could help an ocean maintain a warm environment, a scenario that's
especially likely for titanium Oberon with the oceans may even be warm enough to potentially
support habitability. By investigating the composition of the oceans, sitists can learn about
materials that might be found on the Moon's icy surfaces as well, depending on
whether or not material underneath is pushed up from below by geological activity. There's
evidence from telescopes that at least one Urinus moon aerial as a material that flowed
odo its surface relatively recently, possibly from an icy cryovolcano. In fact,
Miranda, the innermost fifth largest moon, also hosts surface features that appear to
me of recent origin, suggesting that it too may have held enough heat to
maintain an ocean at some point. But the thermal modeling also found that Miranda
is unlikely to have hosted water for long. It loses heat far too quickly,
and he's therefore probably frozen solid. But internal heat wouldn't be the only
factor contributing to a moon's subsurface ocean. Keep finding in the study suggest that
chlorides as all as a ammonia are likely to be abundant in the oceans of
the icy giant's largest moons. Ammonious long being known as an anti freeze,
and the modeling suggests that salts, also likely present in the water, would
be another form of antifreeze, thereby maintaining the body's internal oceans. Digging into
white lines beneath and on the surface of these moons will help scientists and engineers
choose the best science instruments to survey them. For instance, determining that ammonia
and chlorides may be present means spectrometers, which detect compounds by their reflective light,
would need to use a wavelength range that covers both these compounds. Likewise,
they can use that knowledge to design instruments that can probe the deep interior
for liquids. Searching for electrical currents that contribute to the Moon's magnetic field is
generally considered the best way to find a deep ocean. That's how galile emission
scientists confirm Jupiter's ice moon Europa also harbors the global subsurface ocean. However,
the cold water of the interior moons such as Ariel and Umbrell could make the
oceans less able to carry these electrical currents and will therefore present a new kind
of challenge for scientists working to try and figure out what lies beneath this space.
Time still to come, the magic key to getting satellite navigation to work,
and early problems for Europe's deduced mission which is on its sweater the Jovian
system. All that and more still to come on spacetime when you think about
its. Satellite navigation systems such as GPS have totally revolutionized how humans get around,
providing us with precise three dimensional positioning data under a meter. It'll lets
you know exactly where you are, which way you going, and how fast
you're moving. And it all comes down to a series of very accurate,
high performance atomic clocks fitt abeth on the ground and in every single navigation satellite,
and right now the most accurate for civilian use are those fitted aboard the
European Space Agencies Galileos satellite navigation system. The atomic clocks on the Galileo satellites
deliver pinpoint timekeeping maintained to a few billionth of a second thanks to the ultra
rapid and ultra stable oscillation of atoms between different energy states. But sustaining this
sort of performance level demands even more accurate clocks down on the ground. In
order to keep the satellite synchronized and to ensure stability of time and positioning.
The European Space Agencies technicals centered the Netherlands is charged with the job of monitoring
the Galileo system time independently of the satellite operator. It's a task accomplished thanks
one ensemble of high performance atomic clocks, which are kept in thermally stabilize clean
room conditions at ess UTC lab. The collection of refrigerator size the timing clocks
provides stable timing, typically accurate to a billionth of a second. That's almost
ten times better than the Galileo system time. In fact, the UTC Lab,
together with similar clocks in the Navigation Support Office in Germany I used to
set a common time scale, which in turn is one of the inputs for
setting coordinated Universal time or UTC what we call Gretich meantime. Now, exact
positioning requires precise timekeeping. That's because Galileo works by determining the distance from a
satellite to a receiver on the ground or in an aircraft or in a boat
using signals traveling at the speed of light. By measuring the exact time taking
for the signal to cover the distance from the satellite to the aircraft, ground
or boat, and then adjusting for orbital speed. The Earth's rotation atmospheric anomally
is gravity and other known variables, and exact location can be determined. Galileo
satellites operating three planes at an altitude of twenty three two twenty two kilometers above
the Earth, transmitting signals downwards that incorporate a time stamp. A sat NAV
receiver on the ground picks up four or more of those Galileo signals in order
to pinpoint its position. By the time the signals reach the receiver from the
satellite, it's taken about a twelfth of a second. The receiver then multiplies
this difference by the speed of light about thirty centimeters panano second, or a
billionth of a second, in order to derive the exact distance from each of
the satellites in orbit. It then combined to these measurements in a triangulation to
compute its overall position. Now, if one of the clocks is in error
by more than say, three nanoseconds, this positioning value will be off by
more than a meter. To prevent this happening, eight satellites equipped with twin
hydrogen maseratomic clocks. These measure time to an accuracy of one second in three
billion years. There are also two smaller rabidium atomic clocks on its satellite as
well. They act like independent and alternative time sources and are accurate to within
three seconds in a billion years. Still, despite all this accuracy, the
atomic clocks aboard the satellites are prone to drift slightly over time, so a
worldwide network of Galileo ground stations gives a continuous tab on the satellite signals to
identify any clock drift compared to Galileo system time in the areas are then corrected
with an updated navigation message every one hundred minutes or less. This report from
eastv Europe's Galileo constellation is the most precise satellite navigation system in the world,
delivering meter scale accuracy. Its signals let us find our way on foot,
by car, even in boats and aircraft. So how do Galileo satellites thousands
of kilometers away tell you exactly where you are? Simply being so far away
is part of the answer. The satellites fly in three orbital planes twenty three
thousand, two hundred and twenty two kilometers above Earth's surface. Anywhere on our
planet, at least four satellites are visible at any time, the minimum needed
for positioning. Each satellite emits a radio wave containing its transmission time and the
satellite's own position. Because radio travels at light speed, the signal's distance of
travel is measured from the difference between the signal all time code and to the
time the receiver picked it up. It's like working out how far you are
from a thunderstorm by counting the seconds between a lightning flash and its slower thundercrack.
Time is converted into distance. For useful positioning, this timing must be
accurates to a few billionths of a second, the time it takes for light
to travel thirty centimeters. Combine distance measurements from multiple satellites simultaneously, and your
position is pinpointed. A minimum of four satellites is needed, three to fix
the user's latitude, longitude, and altitude, and a fourth to double check
time. Your receiver is smart. It knows the expected locations of the satellites
to cut signal acquisition time from minutes to a few seconds, and as Galileo
signals are very faint, equivalent to a sixty watt lightbulb shone down from space,
they are based on complex codes identifying each separate satellite. The receiver has
copies of all these codes so can make its own full scale replicas of faint
original signals for calculation purposes. These are used to calculate your final navigational fix,
boosting our economy and quality of life by letting everyone everywhere find our way
this space time still the cam early problems for the European Space Agency's Juice mission
in Jupiter and later in the science report a major ants in slowing down the
progression of Alzheimer's All that are more still to come on spacetime. A key
radar antenna aboard the European Space agencies Juice spacecraft has failed to open. US
planned mission managers say the critical sixteen meter radar for icy Moon's expiration antenna has
only unfolded about a third of the way and appears to be jammed. The
antenna is needed to peer beneath the icy crust of the three Jervian moons being
targeted by the mission Anny Meade Callisto in Europa, which are all suspected of
harboring vast subsurface liquid water oceans under their icy crusts. Engineers suspect a tiny
pin maybe protruding, and flight controllers and an he planned to fire the spacecraft's
engines in hopes of shaking the pin loose. That doesn't work, lots of
time to try and figure something else out. That's because Juice, the Jupiter
Icy Mutes Explorer spacecraft won't reach the Jovian system until twenty thirty one. The
one point eight billion dollar mission launched aboard an Iron five rocket from the European
Space Agency's Career Space bought in French Guiana back on April twelfth. The six
thousand and seventy kilogram bus size spacecraft will undertake a series of gravity assists flybys
of the Earth and Moon, as well as Venus, in order to sling
shot itself to its distant deep space targets. Mission managers say all other systems
aboard the spacecraft are operating nominally, with the radio dish, solar panels and
ten point six men in magnetic field probe all deploying successfully this space. Time
and time out to take another brief look at some of the other stories making
using science this week. With the Science Report. In what's being described as
a major step in slowing down the progression of Alzheimer's, drug company Eli Lily
have announced the results of their phase three trials which have shown a thirty five
percent reduction in Alzheimer's progression. The company claims it's drugged on animap significantly slowed
cognitive and functional decline in people with early symptomatic Alzheimer's disease. The trial looked
at how the drug altered a measure of cognition and ability by taking activities of
daily living. It found that for people with early stages of Alzheimer's, there
was a thirty five percent slowing of decline on the scale. Meanwhile, a
report in the journal Neuron has unveiled another potential new drug to help treat Alzheimer's.
Phase three trials showed that the drug lacanamad slowly cognitive decline in patients with
earlier Alzheimer's by binding with a neutralizing ameloid beta planque protein bundles associated with Alzheimer's
disease progression. Scientists have discovered a potential antidote for the poisonous deathcap mushroom.
The fatal fungus is responsible for more than ninety percent of all mushroom related deaths
worldwide. The main toxin produced by deathcap mushrooms is called alpha amanatin, and
the researchers identified a key protein STT three B, which is required for alpha
amanatin to have its toxic effect. Once they identified the protein, the authors
then look for drugs that might block it, and they found one called ADO
Signing Green, which is already approved by the US Food and Drug Administration.
However, a report in the journal Natric Communication says more work still needs to
be done to assess it safety, but when they tested the drug and human
cells exposed to the toxin, it acted as an antidote, blocking the toxic
effects. A report in the British Medical Journal says medical doctors and public health
experts are joining calls to suspend development of artificial intelligence until sufficient regulations are in
place. The researchers site three major reasons why artificial intelligence currently poses a real
risk to public health and safety, the first being its ability to ramp up
surveillance capacity on the public, which can be used to manipulate consumer choices,
spread misinformation and social division, and even enable government oppression. The second reason
is current and potential future development of military weapons that can kill entirely without human
supervision. In other words, it's the Skynet terminator scenario. And the third
is the loss of jobs that will come as artificial intelligence allows the automation of
more and more different types of work. Last week, Jeffrey Hinton, the
man widely seen as the father of artificial intelligence who had his job with Google,
warning about the growing dangers of developments in artificial intelligence. Hinton's views echo
those expressed earlier this year in a public letter by Elon Musks, Steve Wasn't
Act, and more than a thousand other tech leaders calling for a six month
moratorium on all development work on artificial intelligence because of concerns over its use.
Google have just relaunched their new Smarter Bed artificial intelligence chat CHPT. They're hoping
the updates and chances they've made will help people forget about the disastrous first take
when the AI chat butt provided the wrong answer in the process, tanking the
company's stocks by eight percent. However, it didn't take long but bed to
show its faults, displaying some strong and politically biased views as well the new
software. Google has also launched new phones and tablets. With the details,
we're joined by technology editor Alex Sahara Road from Tech Advice Start Life. They've
got AI everywhere in all of its announcements. There were a new Generative AI
experimental section for regular Google Search, So you have to go to g dot
co forward slash Labs and then you can get a generative AI response to your
queries. You can actually see a whole bunch of things for sale that relate
to that if that's something you want to purchase, where Google can actually update
those for sale links one point eight billion times per hour. It's very fresh
starter and it can also show you not only where the information from its generative
AI response came from, but also it will prompt you on other questions you
can ask and will remember what it told you before and we'll remember the context.
So search is going to change, but there's a scatle of the things
that Google bar is now no longer on a waitlist. It's opened up to
a one hundred and eighty countries. Just go to bar dot Google dot com.
If you have a Gmail account you can start using its right away.
If you have a Workspace account you need to get the admin to switch that
facility on, but it's there as well. They also have these large language
model engines behind the whole thing. There's a new thing called Palm two and
they've got four different versions of that, the smallest of which can fit onto
a phone. And so it's a bit like kit Chucker's Guide the Galaxy,
a book that has everything in all the answerity costs that we want without having
to be online. I can see that sort of thing is becoming very popular
very quickly, and they have much larger language models that are to be used
by companies who want their own private things, or just by people who want
to attach GT clone for their own uses without having to go online. So
for all these highlights and more, come to my site tech Advice dot Life
l Ife. I've got a link to the full two hour keynote. There's
also another organization's eighteen minute cutdown version and another version from Google. Lots of
information and details and links to all of their official Google information. They're very
exciting stuff and as well as the software there's some new hardware out as well.
Yeah, Google has become very strong in the hardware with their Picture line
of phones. Very successful, I mean, clearly lots of competition out there,
but they've got the new Pixel seven A, which is the lower cost
device four ninety nine in the US, seven forty nine in Australia. There
are cheaper phones out there, but this has Google's most advanced tens Or G
two chip. It's got a ninety hurt screen so quite smooth scrolling, eight
gear of RAM. It gets the Google updates immediately upon being launched. You
don't have to wait months and months like you do with other brands. Three
years of Android updates, five years of security updates, and of course all
of Google's photo smart don't even have an app called the Voice Recorder that not
only records live audio but gives you a live transcript as well, which is
very handy. Only Google officers a natively. Then there's the Google Tablet four
ninety nine again in the US, eight ninety nine in Australia. Eleven inch
tablet comes with a speaker magnetic stand so that it's like a smart display smart
home speaker when you're not using it as a tablet, but you can just
clip it off. It's magnetically attached and bang it's a tablet in your hand.
And so it's got really dual uses there. It's always going to be
charged when you need it, always ready to go. And finally, the
Google Pixel fold it's like the Sam's Galaxy Z fold eipt it's from Google.
It's got a larger, wider front screen. The Samsung's one is quite narrow
and internally it's got a nice square kind of unfolding internal screen. You can
still see the crease unfortunately, but that's modern technology and its limitations. No
style of support however, if you want that, you're still need Samsung.
And it's seventeen ninety nine US, which is at least two thousand and seven
hundred Australians. So they haven't launched in Australia, probably because it's quite expensive.
It seems to be a huge discrepancy there between wider US citizen and Australian
citizen, and pain for the same product certainly doesn't seem to reflect the exchange
rate. When you look at the tablet, you're four hundred and X dollars
for the US and eight hundred x dollars for Australia. Yeah, I mean
that they're they're putting one hundred and fifty bucks on Yeah for sure, so
Australians do pay more. So Yeah, that's Alexahara Royd from Tech Advice,
Start Life, and that's the show for now. Spacetime is available every Monday,
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