can radars detect life on mars everyone has a dream some of us dream of
mars here are three things that we know about
the red planet number one at a distance of 54.6 million
kilometers from earth mars is the fourth planet from the sun
number two it is smaller than earth number three at this time mars's surface
cannot support life as we know it also here are three things that we don't
know yet number one when are we going exactly number two
if we are staying number three if mars ever supported life as we know it
making science we can try to find an answer to these unanswered questions
now we just have to explore the deepest secrets of mars
literally join me to find out how the use of radars could help us detect life
on this romantic planet
as humans we've always strived to find proof of life on other planets
scientists are now taking a chance on mars
on earth all forms of life need water to survive
it is likely though not certain that if life ever evolved on mars
it did so in the presence of a supply of water
on mars we will therefore search for evidence of life
in areas where liquid water was once stable and below the surface where it
might still exist today on the nasa website we can read because
water is the key to life as we know it earlier mars missions were designed to
make discoveries under the previous mars exploration program
science theme of follow the water the launch of the curiosity mission rover
marked transition between the themes of follow the water
and seek signs of life in addition to landing in a place where past evidence
of water curiosity was seeking evidence of
organics the chemical building blocks of life
places with water and the chemistry needed for life
potentially provide habitable conditions future mars missions as the perseverance
rover of nasa's mars 2020 mission will search for life itself
in places that continually evolve from discoveries by
prior missions new and previously developed
technologies will enable us to explore mars
in ways we never have before resulting in higher resolution images
longer ranging surface mobility and even the return
of martian soil and rock samples for studies in laboratories on earth
as the case of nasa's mars 2020 mission but let's get deeper into what we
discovered a few days ago we know that on mars surface the lack of
a substantial atmosphere makes liquid water impossible but two
years ago in 2018 a group of italian scientists announced
evidence of salt water beneath the southern polar caps of mars
salty lakes at the mars south pole on september 28 2020
they had confirmation of that subglacial lakes on mars
that is water at liquid state a team of researchers led by sebastian emanuel
loro and elena pettinelli university of rome
has confirmed the presence of a saltwater lake system
under the subsurface of mars at the south pole
first thing first how was it possible to make such a huge discovery
well scientists used radars this is actually a really common technique
for instance we use radars to identify subsurface glacial lakes on earth in
regions like antarctica or greenland but how do radars work
a radar device emits radio waves running at the speed
of light that bounce off layers of material in the planet's surface and
subsurface and the way the signal is reflected back
indicates the kind of material that is present
at a particular location if electromagnetic waves traveling through
one material meet another material the waves will reflect or scatter from
the boundary between the materials this means that a solid object in air or
in a vacuum will usually scatter radar radio waves
from its surface radar waves scatter in a variety of ways
depending on the wavelength of the radio wave
and the shape of the target when the signal comes back it bounces
off in a way similar to the way light is reflected by a mirror
they also brought a new approach adapting radar techniques used by
satellites orbiting earth to image buried geological features
their analysis looks not just in how bright an area is
but other metrics as well such as how the signal strength varies
indicating how smooth the reflecting surface is a high reflectivity area
indicates bodies of liquid water trapped under the ice
the marsus mars advanced radar for subsurface ionosphere
sounding radar one of the instruments on board the esa
mars express is an italian instrument developed by the university of rome la
sapienza and thales alenia space it revealed in
2018 a high reflectivity area with a diameter of about 20 kilometers
this could have been possibly explained admitting the presence of a sub-glacial
lake under the mars ice on september 28 2020
scientists confirmed that discovery lake's position
and extension and intensity of the signal were confirmed
but they found out there are other three new high reflectivity areas
this was a mind-blowing discovery the main lake is surrounded by three other
smaller than the first liquid bodies but we cannot say if they are interconnected
due to the radar technical limitations and its distance from the martian
surface says scientist elena pettinelli but the
heat coming from the interior of mars alone
would not be enough to melt the ice into water scientists say that for the water
to be liquid lakes on mars should be salty from a
thermal point of view it has to be salty says pet nelly
in fact salt melts ice and helps keep water from re-freezing by
lowering the freezing point of water this phenomenon is called freezing point
depression that's why if you live in a cold place
in winter you might see trucks spreading a thin layer of salt on roadways
this causes snow and ice to melt on impact rather than freeze
and makes the roads wet rather than icy and dangerous
the freezing point depression as the worlds say is the decrease of the
freezing point of a solvent on the addition of a non-volatile solute
for example salt and water in all cases the
substance present in smaller amounts is considered to be the solute
while the one present in larger quantity is called the
solvent the chemical potential of the solvent in the mixture is lower than
that of the pure solvent so that the resulting liquid solution
has a lower freezing point than the pure solvent that is to have
ice you have to lower the temperature above
zero degrees celsius by the way scientist roberto orozi
principal investigator of mars's experiment
comments the discovery of an entire lake system implies that their formation
process has to be simply and common and that
these lakes would probably existed for most of the
planet's history that's why they could still keep traces
of some forms of life that lived on mars a long time ago
when its atmosphere was similar to the one existing on primordial
earth but how salty can a lake be to support life
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links with a salt content that is about five times that of sea water can support
life but as the concentration approaches 20
times that of seawater life is no longer present said john
priscu an environmental scientist at montana
state university in bozeman in fact in antarctica there's not much
active life in these briny pools so maybe they're just
pickled and that might be the case on mars
so as we can see it's an open debate because in order to have
water in a liquid state lakes have to be salty
due to the low heating from the interior of the planet
but in order to support life they must not be too salty
extreme environments including hyper saline lakes
are so harsh that only a few organisms can survive in them
called extremophiles these organisms are found in the most challenging
environments the hottest saltiest and most
contaminated places on earth extremophilic organisms are capable of
growth and reproduction at a low sub-zero temperature said
harvard's avi loeb one of the study's authors in a
press release they are found in places that are
permanently cold on earth such as the polar regions and the deep
sea and might also exist on the moon or mars
salt loving extremophiles called halophiles
in particular are interesting because the martian soil
is full of salts briny remnants of now evaporated surface water
life on mars would also share with halophiles the challenge of high
uv levels as the atmosphere of mars offers little protection from this
damaging radiation which are the future perspectives
the authors of the discovery recommend to intensify the exploration
in mars polar regions in order to find some
other subglacial lakes in order to determine their compositions
and their astrobiological potential also note that some of the big vips like elon
musk want to go deeper and deeper to find out
every little secret that mars might have hidden
under its red dusty atmosphere he said that he's planning to bring humans to
mars as soon as possible we are developing new technologies to
reach these important goals we expect humans to prepare for human
exploration on the red planet and maybe settle colonies at some point
as always everything will be made possible
starting with small steps for instance we can't wait to see in action the
artemis mission that will open up a new window on space
missions to mars we will send hopefully by 2024 humans to
the moon again and then it will be appropriate to say
to the infinite and beyond the beauty of humankind is that we are
all dreamers and our dreams are big and they become
bigger and bigger every time we understand something new about the
universe we are living in we are romantic people
living in a romantic life in a romantic universe asking ourselves
where do we come from why are we here why are we alone and we
believe that our approach to this infinite romantic unknown is what keeps
us alive that's all for this video thanks for
watching everyone did you find this discovery to be
exciting are you amazed by the unknown that we are facing every day
what do you know about previous missions and studies on mars
is there anything more you want to hear about life on other planets
let me know in the comments below be sure to subscribe and i'll see you next
time on the channel