Original subtitles

the concept of space is familiar to all

of us

generally speaking the knowledge of the

average person

is limited to some basic facts about our

system and the universe around it

but the most exciting things on the

cosmos take place in remote

areas not readily available to our eyes

and if we look beyond the boundaries of

the solar system

a fascinating picture of infinite space

opens up to us

today i invite you on a journey to those

mysterious places realistically quite

beyond our physical reach

and as we get further away from our

earth we will be braving the most

forbidding

areas of space our flight starts in the

vicinity of titan

then we will move on to the most

dangerous asteroids

and a bit later take a look at pluto

right after that we will set out to

observe some potentially habitable

exoplanets

check out the micro quasar ss433

and then see what intergalactic space

looks like

as our journey draws to an end we will

consider the future of our universe

and try to predict what will happen

after its demise

i hope you have fastened your seat belts

let's get going

[Music]

cosmo the first in outer space

apart from the earth titan is the only

celestial body in the solar system with

liquid on its surface

unlike our earth however this liquid

isn't water

but a mixture of liquid hydrocarbons for

the most part

methane and ethane oceans on titan were

first

seen in radar images which were beamed

back by the cassini probe on the 21st of

july 2006.

in the period from 2004 to 2017

the space probe approached titan on 127

occasions

thanks to these photos scientists were

able to successfully map out

the entire surface of this moon in fine

detail

analysis of the relief and its features

revealed that the same processes were

instrumental in its formation

both on titans and the earth's surfaces

the only difference lies in the fact

that water was the main factor for

relief formation on our earth

whereas on titan it was liquid

hydrocarbons

as a result titan's surface is also

covered by lakes

seas rivers and bays just like that of

our planet

it also rains there on a regular basis

too

titans lakes of the most part rather

vast

but not really deep their number

reaching 650

the biggest of them are referred to as

seas or mares and they have been dubbed

after mythical sea creatures

kraken mare lygia mre and pangamare

there are dunes on titan's equator which

is explained by the fact that the

climate in that area is the driest

these areas account for 17 percent of

the overall surface of this moon

with mountains and labyrinths making up

14

and one and a half percent respectively

most of titan's surface

or 65 percent to be precise is covered

by planes

as for mountain ridges they stretch for

several dozens of kilometers

with a height reaching several

kilometers

only 23 impact craters have been

discovered on titan

their diameter over 20 kilometers which

is not more than 0.4 percent of the

total area

most craters are believed to have

disappeared due to highly intensive

erosion processes

that have been taking place for several

hundred million years

due to some organic compounds which

include atoms of nitrogen

titan and its atmosphere are of an

orange hue

now let's talk about big liquid objects

on titan

the area of kraken mare the largest one

discovered on its surface

is approximately 400 000 square

kilometers

and its length measures about 1100

kilometers located in the satellite's

northern hemisphere

this body of liquid is estimated to be

up to 200 meters deep

the second largest body of liquid on

titan like

mra is also situated in the northern

hemisphere

with its width measuring about 500

kilometers and its depth reaching up to

170 meters

lygia mre covers an area of

approximately a hundred thousand square

kilometers the third and the smallest

sea on titan

pangamare is also the most northern of

the three

its diameter measures approximately 380

kilometers

these seas are most likely to be made up

of liquid methane and ethane

as both gases are rather abundant in

titan's atmosphere

regularly forming dense clouds

it must be due to evaporation of methane

and ethane from the surfaces of these

maoris that these gases can be found in

the satellite's atmosphere

there are some dark spots to be seen in

images of titan's surface

they are likely to be drifting chunks of

ice that have emerged from the bottom

as a rule this kind of hydrocarbon ice

floats in temperatures close to 183

degrees celsius below zero

if the temperature drops still lower

nitrogen bubbles in the ice rocks will

account for less than five percent

which makes these rocks sink it is also

highly probable that in some areas of

titan there may be an ice shield

enveloping liquid methane both below and

above

it's worth mentioning that the chemical

composition of the liquid on titan

is different depending on an area since

it is liquid gases with different

boiling points that account for most of

the liquid on titan

the chemical composition largely depends

on temperature

for example the chemical composition of

the liquid at the pearls is different

from that at the equator

which is warmer apart from bodies of

liquid on the surface

there may also be a subsurface ocean of

impressive proportions on titan

and for all we know it may contain water

this hypothesis was put forward as an

inference from this idea

following saturn's tidal effects the

core may get heated up

and a high enough temperature may be

sustained for liquid water to be formed

under titan's surface

besides cassini's images from 2005 and

2007 revealed that some features of

relief had shifted approximately 30

kilometers

since titan is tidally locked to saturn

that is it faces it with the same side

at all times

this shift may be accounted for by the

fact that titan's ice shell is separated

from the main body by a global liquid

layer

the subsurface water is thought to

contain a considerable amount of

ammonium which acts as an anti-freezing

substance

thus decreasing the water's critical

freezing point

coupled with a high pressure from

titan's crust this may be an additional

favorable condition for the subsurface

ocean

this ocean may well lie as deep as

approximately 100 kilometers

with its water rich in various sorts

this liquid

is most likely to be a mixture of salts

and its chemical composition

includes salts containing sodium

potassium and sulfur

the depth of the ocean is different

depending on the area of titan

with liquid freezing and forming an ice

crust in certain areas

the exceptionally high sword

concentration makes it too harsh an

environment to support

any life as for titan's land

there is a chance of encountering simple

life forms on its surface

titan's atmosphere is rather dense and

chemically active

containing diverse organic compounds

this allows us to assume that there may

be life in the atmosphere's upper layers

it seems feasible that simple organisms

could be sustained by gas hydrogen

and also consume molecules of acetylene

after digesting these in return they

could produce

methane it should be mentioned that

relatively recently

highly active organic molecules were

discovered in titan's atmosphere

the substance in question is called

cyclopropanilidine

this is an unstable and highly active

material which cannot be observed on

earth

anywhere but in a laboratory environment

scientists first came

across it in 1985 and clouds of

interstellar gas in space

cyclopropanilidine is crucial in forming

larger organic molecules

its discovery on titan was the first

case of finding it in the atmosphere of

a planet rather than an interstellar

environment

this discovery will certainly help

scientists to see titan's chemical

evolution from a different angle

there are also some alternative theories

about life on this satellite

according to these there could also be

life forms in liquid methane rivers

but this is feasible only on condition

that these organisms live on hydrogen

rather than oxygen

and produce methane rather than carbon

dioxide

unlike organisms on our earth however

since titan does not lie in the

goldilocks zone and its surface

temperature is as low as about 180

degrees below

zero these hypothetical organisms would

differ a lot from those we used to see

on our planet lipid cell membranes for

instance

which are typical earth dwellers

wouldn't be able to survive in such

conditions

some really bizarre analogues would then

be produced by evolution processes

and we can't venture even a wild guess

as to what they would be like

be it as it may climatic conditions on

titan really are

able to sustain certain forms of

microbial life

this is the main object of interest for

nasa's dragonfly spacecraft planned to

be launched to titan in 2027 to

investigate

and who knows perhaps this mission is

destined to reveal

something even more fascinating than

we've already found out

the search for alien life forms is

undoubtedly an arduous task

that will probably not yield any results

until the next millennium

but its global significance can hardly

be overestimated

if at some point we succeed in our

attempts

this will be a major milestone and the

beginning of a new era in the history of

mankind

it will not only allow humans to enhance

their own knowledge

but also begin a long and scrupulous

process of fostering relationships

with intelligent beings from another

world

large objects do approach our planets

now and then

for example on the 14th of november 2020

asteroid 2020 vt4 with a diameter

measuring about 10 meters past our earth

at a distance of 383

kilometers from the surface that is

below the international space station

and most satellites

even though known potential threats are

monitored by scientists at all times

the problem is that most asteroids are

rather dark objects

whose dimensions are quite modest by

space standards which makes them hard to

detect

however an explosion caused by an impact

of a celestial body with a diameter of

just 10 meters

would be tantamount to the atomic

bombing of hiroshima

it may not leave any radioactive waste

but a blast

this powerful would wipe a little town

right off the face of the earth

an asteroid with a diameter measuring 50

meters

that is as big as a modern multi-storey

building would unleash a power of

several dozen kilotons on impact

which would be enough to raise an entire

city almost to the ground

if an asteroid this large were to fall

into an ocean

it would cause a tsunami reaching up to

10 meters

which would drink destruction all the

way it went traveling for hundreds and

thousands of kilometers from the site of

its impact

where this asteroid's diameter to

measure a kilometer or so

it would cause mass destruction

throughout an entire continent

the force of the explosion on impact

could reach as much as thousands of

megatons and tnt equivalent

and its consequences would haunt the

planet for many years to come

it is highly likely that the human

civilization would not survive a

calamity of this scale

nor would other living creatures with

the only exception of protozoans and

exceptionally enduring organisms

mass extinction events did take place in

the history of our earth

the most notorious of them cretaceous

tertiary extinction event

about 66 million years ago it is posited

that dinosaurs and a number of other

species died out as a result of it

as for the most large-scale mass

extinction event it took place

approximately 251 million years ago

coming in between the permian and the

triassic periods

based on results of paleontological

diggings it was estimated that about 90

percent of

sea species and 70 percent land species

died out as a result

one of the things that caused both of

these dramatic calamities

is believed to be the fall of a large

asteroid

today the number of potentially

dangerous objects is estimated to be in

the region of one and a half to two

thousand

although this number may reach four to

six thousand according to the data

provided by the wise telescope

since they're so small and dark these

celestial objects are rather hard to

spot

for example the size of the asteroid

dubbed 2008 dc3

which burned up in the atmosphere just

above sudan in 2008

was anything from 2 to 5 meters it was

spotted just 20 hours before it would

have impacted the earth

fortunately nobody was hurt there is a

special rating scale known as the

palermo scale

it is a generalized scale reflecting

potential impact risk

posed by this or that celestial body

which takes into account the body's

kinetic energy

and the probability of hitting the earth

the higher the value the bigger the

threat to our planet

if a body's palermo scale value is below

-2

this body is practically safe asteroids

with values between -2 and 0 do not pose

any immediate threat

but require monitoring at all times as

for objects with a value above

zero they are realistically dangerous

for the earth

at this point there isn't a single

celestial object out there with a

positive palermo scale value

and there are only two asteroids in the

yellow alert zone

that is their value is between -2 and 0.

both of them fall into the category of

the apollo asteroids

celestial bodies whose perihelion lies

closer to the sun than the earth's

aphelion

and whose orbital semi-major axis is

bigger than that of the earth

thus these objects cross our planet's

orbit from the outside

the bennu asteroid designation 1999

rq36 with a potential hazard index value

minus

1.69 poses a smaller threat to the two

in the year 2135 it will find itself

just 300 000 kilometers away from the

earth

which is slightly closer to us than the

moon bennu's average diameter measures

approximately 500 meters

and the asteroid's mass is anything

between 60 to 78 million tons

if it were to collide with our earth the

resulting explosion would be tantamount

to about a thousand megatons and tnt

equivalent

which would almost certainly cause major

catastrophic disasters

all over the planet in 2016

nasa launched the osiris-rex probe to

bennu in order to obtain samples of the

minerals making up the asteroid

the probe is scheduled to get back to

the earth in 2023

the more hazardous of the two asteroids

is 1950 d a

with a palomo scale value minus 1.42

today it has the highest probability of

hitting our earth

its diameter measures about 1.3

kilometers

and its mass can be anything from 2 to 4

billion tons

1950 da's orbit is elongated and

elliptical

and it crosses the orbits of our earth

and mars 1950 da's closest approach to

the earth is expected in 2035

but a hazardous approach will take place

only as late as on the 16th of march

2880

what would await us if the asteroid did

impact the earth

let's assume no preventive measures have

been successful to deflect this body

and the disaster is inevitable

an enormous chunk of rock with a

diameter almost

one and a half kilometers and a mass

that could be two to four billion tons

heading towards the earth at a speed of

about 14 kilometers per second

this would be the speed of 1950 da at

the moment it hit the earth

if an impact event did occur as

estimated by nasa

of course part of the matter making up

1950 da would burn up and disperse in

the atmosphere as the asteroid slowed

down

and the main body would be likely to

break up into several large rocks and a

great number of small

bits depending on their size each of

them would cause an explosion of not

less than 20 kilotons on impact for the

earth's crust

that's the average power of a modern

nuclear bomb with a comparatively modest

charge the overall power of the

explosions would most likely be over one

and a half thousand megatons

with a bombarded area larger than that

of europe

all constructions within the radius of

300 to 500 kilometers would be raised to

the ground

and even reinforced underground bunkers

wouldn't guarantee enough safety

the energy of the shock wave would allow

it to sweep around the earth several

times while gradually slowing down

and bringing more destruction on its way

with every lap

if the asteroid were to fall into an

ocean a giant

tsunami would rise 40 meters or higher

tsunamis normally travel for thousands

of kilometers

and as they go their destructive forces

practically don't diminish

therefore coastal areas of the

continents lying near the site of the

impact would be submerged in water

with cities and villages effectively

wiped out

multiple impacts of bits of rock would

raise tons of dust in the atmosphere

winds would scatter these dense clouds

all over the sky

and most sunlight would not reach the

planet which would cause a sharp

temperature fall

this phenomenon is known as nuclear

winter

it is highly probable that an impact of

this scale would affect not only the

crust

but the mantle as well the shock wave

would wake up volcanoes

and they would erupt all over the planet

which in its turn would cause

the second wave of tsunamis and

earthquakes

tons of ash released in the atmosphere

would contribute to further temperature

drops

there is quite a popular belief that

after an asteroid hit the earth it would

affect its orbit or orbital period

this would lead to dramatic climate

changes and even render the planets

completely incapable of sustaining life

however according to some estimates an

impact of even the biggest

asteroid in the solar system would not

be enough to do so

an object realistically able to

noticeably change the earth's orbit

should be as big as the moon or pluto at

the very least

be it as it may if it were to happen the

consequences of an impact of this scale

would be much graver than just a change

of orbit or orbital period

the potential impact risk of 1950 das

hitting our earth is just

0.012 there is no room for complacency

though as the impact probability may

rise

following a change of the asteroids

orbit as a result of collisions with

other celestial objects that may well

take place

for a long while it was believed that

the humanity hadn't advanced enough to

prevent any hazards of asteroid falls

all we could do was just observe

potentially hazardous objects

actually doing something about them like

destroying an asteroid or changing its

orbit was confined to science fiction

films and books

however science doesn't stand still even

in 2004 when a threat posed by apophis

was considered grave enough

it was proposed to cover its surface

with light reflecting film

this way sunlight pressure would change

the asteroid's orbit

other suggestions included nuclear

bombings as well as special power

thrusters powerful enough to shift

orbits of celestial bodies

[Music]

in 2018 nasa in collaboration with

spacex approved the dart program

whose aim is to deflect the asteroid's

trajectory by making it collide with an

artificial spacecraft

the binary near-earth asteroid didymos

made up of two components with diameters

measuring 800 and 150 meters is the

target for the dart demonstration

the launch of the spacecraft is planned

for 2021.

celestial bodies and the solar system

may be closely monitored but there is

always a risk of somebody previously

unknown to us

arriving from the galaxy's outskirts and

heading towards the earth

orbital periods of some comets and

asteroids around the earth may last

hundreds and even thousands of years and

their small sizes and dark surfaces

render these potentially dangerous

visitors barely detectable

still the odds of such a disaster as an

impact event are extremely small

and in fact there are many more dangers

that may befall the human race

on our own planet

pluto is the largest transneptunian

object in the solar system

it is also the largest object in the

kuiper belt

just like most bodies in that region of

space pluto is mostly made up of rock

and dice

and its mass is relatively small

approximately 0.22 percent that of the

earth

just to get a slightly broader picture

let's compare pluto with the moon

pluto's mass is about six times smaller

and its volume is about three times

smaller pluto's total area is 17.7

million square kilometers

and we're briefly back to earth again to

compare it with the area of russia

the largest country in the world which

is slightly smaller

17.1 million square kilometers

as for pluto's diameter it reaches

2376.6 kilometers

which is 1097.6 kilometers less than

that of the moon

as for pluto's atmosphere it is for the

most part comprised of gases evaporating

from the ice on its surface

today we know that its chief component

is nitrogen

apart from that two other gases are

methane and carbon monoxide

under the influence of high-energy

cosmic radiation

other more complex compounds form from

these elements

on account of pluto's surface

temperature these compounds are not

volatile

ethane ethylene and acetylene there are

also the so-called tholins

on settling on the dwarf planet's

surface they have a peculiar property of

giving it a brownish hue

the average surface temperature on pluto

is 50 kelvin

that is 223.15 degrees celsius below

zero with every kilometer higher up

this indicator increases by

approximately seven degrees

and so the atmospheric temperature is 40

degrees

higher than that on the surface this

could be accounted for by the greenhouse

effect

caused by methane

we're used to thinking that pluto's

orbit is stable and

unwavering however on closer observation

it transpired that pluto's movement is

rather chaotic

and can be defined in non-linear

equations

it takes a lot of observation to be able

to detect that

when carried out in short time spans

observations reveal seemingly regular

movement

in reality pluto's orbit slightly shifts

in every period eventually changes to

such a point that it is impossible to

retrace its initial

trajectory this dwarf's planet's

rotation is quite peculiar too

namely it is retrograde which is also

the case for both venus

and uranus it means that they rotate in

the direction

opposite to that of the other planets

around the sun

a day on pluto lasts 6.4 earth days

due to its remoteness and small mass

pluto is a rather challenging celestial

object to study

even very big telescopes show it to us

is a tiny spot

seemingly not much different from a

regular star

we have been able to acquire a certain

amount of data with the help of the

hubble space telescope

nevertheless the greatest and most

important portion of information was

made available

after the launch of the new horizons

mission

the first photo of pluto was made back

in september 2006

when the space probe was testing its

lori camera

as the spacecraft approached pluto

closer and closer

more and more features of this dwarf

planet were revealed to us

thus the object's surface was seen to be

far from homogeneous

albedo that is diffuse reflection

properties of the surface

varies from ten to seventy percent

depending on the area of the object

which makes pluto the second object in

the solar system

after arriapatis in terms of contrast in

albedo

this diversity causes periodic

variations in pluto's luminosity and

spectre as it rotates

the dwarf planet's interior must be made

up of 50 to 70 percent

of rock and 30 to 50 percent of ice

its dense rocky core must be embedded in

an icy mantle

about 300 kilometers thick

according to spectral data there is

water ice on pluto's surface

as well but it is mostly camouflaged by

a layer of more volatile ices

there is also frozen methane and carbon

monoxide

as well as traces of other compounds

generally forming with methane and

nitrogen

when exposed to powerful radiation

in particular these are rethane nitriles

and phthalins which make pluto look

brownish

on the fifteenth of july 2015 the new

horizons space probe

flew by pluto 12 and a half thousand

kilometers away from its surface

both sides of the dwarf planet were

photographed during the flyby

the one to be seen on closest approach

and the opposite one

thanks to these images a vast

heart-shaped area measuring eighteen

hundred by fifteen hundred kilometers

was identified

it was later nicknamed pluto's heart or

tombow regio

the left part of this area is believed

to be a crater filled with crystal

nitrogen

also two mountain ranges were identified

in this area

the height of the first reaches 3500

meters

and it was given the name the tensing

montes

the height of the second one dubbed the

hillary montes

reaches up to 1500 meters

the most notable geological object found

on pluto

is sputnik planitia this trench is

likely to be an impact crater with a

diameter measuring 1492 kilometers

sputnik planitia is filled with frozen

gases

and is streaked with a great number of

grooves which divided into irregular

cell-like areas measuring dozens of

kilometers

there may also be cryovolcanism on pluto

the last image taken by the spacecraft

looks to be indicative of just that

the potential cryo volcano that can be

seen in this picture

was dubbed right mons the surface in the

picture is comparatively young by space

standards

and practically devoid of impact craters

this

shows that the crust in this area was

formed relatively recently

and if right mons really is a cryo

volcano

its enormous size of 144 kilometers

across and four kilometers high

easily makes it the largest cryovolcano

in the outer area of the solar system

among other interesting features

discovered by new horizons

there is a blue stratified haze

enveloping the whole of the dwarf planet

in the images the haze is seen to reach

over 200 kilometers high

and is registered by the ultraviolet

spectrometer to persist to the point of

300 kilometers above the surface

the haze is likely to be made up of

particles of non-volatile elements that

originate from atmospheric gases

the ones i've already spoken about these

elements gradually settle on the dwarf

planet's surface

and that is the way this effect is

produced

the new horizons mission is scheduled to

continue until

2026 apart from studying the objects in

the pluto system

the spacecraft has already provided

insights into other kuiper belt objects

too

and even though its fuel supply is

insufficient for a dramatic change of

course

the radioisotope generator's energy

should be enough to last it for another

10 years

immediately after the space probe had

flown by pluto

astronomers used the hubble telescope to

look around for other objects that could

be observed within the framework of the

mission

the first of them ultimatuly is a binary

asteroid in the kuiper belt

whose two components diameters measure

19 and 14 kilometers

it was closely passed by new horizons on

the 1st of january 2019

another object was the asteroid 2014

pn70 measuring 40 kilometers across

it was passed by the probe in march 2019

excitingly apart from that having

traveled 8 billion kilometers away from

the earth

new horizons reached a great vantage

point for better observation of the

stars closest to the sun

proxima centauri and wolf 359

in april 2020 the spacecraft was also

used for double checking the distance to

these stars

apart from the objectives mentioned this

amazing mission

stands a good chance of being able to

reach quite a few more in the future

while the spacecraft keeps beaming back

new images to the earth

we will be able to conduct research

based on the photos of the celestial

bodies it has already passed

for example the pictures of pluto's

largest moon

charon taken on their brief encounter

with a space probe

several centuries ago it was quite

unimaginable to admit of discovering

exoplanets

however everything changed in 1992 as

the polish astronomer alexander

washington was studying the pulsar

psr-1257 plus 12

it was noticed that its pulsation period

was irregular

which was accounted for by the influence

of two planets with a mass

four times that of our earth this

hypothesis was later confirmed

which led to the conclusion that the

first planetary system beyond ours

had been discovered there are three

objects in that system

two of which have a mass similar to that

of the earth and are comparatively close

to their pulsar in the constellation

virgo

due to the fact that it is rather remote

from us and the conditions for

sustaining life are poor

the psr1257 plus 12

system is of little interest to

scientists although its discovery led us

to believe

that the search for earth-like worlds

may eventually be a success

just three years later the first

exoplanet orbiting a sun-like star was

discovered

50 light years away from the earth and

was dubbed 51 pegasi b

just several years later the number of

confirmed exoplanets counted dozens

and today 4173 exoplanets

in 3096 different planetary systems

unknown to science in addition a great

number of earth-like objects

is still awaiting the confirmation of

their status

which is possible after a secondary

registration with telescopes on earth

the number of celestial objects of this

kind in the entire milky way

may well be over a hundred billion with

about one-fifth of them

bearing resemblance to our earth

interestingly

most of the discovered earth-like

exoplanets

are located not very far from our system

ros128b this planet was discovered in

2017 by european scientists with the

help of the high accuracy radial

velocity planet searcher

or halves at the observatory in chile

the object is located in the single star

system

ros 128 which is the 13th closest star

to us

the object is a faint red dwarf with a

mass of 0.15 that of the sun

it was possible to discover this planet

thanks to its gravity

which leads to minor variations of the

stellar spectrum of its parent star

while observing these variations harps

is able to spot planets around stars

in this particular case it took the

telescope approximately 10 years to

collect sufficient data

before discovering this planet this

effort paid off

ros-128b became the second earth-like

exoplanet

lying closest to us it is located 11

light years away from the earth

in the constellation virgo apart from

that

astronomers claim it to be the most

moderate of all known exoplanets

due to its mass its temperature and its

rather calm parent star

it takes this planet 10 days to orbit

its star

it finds itself in the habitable zone

since the temperature

of the photosphere and luminosity of ros

128

are low it is also classified as an

earth-like

type of planet and at the moment ros128b

is one of the most likely candidates to

be a potentially habitable exoplanet

besides research done in 2018 confirmed

that its climate is favorable enough to

sustain life

another exoplanet on the list of

earth-like objects located closest to us

is glieser 667cc

this celestial body is part of the

triple star stellar system

glieser 667 in the constellation

scorpius

it consists of two orange dwarves and

one red dwarf

the first two components a and b lie

12.6 astronomical units from each other

with the third component orbiting them

at a distance of 230 astronomical units

the earth-like planet in this system was

discovered on november the 29th

2011 in the geneva observatory with the

help of the doppler method

the object is 22.7 light years away from

the earth

and is the second exoplanet orbiting its

host

star the mass of gliese 667cc

is about 3.8 times that of the earth

while its temperature range may be

rather similar to the terrestrial one

modeling at the planetary habitability

laboratory

managed by university of puerto rico

reveals

that the average surface temperature of

the atmosphere of gliese 667cc

must be approximately 27 degrees celsius

the planet receives about 90 percent of

energy

compared to that received by the earth

from the sun

also gliese 667cc is almost

certain to be locked in its orbit that

is it faces its star with one on the

same side

if the planet's orbit does not curve too

little and if its mass is not too big

the greenhouse effect produced by the

rather dense atmosphere

must be quite sufficient to create

favorable conditions

for primitive life forms

[Music]

the next deserving object in our list is

hd855

an exoplanet orbiting the orange dwarf

hd-85512

in the constellation velar its star

is a single k-type main sequence star

with the mass 0.69 that of our sun

as for its age it is more than 5.6

billion years old

the exoplanet discovered close to it

is located 36 light years away from the

earth

and its mass is 3.6 times that of our

planet

at the same time hd 85512b

be one of the smallest planets in the

habitable zone

it was spotted in august 2011 with a

harps telescope

the supposed steady-state temperature of

its surface

is something around 25 degrees celsius

if the planet's atmosphere is identical

to that of the earth

its surface temperature should reach 78

degrees celsius

it is also highly probable that there is

liquid water

on this celestial body which is why for

some time it was believed to become the

most likely place

where life would be discovered first

apart from the objects mentioned there

is a number of other celestial bodies in

space

located quite close to us which also

boasts

some unique features many of them may

well contain

various life forms and maybe not quite

as far from us

as we would imagine however we should

bear in mind

that some half a century ago man did not

possess a tenth of information known to

us today

and in the future the progress of our

discoveries

is going to escalate even more

dramatically

for example on december the 18th 2019

the k-op space telescope was

successfully launched in orbit by the

european space agency

it is specifically aimed at exploring

exoplanets

using the transit method it may be this

spacecraft is to contribute to the list

of earth-like exoplanets

and it may become the telescope to first

discover

alien life forms in the universe

science does not stand still and every

new day bears witness to the fact that

mankind continues to actively stride

forward

if this progress does not lose its

momentum sooner or later we are bound to

find an answer to the eternal

mind perturbing question are we alone

in the universe and i hope the answer we

get will prove that life is not a mere

accident

but a logical consequence of the

evolution in our universe

as a rule micro quasars are x-ray

binaries

that is stellar systems made up of two

components

one of them is a regular star similar to

our sun

the other component is a compact object

like a black hole or a neutron star

matter in such micro quasars is

constantly in the process of

accumulating in the compact object

which is accompanied by occasional

outflows of matter at great speeds

these outflows are known as jets and the

nature of these jets reminds one of

processes

taking place in regular quasars

now it is not a regular occurrence in

ordinary quasars

meanwhile as the mass of a micro quasar

is smaller than that of an ordinary

quasar

jets may originate here practically on a

daily basis

the principal difference between micro

quasars and ordinary quasars is in their

mass

and the frequency of matter outflows for

example

the mass of the compact components and

micro quasars is considerably smaller

than the mass of those in regular

quasars

it is just several cellular masses just

to compare

the average mass of a supermassive black

hole in the center of a quasar

may be approximately as much as a

hundred million solar masses

as for the mass of the black hole likely

to be found in the center of ss-433

it must be just a few dozen solar masses

the accretion disk of a micro quasar is

intensely luminescent

with emissions in the optical and x-ray

bands

a regular quasar is an astronomical body

boasting the highest luminosity among

other objects

in the observable universe according to

contemporary scientific views

these celestial bodies are active cores

of galaxies where a supermassive black

hole

sucks in matter all around it thus

forming an accretion disk

as for the disk itself it is a source of

very powerful luminosity

just to give you an idea its luminosity

may sometimes be hundreds of times as

intense as that of all stars in a galaxy

like

ours combined to date

over 200 000 quasars have been

identified

we're able to observe some of these

quasars in the sky

even without using a telescope and so

the rate of discovering new objects of

one or the other category is another

principal parameter

by which regular quasars and micro

quasars differ

if we look at the list of known micro

quasars it contains

just a few entries so far the first

micro quasar was discovered back in 1978

when a source of unusual radio and x-ray

emissions was detected by two

astronomers from the university of

cambridge

as they were looking for debris left

over from supernovae

detected in the constellation aquila

this source was later dubbed

ss433

the object under scrutiny is an

eclipsing x-ray binary system

one of its components is likely to be a

black hole

as for the second component it is a star

of spectral type a

that is a main sequence dwarf star of a

whitish hue

it is assumed that this star's mass is

10 to 30 times that of our sun

and more likely than not the dwarf used

to be considerably heavier in the

earlier stages of its existence

its surface temperature is thought to be

anything from 7000 to eleven and a half

thousand degrees kelvin this temperature

range is typical for stars of this type

it is actually its temperature that

gives the star its pale yellow tint

in fact if we look at the stars closest

to the sun

then sirius altair and viga fall into

the same class as this star

ss-433 is located within the supernova

remnant

w-50 sometimes also called the manatee

nebula

the age of this nebula is estimated at

approximately 20

000 years and the distance between the

nebula and the earth measures about 18

000 light years the jets from ss-433

distort the clouds surrounding the w-50

nebula

according to a certain theory the w-50

nebula and the micro quasar

ss-433 are actually related

and came to be as a result of one in the

same supernova event

which supposedly took place around 20

000 years ago

it takes either of the two objects in

the system 13.1 days to orbit the common

mass center

in fact the way the ss-433 system works

is quite exciting with both components

constantly interacting with each other

matter from the second component that is

the regular star

flows to the first component or the

primary supposedly a black hole

thus forming an accretion disk around it

as it spirals

the matter heats up to extreme

temperatures and emits x-rays

some part of the smatter leaves the

system in two jets

at the rate of approximately 26 of the

speed of light

that is 79 000 kilometers per second

in 2019 thanks to the alma observatory

astronomers managed to get detailed

images of ss-433

it was clear from the emission structure

that the micro quasars jets themselves

are rather narrow

and their shape is irregular and has

nodes

further studies of the object showed

that the shape of the jets is distorted

as a result of precession

that is a process when the jets slowly

rotate on their axis as they spiral

the diameter of either of the two jets

ejected from the micro quasar in two

opposite directions

measures approximately 5 000 times the

diameter of the solar system

as ss-433 is relatively close to the

earth it is particularly valuable to

scientists studying the phenomenon of

micro quasars

images beamed back by the alma

observatory showed its jets for the

first time

and it also helped establish the

direction these jets point out is never

the same

just like a top the spinning toy

gradually slows down

they too rotate on their axis which is

perpendicular to the plane of the

accretion disk

the armor images boasted another

outstanding feature

the shape of ss-433 was predicted in

fine detail thanks to spectroscopic

measurements that had been done in 2018

using the global jet watch telescopes

and so the actual shape largely

corresponds to the new images

where ss433 is really seen to have a

shape reminding one of a corkscrew

it isn't a rare occasion when jets like

that originate here or there in the

universe

as a rule jets of plasma also known as

relativistic jets

are spewed out of the centers of active

galaxies quasars and radio galaxies

when this occurs there are usually two

jets as such

pointing in the opposite directions and

this is exactly what we can observe in

the case of ss433

today the phenomenon of jets like that

wants deeper studying

it is believed that jets originate

following the interaction between

magnetic fields and the accretion disk

around a black hole or a neutron star

as for their size it may be staggeringly

enormous

in the case of the radio galaxy 3c one

two zero for example

the jet stretches for at least several

kilo pass

away from its source it is highly

probable that in the future the regular

star in the ss433

system will shed its outer layer

completely as a result of the influence

of the compact object

its core meanwhile will remain hot and

thus

the star will qualify to be called a hot

sub dwarf

later the star is to be gradually sucked

in by the black hole

and sooner or later after this process

is completed

the ss433 system will assume a classical

look

it will comprise just the compact object

the process of this system's evolution

will of course continue for thousands of

years

so we have plenty of time to study this

phenomenon

and while the micro quasar ss-433 is

active

we will have many opportunities to carry

out detailed observation

that would help us understand the nature

of this celestial object

let's keep in touch

predictably enough the term

intergalactic space is generally used to

refer to parts of space between galaxies

it is believed that certain portions of

these areas are practically devoid of

any matter

which makes their composition quite

close to that of absolute vacuum

with some of its areas stretching as far

as millions of light years in all

directions

intergalactic space is for the most part

filled with ionized gas

generally this gas is hot hydrogen whose

density here

is 10 times less than that in

interstellar environment

namely less than one atom to one cubic

decimeter

there are also heavier elements to be

found here as well

like carbon oxygen and silicon

some part of intergalactic gas is

concentrated in clouds differing from

each other very much in terms of density

and temperature interestingly the

chemical composition of their gas is

diverse

it may contain atoms of hydrogen helium

carbon nitrogen oxygen sulfur

and various metals it is this gas that

more likely than not

feeds stellar formations in all galaxies

there are also much larger objects to be

found in intergalactic space

for example stars were spotted there

quite recently

the total number of intergalactic stars

in the observable universe may reach

several trillion within the milky way

alone

around 650 of these rogue stars have

been pinpointed so far

as a rule intergalactic mata doesn't

emit any light

and is mostly invisible to the potential

observer that is why

its discovery was actually made by pure

chance

it all started with quasars which were

discovered in the 1960s

very soon scientists noticed that the

light from the quasars had

certain missing pieces in some spectra

these particles were absorbed by

something in between quasars and

astronomers telescopes

it later transpired that this invisible

matter was the gas of the intergalactic

medium

the igm in the decades that followed

vast accumulations and filaments of gas

and heavier elements were discovered in

intergalactic space

and even though at first glance it

appears to be empty

its dimensions are so mind-blowing that

there must be more matter

evenly distributed around it than there

is mata in all the galaxies of the

observable universe combined

it is safe to assume that some part of

intergalactic gas has been left out

there after the hypothetical big bang

still as there are heavier elements in

its composition it may only mean that

many of these elements used to be part

of interstellar dust

lost by other galaxies

intergalactic gas actually plays an

important role in the process of the

universe's evolution

under the influence of a galaxy's

gravitational pull

gas is gradually sucked into galaxies at

the rate of one

solar mass a year which is quite close

to the rate of star formation in the

disk of the milky way

apart from that matter exchange among

all galaxies

occurs thanks to this process the point

is that stars in a given area of the

universe collapse and release

part of their matter in intergalactic

space

having been released the mata becomes

part of intergalactic gas

and so later takes part in the processes

of star formation in other galaxies

consequently star formation in galaxies

will not stop

while there is still intergalactic gas

around pulled by gravity

substantial portion of intergalactic gas

is matter remaining after supernovae

which is why temperatures in some areas

of intergalactic environments are

extremely high

sometimes reaching as much as several

million degrees celsius

the high temperature of some areas may

also be accounted for by electromagnetic

radiation

emitted by intergalactic black holes

following mata accretion on their

surfaces

or else by powerful streams of energy

emitted by still more massive black

holes

intergalactic gas plays the role of raw

material in star formation

while intergalactic space is some sort

of a tank used for its storage

the mechanism of intergalactic gas

recirculation

hasn't been studied deeply enough first

of all because unlike galaxies which are

bright and easily seen

this gas emits no light to speak of

in their attempt to study this

phenomenon astronomers have devised

supercomputer foggy foggy modelled the

patterns of intergalactic gas movements

and it is possible to observe how gas

traveled around galaxies in the course

of 13 billion years

most of this matter is carried to

intergalactic environment by stellar

wind

that is thanks to the process of mata

flow from stars to areas beyond their

galaxies

it should be mentioned that this occurs

when particles in a star's atmosphere

accelerate to speeds exceeding the

escape velocity of this star

stellar wind is crucial for stellar

evolution

as a result of this process the mass of

a star diminishes

and the intensity of this process has a

direct impact on this particular star's

lifespan

also stellar wind is capable of carrying

mata enormous distances through space

away from its departure point as it were

moreover

it may have an impact on matter around

it by sharing some of its kinetic energy

results of this process may be clearly

observed in the shapes of some galaxies

or nebulae for instance the emission

nebula

ngc 7635 nicknamed bubble

assumed its shape as a result of this

process

and in the case of galaxy m82 also known

as the cigar galaxy

we can observe how stellar wind from a

great number of stars caused clearly

seen matter rejections from the galaxy

[Music]

apart from the debris left over from

supernovae there is also intergalactic

dust to be found in this environment

today it is posited that it is

intergalactic dust that is to blame for

jinxing estimations of distances on the

intergalactic scale

for example when supernovae quasars or

other galaxies are being observed

among its many properties it is capable

of forming clouds

by 1980 four such nebulae had been

pinpointed within several megapass sects

from the milky way

as for intergalactic stars they are

rather difficult to detect and explore

some of them have been spotted in the

x-ray spectrum with the help of the

chandra x-ray observatory

many of them are binary systems made up

of one regular star as one component

and one compact heavy object like a

black hole is the other

when such celestial bodies lie close to

each other

the more massive component attracts

matter from the regular star

while flowing to its new host mata

spirals away from its source to form an

accretion disk

this disk compresses and heats up to

extremely high temperatures

and as a result it does not simply

become luminescent

but starts emitting x-rays it is next to

impossible to spot most objects of this

kind

using regular telescopes meanwhile

rogue stars inhabiting voids may

eventually prove to be quite a common

thing

rather than something extraordinary and

perhaps about half of starlight is

actually emitted by stars lying beyond

the boundaries of galaxies

it is hard to tell how big their number

may be

and today it is barely possible to

imagine that man will ever visit those

places

objects lurking in those mysterious

parts of space

may be of considerable interest to

science

and who knows perhaps it is

intergalactic space that will be scanned

with all

telescopes by scientists in a few

centuries time

still for now this environment is just

another mystery of the universe

quite beyond our reach at this point it

is places like this that really thwart

our ambition to completely figure out

space

and its properties and it is places like

this that drive us to take

keen interest in how it all works

the earliest theory of the genesis of

our world is what is known as theory of

the stationary universe

or steady-state universe supporters of

this theory claim that the universe has

no beginning and no end

it has always been and always will be in

its steady state of equilibrium

however very soon scientific estimations

prove this theory likely to be wrong

as there are some irreversible processes

taking place in the universe

in the 1910s and 1920s the big bang

theory was formulated and widely

popularized

today it is one of the most consistent

scientific theories

and it is able to account for the

universe's genesis and evolution

dozens of scientists contributed to the

development of the big bang theory

and albert einstein's works on the

general theory of relativity

laid the theories foundation the main

conclusion this theory enabled

scientists to arrive at

is the supposition that the fate of the

universe depends on dark energy

a theoretical type of energy causing

space to expand

be it as it may at this point it is

quite impossible to say anything

definite about this physical phenomenon

there are a great number of theories

about this and each of them has its

praiseworthy aspects and shortcomings

according to data we possess today the

age of the universe is calculated from

the moment of the big bang

and is estimated at slightly less than

14 billion years

the universe is constantly expanding and

depending on the density of dark energy

it will either expand

forever at a regularly increasing rate

or else the expansion will slow down and

reverse

in this case the universe is bound to

compress into an infinitely small

singularity

similar to what it originated from today

science is not ready to give a definite

answer to the question

which of these two possibilities will

prevail however it is ready to suggest

at least

two equally possible scenarios of what

may happen next

referred to as the big rip and the big

crunch

the universe's expansion rate is

proportional to distances between

objects the further some objects are

located from each other

the higher the expansion rate imagine a

balloon pumped with air

there are two dots on it if we pump

still more air into the balloon

the dots will get further away from each

other

that's the way the expansion of the

universe works it is space itself that

expands

the further the dots are initially

located the faster they get still

further apart

at a certain point this rate exceeds the

speed of light

this point is known as the event horizon

all objects beyond it disappear from

view and they drift away beyond the

reach of the most advanced telescopes

never to be observed again

just imagine first the remotest galaxies

and clusters will disappear from the sky

then one by one the milky way stars will

fade away

and to crown it all it will be the turn

for our sun

to go dim what a gloomy sight

if the big rip theory holds good the

universe's expansion rate will be

constantly on the increase

this will lead to expansion forces

gradually overcoming gravity forces

following that first galaxy clusters and

then galaxies

themselves and star clusters will be

broken up

after that it will be the turn for

stellar systems to disintegrate

as host stars will not have sufficient

pool to keep their planets and

satellites from floating away

at the next stage matter will be reduced

to atoms and these will be reduced to

subatomic particles

matter will effectively cease to exist

after this physical laws as we know them

will cease to be

and any further developments are quite

impossible to predict

observations today show that space

expands

and the expansion rate is on the

increase however we're not familiar with

the nature of dark energy

it may well have properties unknown to

us at this point

and these may reverse the expansion

processes

as a result the universe will start

contracting

this may well happen if general

gravitation created by all matter in the

universe

exceeds its expansion force this

scenario is what is known as the big

crunch

in this case processes in the universe

will run in the same manner until its

size decreases five times

galaxy clusters will come together as

one supercluster

which in essence will fill the entire

universe considerably shrunk by this

point

meanwhile inside the galaxies events

like births and deaths of stars

planet formation and so on will keep

taking place

just like before when the universe

contracts 20 times more

its volume will account for just one

percent of that of today's

and all galaxies will blend into one the

relic radiation temperature by that time

will measure

274 degrees kelvin and it will still

continue to grow

this means that there won't be any

liquid water left in the universe

and water is vital for biological life

as we know it

further contraction of space will cause

the universe to heat up even more

planets will first be burnt and then

melted

all matter will crumple into an enormous

cloud of boiling plasma

after that atoms and subatomic particles

will disperse

and eventually the universe will

collapse into a singularity similar to

the one it used to be when it was born

there is a theory which is a kind of a

spin-off of the big crunch theory

it is known as the big bounce theory

according to the big balance theory

on reaching the state of singularity

following the big crunch

the universe will be reborn as a result

of yet another big bang

and the cycle will repeat itself again

and again supposedly forever

as far as it is possible to speak about

eternity and conditions devoid of time

and space i will repeat myself

yet again by saying that our knowledge

about dark is too meager to speak about

the duration

of any of these scenarios for all we

know

the next big rip or big crunch for that

matter will take place in a period when

there are still stars and planets around

but what if it isn't the case what will

happen to the universe

if its ultimate fate is still extremely

remote in time

still the laws of physics imply that the

universe as we more or less know it

cannot exist forever there are four

clearly defined

epochs in cosmology and each of them is

associated with this or that particular

phenomenon

we live in the so-called stelliferous

era

there is a lot of interstellar gas in

the parts of the universe around us

it is used as raw material for stars to

form from

and used stars are born from this gas

and the process will continue

until all interstellar gas has been

depleted

this epoch is expected to be over in the

period from 1 to 100 trillion years from

now

by that time the sun and the

overwhelming majority of other stars

will have depleted their nuclear fuel

subsequently turning into white dwarfs

neutron stars or black

holes i've actually already spoken about

it in an earlier video

the next era is known as the degenerate

era

there will not be any main sequence

stars around anymore

most mata in the universe will remain in

the form of white and brown dwarves and

some mata will persist as neutron stars

and black holes

it will take a great amount of time for

all these objects to cool off

around a duodecillion or 10 to the power

of 39 years

white dwarves will gradually give off

their heat in the form of radiation

and become black dwarves as for brown

dwarves they will cool off too

reactions taking place in their interior

at a sluggish rate

will eventually stop completely

gradually most matter will be slurped by

black holes

at this stage of the universe's

evolution dark matter annihilation and

protons disintegration will be the major

processes

the proton is a subatomic particle that

atoms known to science are built of

it is considered one of the most durable

subatomic particles

its life expectancy as it were accounts

for approximately 100 geodesian

or 10 to the power of 41 years

now by the time this sierra comes to an

end mata in the universe will look like

a great ocean of freely floating

elementary particles with an occasional

neutron star or black hole tucked away

among them

the next era is the black hole era

according to some theories black holes

will form clusters and eventually blend

together

thus forming one single gargantuan black

hole

alternative theories suggest that black

holes will slowly evaporate while

emitting energy before vanishing

completely

black hole evaporation is a quantum

effect produced by what is known as

hawking radiation

the smaller hole the more intense of its

evaporation

which eventually strips the whole of all

its matter and energy

this process is supposed to persist for

10 to the power of 100 years

this number is also referred to as

google

be it as it may eventually only dead

expanses of space will be left in the

universe

this space will contain debris left over

from processes having taken place in the

previous sea parks

photons electrons positrons neutrinos

and quarks

electrons and positrons will collide

thus causing annihilation

the universe may exist in this state

practically forever

until the next big crunch or big rip at

the very least

either way the humanity will be long

gone at that time

its existence is likely to be terminated

in the stelliferous era

our planet meanwhile will remain

habitable for another billion years or

so

and after that it will be burned by the

ever-intensifying glow of the sun

about five or six billion years later

our sun

by then a red giant will shed its outer

layers and become a white dwarf

but what will happen after the universe

dies

disappointing as it is there is

absolutely no way we can answer this

question

the trouble is whatever the scenario

there won't be either time or space as

we know them

even if the big bounce theory or the big

crunch theory is right

or else a new big bang takes place thus

giving birth to a new universe

with a fresh set of galaxies and stars

we will simply never

find out just like we will never find

out what it used to be like in the

universe

before hours because the word must be

heard in silence there must be darkness

to see the stars

it goes without saying that what we've

just seen is an infinitely tiny portion

of fascinating things out there we could

have looked at in this film

their number is infinite and it's going

to take scientists

centuries on end to describe the nature

of each of them

but even objects we already know of

today can be baffling to many scientists

yet with information about them

regularly updated

we will definitely have something

exciting to share with you

let's keep in touch

[Music]

you