hello and welcome to space here from the
observatory of Paris right in the heart
of the French capital we're here to meet
astronomers working on the unique Gaia
mission which has been surveying over a
billion stars around our galaxy trying
to solve some of the mysteries of the
Milky Way
French astronomer Frederick Aaron ooh is
one of hundreds of scientists digging
into the mountain of fresh data from the
gaya Space Telescope the mission has
just released the richest star catalogue
ever recorded but hope is that it will
fill in some of the big gaps in our
knowledge of the Milky Way
written and Gillick this is our galaxy
the Milky Way 100,000 lightyears across
and we're around 26,000 light-years from
the center we really don't know it very
well this is an artist's impression we
don't know the number of arms in our
galaxy or where stars form Gaia will
tell us it's hoped Gaia will tell us a
great deal the ISA Space Telescope has
taken high-precision measurements of 1
billion 692 million nine hundred 19135
stars that's over ten thousand times
more measurements than ESA's previous
mission called Hipparcos it's a pivotal
moment in astronomy all of a sudden we
have a huge sample of objects for which
we have their distance so we know their
intrinsic luminosity and from that we
can deduce their physical properties
which we try to extrapolate with other
methods beforehand just like that boom
we have an answer to have such a star
catalog has long been a goal of
astronomers one major attempt began here
at the observatory of Paris in 1887 a
project called luck aft
2cl producing these intricate star maps
today astronomers have a billion pixel
telescope rotating quietly in a calm
spot in space
yes Gaia's 1.5 million kilometers from
Earth and it's aligned on an axis of Sun
earth Gaia it rotates around itself
every six hours with movements that mean
that it's able to observe the entire
galaxy so in a few years we have a
complete map of the sky so there are
three instruments anis trama tur that
allows you to measure the positions a
photometer used to measure the colors
and a spectrometer which allows us to
measure the radial velocity that's the
speed at which the stars move away from
or towards us this is the result the
view of our galaxy from space the best
image we've ever had of the Milky Way
Finnish astronomer Timo Christie heads
ESA's gaya science team and talks us
through it
these are the real Gaia measurements we
are measuring the number of stars what
we are observing in different parts of
the sky and what do we see we see a
flattened structure that's our Milky Way
that's how the Milky Way disc we see
some dark patches on top of it what does
it mean it means that there we see less
stars there are more stars but there is
dust in front of them and that's why we
don't see the stars the Gaia data has
also been animated into this unique view
of the Milky Way it shows in accelerated
form how the stars are moving through
space and time in our region of the
galaxy looking at this animation and
studying the data the astronomers were
able to peer into the darkness and see
things they hadn't expected
now we think our Milky Way galaxy is a
disc with the spiral structure
everything beautifully rotating around
but what we see orderly with this real
Gaia data release we see that the stars
a little bit further from now son
they don't actually behave that
regularly as we anticipated they are
disturbed something has perturbed our
Milky Way galaxy we don't yet know what
but I can see a lot of studies will be
concentrated on this specific aspect
having the ability to study our galaxy's
history and future from within from a
vantage point inside the Milky Way is
promising a great deal of discovery in
all areas of astronomy
Francois Minya one of the founding
fathers of the Gaia mission is hoping
the fresh data on 1.7 billion stars will
help solve one of the big questions how
many ARMs does a spiral galaxy actually
have
yeah to disengage on my Indonesian
receptors there are all the ingredients
with this day's release with emotions
and the distances to study the arms but
not only are their arms or not but all
through other stars in these arms
different were they born at the same
time do the arms have a unique history
are the arms the results of a merger
with an external galaxy
it's these questions that people are
going to try to answer and the Gaia data
is absolutely fundamental for this kind
of study astronomy has come a long way
since this observatory was founded three
hundred and fifty-one years ago
space telescopes allow precision
measurements of objects millions of
light-years away and we can see that
everything is moving nothing is fixed
everything moves the earth is turning
around the Sun at 30 km/s that's a
hundred thousand kilometers an hour and
then the solar system itself moves
around the galaxy at 230 kilometers per
second that's massive and our galaxy
itself is in a local group and it moves
in this local group it's 60 kilometers
per second and the local group travels
at 600 kilometers per second that's
about two million kilometers per hour
that's huge
everything is in motion you got this to
move on
the Gaia data released this spring marks
a milestone in the study of the Milky
Way more is coming with a spacecraft
continuing to send down measurements 11
hours a day and more data releases do
early in the next decade
and now to the part of the show in which
we take your questions about the
universe and put them to the experts
using the hashtag ask space and we're
here at ESA's headquarters in Paris with
Louisa in hnt or the head of the clean
space office the reason we've had a lot
of questions about space debris
Isaac Gutierrez would like to know how
much space junk is there actually out
there since the 1957 when we have
launched Sputnik we have launched some
5,000 rockets which have delivered
around 8,000 satellite most of the
satellite are dead and they've reached
their head of life some of them are
still operational only around 1200 some
satellites have also fragmented and they
have created smaller parts smaller
debris said today we have some 929
thousand objects larger than 10
centimeter which are monitored we had
another question from ilaria Cinelli she
would like to know considering all of
this space junk out there could we
imagine recycling it in some way one day
we will not recycle on the other hand we
are not there yet we first need to learn
how to capture debris is something which
has never been done it's something which
is not easy and once you learn how to
capture you can also learn how to refuel
change the paths and otherwise so it's a
step approach and in the meantime we
will also need to decrease the cost of
it and it will be done in the future
great thanks very much for your answers
you can ask your questions about the
universe using the ask space hashtag and
we'll try to answer them and you can
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