People do a very good job at defining patterns in things,
especially things that they're not familliar with.
And today, since it's Valentines day,
we're looking at astronomical objects,
that have a shape of a heart.
You might not think it, but on the surface of Mars,
we've actually found quite a few hearts.
These are images that were taken from the Mars Global Surveyor.
In each of these you can actually see clearly the shape of a heart.
Most of them are dips. They're actually depressions in the surface.
In this one you can see clearly this heart structure,
and it's a depression in the ground.
With the light coming from the left, you can see the cliff right here
has a dark side, and it's illuminating this side of the cliff.
This one I particularly like, because it's a crater with a heart
that's in the middle of the crater.
So the crater goes down into the surface,
and then the heart actually pops up from the center.
This is an example of how human beings love to find patterns
in anything that they can, just like when we stare up at the sky
on a sunny day trying to find patterns in the clouds.
In astronomy the same thing kind of happens.
Interesting looking objects tend to get nicknames.
One class of interesting objects are called nebulae,
and these are big clouds of gas in our galaxy.
They're where stars are born.
We often call these nebulae by interesting nicknames,
based on what they look like,
there's the hourglas, the catsign, the owl,
the lagoon, the boomerang,
but today for valentines day we're showing you the heart-nebula.
So you can see this beautiful heart-shape pattern here,
which is glowing hydrogen gas.
It is glowing because in the middle of this nebula is a knot of stars.
This is one of my favourite galaxy pairs.
This is the antennae galaxy,
and these are actually two separate galaxies
that are coming together in a marriage,
of two galaxies to become one.
So maybe a billion years ago these were actually separate galaxies,
and they've been orbiting each other
and getting closer and closer
you can see now that the two are really coming together to form one.
You can see these wings of stars and gas.
It's called antennae galaxy because
these are looking like bugs antennae.
A more updated version of this, made with the Hubble telescope,
is this image.
It zooms in on that central region
and you can really this nice romantic heart-shape.
We're gonna move away from hearts for the moment,
but I am going to show you an image
that has something to do with Valentines day.
This is probably one of the most romantic images made,
if you think of romance not just being about love,
but about big ideas.
The connection with Valentines day is that twenty years ago
a little spacecraft called Voyager I,
shooting out to the outer reaches of the solar system,
it's mission finished to explore the planets,
was commanded to turn around and
take a family portrait of our solar system.
And ofcourse the connection with Valentines day
is that on 14th of februrary 1990,
twenty years ago,
that this little spacecraft was sent the instruction
to turn around, it's mission completed,
and start taking a picture of our solar system family.
And this is the picture it took,
it was four billion miles away from the sun,
and it went and took 60 different pictures,
stiched together here in this panorama,
that captures almost all of the members of the solar system family.
So you see the Sun in the center,
Earth and Venus very close by.
Unfortunately it missed out on Mars and Mercury,
but it got all the rest of the planets,
Jupiter, Saturn, Uranus and Neptune.
Aside from the grandeur of this whole picture put together,
it's really one particular frame of this
that captured the publics imagination.
And that is ofcourse the portrait of earth,
because that's our home.
If we zoom in on that one little picture,
you're seeing a picture of earth from four billion miles away.
Earth is this little tiny dot, right in the center.
So the remarkable thing about this particular image is that
it really gives us a perspective on our place in the solar system,
and just how small and insignificant our precious little home is.
This is a tiny little dot in this one little picture
and that's earth, that's our home.
But really I'm just paraphrasing a great scientist Carl Sagan here.
Because he had some much more profound words to say about this:
Look again at that dot, that's here, that's home, that's us.
On it, everyone you love, everyone you know,
everyone you ever heard of,
every human being who ever was, lived out their lives.
He goes on to call it a mote of dust suspended in a sunbeam.
And that's absolutely true, because
it is this little dot that happens,
purely by chance,
to be caught on some reflected light within the camera,
coming from the sun.
transcription: merijn.vogel@gmail.com