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The galaxy Messier 74

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lies at a distance of over
30 million light years.

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In this latest image from the
NASA / ESA Hubble Space Telescope

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the enormous swirls of this
stunning spiral galaxy

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arc across space, adorned
with glowing pink regions

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of hydrogen gas and
lit by the pale blue light

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of millions of newly
formed stars.

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This is the Hubblecast.

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News and images from the
NASA / ESA Hubble Space Telescope.

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Travelling through time and space
with our host, Dr. J

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EPISODE 11: Galaxy bars
and supermassive black holes
a.k.a. Dr. Joe Liske.

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Welcome to the Hubblecast.

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Over the course of its
seventeen years in space

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the Hubble Space Telescope
has imaged

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literally thousands of galaxies.

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However, this latest image from
the orbiting space observatory

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is clearly a red hot candidate

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for being one of the finest images
of the galaxy ever seen.

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The striking image from Hubble
shows Messier 74,

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a spiral galaxy located about
32 million light years away from Earth.

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In the new image

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Hubble reveals the light
from billions of stars

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in the spiral arms
of this stunning galaxy,

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laced with delicate
tendrils of dust

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silhouetted against
the swirling arms.

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This galaxy,
also known as NGC 628,

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was first observed in 1780
by a French astronomer

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called Pierre Méchain,
who was searching the sky

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for objects
that may be comets.

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Soon after
he discovered the galaxy

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Méchain told his good
friend Charles Messier,

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who then listed it as M74

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in his now famous catalogue
of deep sky objects.

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Of all the objects
in Messier's catalogue

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number 74 has the lowest
surface brightness

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and is so difficult for amateur astronomers
to spot through a telescope

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that it has been given the
nickname "The Phantom Galaxy".

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The stunning new image
also shows

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a sprinkling of
bright red regions

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decorating the spiral arms.

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These are vast, relatively
short-lived clouds

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of hydrogen gas, which glow
due to the strong radiation

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from hot young stars.

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Astronomers call these
clouds HII regions.

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The really bright stars
in the image

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are actually foreground stars

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located within our own
Milky Way Galaxy.

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They are much closer and are
not part of M74 behind them.

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Hubble's image also shows
an intricate network

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of dust lanes weaving
through the galaxy's spiral arms.

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These dusty swirls have
partly been created

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by previous generations of stars
which seeded the galaxy

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with newly formed
chemical elements

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when they died as supernovae.

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In fact two such supernovae
have been seen to explode

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in M74 in recent years.

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In this image of Messier 74
we can see the blue light

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from millions
of young blue stars

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in the two main
spiral arms of the galaxy.

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These spiral arms are not actually statical
'arms' like spokes on a wheel.

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They are in fact density waves
and move around the galaxy's disc

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compressing gas just as sound waves
compress the air on Earth

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creating new generations
of young blue stars.

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Because of the elegant symmetry
of its spiral arms

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astronomers call this
a 'grand design spiral'.

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Messier 74 bears
a strong resemblance

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to another 'grand design spiral',
Messier 51, the Whirlpool Galaxy

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in the constellation of Canes
Venatici, the Hunting Dogs.

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Messier 74 is arguably one of
the most photogenic galaxies

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Hubble has ever observed.

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Whit its myriad of stars
and delicate dust lanes

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it is a place of serene beauty
and grandeur

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on the truly galactic scale.

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This is Dr. J
signing off for the Hubblecast.

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Once again, nature has surprised us
beyond our wildest imagination...

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Hubblecast is produced
by ESA / Hubble

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at the European
Southern Observatory in Germany.

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The Hubble mission is a project
of international cooperation

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between NASA and
the European Space Agency.