Image: Hubble eyes galaxy as flat as a pancake

Dec 31, 2013
Credit: NASA

(Phys.org) —Located some 25 million light-years away, this new Hubble image shows spiral galaxy ESO 373-8. Together with at least seven of its galactic neighbors, this galaxy is a member of the NGC 2997 group. We see it side-on as a thin, glittering streak across the sky, with all its contents neatly aligned in the same plane.

We see so many like this—flat, stretched-out pancakes—that our brains barely process their shape. But let us stop and ask: Why are galaxies stretched out and aligned like this?

Try spinning around in your chair with your legs and arms out. Slowly pull your legs and arms inwards, and tuck them in against your body. Notice anything? You should have started spinning faster. This effect is due to conservation of , and it's true for galaxies, too.

This galaxy began life as a humongous ball of slowly rotating gas. Collapsing in upon itself, it spun faster and faster until, like pizza dough spinning and stretching in the air, a disc started to form. Anything that bobbed up and down through this disk was pulled back in line with this motion, creating a streamlined shape.

Angular momentum is always conserved—from a spinning galactic disk 25 million light-years away from us, to any astronomer, or astronomer-wannabe, spinning in an office chair.

Explore further: Astronomers discover likely precursors of galaxy clusters we see today

Related Stories

Image: Hubble sees galactic glitter

Dec 02, 2013

This sprinkling of cosmic glitter makes up the galaxy known as ESO 149-3, located some 20 million light-years away from us. It is an example of an irregular galaxy, characterized by its amorphous, undefined ...

A spiral galaxy in Hydra

Apr 09, 2012

(Phys.org) -- This image from the NASA/ESA Hubble Space Telescope shows NGC 4980, a spiral galaxy in the southern constellation of Hydra. The shape of NGC 4980 appears slightly deformed, something which is ...

Hubble digs up galactic glow worm

Mar 25, 2013

(Phys.org) —This charming and bright galaxy, known as IRAS 23436+5257, was captured by the NASA/ESA Hubble Space Telescope. It is located in the northern constellation of Cassiopeia, which is named after ...

Hubble view of a special spiral galaxy

Oct 24, 2013

(Phys.org) —The image, captured by the NASA/ESA Hubble Space Telescope, shows part of NGC 3621, an unusual spiral galaxy located over 20 million light-years away in the constellation of Hydra (The Water ...

Recommended for you

Rocky planets may orbit many double stars

Mar 30, 2015

Luke Skywalker's home in "Star Wars" is the desert planet Tatooine, with twin sunsets because it orbits two stars. So far, only uninhabitable gas-giant planets have been identified circling such binary stars, ...

Is the universe finite or infinite?

Mar 27, 2015

Two possiblities exist: either the Universe is finite and has a size, or it's infinite and goes on forever. Both possibilities have mind-bending implications.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.