Melzinhaxuxu - Mel

Weird and Wonderful Irregular Galaxies

Spiral and elliptical galaxies seem neatly put together, but what happened to irregular galaxies? Irregular galaxies have one-of-a-kind shapes and many look like blobs! Why do they look the way they do? Astronomers think the uniqueness of these galaxies results from their interactions with other galaxies — like when they pass close to one another or even collide!

Looking back at the early universe with the help of our Hubble Space Telescope’s “deep field” observations, astronomers can peek at galaxies millions and billions of light-years away. They noticed that these far-away galaxies appear unusually messy, showing more star formation and mergers than galaxies closer to the Milky Way.

We also see irregular galaxies closer to home, though. Some may form when two galaxies pass close together in a near-miss. When this happens, their gravity pulls stars out of place in both galaxies, messing up the neat structure they originally had as spiral or elliptical galaxies. Think of it like this: you happen to have a pile of papers sitting at the edge of a table and when someone passes close by the papers become ruffled and may scatter everywhere! Even though the two galaxies never touched, gravity's effects leave them looking smeared or distorted.

Some irregular galaxies result from the collision between two galaxies. And while some of these look like a blob of stars and dust, others form dazzling ring galaxies! Scientists think these may be a product of collisions between small and large galaxies. These collisions cause ripples that disturb both galaxies, throwing dust, gas, and stars outward. When this happens, it pushes out a ring of material, causing gas clouds to collide and spark the birth of new stars. After just a few million years, stars larger than our Sun explode as supernovae, leaving neutron stars and black holes throughout the ring!

Not all galaxy collisions create irregular galaxies — our Milky Way spiral galaxy has gone through many mergers but has stayed intact! And for some interacting galaxies, being an irregular galaxy may just be a phase in their transformation. We’re observing them at a snapshot in time where things are messy, but they may eventually become neat and structured spirals and ellipticals.

Irregular galaxies are similar to each other, but unique and beautiful because of their different interactions, whether they’re just passing another galaxy or taking part in a dramatic collision. Keep up with NASA Universe on Facebook and Twitter where we post regularly about galaxies.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

It Follows (2014)

Director: David Robert Mitchell

Cinematographer: Mike Gioulakis

let's stand with mama

{Words by Anaïs Nin, from The Diary Of Anais Nin, Vol. 4 (1944-1947) / Cynthia Cruz }

Storm, 1925 - oil on canvas. ― Zdzisław Jasiński (Polish, 1863-1932)

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words by @starpeace

— David Cronenberg, Consumed

“That’s why high school, or a crappy job, or any other restrictive circumstance can be dangerous: They make dreams too painful to bear. To avoid longing, we hunker down, wait, and resolve to just survive. Great art becomes a reminder of the art you want to be making, and of the gigantic world outside of your small, seemingly inescapable one. We hide from great things because they inspire us, and in this state, inspiration hurts.”

— One of the best articles I’ve ever read. Rookie Mag. By Spencer Tweedy. (via wildyork)

Maerten van Heemskerck (detail)