Incredible Image from Hubble of the Horsehead Nebula

Bad Astronomy
The entire universe in blog form
April 19 2013 11:07 AM

Hubble's Knight to Remember

On April 24, 1990, the Hubble Space Telescope was launched into orbit, on its way to revolutionizing astronomy. This week marks the 23rd anniversary of that event, and to celebrate, astronomers released a devastating image of the iconic Horsehead nebula, a vast and dense cloud of gas and dust in Orion:

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

Hubble Horsehead
The Horsehead Nebula, a complex of gas and dust 1500 light years away in Orion. Click to enequuenate.

Image credit: NASA,ESA, and theHubble HeritageTeam (STScI/AURA)

Holy wow. Not only is that beautiful, it’s weird. I’m not used to seeing it this way.

Horsehead nebula
The usual view of the Horsehead in visible light, looking a bit different. Click to embiggen.

Image credit: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)

Advertisement

The Horsehead is superposed on a ridge of bright hydrogen gas, usually seen as a reddish-pink glowing sheet. Because the Horsehead is choked with dust, it’s opaque, and blocks the light from behind it. We see it in silhouette, dark against a bright background.

But the Hubble image is in the infrared. That light, just outside of what our eyes can see, is better able to pierce through the dust. In the Hubble image we’re seeing more deeply into the Horsehead, seeing detail inside the cloud.

So exactly what are we seeing? Just off the top of the Hubble picture is the bright star system Sigma Orionis, composed of five incredibly luminous stars. Combined, they shine with the power of over 75,000 Suns! They are responsible for heating and exciting the gas behind the Horsehead.

The Horsehead itself is the site of ongoing star formation. The dense gas and dust inside the nebula is collapsing to form stars, and, at the same time, the edges are being eroded away by the fierce ultraviolet light of Sigma Orionis. The top of the Horsehead is acting a bit like a shield, protecting the material beneath it, which is why it’s taken on that umbrella-like shape. You can see more sculpted pillars of material around the sides, too, like sandbars in a stream. That’s pretty typical in situations like this.

So the Horsehead is getting blasted from above by Sigma Orionis, which is slowly dissolving away the nebula. Eventually it will disappear, but that will take a few million years. And left behind in its passing will be a set of new, young stars, shining brightly, their light free to cross the cosmos.

It’s all part of the natural cycle of the Universe: Structures come and go, sprawling clouds of gas and dust spawn stars from their own material that will take their place and eventually destroy them…but many of those stars will eventually explode and seed space with the elements and conditions that will help create the next generation of stars. We literally owe our existence to some long-gone nebula like the Horsehead, and to the stars that existed even before it.

So appreciate the beauty of the Horsehead while it’s here, and it’s necessity when it’s gone.

TODAY IN SLATE

Politics

Smash and Grab

Will competitive Senate contests in Kansas and South Dakota lead to more late-breaking races in future elections?

Stop Panicking. America Is Now in Very Good Shape to Respond to the Ebola Crisis.

The 2014 Kansas City Royals Show the Value of Building a Mediocre Baseball Team

The GOP Won’t Win Any Black Votes With Its New “Willie Horton” Ad

Sleater-Kinney Was Once America’s Best Rock Band

Can it be again?

Technocracy

Forget Oculus Rift

This $25 cardboard box turns your phone into an incredibly fun virtual reality experience.

One of Putin’s Favorite Oligarchs Wants to Start an Orthodox Christian Fox News

These Companies in Japan Are More Than 1,000 Years Old

Trending News Channel
Oct. 20 2014 6:17 PM Watch Flashes of Lightning Created in a Lab  
  News & Politics
Politics
Oct. 20 2014 8:14 PM You Should Be Optimistic About Ebola Don’t panic. Here are all the signs that the U.S. is containing the disease.
  Business
Moneybox
Oct. 20 2014 7:23 PM Chipotle’s Magical Burrito Empire Keeps Growing, Might Be Slowing
  Life
Outward
Oct. 20 2014 3:16 PM The Catholic Church Is Changing, and Celibate Gays Are Leading the Way
  Double X
The XX Factor
Oct. 20 2014 6:17 PM I Am 25. I Don't Work at Facebook. My Doctors Want Me to Freeze My Eggs.
  Slate Plus
Tv Club
Oct. 20 2014 7:15 AM The Slate Doctor Who Podcast: Episode 9 A spoiler-filled discussion of "Flatline."
  Arts
Brow Beat
Oct. 20 2014 9:13 PM The Smart, Talented, and Utterly Hilarious Leslie Jones Is SNL’s Newest Cast Member
  Technology
Technocracy
Oct. 20 2014 11:36 PM Forget Oculus Rift This $25 cardboard box turns your phone into an incredibly fun virtual-reality experience.
  Health & Science
Medical Examiner
Oct. 20 2014 11:46 AM Is Anybody Watching My Do-Gooding? The difference between being a hero and being an altruist.
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.