Hubble Delivers Comet ISON Verdict: Still Alive

The entire universe in blog form
Oct. 19 2013 8:00 AM

Comet ISON: Still Alive

As of Oct. 9, 2013, comet C/2012 S1 (ISON) is still alive.

That’s the verdict from a Hubble Space Telescope image taken on that day. At a distance of 280 million kilometers (175 million miles), the comet presented a fine sight to Hubble’s keen eye:

Hubble Comet ISON
I spy with my Hubble eye a spry iceball. Click to hairystarenate.

Photo by NASA,ESA, and theHubble HeritageTeam (STScI/AURA)

Advertisement

There has been some speculation that this comet may disintegrate as it gets near the Sun in late November. Comets are basically dirty snowballs; ice, rock, and gravel mixed together. As the comet warms, the ice turns into a gas, creating the fuzzy head around the solid nucleus, and the long tail that streams away due to the solar wind and pressure from fierce sunlight. If enough of the ice goes away, the comet loses structural integrity and can fall apart. We’ve seen that in images of other comets (including a dramatic one from Hubble back in 2006).

Comet
Comet 73P/Schwassmann-Wachmann losing its grip in 2006.

Photo by NASA,ESA, H. Weaver (JHU/APL), M. Mutchler and Z. Levay (STScI)

The thing to note is that the head of Comet ISON, the tiny fuzzy part at the bottom left, appears intact. If the comet were breaking up, we should see tiny pieces trailing behind it. The image looks clean, so it seems to me this comet still has some sizzle left to go.

ISON is on an orbit that will take it deep into the solar system, practically scraping the Sun’s surface, missing it by only a million kilometers (700,000 miles or so), less than the diameter of the Sun itself. Because it will be so close to the Sun, ISON could get very bright; I’ve seen comets get to naked-eye visibility when this happens!

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!  

Or, it might not. As I’ve said before, comets are basically as predictable as cats. I wouldn’t bet either way.

Still, this latest Hubble image gives me hope this comet may yet brighten quite a bit. We’ll see. If you want to observe it yourself, star charts are available online. I plan on taking a look soon myself. Good comets are rare beasts, and I want to make sure I take every chance I get to see one.

Previous posts about ISON:

TODAY IN SLATE

Politics

Blacks Don’t Have a Corporal Punishment Problem

Americans do. But when blacks exhibit the same behaviors as others, it becomes part of a greater black pathology. 

I Bought the Huge iPhone. I’m Already Thinking of Returning It.

Scotland Is Just the Beginning. Expect More Political Earthquakes in Europe.

Lifetime Didn’t Think the Steubenville Rape Case Was Dramatic Enough

So they added a little self-immolation.

Two Damn Good, Very Different Movies About Soldiers Returning From War

Medical Examiner

The Most Terrifying Thing About Ebola 

The disease threatens humanity by preying on humanity.

Students Aren’t Going to College Football Games as Much Anymore, and Schools Are Getting Worried

The Good Wife Is Cynical, Thrilling, and Grown-Up. It’s Also TV’s Best Drama.

  News & Politics
Weigel
Sept. 19 2014 9:15 PM Chris Christie, Better Than Ever
  Business
Business Insider
Sept. 20 2014 6:30 AM The Man Making Bill Gates Richer
  Life
Quora
Sept. 20 2014 7:27 AM How Do Plants Grow Aboard the International Space Station?
  Double X
The XX Factor
Sept. 19 2014 4:58 PM Steubenville Gets the Lifetime Treatment (And a Cheerleader Erupts Into Flames)
  Slate Plus
Slate Picks
Sept. 19 2014 12:00 PM What Happened at Slate This Week? The Slatest editor tells us to read well-informed skepticism, media criticism, and more.
  Arts
Brow Beat
Sept. 19 2014 4:48 PM You Should Be Listening to Sbtrkt
  Technology
Future Tense
Sept. 19 2014 6:31 PM The One Big Problem With the Enormous New iPhone
  Health & Science
Bad Astronomy
Sept. 20 2014 7:00 AM The Shaggy Sun
  Sports
Sports Nut
Sept. 18 2014 11:42 AM Grandmaster Clash One of the most amazing feats in chess history just happened, and no one noticed.