12 Cool Facts About Comet ISON

From Slate Magazine, here are “12 Cool Facts About Comet ISON“–maybe more than you’d ever want to know–plus photos and a video:

12 Cool Facts About Comet ISON
By Phil Plait
Nov. 21, 2013

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[Comet ISON on Nov. 12, 2013. Photo by Michael Jäger.]

Over the years we’ve had some pretty amazing comets swing by our planet. I remember the ones I’ve seen myself: Hyakutake, Hale-Bopp, Holmes, Pan-STARRS, McNaught… they were all beautiful and amazing sights.

Now we have C/2012 S1 (ISON) passing our way, and it’s certainly grabbing attention. It’s brightened substantially in just the past few days, so now’s the time to see it! The pictures people are taking are phenomenal, and there’s plenty of science pouring in as well.

Everyone loves a good picture, of course, but comets are amazing well beyond just their stunning beauty. So I figured I’d take this opportunity to tell you a few things about this comet, a handful of facts to nourish the part of your brain seeking out wonder. Keep these in mind while you’re gawking at the gorgeous pictures.

1) ISON is a n00b.

Some comets are on long, elliptical orbits dropping them in to the inner solar system before sailing them back out to the depths of space. There, they slow, stop, then fall once again back into the warmth and light. Comet Halley, for example, is on a 75-year orbit that takes it out past Neptune.

But some are more extreme. If they get an extra kick on their way in — perhaps from a collision, or a boost by a planet’s gravity — their elliptical orbit gets turned into an open-ended hyperbola: they have more than enough energy to leave the solar system forever. Once they’re gone, they’re gone.

ISON is a hyperbolic comet, which means this is it: These next few weeks are our only chance to see it. After it swings back out, it ain’t coming back. This is likely its first tour of the inner solar system as well, which is why scientists are so excited about it; we’re seeing a pristine comet, billions of years old, a relic of the ancient solar system. It’s a time capsule, letting us study what conditions were like when the Sun and planets were young.

2) ISON is a sun-diver.

The orbit of ISON takes it very, very close to the Sun’s surface. Next week, on Nov. 28, it will skim a mere 1.1 million kilometers (about 700,000 miles) above the Sun’s surface. Given that the Sun is 1.4 million km across, that’s a mighty close shave! The heat it feels will be intense, and it may not survive the encounter (see #10 below).

3) When it passes the Sun, it will be moving at 360 kilometers per second.

Imagine dropping a rock. The higher you drop it, the longer the Earth’s gravity has to pull on it, and the faster it’ll be moving when it hits the ground.

The fastest a rock can hit the Earth is if you drop it from infinitely far away. When it hits it’ll be moving at escape velocity — and the physics of dropping it is reversible, so if you throw a rock at escape velocity it will continue on forever (hence the term “escape velocity”).

Comet SWAN
[Comet SWAN on a death dive into the Sun in 2012. Photo by NASA / ESA / SOHO]

The same is true for a comet rounding (or, in some cases, impacting) the Sun. Since ISON is falling from essentially infinitely far away, when it goes around the Sun it’ll be moving at the Sun’s escape velocity at that distance, or just about 360 km/sec (225 miles/sec). How fast is that? Well, it’s hundreds of times faster than rifle bullet, for example, and over 1500 times faster than a commercial jet — at that speed, the comet would cross the continental United States in about 15 seconds.

In fact, it will be moving at 0.1% the speed of light! That’s far faster than any human-made space probe has ever traveled. And the only propulsion it uses is gravity.

[CORRECTION (Nov. 22, 2013 at 16:15 UTC): I made an error in the calculation for this section, using the escape velocity for the Sun’s surface, and not for the distance ISON will be from the Sun’s center. This deserves a longer explanation, so I wrote a follow-up post about it, and simply corrected the problem here.]

4) The solid part of ISON is only about two kilometers across.

Comets are actually lumps of rock, gravel, and ice mixed together. This solid part of the comet is called the nucleus, and some are huge; Hale-Bopp had a nucleus about 30 km (20 miles) across.

ISON, though, is tiny, only about 2 km (1.2 miles) across. Heck, plop it down in the middle of the Rocky Mountains and you’d hardly notice it! The size has been estimated using images taken from the Hubble Space Telescope, which in reality only give us an upper limit. It might even be smaller.

Still, that’s enough to make the comet visible to the naked eye even from a distance of a hundred million kilometers! How can that be? Why, it’s because…

5) The coma is well over 100,000 km in size.

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[A very rough comparison of the physical size of ISON’s coma and the Earth. On this scale, the solid nucleus of ISON would be about the size of a bacterium. Comet photo by Damian Peach.]

When you look at a picture of ISON (or any comet), you’re not seeing the nucleus. You’re seeing the gas surrounding it that was once frozen beneath the surface. When the comet gets near the Sun this ice warms and turns directly into a gas. It escapes the weak gravity of the nucleus, forming the fuzzy coma around it.

Since the coma isn’t solid, it doesn’t have a sharp edge. But on Nov. 15, the coma for ISON was estimated to appear about 3 arcminutes across (that’s a size on the sky; the Moon is 30 arcminutes across for comparison). Since ISON was about 140 million km (90 million miles) from Earth at the time, that would put the coma at a size of about 120,000 km (80,000 miles). That’s ten times the diameter of Earth!

6) The tail of the comet is (at least) 8 million kilometers long.

Once the gas (and ejected dust) in the coma is out in space, it can be affected by both the solar wind and the pressure of sunlight. It streams away, forming one or more long tails. Like the coma, this is extremely rarefied gas, so it doesn’t really have an edge, but the tail of ISON has been measured to be at least 8 million km (5 million miles) long. That’s 20 times the distance of the Moon from the Earth.

7) The tail is essentially a vacuum.

Weirdly, despite being bright and obvious, a comet’s tail is incredibly ethereal. The density of atoms in a typical tail can run up to about 50,000 atoms per cubic centimeter. Sound like a lot? In a cubic centimeter of air at sea level, there are 1019 (10,000,000,000,000,000,000) atoms/molecules per cc! Compared to the air we breathe, a comet’s tail is a hard vacuum. It’s only bright because it’s so big, and reflects sunlight.

8) The total mass of the comet is about 2 – 3 billion tons.

Ice isn’t terribly dense; it floats on water! If ISON is a typical mix of ice and rock, it has a density of about 600 kg per cubic meters. Assuming it’s a sphere two km across, that gives it a mass of roughly 2 – 3 billion tons. That may sounds like a lot, but remember, ice is far less dense than rock. A small rocky mountain would be far more massive.

9) ISON is shrinking.

Measurements of how much water ice is leaving the comet’s surface indicate it’s losing about 1029 molecules of water every second (bearing in mind this goes up and down all the time). Doing the math, I get that this is about three tons per second — enough to fill an Olympic pool in about ten minutes. That’s a fair amount, but given the total mass of the comet, it would take about 25 years at this rate for the comet to totally disappear. Since it’s only shedding mass for the few weeks it’s near the Sun, it’s got mass to spare. Thanks to @SungrazingComets and the Comet ISON Observing Campaign for their help with this.

10) ISON may disintegrate.

That doesn’t mean it’s safe, though! Some comets aren’t terribly solid; the ice is what holds them together. As they near the Sun and the ice starts to go away, big chunks can break off (called “calving”). In some cases the comet can disintegrate spectacularly. Even if they survive their plunge down to the Sun, some comets get so close they evaporate; we’ve seen that happen too!

It’s not clear if ISON will survive its close shave with the Sun. As of right now it seems to be OK, but who knows what the next few days will bring.

11) ISON won’t hit the Earth.

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Whenever there’s a bright comet (or near pass of an asteroid), conspiracy buffs start thinking it’ll hit us. Don’t worry about ISON. The closest it will get is on Dec. 26, 2013, when it will be about 60 million km (40 million miles) from Earth. That’s 150 times farther away than the Moon.

12) You can see it for yourself, and it may become visible in broad daylight.

Right now, ISON is bright enough to see naked eye, and easily with binoculars. It’s jumped in brightness twice just in the past week or so! As it gets near the Sun it’ll get brighter, but harder to find because, duh, it’s getting near the Sun.

However, sometimes comets like this get incredibly bright when they are close to the Sun. In 2007, I saw comet McNaught at noon. Yes, noon. It was difficult, and I had to be very careful; you don’t want to wind up looking right at the Sun, especially in binoculars, unless boiled eyeballs is something you want. Seriously, don’t just scan around with binoculars looking for the comet, because it’s very dangerous and can blind you.

There’s no way to know right now, but it’s possible that ISON will be visible in broad daylight to the naked eye for the short time it’s near the Sun. It could be possible to see it during the day if you position yourself so that the Sun is blocked behind a tree, or the edge of a house. It depends on the exact position of the comet relative to the Sun, of course.

Again, doing this is difficult and you shouldn’t attempt it unless you know what you’re doing. I’ll note that in general, glancing briefly at the Sun won’t hurt a normal eye with an undilated pupil, but it’s not a good idea to do it too much, and it’s more dangerous for kids (their lenses let through more UV light than adult eyes).

Your better bet is to wait a few more days. Once ISON rounds the Sun, it’ll be visible in the west after sunset for a few weeks for those of us in the northern hemisphere, so watching it will be far easier (right now you have to get up at about 5:00 a.m., before sunrise, to see it). Here’s a finder chart (Sky and Telescope has another as well) that’ll help you spot it; planetarium software for mobile devices are great too (I like Sky Safari, but there are many to choose from). You can find plenty more finder charts online. I’ll note it’ll fade with time, but around Dec. 20 or so it should be out of the Sun’s glare, and (hopefully) easily visible with binoculars.

[UPDATE (Nov. 22, 2013 at 16:15 UTC): I’ll note that once it passes the Sun, the comet will still be visible in the east before sunrise in the morning as well as in the west after sunset in the evening. I explain this in a follow-up post.]

Seeing a good comet is a wonderful experience, and ISON gives us a chance to experience something that will only come around once, quite literally. This isn’t science fiction, or something out of a movie: This object exists, and it’s just one small part of a much grander universe that’s out there. I hope you can take a moment to drink that in.

Books and Booze for Tennessee Williams

Had a good time handing out clues and drinks last night to contestants in the Books and Booze Scavenger Hunt for the Tennessee Williams Festival. Poet Benjamin Morris and I were posted at Beckham’s Books, in the French Quarter, together with amiable bookseller Daniel. Here we are with drinks at The Beauregard-Keyes House discussing teams’ strategies:

With Ben Morris and Daniel of Beckham's

Things got a little tense during the scoring. None of us understood the rules. Nicola Wolf stepped in to help:

With Nicola Wolf and Ben Morris

Comet in “Best Books of 2013” from Kirkus Reviews

I’m happy to announce that THE NIGHT OF THE COMET has been chosen as one of Kirkus Reviews “Best Books of 2013.” Below’s their original review.

Thank you, thank you. (Bows.)

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THE NIGHT OF THE COMET
by George Bishop

KIRKUS REVIEW

Filled with the kind of wistful longing that characterizes the coming-of-age novel, this latest from the talented Bishop brings stardust and domestic disillusionment to the bayous of Louisiana.

In 1973, when Junior Broussard blows out the 14 candles on his birthday cake, his wish takes the form of one word—Gabriella. Instead of her magical appearance, he receives a telescope from his father, the high school’s geeky science teacher, an amateur astronomer and author of the newspaper’s weekly “Groovy Science” column. His father has become obsessed with the sighting of the comet Kohoutek; the new telescope will provide a father-son bonding opportunity. Junior could care less and soon points his telescope across the bayou to Gabriella’s mansion. As his father is involved with Kohoutek, Junior becomes fixated on the wealthy Martellos across the water. Their life is like a television show—they dress better, look better, seem happier—and he watches them like an anthropologist and a lover and wonders what will become of himself, raised in a house of small dreams and missed opportunities. His mother, Lydia, befriends Mrs. Martello, and the two hatch a plan to throw a charity ball with a comet theme. Lydia is also bewitched by the Martellos (especially husband Frank) and begins to feel she deserves so much more than science teacher Alan Broussard can offer. Their meeting years ago—the beautiful pharmacy counter girl and the new science teacher—is a story Junior begs from his parents, as if the re-telling will provide some magic to keep them together. His father becomes dangerously unhinged, his mother runs away, harboring fantasies of a life with Frank Martello, and the comet will soon appear. Junior is sure it will bring both disaster and magic to their lives. Coming-of-age novels examine youthful revelations about the world—filled with cynicism and wonder and rearranged expectations—and the quality hinges on the honesty of the voice, the truth of the observations, the handling of innocence lost; Bishop succeeds on all these fronts.

A fine story of everyday sadness and otherworldly joys.

Pub Date:Aug. 6th, 2013
ISBN:978-0-345-51600-8
Page count:352pp
Publisher:Ballantine
Review Posted Online:June 23rd, 2013
Kirkus Reviews Issue:July 1st, 2013

Interview in the New Orleans Review

I was recently interviewed for the New Orleans Review by Erin Little of Loyola University. Here it is. My only excuse is that I might’ve had a glass or two of wine before we spoke.

New Orleans Review

INTERVIEW by ERIN LITTLE
George Bishop: The Night of the Comet

Native Louisianan and Loyola alumnus (1983) George Bishop is emerging as a fresh and vibrant voice in the literary South. His previously successful novel Letter to My Daughter (Ballantine, 2010) showcased his ability to capture complex familial relationships in an inviting, though heart-wrenching way. Since then, Bishop has delved even further into the secret lives of families—prompting his characters to admit their shortcomings and disappointments, no matter how difficult that may be. In his second novel The Night of the Comet (Ballantine, 2013) cultural phenomena give way to harrowing realizations for a middle-class Louisiana family. The Night of the Comet soars with quiet truth and a clear-eyed vision.

INTERVIEWER

The Night of the Comet follows your previous successful novel, Letter to My Daughter. How was your creative process different in writing this new novel?

BISHOP

The first novel was comparatively easy because that novel was short in manuscript, only around 110 pages. In fact, I thought I was writing a novella. I had a very clear idea going into my first novel. I dreamed the whole novel before I wrote it, so I knew what the whole novel was about. I knew the voice and rhythm before I started writing. But for Night of the Comet, I didn’t have any of that going into it. I just had ideas. I knew I wanted to write about Comet Kohoutek and I also had recurring images in my head of a man in a raincoat leaping off a roof and a broken telescope. Then I had to build the novel from the ground up.

INTERVIEWER

The Night of the Comet plays out against the backdrop of small town Louisiana. Was it challenging or natural to write about a setting you are so familiar with? Did you find it rewarding?

BISHOP

I grew up in a small town too but it was north of here—Jackson, Louisiana. The small town in this novel is a bayou city. I wanted to set it there because it seemed more exotic to me. For me, to set it in this fictitious town called Terrebonne, I might as well have been setting it in Mongolia. It sounded that exotic to me. I wanted it to be a fictitious town so I wouldn’t be tied to the real geography or history of a city.

INTERVIEWER

What inspired you to choose Comet Kohoutek to aid you in telling this family’s story?

BISHOP

I barely remember Comet Kohoutek from when I was a kid. But I do remember all the excitement surrounding it. A couple of decades ago I made a note in one of my writing journals that I thought Comet Kohoutek could be a good backdrop for a story. But I didn’t know much about the Comet. When I began researching, I discovered interesting information about doomsday cults surrounding the comet and how big it really was then. I had no idea it was that much of an event in America at the time. But then it was a huge disappointment. It became like the laughing stock of comets after its big failure. In the world of astronomy, Kohoutek has become synonymous with huge failure. I thought I could hang the story on the timeline of the comet.

INTERVIEWER

Many readers have described The Night of the Comet as a coming of age story. How do you approach that label?

BISHOP

I don’t like that label. I don’t know who slapped that on the book because I wouldn’t call it a coming of age story. But I understand why it seems like that. I understand you have to label it as something. The fact that it’s told through the point-of-view of a fourteen-year-old kid who’s going through a sexual awakening perhaps makes it a coming of age story. But I was also thinking of it as the family’s story. I see it as a family story, really.

INTERVIEWER

What influenced your choice to set this story in the 1970’s?

BISHOP

The comet was coming in 1973. I had to set it at that time, but I didn’t want to make it a period piece. I didn’t want to make it a stereotypical 70’s piece so I really toned down the cultural references and time markers. I didn’t want it to be a book about the 70’s. I thought that would be too easy. I was also trying to avoid the clichés of Southern fiction. I wanted it to feel timeless.

INTERVIEWER

How did you develop narrator Alan Broussard Jr.’s original voice? What was challenging about adapting a perspective as youthful as his?

BISHOP

Limiting myself to Alan’s voice was the big challenge. It took awhile to come to this first person narrator because I kept trying to switch to third person. I settled on the first person narrator because I thought it felt more intimate and realistic. Once I settled on a fourteen-year-old narrator, I worked really hard to find the balance in his voice. I started out trying too hard to write as a fourteen-year-old. Later, the solution I found was to develop a sort of hybrid narrator—an adult looking back and telling the story. We do that when we tell stories about childhood. We use our vocabulary and understanding to explain how we saw things then. It’s a fourteen-year-old’s perceptions with an adult vocabulary.

INTERVIEWER

Alan Broussard Sr. has a pretty advanced knowledge of the cosmos. Was there heavy research involved in informing Alan Sr.’s perspective? Was the research enjoyable?

BISHOP

Oh yes, it was fun. Research is the fun part. Research is what you do when you can’t write.

INTERVIEWER

In the end, do the stars aid young Alan Broussard Jr. in better understanding his family and his own place in the world?

BISHOP

At the end of the novel, when Alan is an adult, he realizes his life is very small compared to the cosmos. But from the kid’s point of view, he can see his family being affected by the comet. Everyone’s going crazy because of the comet. And Alan gets caught up in it too. His parents and the whole town draw him into it. So I think Alan begins to feel like the comet is screwing up their lives completely. He feels that. He’s also a smart kid, though, so he’s resisting.

Erin Little is an intern for New Orleans Review and an English Writing major at Loyola University New Orleans.

Comet ISON Heats Up, Adds New Tail

This update on Comet ISON from Universe Today. Come on, ISON! Come on!

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Comet ISON Heats Up, Grows New Tail
by Bob King, Nov. 7, 2013

I’m starting to get the chills about Comet ISON. I can’t help it. With practically every telescope turned the comet’s way fewer than three short weeks before perihelion, every week brings new images and developments. The latest pictures show a brand new tail feature emerging from the comet’s bulbous coma. For months, amateur and professional astronomers alike have watched ISON’s slowly growing dust tail that now stretches nearly half a degree or a full moon’s diameter. In the past two days, photos taken by amateur astronomers reveal what appears to be a nascent ion or gas tail. Damian Peach’s Nov. 6 image clearly shows two spindly streamers.

Favorite Astronomy Poems No. 4: “Alone and Drinking Under the Moon,” by Li Po

Today’s Favorite Astronomy Poem is the melancholy “Alone and Drinking Under the Moon,” by famed Chinese poet Li Po (or Li Bai). Here’s a picture to put you in the mood:

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(Fishing Boat Anchored on a Moonlit Night, by Bai Jin, 1388-1462)

The poet Li Po was born in 701, perhaps in Gansu province, in China. He spent much of his life wandering up and down China, writing poetry, drinking wine, and visiting friends. He won the favor of the Emperor, and when the Emperor was overthrown, he was exiled and sentenced to death. He eventually received an imperial pardon and resumed wandering. Legend has it that Li Po drowned when he reached from his boat to grasp the moon’s reflection in a river.

Chinese children still learn his poems today in school. This one, “Alone and Drinking Under the Moon,” has been translated many times into English. I like this version, by Rewi Alley

Alone and Drinking Under the Moon
by Li Po (Li Bai), 701-762

Amongst the flowers I
am alone with my pot of wine
drinking by myself; then lifting
my cup I asked the moon
to drink with me, its reflection
and mine in the wine cup, just
the three of us; then I sigh
for the moon cannot drink,
and my shadow goes emptily along
with me never saying a word;
with no other friends here, I can
but use these two for company;
in the time of happiness, I
too must be happy with all
around me; I sit and sing
and it is as if the moon
accompanies me; then if I
dance, it is my shadow that
dances along with me; while
still not drunk, I am glad
to make the moon and my shadow
into friends, but then when
I have drunk too much, we
all part; yet these are
friends I can always count on
these who have no emotion
whatsoever; I hope that one day
we three will meet again,
deep in the Milky Way.

inRegister Magazine Review of Comet

Thanks to Donna Perreault and Baton Rouge’s inRegister magazine for a fine review of The Night of the Comet.

inRegister

The Night of the Comet

By Donna Perreault
Published Oct 31, 2013

The mystery of our parents’ union: Who hasn’t felt its power? It’s the condition for our existence, the prelude to our birth. To an adolescent sorting out issues of identity, how he ended up with his parents can be both fascinating and perplexing. That’s the experience of 14-year-old Alan Broussard Jr. in George Bishop’s great new novel, The Night of the Comet. He puzzles over his parents’ improbable marriage during the year it unravels.

We learn in the prologue that the Broussard family of Terrebonne Parish is heading toward a crisis. Bishop admits, “I’d always envisioned starting the novel with a cliffhanger.” Junior, as he is called, is grown up now and living in Baton Rouge. He finds himself recalling the night in December 1973 when he watched his father climb a water tower with the apparent intention of leaping to his death. Does he do it? Why does he despair? Find out in the ensuing saga, told from “a strange kind of adult-boy point of view hybrid,” Bishop told inRegister. Junior’s voice conveys the “naiveté of youth” leavened with mature insight.

The eponymous comet that sets Junior’s story in motion is Kohoutek, predicted in 1973 to be “the comet of the century.” So says Alan Broussard Sr. to his high school students in the fictional town of Terrebonne. “You’re in for a real treat this year,” he promises at the semester’s start. “Something really special.” Alan Sr. is an Earth and Space Science teacher and a passionate amateur astronomer. In Junior’s eyes he’s awkward and wacky, a source of daily embarrassment. But as Kohoutek barrels earthward, Alan Sr. becomes a local celebrity.

Junior notes this transformation warily, seeing his dad stir up awe and anticipation in everyone—except his wife, Lydia. But the teen has his own passion to tend to: for his new neighbor Gabriella. The comet, he feels, is an agent of change. But to what end? Bishop notes, “Without getting too symbolic about it, the comet heralds Junior’s arrival into adulthood.”