Astronomy – Geoff Fox: My Permanent Record

I’m Studying Up On Mars

Tomorrow will be busy for me. We’ve got two slooh.com shows about the close encounter between Comet Siding Spring and Mars.

I host, surrounded by cometary experts. I still have to know the science.

This is an unprecedented event. We’ve never seen a comet get so close to a planet.

That worries NASA.

Actually, let me modify that. Their worry is later.

First, cards on the table. NASA is always interested in ‘visitors’ to our part of the solar system. But there’s a lot more buzz for Comet Siding Spring C/2013 A1. It will come close to Mars and to billions of dollars of hardware circling Mars, plus rovers on-the-ground.

Siding Spring is speeding in from the Oort Cloud, a theorized mass of billions of comets 100,000 times farther from the Sun than we are. It will zip by Mars at a closing speed 35 miles per second–186,000 mph.

The comet misses Mars. We’ve all got that, right?

Later, Mars passes through the debris field left in the comet’s wake. Scientists expect some fragments will be drawn toward the planet where we have satellites and stuff.

NASA’s official “Best Estimate” says the particles miss. Their conservative estimate says 90-100 minutes after the closest approach a stream of small debris will come, then quickly go.

Our satellites all had their orbits disrupted, putting them on the far side of Mars when this happens.

T-0 is officially called the “time of the particle fluence center.”

NASA is praying one or more of the rovers will take a photo or two of the comet brightly shining through the Martian atmosphere. That’s pretty damn cool. It will likely happen and will surely include a part of the rover, lest we forget whodunit.

We’ll also get images from whatever sensors can be turned around on satellites.

I’m not sure how much of this is actually advancing science and how much is showing off. An opportunity and challenge like this shouldn’t be squandered, but this is more photo-op than anything. After all, we’re landing on a comet next month!

Everything is now set. It’s too late for change to matter. Any debris that hits the Red Planet was jettisoned off the comet years ago.

Distance and time are very different in space. You can’t think in minutes and seconds or inches and feet. Our best orbital predictions say C/2013 A1 won’t be back for around a million years.

On-The-Air On-The-Web

There was a time when astronomers felt this asteroid had a plausible chance of hitting Earth in 2049. That’s only 35 years.

I spent part of the night on-the-air. Is that right? Does on-the-air still apply? I spent a good part of the night on-the-web doing a broadcast for slooh.com.

Slooh is the “Community Observatory.” They maintain three telescopes, one in Chile and two on the Canary Islands. Slooh members individually assign the telescopes’ “missions.”

It’s a very cool idea. Timeshare telescopes, better than what most could afford, in locations astronomers covet. You view is via the Internet. Members look at comets, asteroids, planets, galaxies and, of course, stars.

That’s a shot of Comet Jacques on the left. I took it last week on one of the Canary Island telescopes.

As part of the company’s outreach, we produce shows on the Internet. It’s me as host, astronomer Bob Berman and observatory director Paul Cox. Tonight we had Lindley Johnson, who runs the show for the Near Earth Object program at NASA. Our show centered on Asteroid 2002 CU11.

Tonight 2002 CU11 passed within .03 AU of Earth. that’s 3% of the distance to the Sun. In space terms, close.

There was a time when astronomers felt this asteroid had a plausible chance of hitting Earth in 2049. That’s only 35 years away!

Since the first prediction 2002 CU11’s orbit has been recalculated with more precision. We’re off the hook for now, but time is on the asteroid’s side.

I love doing these shows. I work with two very smart guys. Bob is encyclopedic in his astronomy knowledge. Paul is just smart. I’m not sure what he’s not smart in. I haven’t seen it. And the British accent makes him sound smarter–unfair.

Usually we do shows from home. Bob is near Woodstock, NY. Paul lives in England. I’m here in SoCal. Our director/producer sits in East Hartford, CT. How cool is that?

I’m in my office using a webcam and headset. It doesn’t quite look like network TV, but it’s obviously pro.

Good TV needs chemistry. It took a few broadcasts to understand each other’s timing and pace.

My job is to be the dumb guy. That’s not to say I don’t know anything about space and astronomy, but these guys are the experts. I ask questions viewers would like answered and make sure we stay on topic. Think of me as a batting practice pitcher.

I am lucky to once again do a show with substance. Not everyone can say that.

Now It Can Be Told: My Stuff For Slooh

As some of you may know, I’ve been doing some work for slooh.com. Slooh is an astronomy community. Its three telescopes are available to the members. Two of the scopes are in the Canary Islands. One is in Chile. Each is in a superb location to clearly view the nighttime sky.

My job is to produce videos and host webcasts for Slooh.

My job is to produce videos and host webcasts for Slooh. We’ve got one coming up Friday at 6p EDT/3p PDT about Comet 209P/Linear. It’s the object responsible for what could be an amazing meteor shower Friday night.

Slooh has also just announced a partnership with NASA in their Grand Asteroid Challenge. I produced a 2 1/2 minute video for that (below).

If you would have stopped me when I got into broadcasting and told me I’d be able to edit something like this without leaving my home office I’d have thought you nuts! These capabilities are beyond amazing.

I designed this PC specifically for editing It’s equal to the task. I couldn’t be happier.

I’m pretty happy with how the video came out too.

I’m Studying For The Eclipse

The small “D” shaped area where the maximum annular eclipse will be seen is so remote, even for Antarctica, it’s predicted no one will watch it live! No one!

I’m studying up. I’ll be hosting a webcast covering the eclipse late Monday evening on slooh.com.

An eclipse takes place late Monday night, my time. That’s early Tuesday morning back on the East Coast.

Academic. Neither place will see it.

The eclipse takes place Tuesday afternoon in Australia. They get a little touch of this annular eclipse.

Annular eclipses occur when the Moon is relatively close to the Earth. That makes it smaller in the sky than the Sun, allowing a small ring of the Sun to remain visible.

As eclipses go, this one just barely makes it.

Much of Antarctica and Australia will see part of the Sun blocked. Only in a tiny region of Antarctica will see the full annular eclipse. There it happens with the Sun on the horizon for just 49 seconds!

The small “D” shaped area where the maximum annular eclipse will be seen is so remote, even for Antarctica, it’s predicted no one will watch it live! No one!

I’m studying up. I’ll be hosting a webcast covering the eclipse late Monday evening on slooh.com. We should have access to live video from Australia where, in some spots, over half the Sun will be blotted out temporarily.

It’s a good chance to rustle up a little scientific curiosity.

Keeping NASA’s Planetary Discoveries In Perspective

The headlines are breathless and shouted. “NASA’s Kepler Mission Announces a Planet Bonanza, 715 New Worlds.”

Big deal? Maybe it is. Likely it isn’t.

The Kepler mission points an orbiting telescope at a small slice of the sky. Day-after-day it watches the light from the stars in that slice, looking for variations in intensity.

When a planet crosses in front of its star as viewed by an observer, the event is called a transit. Transits by terrestrial planets produce a small change in a star’s brightness of about 1/10,000 (100 parts per million, ppm), lasting for 1 to 16 hours. This change must be periodic if it is caused by a planet. In addition, all transits produced by the same planet must be of the same change in brightness and last the same amount of time, thus providing a highly repeatable signal and robust detection method. – NASA

The planets aren’t actually being seen. That’s why the image at the top of this entry is an artist’s conception, not a photo. Kepler is instead looking for a predictable dimming as planets pass between the stars and Earth.

The rest is speculation! We have no idea what the planets are made of or conditions on their surface.

NASA looks for planets in the ‘habitable zone.’ That doesn’t mean they’re habitable! These objects are incredibly far away. Our data is thin.

NASA readily admits what is doesn’t know, but since that’s not the glamorous part of the release we seldom hear it.

One of these new habitable zone planets, called Kepler-296f, orbits a star half the size and 5 percent as bright as our sun. Kepler-296f is twice the size of Earth, but scientists do not know whether the planet is a gaseous world, with a thick hydrogen-helium envelope, or it is a water world surrounded by a deep ocean.

Even the Earth, the benchmark for habitable planets, is only ‘habitable’ over a small portion of its surface. We can’t live in the ocean, or tall mountaintops, or where it’s too hot or cold, or too dry or wet. We’re picky eaters in the world of habitation!

So, what does the Kepler mission and these discoveries mean to us? From a practical standpoint, little. Maybe nothing!

These planets are too far to ever consider visiting. Our lives won’t change. We’ll learn enough to solidify some theories, no more.

Kepler is an amazing engineering accomplishment. That’s indisputable. It has taken complex planetary theories and made them observable. No small trick. Just don’t expect an exoplanet photo or financial payoff soon… or ever.

Sunsets: California Photography’s Low Hanging Fruit

Shooting sunset photography here is like shooting fish in a barrel! Four out of five days the sky is ablaze with color. With little horizon blockage the results are easily obtained and still spectacular.

My new spot is up Portola Parkway toward the toll road. There’s wilderness on both sides and a nearly uninterrupted path to the setting Sun. Thank you highway planners for leaving a place for me to pull over that’s just right.

Oh — and sunset is in the afternoon. Much easier than the East Coast’s sunrise!

This picture shows office buildings near John Wayne Airport (approximately 8 miles) and the distant mountains on Santa Catalina Island (around 46 miles distant).

All the pictures are clickable for larger version.

Comet Ison Taught Me A Lot

As a meteorologist on TV I was often called on to be a science generalist. From earthquakes to volcanoes to comets, I had to know enough get on the air and provide context. It was a part of the job I relished.

Comets appeared from time-to-time, allowing me to get some shaved ice and dirt and give a quick lesson. There are not many people who get the opportunity to teach science on TV. It was an honor.

What I knew would not have been enough for Comet Ison. This comet was unusual. I learned a lot.

Astronomers first caught sight of Ison in September 2012 when was 585 million miles away. Even at that distance it was bright enough to hint at big things ahead.

Automated spotting programs make comet discoveries easier. Computers look for objects that are moving while the rest of the star field stays relatively in place.

By October a paper delivered to the American Astronomical Society’s 45th Annual Division for Planetary Sciences meeting noted Comet Ison was rotating in such a way that only one side was getting heated by the Sun and it was already spurting water ice into space.

Comet Ison is/was a sungrazer. Sungrazer’s are comets which get close enough to the Sun to be intensely affected by its gravity and heat. We’d never spotted a sungrazer so far out. Probably from the Oort Cloud, this was Ison’s first trip to the rodeo.

Until Ison, all the comets I’d talked about stayed far enough away from the Sun and had ‘visited’ this part of the solar system often enough that they weren’t in peril. This one was headed inside the Roche limit.

The Roche limit, sometimes referred to as the Roche radius, is the distance within which a celestial body, held together only by its own gravity, will disintegrate due to a second celestial body’s tidal forces exceeding the first body’s gravitational self-attraction. – Wikipedia

So, if Ison was a mass of rocks, pebbles and dirt held together by ice and its own internal gravity, the Sun would probably break it apart. That’s what happened. If Ison was an asteroid or some other giant space boulder we’d probably be looking at it still. Whatever does exist today is a small fraction of its former self.

I know this now. I didn’t know this a week ago or when I was talking about much colder comets on TV.

We see comets and their signature tail because heat (usually not very much heat) allows ice to melt which in turn allows gases to vent and dust to be set free. A comet’s tail is blown by the solar wind, a field of energy blasted into space from the Sun. The tail points away from the Sun and has no relation to the direction the comet is actually moving.

If all the ice has melted and the nucleus disintegrated there’s nothing left to view. That seems to be the case. There will be no “Comet of the Century” in the December sky.

We’re very lucky it’s 2013. There are a few satellites, some far from Earth, specifically designed to monitor activity like this. They provided amazing images as Ison whipped its way around the Sun and back toward deep space.

Over the next few months, as astronomers and other specialists look at the tsunami of data produced, we’ll learn more. It’s likely we’ll find Ison’s exact makeup and what caused its demise. I wouldn’t be surprised to see some animations simulating Ison’s final interactions with the Sun.

This comet was a tease. We were told it could be the big one. Obviously, it was not.

It wasn’t a disappointment to me. My knowledge has expanded. I might have been a terrible student as a kid, but grown-up Geoff loves to learn.

Over the last few weeks I’ve heard a lot of those in the know compare comets to cats. The both have tails and they both do what they want to do.

Ciao, Ison.

Billions Of Stars

I just read an article from The Royal Astronomical Society. British. Nearly 200 years old. Well respected.

RAS says, “Astronomers anticipate 100 billion Earth-like planets.” That’s a lot.

It’s also a meaningless number.

Distant space travel is impractical. We’ll never visit a planet beyond our solar system.

I’m sorry. I don’t mean to be a wet blanket but, it’s true.

Humans can only live within a tight range of parameters. We need oxygen and moderate temperatures. We need food. We need to return to Earth! Carrying enough supplies to accomplish that is orders of magnitude beyond any capability we have now.

Time is a problem too. The nearest star, Proxima Centauri, is 4.24 light years away. Our farthest satellite, Voyager 1, is a little over 17 light hours away and it’s been in space since 1977!

To go light years would take centuries!

We know about a few extrasolar planets. Not as much as you think.

We know they’re there, orbiting some distant stars through mathematics. We don’t actually see them. We do see the gravitational effect they exert on their star. These space wobbles are covered nicely by the laws of physics.

But that’s all we’re really seeing–stars wobble. All we know about any planet beyond our solar system is implied from the actions of things we can see.

It’s cool that astronomers can make these projections. Alas, they have no practical application or purpose.

The Paradox Of Distance

The Earth’s orbit is stretched a little bit. You could call it egg shaped and not be far off. On top of that the Sun isn’t in the center of the ‘egg!’

I want to exercise my geekiness a little today. This is a significant day from a scientific standpoint. Earlier this afternoon Earth was at perihelion–its closest distance from the Sun.

Most people think the Earth’s orbit around the Sun is circular. Bzzzzzzzzzz. Wrong.

The Earth’s orbit is actually stretched a bit. Call it egg shaped. You won’t be far off. On top of that the Sun isn’t in the center of the ‘egg!’

This afternoon we were 91,402,500 miles from the Sun. At our farthest point in early July we’ll be 94,509,130 miles distant.

Obviously this has little effect on our temperature. This time of year we’re at our coldest.

The relative difference between summer and winter temperatures doesn’t come from solar distance but rather the elevation of the Sun in the sky. It’s higher in the summer. Its rays cut through less atmosphere to heat the ground. It is more efficient.

Where the Earth’s distance does affect us is the length of the seasons. They’re not equal!

Winter 88.994 days
Spring 92.758 days
Summer 93.651 days
Autumn 89.842 days

Here in the Northern Hemisphere spring and summer are a full week longer than fall and winter. No complaint from me there!

Sometimes when I write really dweeby or nerdy blog entries my wife will read the first few sentences then bail. There’s no chance she’s still reading now!

You’re Nobody If You Don’t Die In The Times

Dr. Sandage was a man of towering passions and many moods, and for years, you weren’t anybody in astronomy if he had not stopped speaking to you.

I read the obituaries in the New York Times nearly every day. Unlike a local paper the Times is geographically agnostic with obits reserved solely for the accomplished. The Times obituaries introduce me to lots of people who weren’t necessarily famous–like Dr. Allan Sandage. He died this past weekend.

Dr. Sandage was an accomplished astronomer who spent the bulk of his adult life trying to ascertain the value of the Hubble constant. This single number allows astronomers to estimate the age of the universe. He was a prolific author with over 500 scholarly papers published under his name.

That’s not why I’m writing this!

What I like best about Allan Sandage is summed up in this one sentence from Times writer Dennis Overbye’s masterfully poignant obituary:

Dr. Sandage was a man of towering passions and many moods, and for years, you weren’t anybody in astronomy if he had not stopped speaking to you.

Wow. I feel sorry he didn’t stick around long enough to read that. He probably would have agreed. It’s a helluva way to be remembered.

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