How Random Is Life?

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A little asteroid just whizzed by Earth. Not terribly large. Estimates say 20-60 feet long. 2015 HD-1 is one of billions of rocks randomly orbiting the Sun. Tonight it came really close to us.

With asteroids, astronomers calculate the object’s closest distance from Earth and compare that with our distance from the Moon. 2015 HD-1 was only .17 LD (Lunar distances) from our planet. Roughly 40,000 miles.

Astronomers have only known about this interplanetary speck a few days. An automated sky search run by the University of Arizona found it first. It was magnitude 20.1. Very dim.

Sixty feet long isn’t enough to do the Earth in. A sixty footer would probably break up in the atmosphere. Much of it would burn, but plenty of large rocky fragments would fall to earth. And there’d be a destructive sonic boom.

When an asteroid exploded over Siberia a few years it was flying glass from the sonic boom that injured nearly 1,500.

We didn’t know it existed until Saturday. How random is life?

I Love You NASA, But…

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I was just reading a release on the progress of NASA’s New Horizons mission. It was sent toward Pluto back when Pluto was still a planet. It gets there this summer.

New Horizons is still over 100 million miles out, but closing fast. Low-res images of two of Pluto’s four moons are coming in. It’s an amazing achievement.

But why?

Actually, I know why. Space technology creates many well paying jobs. It’s a political landmine to cut.

Unfortunately, there is almost no practical payoff to space. All the good discoveries happened decades ago. I’ve been hearing about pharmaceuticals and metallurgy in space for the last forty years! Don’t hold your breath.

i19_025588I don’t know what they do on the International Space Station on a daily basis, but it’s the modern version of a ham radio operator’s basement from the sixties. And, it’s expensive.

What we need is to better explore Earth. We need to understand and leverage the natural power around us. There is untapped energy in tides and ocean currents. There is great heat at the center of the Earth.

The same types of skills NASA employs for space are needed for Earth! Only the mission need be changed.

Could harnessing heat from the Earth’s core be any more difficult that sending a mission to Pluto?

This is a pipe dream. I don’t see it happening. I wish it would.

There are so many bright and wonderfully talented people at NASA. Their accomplishments are way beyond mind boggling. They’re just solving the wrong problems.

I’m Studying Up On Mars

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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.

Comet-Siding-Spring-Trajectory-Mars-br2Siding 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.

Keeping NASA’s Planetary Discoveries In Perspective

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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.

Rain Coming And Folks Are Excited

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“It will be good for the state.” Those were Helaine’s words a few minutes ago. We were talking about the threat of rain in SoCal. We’ve had hardly any since last year’s rainy season–also a dud.

The image above is a screengrab from the afternoon GFS, using BUFKIT. If you want to know what kind of person I am, I find it fascinating. I like charts, graphs and numbers. They like me back!

I’m not going to be a whiner. Drought sounds and is bad. However, our infrastructure was designed knowing we get droughts. It needs much less than normal rain to work properly. No one is being forced to conserve.

We will finally end the fire season. That will be a relief to many. California has a tendency to burn.

Our first rain comes Wednesday evening. A cold front off a low hitting the California Coast near the Oregon border is the trigger. Not a lot. The GFS says around a quarter inch.

Meteorologists are lucky here. I’ve read and seen all sorts of quantitative precipitation forecasts (QPF). It’s our least accurate prediction. They’ll all be wrong, but unlike snow, no one will check up on them.

The rain (and snow) should be significantly heavier farther north, including the Sierra Mountains. They are our sponge! Snowfall in the mountains is slowly released through early summer. Much of what would run to the ocean now flows toward the Southland.

Water from the Sierras is California’s lifeline. It’s how we house people and grow crops in the desert! Like so many other spots in America, we have overcome nature to tame a place not naturally suited for any of what now happens on it.

The second wave of rain arrives Friday morning. The GFS shows three inch range, much more than this area can easily perc. Flooded intersections and slow traffic will follow. Thunderstorms, less frequent here than back east, are possible with heavy embedded downpours.

NEXRAD is pretty bad here. Too much topography. There are lots of holes using individual radars. This is one place where composites help.

During these storms our temperature will stay in the 60s.

Friday’s deluge will taper to showers then some scattered drizzle under cloudy skies through Sunday. People here are looking forward to this brief change. I will miss my friend, the blue sky.

Comet Ison Taught Me A Lot

743538main_image001_0As 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.