A Change of Perception

Is It Just Me, Or Are Asteroids More Dangerous Than They Used To Be?


I’m certainly much more aware of them. I don’t think they’re any more dangerous than they used to be, because we’re living at the bottom of a pond that’s called the “atmosphere”, and apart from the very biggest ones, they’ll burn up in the atmosphere or explode well before they reach the bottom of the pond.

What’s changed over the last few years has been my perception of the solar system. I used to think of it as consisting of 8 or 9 planets going round the Sun in serene circles. Nothing much ever happened: it was all very orderly and predictable.  In fact, it was pretty boring.

But with the near-simultaneous arrival of asteroid DA14 and the Chelyabinsk fireball on 15 February 2013, and regular reports (and videos) of other fireballs and other asteroids, I came to realise that the solar system was actually teeming with rocks ranging from a few metres in diameter to a few kilometres in diameter. There are millions of them. New ones are being discovered nearly every day. And these are just the ones that come near enough for astronomers to see them.

Because we don’t know where most of them are. There are millions and millions of rocks in orbit around the Sun, and we don’t know where most of them are.

And so, for me at least, the solar system has ceased to seem as orderly and predictable as it used to be. Asteroid DA14’s full designation was 2012 DA14, and the 2012 bit was the year it was found. So it was found less than a year before it came back round and nearly hit the Earth. And the Chelyabinsk asteroid remained completely undiscovered until it exploded over Chelyabinsk.

Asteroids are rocks which have orbits quite near the Sun, similar to the planets. And most of the asteroids are reckoned to lie between Mars and Jupiter in the Asteroid Belt. If they come from much further out, they’re usually called comets. Pluto’s orbit has a radius of about 40 AU ( 1 AU = distance of Earth from Sun), and comets usually come from beyond that distance. And there are reckoned to be trillions of comets in a cloud – the Oort cloud – that extends up to 200,000 AU from the Sun.

These comets have such long periods that we seldom see them. I saw comet Hale-Bopp in 1997. The previous occasion on which it had been seen was over 4,000 years earlier.

So instead of just having 8 or 9 planets orbiting up to 40 AU from the Sun, my solar system now has millions of added asteroids, and trillions of  added comets, and is now 200,000 AU in radius. And we know where less than 0.001% of them are.  It’s a zoo.

Bearing in mind that that the asteroid or comet that wiped out the dinosaurs was about 10 km in diameter, comet Hale-Bopp’s nucleus was about 60 km in diameter. It reached perihelion on 1 April 1997. Yet it was only discovered on 23 July 1995, by a couple of amateur astronomers, when it was between Jupiter and Saturn. So there were less than two years between its discovery and its close approach to the Sun. It didn’t come anywhere near the Earth, but if it had, we’d have had less than 2 years to do anything about it.  So if there is something on track to hit the Earth, that’s the kind of advance warning there’s likely to be. Maybe a lot less.

So, no, I don’t think asteroids are any more dangerous than they used to be. But I’ve come to realise that they’re far more numerous than I used to believe. And the solar system is a far bigger place than I ever used to imagine. And more or less completely unpredictable. It used to look like a very orderly garden, with planets trundling around well-worn circular paths: now it looks like a unpredictable wilderness, changing from month to month, with streams of dust and rocks criss-crossing it in all directions.

And that’s quite a large change of perception.


About Frank Davis

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10 Responses to A Change of Perception

  1. Smoking Lamp says:

    The risk is likely the same as it ever was; however the ‘Department of Fear’ needs to emphasize risks to gain compliance.

  2. mikef317 says:

    Totally off topic. Totally mad. A drug (Chantix) to “cure” sugar addiction.

    Quotes from the link below.

    …researchers…found that drugs used to treat nicotine addiction are also effective in treating sugar addiction in animals.

    …Dr. Selena Bartlett wasn’t studying sugar at all… Bartlett was studying alcohol’s effects on the brain when she stumbled on sugar.

    Initially using sugar as a control, she was shocked to realize that it performed the same mechanism on the brain. “Sugar and alcohol affect the brain in the same way—the brain region that underlies addiction,” she tells me. Both elevate dopamine levels in the same reward pathway, which in turn drives our motivation to keep consuming.

    Shortly after connecting alcohol and sugar’s effect on the brain, a colleague who’d been studying nicotine’s effect on the brain, saw the scans. Much to Bartlett’s surprise, the nicotine brain scans mirrored those of alcohol and sugar as well. “We realized they were all driving changes in the exact same pathway of the brain,” she says. “We were aghast.”

    …[Performing tests on rats], Bartlett used the popular FDA-approved drug Chantix…

    Since nicotine and sugar wear down the same receptors, they both respond to the same drug. The results not only highlight varenicline’s [Chantix’s] ability to curb sugar cravings, but suggest that these drugs could prove a novel new treatment for the obesity epidemic in the future.


    Tobacco, alcohol, and now sugar. Chantix must truly be a wonder drug.

    No mention of the “popular,” “FDA approved” drug’s link to suicide attempts.

  3. waltc says:

    It works by killing your ability to experience pleasure. So whether you get you pleasure from a Marlboro, a cupcake or a shot of J&B, none of them will be able to please you any more. And maybe neither will the high you (supposedly) get from jogging or the onr you more probably get from sex. So nothing eases you and nothing pleases you. You might turn to hard downers for relief or just slit your wrists as the suicide data from Chantix shows.

    • nisakiman says:

      Sounds like a winner, Walt. No wonder Big P is trying to find more outlets for it. And as a bonus, just think of all those antidepressants they’ll be able to sell to the ones who bottled out of topping themselves (or just failed to do the job properly).

      Once you get the ball rolling, it’s a license to print money. Those Pharma boys certainly know their onions when it comes to turning a profit.

  4. garyk30 says:

    ” planets trundling around well-worn circular paths:”

    So it would seem; but, the Sun is not stationary.

    While the Earth orbits the Sun at about 65,000 mph, the Sun is orbiting the Galactic Center at about 500,000 mph.

    For every mile Earth goes along it’s orbit, it goes about 8 miles sideways.

    If Earth’s orbit around the Sun were perpendicular to the Galactic plane,Earth’s path thru space would be a loose spiral around the Sun’s orbit.

    If Earth’s orbit around the Sun were on the same plane as the Galactic Plane, Earth’s orbit would look like a sine wave along the Sun’s orbital route.

    I believe that our orbit is about 60 degrees off of the Galactic Plane.

    We are always moving thru Space unknown in sort of a weird loose spiral along the Sun’s orbital route.

    • Frank Davis says:

      Well, yes, the sun and its planets are indeed trundling along a well-worn path around our galaxy, the Milky Way.

      • garyk30 says:

        And our galaxy is moving outward from the ‘Big Bang’ at about 1.3 million mph.

        If you were sitting in a chair on the Equator:
        Earth’s rotation of 1,000 mph

        Earth moving around Sun at about 67,000 mph

        Sun moving around center of galaxy at 500,000 mph

        Galaxy moving outward at about 1.3 million mph

        ZOOM to somewhere!!!

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