Santa Cruz Good Times

Saturday
Sep 20th
Text size
  • Increase font size
  • Default font size
  • Decrease font size

How to Blow Up an Asteroid Heading Toward Earth

slug_asteroidImagine this: an asteroid is on a collision course with Earth. Not good. Now imagine that we’re able to blow it up, but it re-forms in, say, a few hours. Not good at all.

The latter is what Don Korycansky of the University of California, Santa Cruz, and Catherine Plesko of the Los Alamos National Laboratory in New Mexico discuss in their paper, “Re-aggregation times of potentially hazardous object fragments after a hazard mitigation impulse.”



According to the paper, many of the proposed techniques for changing the orbit of a potentially hazardous object (PHO), if one were to head our way, involve short-duration impulses such as stand-off blasts, surface detonations, and kinetic impacts. However, “such methods have the potential to knock fragments off the parent body… The resulting fragments may continue to threaten ground or orbital assets if they have not been dispersed far enough on diverging trajectories, or collectively deflected away from the original Earth-intercepting trajectory to a sufficient degree,” states the paper.

How long it would take the fragments to re-aggregate depends on the “physical properties of the original object and the impulse applied,” the paper continues. Korycansky and Plesko simulated blowing up asteroids one kilometer across with varying impulses to see how long it takes for the asteroids to put themselves back together. They presented the simulations at the Lunar and Planetary Science Conference in Houston, Texas earlier this month.

The results are a little alarming: when the fragments dispersed at a relatively low speed, it took only hours for the fragments to coalesce into a new rock. In other words, hitting an asteroid with a bomb that’s too small would cause the fragments to fly apart slowly, allowing them to re-clump under their mutual gravity – in two to 18 hours.

Not to fear, though. Other studies have shown that a 900 kiloton nuclear weapon (which is within our capability) is enough to blow up a one kilometer asteroid – and keep it blown up.
Comments (0)Add Comment

Write comment
smaller | bigger

busy
 

Share this on your social networks

Bookmark and Share

Share this

Bookmark and Share

 

Catwalk on the Wild Side

Meet the artists and designers behind this year’s edition of FashionART, SantaCruz’s most outrageous fashion show

 

The New Tech Nexus

Community leaders in science and technology unite to form web-based networking program

 

Watch List

From Google to the government to data brokers, why your privacy is now a thing of the past

 

The Peace Equation

Sunday is the United Nations’ International Day of Peace, a global peace-building day when nations, leaders, governments, communities and individuals are invited to end conflict, cease hostilities, creat 24 hours of non-violence and promote goodwill. Monday is Autumn equinox as the Sun enters Libra (right relations with all of life). The Soul Year now begins. We work in the dark part of the year (Persephone underground) preparing for the new light of winter solstice. Tuesday to Wednesday is the Virgo new moon festival. We know two things about peace. “The absence of war does not signify peace.” And “Peace is an ongoing process.” In its peace-building emphasis, the UNIDP, through education, attempts to create a “culture of peace, understanding and tolerance”. Esoterically we are reminded of the peace equation: “Intentions for goodwill (and acting upon this intention) create right relations with all earth’s kingdoms which create (the ongoing process of) peace on earth.” At noon on Sunday, in all time zones, millions of participating groups will observe a moment of silence for peace on earth. Bells will ring, candles will be lit, and doves released as the New Group of World Servers recite the Great Invocation (humanity’s mantram of direction). To connect with others around the world see www.cultureofpeace.org    Let us join together with the mother (Virgo). Goodwill to all, let peace prevail on earth. The dove is the symbol for the day.
Sign up for Good Times weekly newsletter
Get the latest news, events

RSS Feed Burner

 Subscribe in a reader

Latest Comments

 

Sweet Treats

Local cannabis bakers win award for cookies

 

What fashion trends do you want to see, or not see?

Santa Cruz  |  High School Guidance Counselor

 

Best of Santa Cruz County

The 2013 Santa Cruz County Readers' Poll and Critics’ Picks It’s our biggest issue of the year, and in it, your votes—more than 6,500 of them—determined the winners of The Best of Santa Cruz County Readers’ Poll. New to the long list of local restaurants, shops and other notables that captured your interest: Best Beer Selection, Best Locally Owned Business, Best Customer Service and Best Marijuana Dispensary. In the meantime, many readers were ever so chatty online about potential new categories. Some of the suggestions that stood out: Best Teen Program and Best Web Design/Designer. But what about: Dog Park, Church, Hotel, Local Farm, Therapist (I second that!) or Sports Bar—not to be confused with Bra. Our favorite suggestion: Best Act of Kindness—one reader noted Café Gratitude and the free meals it offered to the Santa Cruz Police Department in the aftermath of recent crimes. Perhaps some of these can be woven into next year’s ballot, so stay tuned. In the meantime, enjoy the following pages and take note of our Critics’ Picks, too, beginning on page 91. A big thanks for voting—and for reading—and an even bigger congratulations to all of the winners. Enjoy.  -Greg Archer, EditorBest of Santa Cruz County Readers’ Poll INDEX

 

Santa Clara Wine Trail

My memories of growing up in England include my mother pouring port after Sunday dinner—and sometimes a glass of sherry before dinner. My family didn’t drink much wine back then, but we certainly made up for it with the port and sherry.