Asteroids & Comets

Rampaging Herds Of Fat Space Cows Built The Planets*

August 17, 2009

Antiope

Our understanding about how the planets in the Solar System evolved has just taken a huge leap forward with a new paper published in the journal, Icarus.

According to current theories, the dusty proto-planetary disk surrounding the sun during Solar System evolution spawned the accretion of small rocky bodies that gradually clumped together to form larger and larger asteroids. These asteroids then gradually swept up debris from the disk, eventually forming planetary bodies.

But there's a problem, the accreting asteroids would have dropped out of solar orbit due to drag caused by the dust and gas in the sun's accretion disk. So how did the material that makes up the asteroids and planets in our Solar System avoid being eaten by the sun?

*DISCLAIMER: The title has little to do with the research mentioned in this article and it certainly does not reflect the views of the scientists involved in this fascinating research. Linking cows with asteroids is a product of the authors questionable imagination only. The reason behind the obscure title will be revealed soon...

Continue reading >

Mining Asteroids And Getting Rich (Or Not)

June 29, 2009

Atlas

This special Space Disco Guest Article, is written by friend and co-author Greg Fish. Greg and I are currently putting the finishing touches to a book called Astroeconomics: Making Money from the Vacuum of Space, where we investigate the various opportunities space exploration presents to the world. In this post, Greg dips into one of the topics from Astroeconomics and discusses the pros and cons of asteroid mining (and discovers there are actually more 'cons' than we originally thought).

Continue reading >

Asteroid Tsunamis, Kepler's 1st Photo, Mission to Ceres (Video)

April 20, 2009

Saddle up for this week's Discovery Space Wrap Up, ladies and gents: Asteroid tsunamis aren't as bad as we thought, Kepler planet-hunting telescope sees first light, Scientists want to land on Ceres in the Asteroid Belt, and Colbert gets "treaded" by NASA:

Continue reading >

Comet Lulin, Kepler Spacecraft, Milky Way 'Ripples' (Video)

February 23, 2009

The latest video from yours truly:

Note: Thankfully, YouTube has a wonderful annotations editor -- which lets me add in nifty facts and correct my word fumbling that I don't notice until after shooting a decent 3-5 minute take.

Continue reading >

Comet Lulin, as Superman Would See It

February 20, 2009

Comet Lulin near the Earth? Check.

X-ray, ultraviolet and optical vision? Check.

Superman-like photo? Check:

Comet-lulin-x-ray-uv

This middle of this gorgeous shot was snapped by NASA's Fermi Swift telescope. The starry background, taken by the the Digital Sky Survey, was merged into it to create this final product.

Red reveals the portion of the comet in X-ray, while purple/blue shows it off in ultraviolet and visible wavelengths.

Lulin certainly looks cool, perhaps even by Superman's standards, but what does this pic tell us?

Continue reading >

Cosmic Collisions

January 24, 2009

Cosmic collisions. If those two words don't send your neurons into a tizzy, I question whether you are human.

Asteroid-impact-earth You should imagine asteroids smacking into the Earth, fire and destruction, and all of that other Armageddon goodness we humans are oh-so-fascinated with. Which is why the Discovery Channel decided to bring you a great three-part special called, well, "Cosmic Collisions."

Click here for the schedule which you can ask to send you an e-mail reminder. Cool right? Very useful for forgetful types (e.g. myself).

As of this posting, the first episode called "Galaxies" is set to air Wednesday, Jan. 28 at 10:00 p.m. ET.

And for the behind-the-scenes scoop on what the show covers, visit the Wide Angle I put together.

You can test your know-how by taking this quiz, browse real and imagined outer space smashups in a slide show, find out what comets have to do with life on Earth, discover the difference between asteroids and meteorites, and investigate what will happen to life on Earth after Andromeda whacks our host galaxy in a few billion years.

By the way: the show's timing couldn't be better! Ever heard of how a Mars-sized object gave Earth the kiss of death about 4.5 billion years ago, resulting in the created of the moon?

Well, get a load of this new story -- we now know the moon cooled from an "ocean of magma" into the solid body we look up at today about 100 million years after obliterating early Earth. That's more than twice as good as the estimate we had before, thanks to a little zircon crystal in a moon rock (which you can bet is more valuable than those impostor diamond rings).

Anyhow, feel free comment about the show below. And for reading all the way to the end of this post enjoy this special treat. It's a little something we cooked up but haven't officially put up on Discovery Space!

Photo: Don Davis, NASA

Boulder-Sized Asteroid Headed Our Way...

October 06, 2008

...and fortunately, it won't make it to the ground!

This just in from the Harvard-Smithsonian Center for Astrophysics (emphasis added):

A tiny asteroid discovered just hours ago at an Arizona observatory will
enter Earth's atmosphere harmlessly at approximately 10:46 p.m. Eastern time
tonight (2:46 a.m. Greenwich Mean Time). There is no danger to people or
property since the asteroid will not reach the ground. It is between 3 and
15 feet (1-5 m) in diameter
.

...

"A typical meteor comes from an object the size of a grain of sand,"
explained Gareth Williams of the Minor Planet Center. "This meteor will be a
real humdinger in comparison!"

Jules_verne_reentryA humdinger indeed, but remember last week? That's when the European Space Agency's 32-foot-long unamnned spaceship called Jules Verne blew to bits last week.

I'm guessing our doomed space rock will give us a show about 25 percent as awesome a show as the Jules Verne reentry, but that's my unscientific guess. Check out the video:

Ok, now the important question: Where?!

More from the release (emphasis added):

The meteor is expected to be visible from eastern Africa as an extremely
bright fireball traveling rapidly across the sky from northeast to
southwest. The object is expected to enter the atmosphere over northern
Sudan
at a shallow angle.

"We're eager for observations from astronomers near the asteroid's approach
path. We really hope that someone will manage to photograph it," said
Williams.

So all you northern Sudanese readers checking this blog post out, get off your butts in about 5 hours and have your cameras ready.

If you're curious what might happen if an asteroid (way) larger than a 3-to-15-foot boulder visited Earth, look no further.

And speaking of hug asteroids headed toward our dinky little planet, click here.

Photo: ESA

Anatomy of an Asteroid Impact

September 22, 2008

It's 1998, and Earth is in between a 6-mile-wide space rock and a hard place.

Thankfully, Harry Stamper (Bruce Willis) and his roughneck gang of drillers have volunteered to hitch rides on two space shuttles to save your sorry behind from approaching doom.

If you have good taste in painfully bad movies, you know we're on set of the sci-fi action movie Armageddon. For the rest of this post to work, however, we need to negate the happy ending where Willis' character saves humanity by staying on the asteroid to manually detonate a nuclear warhead. (Hey, the movie came out a decade ago -- so you can take your spoiler alert and shove it where the sun don't shine!)

Impact_calculator Actually, let's just forget about the entire movie.

As Phil Plait has famously pointed out, it's a complete load of junk. But now that you're thinking asteroid + Earth = bad, check out Chris Lintott's latest post.

Found at Down2Earth.eu, a site run by Cardiff University's Ed Gomez, the asteroid impact calculator is quite possibly one of the coolest things I've ever seen. Making it cool, of course, is that it's based on real science -- that of Robert Marcus, H. Jay Melosh and Gareth Collins.

Here's a scientifically accurate (and horribly frightening) scenario I constructed for you using the tool:

It's late summer afternoon on a Saturday, and it's time to relax.

You're 75 miles out on New York's Long Island -- Southampton, to be precise -- having a fine time drinking fancy-schmancy cocktails and chowing down some barbecued food with friends at some lush estate. Feeling a wee bit tipsy and seeking to catch some rays, you recline into a chair.

View Larger Map

All of the sudden, you happen to catch a glimpse of a 4-mile-wide fireball screaming across the sky at 84,000 miles per hour (that's five times faster than a space shuttle at top speed). It's headed directly for New York City.

Moments later, a sonic boom about as loud as a wood chipper rattles windows and further freaks out of your guests.

Moments after that, the brightest light you've ever seen ignites on the western horizon for roughly nine seconds, giving you an instant sunburn. Some of your party goers gazed directly at it too long, and are now permanently blinded. As people scream and shout for about ten seconds after that, the ground shakes with a 6 to 7 magnitude earthquake.

Ok, you're still alive and the house is still standing as everyone around you cries bloody murder. But you, you're smart... You know the worst isn't over.

You try and tell everyone to get away from the house and trees -- or anything that's tall -- and plug their ears. Because in about five to six minutes, the airborne shockwave is going to arrive.

When it does, the windows blast into smithereens, about 1/3 of the trees fall over, and others lose a shocking amount of leaves and branches. Your reclining lawnchair can be found a few dozen feet away.

---

Sooner or later, the reports come in from places that are alive to report anything at all.

Scientists say an asteroid 1,300 feet wide -- about as big as the Empire State Building is tall -- slammed into the East River, turning most of New York City into a crater about 5.5 miles wide.

The hole in the ground is 1/3 of a mile deep, and anything within a couple miles of the impact zone was vaporized into soot, or buried under a mound of debris 10 feet thick.

Asteroid_crater_depth_2

Parts of the Bronx, Queens and Brooklyn closest to the site are utterly destroyed -- and so is Newark, New Jersey. Trees lit on fire and buildings were reduced to rubble, and there are no survivors.

In areas a few miles farther away, most of the buildings are collapsed or badly damaged. Grass and newspapers were set afire, and nearly all the trees blown down or stripped bare of leaves.

Swimmers at Long Beach, just 17 miles away, are covered in third-degree burns.

My point is not to be a doom-and-gloom guy here; it is to show real science applied in a cool and informative way. According to this nifty tool, the above is a realistic portrait of what could happen. And about every 128,000 years.

Asteroid_impact_calculator_2At right, is what my scenario looked like in the tool. I picked a porous rock, but you have some other options.

If we change the density to that of a 400-meter hunk of iron:

  • the fireball is nearly 7.5 miles wide
  • the crater is 11 miles wide
  • you could double your distance away and still encounter my Southampton scenario (everything about ~100 miles away is rubble)
  • happens every 465,000 years

If we change it to a 400-meter chunk of ice:

  • the fireball is 3.5 miles wide
  • the crater is 3.5 miles wide
  • you could be 15-20 miles closer before encountering my Southampton scenario
  • happens every 94,000 years

Perhaps surprising is that in all cases, the crater depth is about the same -- whodathunk it!

I'd love to supply you with all sorts of facts and figures about real-world examples, but it's way funner to play with this tool. That being said...

Go ahead construct your own disaster scenario we might be able to avoid if we provide more funding to pay attention to the sky... (That's a big *nudge nudge, wink wink* to lawmakers.)

Photos: Down2Earth.eu/LCOGT.net/Ed Gomez



about

Dr Ian O'Neill produces Discovery Space for the Discovery Channel. He is a solar physicist, but loves to write about manned space exploration and exposing the myths behind bad science. He can also be found ranting about space on Astroengine.com.

Dr Ian O'Neill
social
Follow Me!
Follow me on Twitter! Discovery Space on Facebook My FriendFeed Space Disco RSS Feed







Advertisement



SITE SEARCH
SUBSCRIBE TO OUR NEWSLETTERS
CREDITS DCL |
DISCOVERY SITES Discovery Channel / TLC / Animal Planet / Discovery Health / Science Channel / Planet Green / Discovery Kids / Military Channel /
Investigation Discovery / HD Theater / Turbo / FitTV / HowStuffWorks / TreeHugger / Petfinder / PetVideo / Discovery Education
VIDEO Discovery Channel Video Player
SHOP Toys / Games / Telescopes / DVD Sets / Planet Earth DVD Sets / Gift Ideas
CUSTOMER SERVICE Viewer Relations / Free Newsletters / RSS / Sitemap
CORPORATE Discovery Communications, Inc / Advertising / Careers @ Discovery / Privacy Policy / Visitor Agreement
ATTENTION! We recently updated our privacy policy. The changes are effective as of Tuesday, October 30, 2007. To see the new policy, click here. Questions? See the policy for the contact information.