Yearly Archives: 2009

bolides, meteors

Stuff Hits Earth: News at 11

Leave a comment

Fireball Over Sweden

Meteor Fireball in Sweden (Courtesy www.meteoritesusa.com)
Meteor Fireball in Sweden (Courtesy www.meteoritesusa.com, http://nachrichten.t-online.de/c/17/40/62/72/17406272.html, and sydsvenskan.se))

Last night (January 17) a fireball lit up the skies over Malmö, Sweden and was seen by people in Germany and the Netherlands. You can see a security camera view of the event here. It looks pretty spectacular and no doubt anybody who saw it was probably quite surprised and shocked.

Now the object at the heart of this fireball was probably a chunk of rock that broke up and scattered its pieces to the ground as it blasted through our atmosphere. There aren’t (yet) any reports of damage, and I imagine meteorite hunters will be swarming around suspected impact sites to gather evidence.

Stuff coming in from space is a pretty common occurrence on our planet. Most of it is dust-particle-sized or maybe the size of peas, and those pieces tend to burn up high above the surface and leave behind glowing trails. That’s usually what we see during a meteor storm.

Speaking in general terms, larger stuff (rock-sized and a bit larger) creates bolides, like the one that flared over Sweden last night.  Most of the time these just break up and scatter out, leaving behind lots of cool smaller rocks for meteorite hunters to collect.

The largest material is what scientists worry about — those are typically tens of meters across and larger.  That’s not what Swedes and others saw last night. I’m taking about things the size of houses or small mountains can do some real damage to Earth’s surface, including gouging out craters and  slamming into populated areas. In the worst-case scenarios — like impacts of objects at least 1 kilometer across and larger — those actions could disrupt the atmosphere and perturb our global climate.  One of these large impactors could create so much damage that global temperatures could plunge, leading to crop damage and destruction, and societal breakdowns. According to the folks at NASA’s Ames Research Center Impact group (led by astronomer David Morrison), studies have been done that suggest that the minimum mass of an impacting body that would produce global consequences is several tens of billions of tons. An object with that much mass would set off a groundburst explosion with enough energy to equal a million megatons of TNT. The only thing worse than that would be nuclear war (unless we had several hits of that size).

Compared to that, last night’s bolide is a mere “plinker”.

Thanks to Daniel Fischer of Cosmos4U and the Cosmic Mirror for passing along news of the Sweden bolide.

headlines, News, nonsense

Don’t Always Believe Flashy Headlines

4 Comments

Nonsense Writ Small

As a trained science journalist, I know that headline writers don’t have a lot of room to encapsulate a story into a very few words.  Complex stories suffer from this most — particularly science stories. Add to that a headline writer’s propensity to have — um… “fun” with a headline and you get some pretty silly results.  Still, that doesn’t excuse the spate of headlines claiming that life has been found on Mars (when, in fact, it’s METHANE that has been found on Mars), or that scientists are “baffled” by lights in the sky, as in “Scientists left baffled as mysterious columns of coloured light appear in the night skies” (as reported in a tweeted link by my friend Daniel Fischer.  I’ve checked out the stories behind the silly headlines and lo, and behold, there’s NO life found on Mars and scientists HAVE figured out what’s causing some beautiful sky pillars to appear in areas where sunlight is glinting off of atmospheric ice crystals.

The best headlines about the methane on Mars take into account the idea that methane “could” signal the existence of life on Mars, and the accompanying stories bring up the fact that methane is caused by both geological AND living organisms.  But, the worst ones are just breathless and misleading.  Some headlines and stories try to be cute (Mars, the “farty” planet), which is okay if the cuteness isn’t terminal.

The lesson here?  Don’t believe headlines. Read stories in full and don’t believe it when a journalist wimps out and doesn’t do his/her job in a headline or story.  There’s always more than meets the eye in any story (not just the science ones) and you deserve the whole story, not just what somebody thinks sounds or looks “cute” in a headline or story.

Here’s a challenge: go to a number of news sites (CNN, the BEEB, etc.) and read the headlines on science stories (political stories are good for this, too). Then, read the stories and see how much they either support or divert away from the full story.  It’s a good critical thinking exercise.