Massive comet exploding over Chile 12,000 years ago may have created strange glassy rocks
[ad_1]
Be grateful you weren’t in what is now Chile’s Atacama Desert 12,000 years ago.
Today, a 47-mile (75 kilometers) swath of the desert is strewn with strange dark, glassy rocks that have long puzzled scientists. New research finds that those rocks are quite similar to comet particles collected by a NASA mission. The scientists behind the work now think that all those years ago, one or more huge comets exploded together in the skies over the region, causing tornado-force winds, scorching a wet, grassy landscape, and scattering the area with warped and twisted glass that still contains minerals generally found only in meteorites.
“This is the first time we have clear evidence of glasses on Earth that were created by the thermal radiation and winds from a fireball exploding just above the surface,” Pete Schultz, a geologist at Brown University in Rhode Island, said in a statement.
Related: Asteroids and comets pummeling Earth delayed rise of oxygen
“To have such a dramatic effect on such a large area, this was a truly massive explosion,” he said. “Lots of us have seen bolide fireballs streaking across the sky, but those are tiny blips compared to this.”
Schultz and his colleagues wanted to compare the strange Chilean glass, which ranges from dark green to black, with the work of a NASA mission called Stardust, which launched in 1999. Stardust visited a comet called Wild-2 to trap particles of its dust, which the spacecraft delivered to Earth in 2006. The samples were scientists’ first-ever pristine samples of cometary dust from out beyond the orbit of the moon, according to NASA.
For the new research, Schultz and his colleagues collected 300 pieces of the strange glassy rock to analyze from two patches of the region. In addition, the team cut thin, polished slices out of 20 of those samples to study under a microscope. In all of those slices, the researchers found dozens of grains and fragments that didn’t match the region.
Those anomalies included a mineral called troilite, which is typically found in meteorites, and decomposed zircons that suggest the samples reached temperatures hotter than 3,000 degrees Fahrenheit (1,670 degrees Celsius). Other traits the researchers noted aren’t exclusive to meteorites but are quite common in an extraterrestrial context and match what scientists have seen in meteorites or the Wild-2 samples.
“Those minerals are what tell us that this object has all the markings of a comet,” Scott Harris, a planetary geologist at the Fernbank Science Center in Atlanta and a co-author on the new study, said in the same statement. “To have the same mineralogy we saw in the Stardust samples entrained in these glasses is really powerful evidence that what we’re seeing is the result of a cometary airburst.”
In addition, the researchers noted signs of a dramatic past on the glass, which show “sliding, shearing, twisting, rolling, and folding (in some cases, more than twice) before being fully quenched,” the scientists wrote in the paper.
Scientists have considered other scenarios to explain the strange glass over the years. At the time, the region featured oases and grassy wetlands, so some have suggested that vast grass fires could have melted the sandy soil to form the glassy rocks.
“There may be lots of these blast scars out there, but until now we haven’t had enough evidence to make us believe they were truly related to airburst events,” Schultz said. “I think this site provides a template to help refine our impact models and will help to identify similar sites elsewhere.”
Scientists can’t yet precisely date the glassy rocks, although other research on the phenomenon has suggested the strange rocks formed between 12,300 and 11,500 years ago.
Intriguingly, that’s close to the time when the remains of large mammals like horses and ground sloths stop showing up in the fossil record, and around when some scientists think humans started building settlements in northern Chile — although there’s no way to know right now whether any of the three events are connected.
“It’s too soon to say if there was a causal connection or not, but what we can say is that this event did happen around the same time as when we think the megafauna disappeared, which is intriguing,” Schultz said. “There’s also a chance that this was actually witnessed by early inhabitants, who had just arrived in the region. It would have been quite a show.”
The research is described in a paper published Tuesday (Nov. 2) in the journal Geology.
Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.
[ad_2]
Original Post
I have been exploring for a little bit for any high quality articles or blog posts in this sort of space . Exploring in Yahoo I eventually stumbled upon this web site. Studying this info So i¦m happy to convey that I’ve a very good uncanny feeling I discovered just what I needed. I such a lot surely will make certain to do not forget this website and give it a look on a relentless basis.
We’re a bunch of volunteers and starting a brand new scheme in our community. Your site provided us with valuable info to paintings on. You’ve performed an impressive process and our entire group will be grateful to you.
I think other site proprietors should take this website as an model, very clean and wonderful user friendly style and design, as well as the content. You’re an expert in this topic!
I think other site proprietors should take this site as an model, very clean and magnificent user genial style and design, as well as the content. You are an expert in this topic!
You completed a number of fine points there. I did a search on the theme and found a good number of people will go along with with your blog.
Valuable information. Lucky me I found your web site by accident, and I’m shocked why this accident did not happened earlier! I bookmarked it.
Thanks for sharing excellent informations. Your site is very cool. I’m impressed by the details that you’ve on this site. It reveals how nicely you perceive this subject. Bookmarked this web page, will come back for more articles. You, my pal, ROCK! I found simply the information I already searched all over the place and simply could not come across. What an ideal site.
It is truly a nice and helpful piece of info. I am satisfied that you shared this helpful information with us. Please keep us up to date like this. Thanks for sharing.
Magnificent beat ! I wish to apprentice while you amend your website, how could i subscribe for a blog website? The account helped me a acceptable deal. I were a little bit acquainted of this your broadcast offered vivid clear concept
excellent post, very informative. I wonder why the other specialists of this sector do not notice this. You must continue your writing. I am sure, you’ve a huge readers’ base already!
Fantastic goods from you, man. I have understand your stuff previous to and you’re just extremely magnificent. I actually like what you have acquired here, really like what you’re saying and the way in which you say it. You make it entertaining and you still care for to keep it wise. I can not wait to read much more from you. This is really a tremendous website.
I have been absent for some time, but now I remember why I used to love this web site. Thank you, I will try and check back more frequently. How frequently you update your site?
Very nice post. I just stumbled upon your weblog and wanted to say that I’ve really enjoyed browsing your blog posts. In any case I will be subscribing to your rss feed and I hope you write again very soon!
I truly value your piece of work, Great post.
I really like looking through and I believe this website got some genuinely utilitarian stuff on it! .
Very interesting information!Perfect just what I was looking for!
I was looking at some of your content on this site and I think this website is really informative! Keep putting up.
I’m still learning from you, while I’m improving myself. I definitely enjoy reading all that is posted on your website.Keep the stories coming. I liked it!
I’ve been browsing on-line more than three hours these days, but I never found any fascinating article like yours. It¦s beautiful price sufficient for me. In my view, if all web owners and bloggers made good content material as you did, the web will be a lot more helpful than ever before.
I like what you guys are up too. Such clever work and reporting! Carry on the superb works guys I have incorporated you guys to my blogroll. I think it’ll improve the value of my website :).
Thank you for the auspicious writeup. It in fact was a amusement account it. Look advanced to more added agreeable from you! However, how could we communicate?
What¦s Taking place i am new to this, I stumbled upon this I’ve found It absolutely useful and it has helped me out loads. I’m hoping to give a contribution & help other customers like its aided me. Great job.
I am glad to be a visitor of this staring web site! , thanks for this rare info ! .
What i don’t realize is actually how you are not really much more well-liked than you may be right now. You’re very intelligent. You realize thus considerably relating to this subject, made me personally consider it from numerous varied angles. Its like men and women aren’t fascinated unless it is one thing to do with Lady gaga! Your own stuffs outstanding. Always maintain it up!
Does your site have a contact page? I’m having a tough time locating it but, I’d like to send you an email. I’ve got some creative ideas for your blog you might be interested in hearing. Either way, great site and I look forward to seeing it improve over time.
Utterly indited articles, regards for selective information. “In the fight between you and the world, back the world.” by Frank Zappa.
Really fantastic info can be found on web blog.
What Is Exactly ZenCortex? ZenCortex is an optimal hearing function support
I was wondering if you ever thought of changing the structure of your site? Its very well written; I love what youve got to say. But maybe you could a little more in the way of content so people could connect with it better. Youve got an awful lot of text for only having 1 or two pictures. Maybe you could space it out better?
I’m very happy to read this. This is the type of manual that needs to be given and not the accidental misinformation that’s at the other blogs. Appreciate your sharing this best doc.
Nice post. I learn something more challenging on different blogs everyday. It will always be stimulating to read content from other writers and practice a little something from their store. I’d prefer to use some with the content on my blog whether you don’t mind. Natually I’ll give you a link on your web blog. Thanks for sharing.
certainly like your web-site however you need to check the spelling on quite a few of your posts. A number of them are rife with spelling issues and I find it very troublesome to tell the truth however I¦ll certainly come again again.
I used to be more than happy to find this net-site.I wished to thanks to your time for this excellent learn!! I positively enjoying every little little bit of it and I’ve you bookmarked to take a look at new stuff you blog post.