Surprise: Earth Is Hit By a Lot More Asteroids Than You Thought

by Jason Major on April 22, 2014

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“The fact that none of these asteroid impacts shown in the video was detected in advance is proof that the only thing preventing a catastrophe from a ‘city-killer’ sized asteroid is blind luck.”

- Ed Lu, B612 Foundation CEO and former NASA astronaut

When we think of recent large asteroid impacts on Earth, only a handful may come to mind. In particular, one is the forest-flattening 1908 Tunguska explosion over Siberia (which may have been the result of a comet) and another is the February 2013 meteor that exploded over Chelyabinsk, shattering windows with its air blast. Both occurred in Russia, the largest country on Earth, and had human witnesses — in the case of the latter many witnesses thanks to today’s ubiquitous dashboard cameras.

While it’s true that those two observed events took place 105 years apart, there have been many, many more large-scale asteroid impacts around the world that people have not witnessed, if only due to their remote locations… impact events that, if they or ones like them ever occurred above a city or populated area, could result in destruction of property, injuries to people, or worse.

(And I’m only referring to the ones we’ve found out about over the past 13 years.)

A new video released by the B612 Foundation shows a visualization of data collected by a global nuclear weapons test network. It reveals 26 explosive events recorded from 2000 to 2013 that were not the result of nuclear detonations — these were impacts by asteroids, ranging from one to 600 kilotons in energy output.

Update: a list of the 26 aforementioned impacts and their energy outputs is below:

8/25/2000 (1-9 kilotons) North Pacific Ocean
4/23/2001 (1-9 kilotons) North Pacific Ocean
3/9/2002 (1-9 kilotons) North Pacific Ocean
6/6/2002 (20+ kilotons) Mediterranean Sea
11/10/2002 (1-9 kilotons) North Pacific Ocean
9/3/2004 (20+ kilotons) Southern Ocean
10/7/2004 (10-20 kilotons) Indian Ocean
10/26/2005 (1-9 kilotons) South Pacific Ocean
11/9/2005 (1-9 kilotons) New South Wales, Australia
2/6/2006 (1-9 kilotons) South Atlantic Ocean
5/21/2006 (1-9 kilotons) South Atlantic Ocean
8/9/2006 (1-9 kilotons) Indian Ocean
9/2/2006 (1-9 kilotons) Indian Ocean
10/2/2006 (1-9 kilotons) Arabian Sea
12/9/2006 (10-20 kilotons) Egypt
9/22/2007 (1-9 kilotons) Indian Ocean
12/26/2007 (1-9 kilotons) South Pacific Ocean
10/7/2008 (1-9 kilotons) Sudan
10/8/2009 (20+ kilotons) South Sulawesi, Indonesia
9/3/2010 (10-20 kilotons) South Pacific Ocean
12/25/2010 (1-9 kilotons) Tasman Sea
4/22/2012 (1-9 kilotons) California, USA
2/15/2013, (20+ kilotons) Chelyabinsk Oblast, Russia
4/21/2013 (1-9 kilotons) Santiago del Estero, Argentina
4/30/2013 (10-20 kilotons) North Atlantic Ocean
(Source: B612 Foundation)

To include the traditonally macabre comparison, the bomb used to destroy Hiroshima at the end of World War II was about 15 kilotons; the Nagasaki bomb was 20.

Sentinel will orbit the Sun, looking outwards for NEOs that could potentially impact our planet.

Sentinel will orbit the Sun, looking outwards for NEOs that could potentially impact our planet.

This evening former NASA astronauts Ed Lu, Tom Jones, and Apollo 8 astronaut Bill Anders will present this video to the public at a live Q&A event at the Museum of Flight in Seattle, Washington.

CEO and co-founder of the B612 Foundation, Ed Lu is working to increase awareness of asteroids and near-Earth objects with the ultimate goal of building and launching Sentinel, an infrared observatory that will search for and identify as-yet unknown objects with orbits that intersect Earth’s. The event, titled “Saving the Earth by Keeping Big Asteroids Away,” will be held at 6 p.m. PDT. It is free to the public and the visualization above is now available online on the B612 Foundation website. A press event will also be taking place at 11:30 a.m. PDT, and will be streamed live here.

Currently there is no comprehensive dynamic map of our inner solar system showing the positions and trajectories of these asteroids that might threaten Earth. The citizens of Earth are essentially flying around the Solar System with eyes closed. Asteroids have struck Earth before, and they will again – unless we do something about it.

– B612 Foundation

Want to support the Sentinel mission? Donate online here.

Added 4/24: The April 22 press conference at the Museum of Flight can be watched in its entirety below:

Technical note: While B612 and Ed Lu are presenting a new visualization on April 22, the data behind it are not entirely new. Previous surveys on NEA populations have determined within reasonable parameters the number of objects and likelihood of future impacts of varying sizes using data from WISE and ground-based observatories… see a series of slides by Alan Harris of JPL/Caltech here. (ht Amy Mainzer)

Also, if you have questions on the asteroid visualization, there are some FAQs on the B612 site here.

About 

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Spacedad2 April 22, 2014 at 8:53 PM

On July 23, 2001, I was driving a pickup truck in the mountains north of Williamsport, Pennsylvania when there was a loud bang, and it felt like all 4 tires on the truck exploded. It turned out that a meteorite had exploded. Much like the meteorite over Chelyabinsk, Russia last year, it was visible for hundreds of miles. They eventually decided it had exploded about 25 miles from where I heard it. Astronomers calculated it was probably a couple of meters across, and may have weighed 30 tons. I have been hit by the blast wave from an exploding meteorite. The universe keeps throwing rocks at us. The question isn’t IF a city will be destroyed by one, but WHEN. The asteroid retrieval mission that NASA wants to work on isn’t an idle whim. We need as much experience in dealing with asteroids and meteorites as we can get.

PrometheusOnTheLoose April 23, 2014 at 1:32 AM

For those wondering about planet formation . . . there it is.

Considering the accumulation of mass, I’d bet that one of the reasons why the dinosaurs were able to grow so big was due to less downward tug by gravity during their age.

Dalibor Frívaldský April 23, 2014 at 8:59 AM

According to this: http://curious.astro.cornell.edu/question.php?number=470 , some 3.7e7 to 7.8e7 kg of material “fall” on Earth every year. According to wiki, dinosaurs first appeared 2.31e8 years ago. That means, since the appearance of the dinosaurs, the Earth accumulated somewhere between 8.5e15 to 1.8e16 kg of material. According to wiki, the mass of Earth is 5.97e24 kg. So unless there was some really really HUGE impact event between the extinction of the dinosaurs and us, the mass of Earth changed by only 0.000001% – the gravity change would be similar. This does not support your idea for the reason of the dinosaurs being so big.

gopher65 April 23, 2014 at 6:42 PM

Things like insects could grow larger because the atmosphere was 33 to 35% oxygen back then instead of 20% today. (At 35% oxygen green wood catches fire like dry kindling, explaining the excess of forest fires at the time.)

Don’t know if the same holds true for everything else, but maybe it does?

philw1776 April 23, 2014 at 9:49 AM

Watching the video with the ocean impacts, why do asteroids hate whales so much? OK, OK, maybe because the Earth is mostly an ocean planet.

Jeffrey Boerst April 24, 2014 at 1:21 AM

It’s all Cetaceans and for the answer, Douglas Adams, the only human that possessed it is now deceased…. ;)

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