The Sky Is Falling

Yes… The sky is falling… Literally.

Anyone who spends a good amount of time observing the night sky is well aware of how common meteors are. On any given night you will see five to ten meteors an hour is you observe carefully from a dark site. This rate goes up dramatically during a meteor shower. Most of the meteors you will see are quite small, ranging from dust grains to smallish sand sized bits. Anything large can be quite spectacular. Something the size of a pebble will create a bright meteor, a bright fireball that streaks across the sky.

Bolide Events from 1994 to 2013
The graphic shows atmospheric impact events from 1994 to 2013, credit NASA’s Near Earth Object (NEO) Program
I have personally witnessed many bright fireballs, it is just a function of how much time you spend outside at night. Meteors that are bright enough to light up the landscape, that leave glowing trains of vapor behind, clouds that last for many minutes, that twist and drift in the high atmospheric winds.

Estimates vary widely, but something like 50,000 tons of meteoric material rains down on the Earth every year. The process that allowed our planet to form continues to this day.

Occasionally a larger object enters the atmosphere. Something big enough to reach the ground intact. Or even something big enough to cause damage from the impact. How often this occurs would be a surprise to most of our fellow citizens who pay little attention to the the natural world around them.

The Chelyabinsk event got the world’s attention. A medium sized object exploded in the atmosphere directly over a mid-sized city causing modest damage. Due to the prevalence of camera gear in modern Russia we were treated to an unprecedented view of this event. With historical events like Tunguska, all we have is eyewitness accounts and a few grainy black and white photographs of the damage taken years after the impact. Now we get dozens of videos of the event that detail how it occurred from dozens of viewpoints.

While this event is unusual, it was not unprecedented, objects of this size will continue to impact our planet. Meanwhile the event fades from public awareness, at least until it happens again… Which it will.

To drive home this point researchers at NASA’s Near Earth Object (NEO) Program have released a map of impacts over the last few years. Using atmospheric sensors that detect the pressure wave of the airburst they were able to locate and estimate the size of the larger events. For further details you can read the press release.

The Chelyabinsk meteor can be seen as a large dot over southern Russia. That event may be the largest dot on the map, but it is not alone. It is the number of other dots that may surprise some people. Our planet is impacted regularly.

Mikaelyan Meteor
A meteor breaking up over Groningen, Netherlands, 18:57, 13 Oct 2009, photo by Robert Mikaelyan, used with permission

Meteor Fireballs

Thanks to all of those folks who posted comments about meteor fireballs. As I mentioned, these sort of events are not all that uncommon, and occur regularly across the globe. What is unusual is good photos of the event. This did happen this week, a photographer had a good camera at the ready when a similar fireball came in over Groningen, Netherlands on October 13th. Great photos of an event much like the one we saw last week over Hualālai. Check out his page for the full set of photos including the final breakup, the website is in Dutch, but a Google translation will let you follow the description.

Mikaelyan Meteor
A meteor breaking up over Groningen, Netherlands, 18:57, 13 Oct 2009, photo by AndrewPosted on Categories Meteor ShowersTags , Leave a comment on Meteor Fireballs

Fireball Over Hualālai Update

Looks like several folks saw this meteor come in, including the entire evening crowd at the VIS. Another report from Kali on Maui emphasizes just how bright it was.

Larry O’Brian reports from the VIS…

The highlight of the evening was unquestionably a spectacular fireball that burned brilliant green, slow- moving, threw off at least one fragment, the whole enchilada. No sound, other than thirty people shouting ‘wow!’ I first caught it around, say, Aquila heading towards Ophiuchus, but people were already calling out about it.

Between Larry’s excellent report and my own sighting I can place this meteor coming in steeply somewhere over or just south of Hualālai. From around the summit to out to sea beyond Kealakekua, much closer than I would have thought. Given the breakup and low altitude the proximity implies there could have been pieces reaching the ground. Anyone in South Kona report something hitting their roof?

Any readers want to join me search an entire 9,000ft volcano for meteor fragments? Spotting dark fusion crusted meteors on top of fresh black a’a basalt ought to be easy… Not!!!

Fireball Over Hualalai

Nice meteor fireball just a few minutes ago. Just as Deb and I were driving down Waikoloa Road, about 8:06pm, due south over Hualalai. It lit up the landscape a bit, very bright, with fragments flying off as it came in.

Given the time, mid-evening with dinner events and Iron-Man festivities underway, I suspect more than a few people along the coast noticed this one.