Fireball Over British Columbia and the American Northwest

Reports have been coming in of a slow bright fireball seen over the Canadian province of British Columbia and the states of Washington and Oregon. Most reports put the time of the fireball at ~8 pm local time on the evening of September 12. The fireball traveled from east to west.

Thanks to everyone who has submitted reports to this blog. Please also submit reports to the American Meteor Society’s Fireball page.They are the official archive of fireball sightings and all reports will be made available to the scientific community.

The east to west motion can rule out the re-entry of man-made space junk since 99.9+% of man-made stuff orbits the Earth from west to east. The slow motion (described as much slower than a typical meteor) and the long duration of the fireball suggest that this was due to a very small asteroid (probably no bigger than a basketball) rather than a small piece of cometary dust like most meteors.

It is possible the fireball dropped some meteorites though the lack of any reports of sonic booms suggests that material didn’t survive to reach the lower atmosphere. As close as the fireball may have seen it was much higher than an airplane. If it was similar to most slow bright fireballs, it first became visible at an altitude of 70-100 km and faded out between 20-40 km up.

The some local news stories on the fireball can be found at The Province, CBCNews, Time Colonist, and the Vancouver Sun.

The map below shows the location of sightings reported to this blog. [Map was last updated on Sept 15 at 9:30 am PST]

Sept12_BC_fireball4

Meteor or Not?

Below are a collection of YouTubevideos of meteors and phenomenon that are mistaken for meteors. First some real, albeit very bright, meteors or fireballs.

Australia Fireball

1972 Daylight Fireball

1992 Peekskill Meteorite

Meteor Compilation

The next few videos are related to meteors but involve the re-entry of man-made spacecraft rather than small natural bodies.

Jule Verne Re-Entry

Russian Rocket Re-Entry

Shuttle Break-up

Shuttle Re-Entry

The final video is of an object going up into space rather then coming down. This is of a rocket launch from the USAF Vandenberg AFB in southern California. I have seen a few of these launches from Tucson.  Even though we’re 100s of miles away, launches can be easy to see if the lighting is right.

Rocket Launch

There’s Alot Going On Up There

Except following an exceptional event, this blog usually only gets a comment or two every day. Over the past few days/nights, I’ve been swamped in comments. They all involve stuff being observed in the sky. Some I can’t explain. That doesn’t mean people saw UFOs or anything weird, just that I can’t pinpoint a possible explanation from the given description.

[Note: If you see something cool in the sky and want help in ID’ing it, at a minimum give the time you saw it (doesn’t have to be exact) and your location (city or county is fine). If you could also describe where in the sky it was (high up, to the west, etc) that would be great too.]

Since I started this blog in early September of last year, I’ve received over 150,000 visitors and 1000+ comments. I’d like to thank everyone who visited an left a note.

Since July 23rd, 55 comments have been written. Rather than respond to each comment individually, I’ll try to identify as many things as I can.

Jupiter

First off, lots of people have been startled by a bright star that is visible in the southern sky. The star rises around 8pm in the southwest and is located due south and about 40-50 degrees up around midnight. Some have noted that it is brighter than any other star and doesn’t appear to twinkle like a star. That’s because it isn’t star but the planet Jupiter. Right now Jupiter is about as bright as it gets. It is about ~13 times brighter than the brightest star visible in the sky at the same time. Even though Jupiter just got hit by a comet a few days ago, its brightness is normal and, in fact, it gets this bright for a few months every year.

Midwest Fireball

Both this blog and the American Meteor Society’s Fireball page have received many reports of a bright fireball seen from Kansas to Kentucky at 12:15 am (give or take 10-15 minutes) on the morning of July 26. The fireball appears to have been as bright as the Full Moon and was observed to fragment. So far there have been no reports of any sonic booms associated with it. This fireball was slow and bright enough that it may have been large enough to have produced meteorites that survived to reach the ground.

July26_Midwest_fireball

Reported sightings of the July 26th (12:15am) fireball. Reports from the American Meteor Society and this blog. Map created with Google Earth.

Lots of Other Meteors

Right now we are witnessing the peak of a few minor showers. The best of which are the Southern Delta Aquariids and, to a lesser extent, the Alpha Capricornids. Meteors from these showers are observable for almost the entire night, except for an hour or 2 after sunset. They can be extremely bright and of almost any color though they will usually be blue or green. It is not uncommon for these meteors to leave faint trails that are observable for a few seconds after the meteor. Unlike the giant Midwest fireball talked about above, these meteors are relatively fast and only last for a second or two.

Probable Asteroid or Comet Impact on Jupiter

Amateur astronomers from Australia and Japan may have detected the results of an asteroid or comet impact on Jupiter. This would be only the 2nd recored impact on Jupiter and the first since Comet Shoemaker-Levy 9 just over 15 years ago.

On the night of July 19, Anthony Wesley of Murrumbateman, Australia noticed an unusual dark spot in Jupiter’s South Polar Region. An independent discovery was also made by Toshirou Mishina of Yokohama, Japan. Though dark spots are common on Jupiter, they are rarely this dark and almost never appear in the polar regions.

Professional astronomers from JPL/Caltech used NASA’s Infrared Telescope Facility (IRTF) on Mauna Kea in Hawaii to study the spot. According to a Twitter post made by one of the astronomers, the spot appears to be a legitimate impact feature. “Live” comments on the observations can be read on Leigh Fletcher’s Twitter page.

Wesley has produced a webpage with pictures (which are excellent) and updates. His page can be found here.

Additional pictures and news can be found at Spaceweather.com.

Mason-Dixon Fireball – July 6

There have been reports of a fireball accompanied by sonic booms over PA and MD. The fireball was observed shortly after 1 am on the morning of Monday, July 6. Based on reports sent to this blog, the American Meteor Society and local news outlets, the fireball was seen from OH to CT including reports from PA, MD, NY and NJ.

The map below shows the location of sightings (yellow stars) and sonic booms (red circles). It is obvious that the sonic boom reports are clustered in the area of York and Lancaster, Pennsylvania.

PA_fireball

What was it? Most likely the fireball was the result of a small asteroid (no bigger than a basketball) hitting Earth’s atmosphere at ~10 miles per second. The reports all confirm the telltale signs of a small asteroid ablating and breaking up in the atmosphere (blue green glow, long tail, multiple fragments, delayed sonic booms). There is a good chance that this fireball dropped a number of meteorites and I’m sure meteorite hunters are already in the area.

Additional information can be found at WGAL 8 and The Baltimore Sun.

Also remember to submit reports of this fireball to the American Meteor Society. These reports are a great help for understanding these objects and in the recovery of meteorites.

Meteorite Found?!! – June 23 AZ fireball

Jack Schraeder of Sierra Vista, AZ has reported finding a probable meteorite from June 23rds fireball over southern Arizona. He made his announcement of the find on the meteorite-list user group. A picture can be found at the Rocks From Space site.

According to the Rocks From Space site, the meteorite is a brecciated H chondrite weighing 155.6 grams (5.5 oz). It was found ~45 hours after the fall which corresponds to the evening of Thursday June 25. No info has been released on the location of the find or whether any additional meteorites have been found.

Sounds from the Arizona Fireball

Last Tuesday’s fireball over southern Arizona was accompanied by many reports of sounds. These sounds ranged from bangs and rumbles to a crackling sound. The map below is an updated version of one posted last week. Though the path of the fireball has not changed and is still considered uncertain, many sounds reports have been added.

The majority of sound reports are of the distant thunder, low rumble variety. These sounds were heard 1-3 minutes after the fireball was seen and were strong enough to rattle houses in some cases. Some observers likened it to a sonic boom. In fact, that is exactly what they heard, a series of sonic booms. As the fireball descended through Earth’s atmosphere, its broke into numerous pieces. As these pieces decelerated from supersonic to subsonic speeds, they created a sonic boom. There could easily have been dozens to hundreds of small sonic booms though they probably all merged into one.

It is interesting that the sonic boom reports (circles with a heartbeat symbol on the map below) are mainly located to the north and west of the fireball’s path.  Except for reports from the Sierra Vista area immediately to the east of the path, there are no other reports from the East (Benson, Bisbee, Tombstone, Douglas, Willcox, etc.). It is unknown if this is due to something intrinsic to the fireball or just a population density bias (fewer people living out there, hence fewer eyewitnesses reports).

Tucson_Fireball_sounds

Map of sounds heard from the June 23 fireball. Circles with a "heartbeat" pattern denote delayed sonic booms while purple triangles denote sounds heard at the same time the fireball was seen.

The purple triangles denote a different kind of sound phenomenon. These are sounds heard by the observer while the fireball was visible. Most sounds are created at the fireball and then take time to travel to the observer since the speed of sound is many times slower than the speed of light. Hearing sounds at the same time as seeing the fireball suggests that the sound traveled as fast as light. Well, not quite. The shock wave produced by a fireball is so hot that it radiates across most of the EM spectrum. Sometimes structures near an observer (houses, trees, etc) act as antenna and pick up these waves and vibrate. As a result, a buzzing or crackling sound can be heard at the same time as the fireball is seen.

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