What Does a 97% Eclipse Mean Anyway?

Marshall’s Meteoroid Environment Office’s very own Dr. Bill Cooke, created this graphic showing the idealized view through a telescope with an H-alhpa filter at maximum eclipse for 4 locations: Birmingham, which will experience a 93% eclipse, Atlanta, which will have 97% of the Sun covered, the 97% eclipse in Huntsville, and the 99.6% eclipse in Chattanooga, which shows only the tiniest sliver of Sun down on the bottom.

The Greatest Meteor Show of All Time

By Bill Cooke

At NASA, we get very excited about many astronomical events — to name just a few, the return of Halley’s Comet back in 1985/86; the impact of the fragments of Comet Shoemaker-Levy 9 with Jupiter in 1992; the Leonid meteor storms of 1998, 1999, 2001 and 2002; and, of course, the upcoming total solar eclipse on Aug. 21 of this year.

Some of these events get blown a bit out of proportion. A classic example is that every time Mars comes to opposition (closest approach to Earth), the internet reverberates with the very false statement that Mars will appear as large as the Moon at that time. Nothing could be farther from the truth, as Mars, at its very closest to Earth, appears only 1/70th the apparent diameter of the Moon.

This year we have a new one — reports are circulating that this year’s Perseids will be the “brightest shower in recorded human history,” lighting up the night sky and even having some meteors visible during the day. We wish this were true… but no such thing is going to happen.

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Thursday, Aug. 13, 2015, in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)

For one thing, the Perseids never reach storm levels (thousands of meteors per hour). At best, they outburst from a normal rate between 80-100 meteors per hour to a few hundred per hour. The best Perseid performance of which we are aware occurred back in 1993, when the peak Perseid rate topped 300 meteors per hour. Last year also saw an outburst of just over 200 meteors per hour.

This year, we are expecting enhanced rates of about 150 per hour or so, but the increased number will be cancelled out by the bright Moon, the light of which will wash out the fainter Perseids. A meteor every couple of minutes is good, and certainly worth going outside to look, but it is hardly the “brightest shower in human history.” The Leonid meteor storms of the late 1990’s and early 2000’s were much more spectacular, and had rates 10 times greater than the best Perseid display.

So, if not this year’s Perseid shower, what was the greatest meteor show of all time? I think many meteor researchers would give that award to the 1833 Leonids, which had rates of tens of thousands, perhaps even 100,000, meteors per hour. During a good Perseid shower under ideal conditions, you can see about one meteor per minute. Now imagine yourself being back in 1833, on the night of Nov. 12. Looking outside, you would see something like 20 to 30 meteors PER SECOND. No wonder we read accounts like this one from South Carolina (Chambers, A Handbook of Descriptive and Practical Astronomy, Volume 1, 1889):

“Upwards of 100 lay prostrate on the ground…with their hands raised, imploring God to save the world and them. The scene was truly awful; for never did rain fall much thicker than the meteors fell towards the Earth; east, west, north and south, it was the same.”

Now, THAT’s a meteor shower. The 1833 storm had a profound effect on those that witnessed it; it also gave birth to modern meteor science. Those of us who study meteors dream of such a display happening sometime within our lifetimes.

But it won’t be caused by this year’s Perseids.

Cooke leads NASA’s Meteoroid Environment Office at the agency’s Marshall Space Flight Center.

 

Fireball spotted northwest of Chicago, February 6, 1:25 AM CST

There was a very bright green fireball seen by hundreds of eyewitnesses surrounding Lake Michigan early this morning at 1:25:13 AM Central Time (February 6, 2017). The reports from these individuals and the video information from dash cameras and other cameras in the region indicate that the meteor originated 62 miles above West Bend, Wisconsin and moved northeast at about 38,000 miles per hour. It disrupted about 21 miles above Lake Michigan, approximately 9 miles east of the town of Newton. The explosive force of this disruption was recorded on an infrasound station in Manitoba, some 600 miles away – these data put the lower limit energy of the event at about 10 tons of TNT, which means we are dealing with a meteoroid – orbit indicates an asteroidal fragment – weighing at least 600 pounds and 2 feet in diameter. Doppler weather radar picked up fragments (meteorites) falling into Lake Michigan near the end point of the trajectory.
YouTube Preview Image
Ground track and Doppler radar signature (done by Marc Fries at NASA Johnson Space Center); an animation of the orbit and approach of the meteoroid is being prepared and should be available soon. We will continue to look at data as it comes in and revise the calculations if necessary.

Links to videos of this event:

Lisle, IL Police Department
https://www.youtube.com/watch?v=cF0POBcZQRk

From Highway in Wisconsin:
https://twitter.com/KrazyPhukinFoo/status/828543708299657216
https://www.youtube.com/watch?v=-AozuKJZK_4

Chillicothe IL Police Department:
https://twitter.com/chillipd?ref_src=twsrc%5Etfw

Morton Grove Police Squad
https://twitter.com/NWSChicago/status/828532116300394496

Roof of Atmospheric, Oceanic & Space Sciences Building – University of Wisconsin https://www.youtube.com/watch?v=LHubXCtdEbo

EarthCams:

Looking over Lake Michigan, from Michigan Coast: (looking too north to see the meteor itself) http://www.earthcam.com/usa/michigan/grandhaven/lakemichigan/?cam=lakemichigan
Bright flash at 2:25:13

Five Planets Align in Early Morning Sky

The graphic below illustrates the five planets as they are visible, with the naked eye, from Huntsville, Alabama.  It shows their positions in the sky around 6:30 AM during the week of January 18 and continuing for the next few days. Mercury will be close to the Sun, over in the East, and Jupiter will be over in the West, with Venus, Saturn, and Mars between the two. Pluto is near Mercury, but is invisible to the eye, requiring a telescope for viewing.

The last time an alignment such as this occurred was about 10 years ago. This pre-sunrise configuration will be similar for other northern latitudes.

In the graphic, the yellow line is the ecliptic, which is the plane of the Earth’s orbit. The orbits of the major planets lie close to this plane, which is why they appear close to the ecliptic in the night sky.

Image generated by Bill Cooke using SkySafari Pro software.
Image generated by Bill Cooke using SkySafari Pro software.

Bright Fireball Detected by 6 NASA All Sky Cameras

http://youtu.be/wGE7OQSCkyA[/embedyt]

We have received numerous reports concerning a bright fireball that occurred over Georgia at 5:33:55 PM CST (6:33:55 PM EST). All 6 NASA all sky meteor cameras in the Southeast picked up the meteor at an altitude of 50 miles above the town of Georgia (SE of Atlanta). From its brightness, it is estimated that this piece of an asteroid weighed at least 150 pounds and was over 16 inches in  diameter. It entered the atmosphere at a steep angle and moved almost due south at a speed of 29,000 miles per hour. The NASA cameras tracked it to an altitude of 17 miles above the town of Locust Grove, where it had slowed to a speed of 9000 miles per hour, at which point the meteor ceased producing light by burning up. It is possible that fragments of this object survived to reach the ground as meteorites.

A more detailed analysis will be performed tomorrow and further details will follow if this analysis still indicates the possibility of a meteorite fall.

Ground track, still images from the cameras, and a movie from the NASA camera located in Cartersville, Georgia attached.

image001image002image003image004

Join NASA’s Geminid Meteor Shower Tweet Chat on December 13-14

The Geminid meteor shower peaks on the night of December 13 through the morning of December 14. Geminid rates can get as high as 100 per hour, with many fireballs visible in the night sky. Best viewing is just before dawn.

NASA Tweet Chat: Observe the Geminid Meteor Shower
On the night of December 13, astronomer Bill Cooke from the Meteoroid Environment Office at NASA’s Marshall Space Flight Center will answer questions about the Geminid meteor shower via a live tweet chat. To ask questions, simply use the #askNASA or @NASA_Marshall. Cooke, Rhiannon Blaauw and Danielle Moser will be available to answer questions between the hours of 10 p.m. CST, beginning the evening of December 13, until 2 a.m. December 14 CST.

How to View the Geminid meteor shower
The best opportunity to see the Geminid Meteor shower is during the dark pre-dawn hours of December 14.

For optimal viewing find an open sky – because Geminid meteors come across the sky from many all directions.

Lie on the ground and look straight up into the dark sky. Again, it is important to be far away from artificial lights. Remember, your eyes can take up to thirty minutes to adjust to the darkness, so allow plenty of time for your eyes to adjust

About the Geminids
Geminids are pieces of debris from an object called 3200 Phaethon. Long thought to be an asteroid, Phaethon is now classified as an extinct comet. Basically it is the rocky skeleton of a comet that lost its ice after too many close encounters with the sun. Earth runs into a stream of debris from 3200 Phaethon every year in mid-December, causing meteors to fly from the constellation Gemini. When the Geminids first appeared in the early 19th century, shortly before the U.S. Civil War, the shower was weak and attracted little attention. There was no hint that it would ever become a major display.

Nature's 'light show' is how NASA describes the Geminid meteor shower - a meteor flash is seen here with an aurora borealis shimmer in Norway
Nature’s ‘light show’ is how NASA describes the Geminid meteor shower – a meteor flash is seen here with an aurora borealis shimmer in Norway

Draconid Meteor Shower Peaks October 8

A Draconid disappears behind a tree in this image taken by a Canadian all sky camera (Credit: UWO Meteor Physics Group)..
A Draconid disappears behind a tree in this image taken by a Canadian all sky camera (Credit: UWO Meteor Physics Group)..

The Draconids are an “occasional” shower – they are either in outburst, with a fair number of meteors, or are so few the casual observer would not notice them. Rates this year are expected to be about 10 per hour on the night of October 8 into the early morning of the 9th, most of them faint. The moon phase is favorable for the Draconid peak, so a sharp eyed observer may be able to spot a few during the course of the evening. The faintness of the Draconids is due in part to the fact that they are very slow for meteors, about 40,000 mph. As a consequence, it takes a larger Draconid to produce enough light to be really noticable (the brightness of a meteor is related to both its size and speed), and there are few of those unless the shower is in outburst, which is forecast to happen in 2018.

The next meteor shower is the Orionids on the night of October 21 into the morning of the 22. Rates are predicted to be about 20 per hour, and the gibbous Moon should set by 1 AM, permitting good viewing just before dawn when the rates will be at their highest

NASA Marshall to Host Ustream Event About Perseid Meteor Shower August 12; Experts to Answer Questions Online

Perseid Meteor Shower Banner

Enjoy a summer evening of sky watching as the annual Perseid meteor shower peaks on the night of August 12 through the morning of August 13. Join meteor experts from NASA’s Marshall Space Flight Center for live Ustream commentary during the shower. Perseid meteor rates can get as high as 100 per hour, with many fireballs visible in the night sky

How to View the Perseid meteor shower

The best opportunity to see the Perseid meteor shower is during the dark, pre-dawn hours of August 13. The Perseidss streak across the sky from many directions. For optimal viewing, find an open skyline, where you can view the horizon without obstructions, such as buildings or trees.  Try to view the Perseids as far away from artificial lights as possible. The darker the sky, the better viewing experience you can have. Lie on the ground and look straight up. Remember, your eyes can take up to 30 minutes to adjust to the darkness, so allow plenty of time for your eyes to adjust.

About the Perseids

The Perseids have been observed for at least 2,000 years and are associated with the comet Swift-Tuttle, which orbits the sun once every 133 years. Every August, the Earth passes through a cloud of the comet’s debris. This debris field consists of bits of ice and dust — most over 1,000 years old — and burns up in Earth’s atmosphere to create one of the best meteor showers of the year. The Perseids can be seen all over the sky, but the best viewing opportunities will be across the northern hemisphere. Those with sharp eyes will see that the meteors radiate from the direction of the constellation Perseus.

NASA Ustream: Observe the Perseid Meteor Shower

On Aug. 12, NASA’s Marshall Space Flight Center in Huntsville, Alabama, will host a live Ustream broadcast about the Perseid meteor shower. The event will highlight the science behind the Perseids, as well as NASA research related to meteors and comets. The broadcast will air 9 p.m. CDT Aug. 12, to 1 a.m. CDT Aug. 13 on the following Ustream channel: http://www.ustream.tv/channel/nasa-msfc

Special guests will include meteor experts Dr. Bill Cooke, Danielle Moser and Rhiannon Blaauw, all of NASA’s Micrometeoroid Office, located at Marshall. They will provide on-air commentary, as well as answer questions online, using Marshall social media accounts. Also scheduled to join the broadcast, via telephone, are experts from NASA’s Johnson Space Center, in Houston; NASA’s Goddard Space Flight Center in Greenbelt, Maryland; the American Meteor Society; the SETI Institute in Mountain View, California; and others.

There are two methods to join the online conversation during the broadcast. NASA followers can tweet questions to “@NASA_Marshall” using the hashtag “#askNASA.” Followers may also post questions on the Marshall Facebook account, replying to the 9 p.m. Aug. 12 Perseid “Q&A” post at: https://www.facebook.com/nasamarshallcenter

Bright Sky Event Over Southeastern United States – June 29

Meteor across SEComposite image showing bright event located near Rosman, North Carolina.

There was a bright event seen across several Southeast states last night at 12:29:30 AM CDT (1:29:30 EDT). Based on the data we currently have, this object was not a meteor or fireball. Tracked by 5 NASA cameras in the SE, it is moving at roughly 14,500 miles per hour, which is too slow to be a meteor. As you can see in the video, it has also broken into multiple pieces, which, combined with the slow speed, indicates a possible reentry of space debris. There are over 120 eyewitness accounts on the American Meteor Society website (www.amsmeteors.org)

https://youtu.be/9LgpqyDMu0U[/embedyt]

https://youtu.be/Vmq9k9hOXDs[/embedyt]

Fireball Over Southern Tennessee

At 8:26:38 pm CDT on Tuesday, Sept. 23, a 2 inch piece of an asteroid entered the atmosphere above the town of Lutts in southern Tennessee. Moving almost due west at a speed of 46,300 miles per hour, it traveled some 52 miles before burning up 25 miles above the Tennessee farmland. At its peak, the fireball was about twice as bright as the planet Venus, and was seen by many in north Alabama, Mississippi, and Tennessee.

fireball map