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Sunday, February 17, 2013

Panorama of the Chelyabinsk Fireball Smoke Trail!

Panorama of the Chelyabinsk Fireball as it fell to earth on February 15, 2013. This is the smoke train left behind as the meteoroid, travelling at 40,000 mph, was incinerated by friction from the earth's atmosphere. The great heat, together with the huge differential pressure between the front and back of the meteoroid, caused it to explode about 12-15 miles above the earth. Click for full-size view.
Update [Feb. 17, 2013]
There is now speculation that the meteoroid may have been cometary in nature due to the bright white color of its trail, indicating water vapor rather than smoke arising from seared rock or metal. In addition, the trajectory, a pair of trails close together, spreading out, then comping back together is indicative of an object smoking from two ends of a single projectile, not one that blew apart. If it had blown apart it would not be seen to merge again later.

So, for now this meteoroid is speculated to be an icy, cometary body emitting steam from two ends as it is heated in the earth's atmosphere, spinning as it falls to earth.

/Ira
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Saturday, February 16, 2013

Update on Chelyabinsk, Russia Meteor

The meteor that crashed near Chelyabinsk, Russia on Feb. 15, 2013 was about 50 now 55 feet in diameter when it entered the earth's atmosphere at an angle of 20 degrees to the horizon, moving at a speed of some 40,000 MPH and is estimated to have weighed 10,000 tons and delivered an explosive force of 300 now 500 kilotons of TNT, about 15x 25x the explosive force of the atomic bomb dropped on Nagasaki, ending WWII. It was about 1/3rd the size of mini-asteroid 2012 DA14 that coincidentally swept by the earth that same day at a distance of 17,200 miles. Although the chances of both coming so close to earth on the same day were minuscule, according to NASA the two were unrelated since the Chelyabinsk Meteor came from a completely different direction. Over 1,100 people were injured, mostly by breaking glass from the exploding fireball.

Orbits of asteroid 2012 DA14 and the Chelyabinsk Meteor. The Chelyabinsk Meteor was estimated at 15 feet in diameter (contrary to the caption here), weighing 10,000 tons, entering the earth's atmosphere from the direction of the sun in daylight. NASA has traced it's orbit back originating in the asteroid belt between Mars and Jupiter. Asteroid 2012 DA 14 was some 3x larger in size, comparable to the size of the Space Shuttle, and passed close by earth at a distance of 17,200 miles, between the ring of orbiting geosynchronous satellites and the surface of our planet.

It is not uncommon for stony meteors to explode in flight. The Chelyabinsk Meteor exploded into fragments at a height of about 12-15 miles, according to NASA. You can see and hear the explosion in many of the videos that were posted online.

Chelyabinsk is a large industrial city about 920 miles west of Moscow in the Ural Mountains. It is the location of one of only two plutonium processing plants in Russia whose output is used in making nuclear bombs. Had this meteorite struck during the cold war it could have mistakenly  triggered nuclear armageddon.

Comparison of different size meteors and the damage they can inflict. The Tunguska Event, also in Russia in 1908, destroyed 800 square miles of Siberian Forest. Had it fallen in a populated area it would have been an unparalleled disaster. The 10 kilometer asteroid that fell 65 million years ago in what is now Mexico was a planet killer, wiping out the dinosaurs and some 90% of the species then living.

As of this writing the only sign of the meteoroid on the ground is this 30 foot wide hole a fragment of it made in the ice covering Lake Chebarkul near the town of Chelyabinsk. The temperatures here get below 0 degrees Fahrenheit at night, so the ice is probably over 12 inches thick. So far Russian divers have found nothing in the lake, an unfortunate place for a large chunk to have landed since it will quickly become contaminated with debris from earth.

A thirty-foot hole in Lake Chebarkul marks the landing place of a fragment of the Chelyabinsk Meteorite.


Here is a terminological clarification:

Meteor: A streaking light in the sky, caused by a rock from space burning up as it enters the earth's atmosphere. Also called a "shooting star".
Meteoroid: The rock that burns up in the earth's atmosphere.
Meteorite: What a meteoroid is called when it strikes the earth, leaving pieces of itself behind.
Bolide: A meteor so bright that it can be seen in the daytime.
Fireball: Common name for a bolide.



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Friday, February 15, 2013

OMG!!! Giant Meteorite Strikes Russia! 500 people Reported Injured!!!

On the day of the close passage of asteroid 2012 DA14, a giant meteor was seen creating a fireball above the town of Chelyabinsk, Russia in the Ural mountains 950 miles east of Moscow. Five hundred people were reported inured, mostly by flying glass, so far none seriously, as it exploded in the skies above town and crashed to earth nearby.

This is the third time in a little more than 100 years that Russia has been struck by a gigantic meteorite or comet/asteroid. In 1908 a huge comet, some think asteroid, obliterated a large Siberian forest, the Tunguska Event. In 1947, the largest witnessed fall of a meteorite in modern times occurred in the Sikhote-Alin mountains of eastern Siberia, dropping over 100 tons of meteoritic material, and now this event on Feb. 15, 2013, size as yet unknown. This will be a field day for meteorite hunters and scientists. One cannot help but speculate that this event is connected to the close passage of asteroid 2012 DA14 happening later tonight. It seems too odd to be a coincidence, but lots more work remains to be done.

In the mean time, treat yourselves to this compilation of dashboard videos that show the giant meteor as it passes over Chelyabinsk, Russia.



   A straight-on view as the meteor roars overhead, followed by earth shattering explosions.



Compilation of dashboard videocams.


 Huge explosions in this video!



  Student video near university with huge explosions and glass breaking everywhere.


A photo of the Russian meteor fireball as it crashed to earth in Russia on Feb 15, 2013 in Chelyabinsk, Russia.

The Sikhote-Alin meteorite fell on February 12, 1947, strikingly close in time to the fall of today's meteorite, and not that far away in the Sikhote-Alin Mountains of eastern Siberia. There were not many cameras around then, but the fall was witnessed by a nearby artist, P.J. Medvedev, who painted a picture that was reproduced in a Soviet Union stamp issued 10 years later to commemorate the event. Much was learned about meteorites from that fall, and even more will be learned from today's.

The Sikhote-Alin meteorite fall of February 12, 1947 was commemorated 10 years later on this Soviet stamp. The artist lived nearby and painted this picture as he witnessed the event. 
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Asteroid 2012 DA14 Heading Toward Planet Earth

You've probably been reading about Asteroid 2012 DA14 which is headed for a close encounter with earth this Friday night, February 15th. DA14 is about 150 feet in diameter and will whiz by the earth at a distance of some 17,200 miles, within the ring of geosynchronous satellites that orbit the earth. Yes, this is a close call, but the asteroid will not strike the earth or any satellites in orbit around the earth. So, what will happen as it sails by? Nothing, nothing at all. Call it a close miss. But you will be able to observe this fast moving celestial body from Israel, starting at about 10:00PM local time and lasting through the early hours of Saturday morning.

The chart below shows the expected path of 2012 DA14 through the skies above Israel with time ticks representing Greenwich Mean Time. Add two hours to convert to Israeli local time.  Although it will move quickly compared to most celestial bodies because it is so close to earth, you will still not see it move at the speed of a plane or even satellite. As you can see from the chart, it will take over eight hours to go from the tail of Leo to the NorthStar. So, you will only be able to identify it by its motion if you watch for an extended period of time. You will also need binoculars since at a brightness between magnitude 7 and 8 it will not be a naked eye object.


Asteroid 2012 DA14's path through the skies above Israel. Timing ticks are in Greenwich Mean Time (GMT) so you will have to add two hours to find the asteroid's position in Israeli local time. It will shine between magnitude 7 and 8, so you will need binoculars or a telescope to see it.
If it's cloudy or you don't want the challenge of finding it outside, many observatories around the world will be live-streaming the event.  Israel's own Bareket Observatory is offering a free live webcast of the close approach on February 15 beginning at 10:15 Israeli local time, for a duration of about 3 hours. For more information, visit Baraket Observatory’s website. You’ll be automatically transfered to the live images, during the event.

NASA Television will provide commentary starting at 9:00PM Israeli local time on February 15. The commentary will be streamed live online at http://www.nasa.gov/ntv and http://www.ustream.tv/nasajpl2  

An object this size, thought to have a mass of 130,000 metric tons, would pack an explosive force of about 2.4 megatons of TNT if it struck the earth. The atomic bomb that leveled Hiroshima packed a blast of .02 megatons, so this asteroid could pack a wallop 120x as large as Little Boy. While not a planet killer, like the asteroid that struck the Yucatan Peninsula 65 million years ago and wiped out the dinosaurs, it is still something to be reckoned with. Fortunately, over 70% of the earth is water and there are still significant wilderness areas, so chances are it would strike an unpopulated area. Still it would be difficult to predict its actual strike zone, creating world-wide fear and uncertainty. This is the reason astronomers now scan nightly for Near Earth Objects (NEOs) in attempt to locate them before they strike the earth. The geological record shows that on average an "earth killer" asteroid strikes our planet every 50 million years. The last one was the Yucatan Peninsula strike some 65 million years ago, so we are about 15 million years overdue for extinction, in case you needed something else to worry about.

The last time an object this large struck the earth was the mysterious Tunguska Event of June 30, 1908, when a comet, some think asteroid, struck a remote region of Siberia and laid waste to a vast area of forest. Asteroids about 150 feet in diameter are thought to be about the size of the one that struck Arizona about 50,000 years ago, creating the great Meteor Crater which is 3/4 of a mile wide and 500 feet deep.



The orbit of asteroid 2012 DA14, shown looping within the orbits of the moon and the ring of geosynchronous satellites that orbit the earth. A close call!


Update: February 16, 2013

This video was taken by Francois Colas at Pic du Midi Observatory in France. It is a time lapse of 15 minutes of travel compressed into 16 seconds.





2012 DA14 2013 feb 15th Pic du Midi from Francois Colas on Vimeo.




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Monday, February 11, 2013

New Moon of Adar with Mercury!

I was out again tonight, photographing the new moon of Adar together with Mercury. Mars is somewhere in here below Mercury, but lost in the haze. This time I managed to include the dome of the Weiss Observatory 40-inch telescope. I was right up next to the rim of Machtesh Ramon, a bit scary after dark. I'll try again tomorrow night when the moon will be bigger and brighter.

The new moon of Adar 5773 on February 11, 2013, 6:15PM local time, just 28 hours old!. Mercury is seen to the lower left of the moon, with the dome and slit of the Weiss observatory 40-inch reflector to the right.

Saturday, February 9, 2013

2013 Conjunction of Mercury and Mars

Mars and Mercury were in conjunction (closest together in the sky) on Thursday, February 7. Although I'm not usually an astrophotographer, I went out to capture the event. Since they would only be visible low in the west right after sunset, I decided to go up to the high plateau overlooking Machtesh Ramon to capture the event. It was definitely worth while, because not only did I get to glimpse them in the evening sky, I also got a wonderful view of the Weiss Observatory before sunset and the rarely seen Zodiacal Light after sunset.

Because Mercury and Mars were so close to the horizon immediately after sunset, I was only able to view them with binoculars, where they were hard to see against the bright afterglow of the sun. But once spotted, they were easy to hold.

Mars and Mercury set above the rim of Machtesh Ramon (Ramon Crater) high above the little Negev town of Mitzpe Ramon on February 7th. As you can see, you would need an absolutely clear western horizon to view this conjunction, since the two planets are so low in the sky.
It was a truly beautiful, silent night as the sun set, not very cold and quite still with no wind, and I was perched on the rim of the crater watching the sky darken. As it did I was treated to a rare sight: The Zodiacal Light. I had see it the previous week on a star tour and pointed it out to my guests. The Zodiacal Light is a pyramid of light that can be seen shining up from the horizon almost vertically 30 degress to 40 degrees into the sky, shortly after sunset, usually during January and February. It is the light that billions of tiny particles of interplanetary dust in our solar system back sctter towards us as they reflect the light of the sun. It is the primordial stuff of creation. It's easiest to see in January and February because the Zodiac, or the ecliptic as astronomers call it, the plane of the planets' orbit around the sun, makes a nearly vertical angle with the horizon in those months, raising the Zodiacal Light high into the sky and making it easy to see. You need a really dark and clear sky to see it, which is one reason why I never viewed it until I came to Mitzpe Ramon. Last Thursday night was only the third time in my life I have seen the Zodiacal Light!

The Zodiacal Light, a pyramidal shaped cone of light that rises from the horizon about 40 degrees into the night sky shortly after dark. The light is a reflection of sun light off myriads of tiny particles of interplanetary dust in our solar system, left over from the dawn of creation. The two red glows at the horizon to either side of the Zodiacal Light are distant towns in the Negev in the direction of the Sinai Peninsula.

As long as I was out I decided to try my hand at a little constellation and casual deep-sky photography. My first target was M31, the great spiral galaxy in the constellation Andromeda  This spiral galaxy is our nearest neighboring spiral galaxy at 2.5 million light years away. This is the most distant object you can see with your naked eye, and one of the naked eye treats of my star tours.

M31, the farthest object visible with the naked eye, 2.5 million light years from earth. Here it is seen as a cigar shaped smudge of light with a bright core. In the sky it subtends an angle of 4 degrees, eight full moon diameters, although it requires a telescope to see that much of it. To the naked eye it appears to subtend an angle of about 1/2 degree, or one full moon diameter.
One more photo. The Constellation Orion, one of the most popular constellations in the sky. Bright stars,  the Great Nebula (M42), and it actually looks like a giant hunter. What's not to like!?


The constellation Orion, a magnificent star forming region if the Orion-Cygnus spur of the Milky Way galaxy. Most of the stars are about 1300 light years from earth.

If you're looking for something to do in Mitzpe Ramon, why not try a star tour where you can see these wonders with your own eyes.

And remember...Keep on lookin' up!
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Thursday, February 7, 2013

We're Having a Heat Wave - NOT

That great Jewish song writer, Irving Berlin wrote this:

We're having a heat wave, 
A tropical heat wave, 
The temperature's rising, 
It isn't surprising, 
She certainly can can-can. 

She started a heat wave 
By letting her seat wave 
In such a way that 
The customers say that 
She certainly can can-can. 

Gee, her anatomy 
Makes the mercury 
Jump to ninety-three. 

We're having a heat wave, 
A tropical heat wave, 
The way that she moves 
That thermometer proves 
That she certainly can can-can.




But this does not describe this winter's weather in Mitzpe Ramon. Ever since the first day of Succot, even before we prayed for rain, rain has come pouring down with abundant clouds in the sky. I've had to cancel many a star tour due to cloudy weather. But we might as well share and enjoy one of the benefits of a stormy desert winter, the beautiful clouds that grace the skies around the Machtesh. So, here ya go:

Today's stormy sunset with the sun looking like a globe shining on an alien planet.

Alien planet sunset - actually Mitzpe Ramon, overlooking the Machtesh Ramon,, February 6, 2013.
Mares' Tail clouds of January, preceding stormy weather and rain.

Cumulonimbus clouds at sunset, above Machtesh Ramon.

A break in the clouds, but not the weather, above Machtesh Ramon, looking toward Shein Ramon, Ramon's Tooth ridge.

A clear full moon night in December, as the moon rises above Har Nimrod.

Peculiar clouds above Mitzpeh Ramon.

More Mares' Tail clouds, heralding rain, at sunset.

Fan of light, sunrise over Machtesh Ramon.
If you're looking for something to do in Mitzpe Ramon this winter, nothing beats a star tour, except cloud photography when it's stormy outside.

We're not Having a heat wave...A tropical heat wave...Remember to keep on lookin' up!

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Wednesday, February 6, 2013

The Truly Great Nebula in Orion

One of the most famous nebulae in the sky is the Great Nebula in Orion, also known by its number in Charles Messier's catalog of deep sky objects as M42. This star formation region is in the constellation Orion, also one of the best known and most easily identified constellations in the sky. Orion is prominently placed high in the south early in the February night sky, and is so filled with wonders that I could spend an entire star tour talking just about it.

The constellation of Orion rides high in the south of a mid-winter's night. The bright red star to the upper left is Betelgeuse, an old star nearing the end of its life. At the bottom right shines Rigel, the brightest star in the constellation and a young, hot blue-white star. M42, the Great Nebula in Orion, is the central, reddish object in the sword, hanging from the three stars in Orion's belt.
M42 is a stellar nursery, or star factory as the metaphor is sometimes used. A region of our galaxy where ionized Hydrogen gas and interstellar dust are collapsing to form new stars. All stars are born is such regions, including our own sun, and evenutually evolve into open clusters whose members are flung out of the cluster through interactions with the gravity of the galactic disk. So, we are all related to brother and sister stars that have since gone their own ways, every one of us.

M42 looks pinkish in photographs because the four, newly born stars in its center, called the Trapezium because of their shape, emit utraviolet light that knocks an electron off of the atoms of hydrogen gas, causing these atoms to become positively charged, or ionized. When the electron recombines with the hydrogen atom this characteristic pink glow is emitted. The color of the glow is usually not evident to the naked eye or in any but the largest telescope, since the light is not bright enough to activate our color vision. But in photographs  even short ones as above, the beautiful pink hue is evident. To the naked eye or small telescope the glowing gas cloud just looks a milky white, still a magnificent view.

M42 has long been one of the most photographed and studied regions of the sky. My friend Eddie Lubat, an amateur astrophotographer in New New Jersey, recently took a photograph of the M42 region that is one of the best I have ever seen. It not only captures the beauty and subtle details of M42 itself, but also much of the surrounding area that is often omitted in pictures of the nebula.

M42 region by Edward Lubat. The M42 nebula itself is the large pinkish area in the center right. The four stars of the Trapezium are here too small to be seen individually, but their combined light is the white glow in the center of the nebula. There is a dark lane of interstellar dust separating M42 from nearby M43 to the center left. Then there is an even larger lane of interstellar dust to the left of M43, separating it from the star cluster, far left, whose light illuminates the "Running Man Nebula", the dark feature in the bright reflection nebula to the left center. Photo by Edward Lubat.

The great gas-flowing features in the area are real, caused by the infalling gas that is forming stars, the outflowing gas that is blown away by the stellar winds of the stars that have formed, and by the collisions of this gas with stationary regions of hydrogen, giving rise to bow shocks that look like bubbles. This region is about 1345 light years away and 24 light years across in the Orion-Cygnus arm of the Milky Way galaxy.

This is one of the objects we spend time viewing and studying both naked eye and in the telescopes on my star tours on cold winter evenings. Come on by and have a look!




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Tuesday, February 5, 2013

Mercury and Mars in the February Evening Sky

Observing alert for Mercury and Mars. These two planets will appear within one degree (twice the diameter of a full moon) of each other just after sunset on the Thursday evening of February 7, 2013. You will need a very clear horizon to the south west, and possibly binoculars, to see them both this close to sunset.

Mars will continue to disappear into the sun, but Mercury will continue rising into the evening sky for its first sunset apparition of the new year. Keep an eye out for it as February advances.

Mercury and Mars appear just south of west in the early evening sky on Thursday, February 7. This view is for 5:45PM on the night of February 7, but the two planets will continue to be close to each other for the next couple of days.

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