Tag: NASA

Fireball in the Sky!

The NASA All Sky Fireball Network detected this beauty on May 16, 2013 at 03:11:50 UTC.  Observed by 6 meteor cameras, this fireball penetrated deep into the atmosphere, making it down to an altitude of 36 km (22 miles).

A view of the fireball from Cartersville, Georgia.  (NASA/MEO)

The 350 gram meteoroid responsible for this brilliant display entered the atmosphere at around 22 km/s (49,000 mph) — slow for a meteoroid! — and decelerated to about 10 km/s (22,000 mph) before disintegrating over northwest Georgia.

Map showing the location of 6 cameras in the NASA All Sky Fireball Network.  Color-coded circles indicate the approximate field of view of each camera.  The meteor’s path is shown in white. (NASA/MEO/D. Moser)

Calculations indicate a radiant in the constellation Libra.

Eta Aquarids Caught on Camera

 

Same meteor — same location — two different meteor cameras! The video shows the same meteor (an Eta Aquarid!) from one of our all-sky cameras and from our wide-field camera (~20×15 degree FOV) both located at Marshall Space Flight Center in Huntsville.

 

 

(Credit: All Sky Camera Network)

NASA All Sky Fireball Network Captures Eta Aquarids

A composite image of 13 Eta Aquarid meteors from the NASA All Sky Fireball Network station in Mayhill, New Mexico the morning of May 6, 2013.  Clouds seriously hampered our view of the ETAs this year. Observations reported to the International Meteor Organization indicate an outburst in the early hours of  May 6th UTC.

(Credit: All Sky Camera Network)

Why Wasn't the Russian Meteor Detected Before it Entered the Atmosphere?

This is the question that keeps cropping up, and it deserves an answer. Images are being posted showing the fragments and they look like ordinary chondrites of asteroidal origin. This material is dark, and not very reflective, which makes it difficult to spot out in outer space, especially if the object is bus or house size.

Astronomers measure brightnesses in magnitudes — the larger, more positive the number, the fainter the object is. The Sun is magnitude -27, the planet Venus -4, the star Vega 0, and the faintest star you can see is about +6. The best asteroid survey telescopes have a magnitude limit of about +24, which is about 16 million times fainter than what you can see with the unaided eye.

We can now use the latest orbit determined by Dave Clark (and yes, the meteor came roughly from the East, not from the North as stated in the initial NASA reports) and combine it with the estimated size and reflectivity to figure out when we should have seen the meteoroid in the asteroid survey telescopes. The calculations can be displayed in a graph like this one. Note that, even with very large telescopes, the meteoroid would not have been visible until a mere 2 hours (135,000 km from Earth) before impact — very little time to sound a warning.

Even if we had been looking at the right spot and the right time, there is another problem — the meteoroid would be in the daylit sky, and telescopes cannot see faint objects in the daytime.

Simply put, the meteoroid was too small for the survey telescopes and came at us out of the Sun.

NASA Statement on the Russian Meteor

 According to NASA scientists, the trajectory of the Russian meteor was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object. Information is still being collected about the Russian meteor and analysis is preliminary at this point. In videos of the meteor, it is seen to pass from left to right in front of the rising sun, which means it was traveling from north to south. Asteroid DA14’s trajectory is in the opposite direction, from south to north.

Asteroid 2012 DA14 and the Eta Carinae Nebula

This image shows asteroid 2012 DA14 and the Eta Carinae Nebula, with the white box highlighting the asteroid’s path. The image was taken using a 3″ refractor equipped with a color CCD camera. The telescope is located at the Siding Spring Observatory in Australia and is maintained and owned by iTelescope.net.

Image credit: NASA/MSFC/Aaron Kingery

 

NASA Experts Discuss Russia Meteor in Media Teleconference Today

NASA experts will hold a teleconference for news media at 4 p.m. EST today to discuss a meteor that streaked through the skies over Russia’s Urals region this morning.

Scientists have determined the Russia meteor is not related to asteroid 2012 DA14 that will pass safely pass Earth today at a distance of more than 17,000 miles. Early assessments of the Russia meteor indicate it was about one-third the size of 2012 DA14 and traveling in a different direction.

Panelists for the teleconference are:

— Bill Cooke, lead for the Meteoroid Environments Office at NASA’s Marshall Space Flight Center in Huntsville, Ala.
— Paul Chodas, research scientist in the Near Earth Object Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The teleconference will be carried live online at:

https://www.nasa.gov/newsaudio

For detailed information concerning the Earth flyby of 2012 DA14, visit:

https://www.nasa.gov/topics/solarsystem/features/asteroidflyby.html

The Upcoming Asteroid Flyby — Can I See It?

This is the most common question we are asked, and the answer is “maybe.” It all depends on where you are located and what sort of equipment you have.
 
Closest approach will be around 19:25 UTC on February 15; this will be when the asteroid will be at its brightest. Even at this time, when 2012 DA14 is only about 17,000 miles above Earth’s surface, it will not be visible to the unaided eye due to its small size. Observers in Indonesia (which is favored to see close approach) will need binoculars to catch a glimpse of the asteroid as it moves rapidly through the sky.
 
The rest of us will need to use a telescope. In North America, 2012 DA14 will be no brighter than magnitude 11 when the Sun sets on the 15th. This is over 60 times fainter than the faintest star you can see with your eyes under perfect sky conditions. Also, it will still be moving quickly through the constellations — over 3 degrees (6 Moon diameters) per hour — and this speed, combined with its fading, will make it a challenging target, even for experienced amateurs. Algorithms in many of the software programs used to drive telescopes are not suited for fast movers like this one, and may point the telescope in the wrong locations (A test we conducted using a popular software package showed that it would point the telescope over a degree away from the actual position of DA14, well outside the one half degree field of view of most instruments). So seeing 2012 DA14 before it fades beyond the limit of most amateur telescopes will not be a simple task; it will require some thought and advanced planning. An invaluable tool in planning your observations is the JPL Horizons website (http://ssd.jpl.nasa.gov), which can calculate the precise positions of 2012 DA14 for your location.
 
So can I see 2012 DA 14? The answer is yes — if you have access to a decent telescope, if you take the time to figure out where you need to look in advance, and if your sky is clear. A lot of work, but the reward is a glimpse of a house-size visitor from another part of the Solar System as it whizzes by our planet at a distance closer than many of the communications satellites we depend upon in our daily lives. A rare event, to be sure.
 
Those without telescope access may also get a glimpse. NASA will be streaming the latter part of the asteroid flyby on Ustream at http://www.ustream.tv/channel/nasa-msfc – if the skies are clear in Alabama and the MSFC-based telescope can view DA14, you can use the Internet to get a peek at 2012 DA14 (which will look like a fast moving star) from the comfort of your home.

 

Geminids: How Low Do They Go?

The Marshall Meteoroid Environment office put together the plot below showing the distribution of end heights of Geminids seen with our fireball camera network. 85% of Geminids burn up 40 to 55 miles above Earth’s surface and 15% get below 40 miles altitude.
 
Geminids penetrate deeper into the atmosphere than the Perseids because they are moving slower (78,000 mph for the Geminids compared to 130,000 mph for the Perseids) and are made up of denser material, owing to the fact that the Geminid parent body is rocky asteroid 3200 Phaethon and the Perseid parent is a comet yielding more fragile material.
 

This video shows meteors captured by a wide-field camera at the NASA Marshall Space Flight Center on the night of December 12. There are 141 events; at least 77 of these are Geminids, based on their angular speed and direction of travel. Near the end of the movie, a couple of satellites are visible crossing the field of view.

For those of us sky watching for meteors , this means we have a good chance of viewing a Geminid meteor. Tonight, December 13, into the early morning of December 14 is the peak. Happy meteor watching!

Meteor Over Texas

This morning at 6:43 AM Central Standard Time, eyewitnesses across Texas and adjacent states saw a very bright fireball streaking across the sky, moving roughly east to west. It was also recorded by a NASA meteor camera in Mayhill, New Mexico some five hundred miles to the West, which is very unusual and testifies to the brightness of the event. This was not the re-entry of Kosmos 2251, which was destroyed in a collision with an Iridium satellite in February 2009; it is a meteor, most likely a fragment from the asteroid belt and not associated with the Geminid meteor shower. 

Preliminary results indicate that there are meteorites from this meteor on the ground north of Houston, Texas–analysis is currently underway to refine the impact area. If pieces are recovered, it will be the 13th meteorite fall recorded in the state since 1909, and the first since Ash Creek, which fell in February of 2009.

A video (in Windows Media format) of the fireball as recorded by the NASA camera in New Mexico is attached to this message. The Moon is the bright object at lower center; the fireball is on the horizon at left and is surrounded by a white box when the camera detects it. Up is north, and left is east in the video.