Fireball Over Mexico City - Space Junk? [Sunset plane and contrail]

[derrick06]

My buddy from the UK sent me this one a few years back and I never thought of putting it on here until recently. He is an amateur astronomer and comes across a lot of videos of abnormal sites in the sky. He believes this to be a video of some space junk falling over Mexico and being illuminated by the sun set. It sure appears to be that especially considering it's slow rate of speed. Any tips from those on here that are well versed in identifying materials burning up in earths atmosphere? What tips do you have for the average person on identifying space junk and/or other abnormal sites. Here is the link to the video from "The Telegraph" a UK news source. What causes the front to be quite reddish? High heat? The quality of the video is thankfully not too bad here.

http://www.telegraph.co.uk/news/new...ufo/8619831/Fiery-UFO-filmed-over-Mexico.html

 

[Mick West]

Judging by the size, position, time of day, and speed, I'd say it's a short sunlit contrail, with the plane also reflecting the set sun from over the horizon, the direct reflection giving a large flare. The shape of the contrail looks like it's from a 747

747 contrails for comparison. Note the distinctive twist.

And here's an example of how even a small area of reflection can give quite a big flare:

747 contrail with a comet in the background!
http://sagansense.tumblr.com/image/46129422515

Imagine this, but with the sun reflecting off the plane into your eyes:



See also:
http://contrailscience.com/short-sunlit-contrails-look-like-ufos/

 

[deirdre]

wow. that's one seriously powerful camera!

 

[Mick West]

wow. that's one seriously powerful camera!

Bit of digital zoom there I think, which does not help.

 

[cosmic]

Any tips from those on here that are well versed in identifying materials burning up in earths atmosphere? What tips do you have for the average person on identifying space junk and/or other abnormal sites.

You can check a current or past event against a list of satellite reentries. With increasing frequency, people are mistaking sunlight reflected off contrails at sunrise/sunset for "space junk" -- but chances are they've never actually witnessed a reentry. Satellites, rocket bodies and the like will commonly fragment in the atmosphere, as in the following clips:

Meridian 5 satellite:



Cygnus cargo module:



JAXA's Hayabusa spacecraft:




Objects from orbit streaking through the atmosphere generally don't leave behind persistent, luminous trails which barely change in appearance for minutes on end. In several recent cases of mistaken identity that's where inexperienced observers have been confused by illuminated contrails (see these threads on recent "sightings" from Oregon and Maine).

While there appear to be growing numbers of reentries per year, the odds of them being visible from populated areas during favorable observing conditions are pretty slim. In 2013, for example, there were 57 reentry events, but only five were actually witnessed from the ground.

Casual skygazers are probably unaware that orbital debris is actively tracked, and reentries are predicted well in advance -- if a visible event is expected, it's usually written about in the press several days ahead of time. You don't just show up with a camera or smartphone and film an object nobody knew was coming.

 

[derrick06]

Cheers for the information everyone! So it appears to be in fact an aircraft's contrails being illuminated and the bright red seems to be reflection of light off of the plane itself then? As Mick stated perhaps it's the zoom that prevents the details expected from the contrails form being visible.

 

[cosmic]

For additional reference:

A couple of new videos captured a daytime meteor over Canada. These clearly illustrate how quickly meteors zip across the sky, traveling at tens of thousands of kilometers per hour.





This fireball was estimated to be 50-100cm.

 

[derrick06]

Wow those are fantastic sights. Definitely a different sight from your average nighttime meteor shower.

 

[cosmic]

Definitely a different sight from your average nighttime meteor shower.

Fireballs like that don't stand out as much during daylight hours but otherwise appear the same.



Meteors on average are typically very small, from grain-of-sand size to small pebbles, generally less than a gram. The ones in these videos are just more substantial.

The main reason I'd posted the daylight footage is to show their appearance is markedly different from aircraft & contrails. As was the case in the articles about the "sighting" from Spain or even the Telegraph story in the opening post, people who confuse aircraft with meteors probably haven't spent much (if any) time observing the latter.

 

[derrick06]

Fireballs like that don't stand out as much during daylight hours but otherwise appear the same.



Meteors on average are typically very small, from grain-of-sand size to small pebbles, generally less than a gram. The ones in these videos are just more substantial.

The main reason I'd posted the daylight footage is to show their appearance is markedly different from aircraft & contrails. As was the case in the articles about the "sighting" from Spain or even the Telegraph story in the opening post, people who confuse aircraft with meteors probably haven't spent much (if any) time observing the latter.

Wow Cosmic that footage was stunning! So that meteor finished disintegrating? Did it explode? Was the green light just caused by the clouds? Definitely an abnormal but beautiful sight to see. Too bad many people are so "cosmophobic" these days haha

 

[Jason]

For additional reference:

A couple of new videos captured a daytime meteor over Canada. These clearly illustrate how quickly meteors zip across the sky, traveling at tens of thousands of kilometers per hour.





This fireball was estimated to be 50-100cm.

OT; Is there a region on planet earth where they are more likely to see bolides? I was just thinking that it seems like the northern hemisphere seems to be more prone to meteors and such.

 

[Mick West]

OT; Is there a region on planet earth where they are more likely to see bolides? I was just thinking that it seems like the northern hemisphere seems to be more prone to meteors and such.

Most of Earth's habitable land and population (around 90%) is in the north. So they are just much more likely to be seen in the north.

 

[WeedWhacker]

Is there a region on planet earth where they are more likely to see bolides?

As mentioned above, the actual sighting of a "bolide" tends to be limited....and even the term still under discussion, as to what it means.

The term "bolide" (still in contention for some people) will occur where the geography...that is, the continents where Humans reside....are most favorable for viewing such events. And of course, given that there might be "line-of-sight" issues, various times of day, etc.

Not to imply that when not seen by Human eyes (to relate the tale later), does not mean it has not occurred.

My several years of "de-bunking" Apollo deniers (for example) have involved investigating their multiple claims that Apollo Moon samples are merely meteorites acquired in Antarctica. Convenient, for those deniers. But, scientifically inaccurate, and easy to refute.

 

[WeedWhacker]

I just wanted to add that the term "space junk" is rather broad. The gist of this thread OP is that which is viewed, from the ground...and whether it is simply an illuminated airplane contrail, or an actual entry of something that is being "burned up" due to atmospheric friction, at VERY high velocities.

These "somethings" can be man-made, or extraterrestrial in origin ("extraterrestrial", but generally not "extra-Solar").

The distinction can seem odd....but also, "Space Junk" (more correctly, Space "Debris") in other terms can refer to the multitude of waste that is in Near-Earth Orbit, after these many decades of various space programs, and can pose threats to man-made space vehicles, if encountered.

These pieces of "Debris" can occasionally de-orbit....but usually pose no threat to the surface, unless especially large in mass....in which case, usually they inspire media attention.

 

[Jason]

Most of Earth's habitable land and population (around 90%) is in the north. So they are just much more likely to be seen in the north.

Astronomers usually look at a band of the sky around the ecliptic -- the imaginary path that the Sun follows along the zodiac constellations.
http://www.mythicalireland.com/astronom ... liptic.gif
http://www.southernstars.com/products/s ... liptic.png
Something like 10º-20º above and below the ecliptic; that still leaves a bit piece of sky that is usually not monitored, but that still captures most of the stuff in the solar system. Must material in the solar system stays reasonably close to the same orbital plane, therefore you'll find more asteroids close to it than farther away.

But that's the statistics. You can still have asteroids that have high-inclination orbits that take it far above the ecliptic, and people won't generally be looking for them because they concentrate their efforts close to the ecliptic. source; astrophysicist but only know him by his screen name Satanclaws

 

[cosmic]

So that meteor finished disintegrating? Did it explode?

It looks like it's disintegrated by the end. Hard to be sure from the video.

Was the green light just caused by the clouds?

Maybe due to composition of the object (or maybe not).

Can fireballs appear in different colors?
Vivid colors are more often reported by fireball observers because the brightness is great enough to fall well within the range of human color vision. These must be treated with some caution, however, because of well-known effects associated with the persistence of vision. Reported colors range across the spectrum, from red to bright blue, and (rarely) violet. The dominant composition of a meteoroid can play an important part in the observed colors of a fireball, with certain elements displaying signature colors when vaporized. For example, sodium produces a bright yellow color, nickel shows as green, and magnesium as blue-white. The velocity of the meteor also plays an important role, since a higher level of kinetic energy will intensify certain colors compared to others. Among fainter objects, it seems to be reported that slow meteors are red or orange, while fast meteors frequently have a blue color, but for fireballs the situation seems more complex than that, but perhaps only because of the curiosities of color vision as mentioned above.

The difficulties of specifying meteor color arise because meteor light is dominated by an emission, rather than a continuous, spectrum. The majority of light from a fireball radiates from a compact cloud of material immediately surrounding the meteoroid or closely trailing it. 95% of this cloud consists of atoms from the surrounding atmosphere; the balance consists of atoms of vaporized elements from the meteoroid itself. These excited particles will emit light at wavelengths characteristic for each element. The most common emission lines observed in the visual portion of the spectrum from ablated material in the fireball head originate from iron (Fe), magnesium (Mg), and sodium (Na). Silicon (Si) may be under-represented due to incomplete dissociation of SiO2 molecules. Manganese (Mn), Chromium (Cr), Copper (Cu) have been observed in fireball spectra, along with rarer elements. The refractory elements Aluminum (Al), Calcium (Ca), and Titanium (Ti) tend to be incompletely vaporized and thus also under-represented in fireball spectra.

Definitely an abnormal but beautiful sight to see. Too bad many people are so "cosmophobic" these days haha

On average, one object that size enters Earth's atmosphere every day, so it's quite normal.

 

[cosmic]

OT; Is there a region on planet earth where they are more likely to see bolides? I was just thinking that it seems like the northern hemisphere seems to be more prone to meteors and such.

The northern hemisphere on average gets a better deal than the southern hemisphere -- but many bolides are stragglers, not associated with any particular shower. I'd imagine the graphic Mick posted still applies.

Major Meteor Showers

For meteor observers, those located in the northern hemisphere have a distinct advantage as shower activity is stronger there than that seen by observers located south of the equator. The reason for this is that most of the major showers have meteors that strike the Earth in areas located far above the equator. As seen from the northern hemisphere these meteors would appear to rain down from high in the sky in all directions. From those situated in the southern hemisphere only a small percentage of this activity is visible. Any activity would appear to travel upwards from radiants located low in the sky.

There are a few meteor showers best seen from the southern hemisphere. These would include any radiant with a declination (celestial latitude) below -20 and those that reach maximum activity during the southern hemisphere's winter months (July-August-September). These showers would include the Alpha Centaurids, Gamma Normids, Pi Puppids, Piscis Austrinids, Delta Aquarids, Alpha Capricornids, Dec Phoenicids, and the Puppid/Velids.

What you quoted in #15 appears to reference sky surveys and missions to catalog asteroids and near earth objects (i.e. objects larger than 140m). That's really not applicable to fireballs/bolides since on average they're the size of a basketball and too small and distant to be detected in advance.

 

[cosmic]

I just wanted to add that the term "space junk" is rather broad.

I've often wondered how much variation exists in casual usage. To me, "space junk" is synonymous with orbital debris attributed to human activities.

 

[WeedWhacker]

I've often wondered how much variation exists in casual usage. To me, "space junk" is synonymous with orbital debris attributed to human activities.

Yes, my interpretation has always been "space junk" as a phrase is attributed to man-made orbital debris, that eventually de-orbits. (OR, that can remain for hundreds of years in orbit.....various orbital planes and inclinations....and thus a hazard to always be considered for all future spacecraft launches).

 

[Jason]

What you quoted in #15 appears to reference sky surveys and missions to catalog asteroids and near earth objects (i.e. objects larger than 140m). That's really not applicable to fireballs/bolides since on average they're the size of a basketball and too small and distant to be detected in advance.

You're right Cosmic, and I didn't put the whole quote in because I lost the page after copying it and was too lazy. But due to the ecliptic where most of the "stuff" in our solar system lie, and our axial tilt we see more asteroids or what have you in the northern hemisphere.

 

[Mick West]

You're right Cosmic, and I didn't put the whole quote in because I lost the page after copying it and was too lazy. But due to the ecliptic where most of the "stuff" in our solar system lie, and our axial tilt we see more asteroids or what have you in the northern hemisphere.

The axial tilt is not really anything to do with it. There are more meteor showers in the north, but that's more coincidence than anything, it's to do with the way the Earth intersects the paths of comets - which can be significantly out of the ecliptic. There are only a few major meteor showers, and there just happen to be more bigger showers in the north right now.
http://ase.tufts.edu/cosmos/view_picture.asp?id=1305

The Earth's orbit intersects a stream of meteoric material left along the orbit of comet Halley, producing two meteor showers, the Eta Aquarids in May and the Orionids in October. Other comets intersect the Earth's orbit just once during their trip around the Sun. Annual meteor showers are created when the Earth enters the intersection point, such as the August Perseids produced by debris from comet Swift Tuttle. The orbit of comet Halley is inclined by 162 degrees with respect to the ecliptic, the plane of the Earth's orbit, while the orbit of comet Swift Tuttle has an inclination of 114 degrees.

But, AFAIK, larger bolides are basically random, and can hit anywhere.

 

[derrick06]

It looks like it's disintegrated by the end. Hard to be sure from the video.



Maybe due to composition of the object (or maybe not).

Can fireballs appear in different colors?
Vivid colors are more often reported by fireball observers because the brightness is great enough to fall well within the range of human color vision. These must be treated with some caution, however, because of well-known effects associated with the persistence of vision. Reported colors range across the spectrum, from red to bright blue, and (rarely) violet. The dominant composition of a meteoroid can play an important part in the observed colors of a fireball, with certain elements displaying signature colors when vaporized. For example, sodium produces a bright yellow color, nickel shows as green, and magnesium as blue-white. The velocity of the meteor also plays an important role, since a higher level of kinetic energy will intensify certain colors compared to others. Among fainter objects, it seems to be reported that slow meteors are red or orange, while fast meteors frequently have a blue color, but for fireballs the situation seems more complex than that, but perhaps only because of the curiosities of color vision as mentioned above.

The difficulties of specifying meteor color arise because meteor light is dominated by an emission, rather than a continuous, spectrum. The majority of light from a fireball radiates from a compact cloud of material immediately surrounding the meteoroid or closely trailing it. 95% of this cloud consists of atoms from the surrounding atmosphere; the balance consists of atoms of vaporized elements from the meteoroid itself. These excited particles will emit light at wavelengths characteristic for each element. The most common emission lines observed in the visual portion of the spectrum from ablated material in the fireball head originate from iron (Fe), magnesium (Mg), and sodium (Na). Silicon (Si) may be under-represented due to incomplete dissociation of SiO2 molecules. Manganese (Mn), Chromium (Cr), Copper (Cu) have been observed in fireball spectra, along with rarer elements. The refractory elements Aluminum (Al), Calcium (Ca), and Titanium (Ti) tend to be incompletely vaporized and thus also under-represented in fireball spectra.

On average, one object that size enters Earth's atmosphere every day, so it's quite normal.

Thank you ^_^ Definitely learned something there!

 

[ricl]

This is the same as the YouTube video from Jul 6, 2011



The most likely explanation is that, as the Sun is setting to the right hand side of the video, what is being observed is nothing more than sun light being reflected off the airplane (centre reddish dot and that the plumes to each side are the (very short) contrails from the engines.