Ultimate space simulation software

 
User avatar
midtskogen
World Builder
World Builder
Posts: 1098
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Show off your work

09 Nov 2020 08:52

Not more widespread, but we have cameras everywhere, so whatever is visible is often captured on video.  Fireballs like on the NJ video happen many times every day somewhere on Earth.

The fireball in Sweden is very exciting.  The current solution points to an object falling steeply (~70° slope) entering at about 17 km/s, penetrating deeply into the atmosphere.  Still bright when it when under the horizon at 0.7° altitude more than 400 km away, at which point it was 17 km above ground.  How low the luminous path really was can't be said, but for comparison Chelyabinsk was observed down to 13 km.

The meteor generated a powerful infrasound event which was clearly recorded in Norway 21 minutes later.  Any seismic stations near the fall might also have recorded the blast as a seismic event.  That remains to be investigated.
NIL DIFFICILE VOLENTI
 
A-L-E-X
Star Engineer
Star Engineer
Posts: 2305
Joined: 06 Mar 2017

Show off your work

09 Nov 2020 08:55

Thanks, Mid!  Would the one you captured also be classified as a "low flying meteoroid"?

Did you see or hear anything of it yourself?  I have heard that although humans can't clearly hear infrasound that it can affect human emotions  (like a feeling of dread that sometimes happen during thunderstorms or in the presence of strong electromagnetic fields that generate infrasound)?
 
User avatar
midtskogen
World Builder
World Builder
Posts: 1098
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Show off your work

09 Nov 2020 12:07

A-L-E-X wrote:
Source of the post Would the one you captured also be classified as a "low flying meteoroid"?

I'd rather call it a survivor. :)
A-L-E-X wrote:
Source of the post Did you see or hear anything of it yourself?

No, I live on the wrong hill side, but my cameras recorded the brightening of the sky, though I live 400 km away.  That's also way too far away for audible sound.

A-L-E-X wrote:
Source of the post I have heard that although humans can't clearly hear infrasound that it can affect human emotions

I don't think such a brief inaudible rumble can influence at all.
NIL DIFFICILE VOLENTI
 
A-L-E-X
Star Engineer
Star Engineer
Posts: 2305
Joined: 06 Mar 2017

Show off your work

10 Nov 2020 08:52

Maybe not the brief ones but Mid read this, it is very interesting research:

https://en.wikipedia.org/wiki/Infrasoun ... _reactions

I think you would especially be interested in side effects of infrasound reported by people who live or work near wind turbines ;-)  the presence of infrasound and its association with "ghost" sightings is also interesting.

also

https://en.wikipedia.org/wiki/Infrasoun ... l_reaction

This might be how some animals can "predict" earthquakes
 
User avatar
midtskogen
World Builder
World Builder
Posts: 1098
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Show off your work

11 Nov 2020 11:47

CNEOS now lists this fireball event. They estimate the energy as 0.33 kt TNT equivalent, entry speed of 16.7 km/s (my estimate is 17.4 km/s), slope 73.2 degrees (mine 70.4 degrees), overall a very good match considering different observation methods.  The energy and entry speed implies an entry mass of about 9 tonnes, which also agrees well with my absolute magnitude of -17.5.  Events of this magnitude happen perhaps less than 10 times a year globally, so seeing this in my "neighbourhood" over land is very exciting.  The infrasound of the blast was even recorded in Russia more than 4000 km away.  CNEOS gives 22 km as the altitude for the airblast, which is very, very low.  I think it was still bright with a lot of speed at 17 km.  Now the question is whether anything could survive this all the way to the ground.
NIL DIFFICILE VOLENTI
 
A-L-E-X
Star Engineer
Star Engineer
Posts: 2305
Joined: 06 Mar 2017

Show off your work

11 Nov 2020 14:59

it is weird other astrophotographers are commenting on this uptick of fireballs starting in November and they are theorizing it is because of the amazingly warm and dry desert-like air we have had for 7 days now that make hem more easily visible.

I'll post a comment from one:

There have been a lot of fireballs and bright meteors this week, definitely higher than the ambient rate it seems. I didn't catch any of the big ones from dashcam videos making the rounds, but I have seen one or two high-end meteors per evening lately, mostly from west to east. Too lazy to open up Stellarium to figure out what the radiant might be.

Maybe it's a sign that we're about to enter one of the famous Leonid outbursts? There are also probably some non-celestial factors contributing to high report rates. This stretch of fair weather across most of the east has allowed outdoor dining and gatherings to continue deep into the autumn, so if something happens during the increasingly dark evenings, it'll have been hard to miss. I mean, last night I was outside in shorts and a tee, starhopping around the winter constellations with a pair of binos. It was bizarre. Mid-60s under clear skies is something that simply doesn't happen in the middle of November.
 
User avatar
midtskogen
World Builder
World Builder
Posts: 1098
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Show off your work

16 Nov 2020 00:04

Still working on this meteor event.  We now have good reasons to believe that the entry mass was in the 5 - 10 tonne range, still bright when passing aircraft cruising altitude, and not going subsonic until 3 - 7 km above ground.  Wow.  It means that terminal velocity was probably not reached, though close.  There was not so much delay between the flash and sound (at one location as little as 27 seconds), and some report a whistling projectile sound (falling pitch) following the initial blast.  Further away it was described more as a helicopter sound.  This is fascinating.  So far nothing has been found on the ground, but it could be several hundred kg in a relatively small area.
NIL DIFFICILE VOLENTI
 
A-L-E-X
Star Engineer
Star Engineer
Posts: 2305
Joined: 06 Mar 2017

Show off your work

16 Nov 2020 06:20

A bolide!  No chance this and the other stuff that has been seen over the past couple of weeks was related to the Leonids right?  You captured a brilliant colorful one last night!
 
User avatar
midtskogen
World Builder
World Builder
Posts: 1098
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Show off your work

16 Nov 2020 06:49

A-L-E-X wrote:
Source of the post No chance this and the other stuff that has been seen over the past couple of weeks was related to the Leonids right?

No chance whatsoever that the bolide is related to the Leonids.  The Leonids enter the atmosphere at 71 km/s.  Whatever crashes with Earth at that speed either instantly gets destroyed in the upper atmosphere or cause a disaster.  The bolide entered at 17 km/s, which is a pretty typical speed for stuff from the asteroid belt.  It fell at a steep slope, and ground impact might have been as soon as just 25 seconds after entry (still speculative, but some data suggest it), which is unusual and way faster then Chelyabinsk (which fell at a narrow angle).
NIL DIFFICILE VOLENTI
 
A-L-E-X
Star Engineer
Star Engineer
Posts: 2305
Joined: 06 Mar 2017

Show off your work

16 Nov 2020 07:11

Wow it does seem unusual that we have captured 3 asteroid events in the first couple of weeks of November, but as you said, more widespread cameras as well as unusually clear weather may be the reason for that.
 
User avatar
Watsisname
Science Officer
Science Officer
Posts: 2012
Joined: 06 Sep 2016
Location: Bellingham, WA

Show off your work

24 Nov 2020 01:20

Further images of the "Promethean Fire" plasma effect, which changes over time as the gas mixture breaks in. Especially in the last month, the tendrils have slowed down dramatically, grown fuzzier and more colorful, creating gently waving ghostly structures like flowers or trees. It's been something quite marvelous to apply photography to.

Image

► more

Who is online

Users browsing this forum: No registered users and 1 guest