[PublicAnimalNo9]

$1:

The Milky Way Project

I signed my ass up for that! It's not very often the average person gets to contribute to something so beautiful, humbling and awe inspiring.

[DrCaleb]

Spent many a blurry eyed hour at my computer with that!

[Canadian_Mind]

Saw a prolonged shooting star last night at around 7:30. What would it have to be made of to have a bight yellow centre with a green aura around it? It lasted for a relatively long time; long enough for me to think it was a plane, realise it was a shooting star, and point it out to the gf while I was driving (about 5 seconds or so).

[Jabberwalker]

No nav lights?

[DrCaleb]

Canadian_Mind Canadian_Mind:

Saw a prolonged shooting star last night at around 7:30. What would it have to be made of to have a bight yellow centre with a green aura around it? It lasted for a relatively long time; long enough for me to think it was a plane, realise it was a shooting star, and point it out to the gf while I was driving (about 5 seconds or so).

Green is given off by many elements when they burn; Copper, Tungsten, Boron just to name a few. Yellow can be sodium, but nearly anything can burn yellow if hot enough.

Did you hear popping and fizzling of the meteor at the same time? That's pretty rare event, if you think of how far away the meteor is.

[Canadian_Mind]

DrCaleb DrCaleb:

Green is given off by many elements when they burn; Copper, Tungsten, Boron just to name a few. Yellow can be sodium, but nearly anything can burn yellow if hot enough.

Did you hear popping and fizzling of the meteor at the same time? That's pretty rare event, if you think of how far away the meteor is.

I was wondering if the green was the meteor causing an aurora as it went through.

And I was driving south on highway 17. Wouldn't have heard it. It had to be very far away, in the 5 seconds it only moved across about 2 or 3 degrees of the sky.

When I saw it I was around 53* north by 110* west. The meteor itself was at about 190* relative to my location and 5* above the horizon. Occurred roughly around 730pm MST.

Jabber - I know you were making a joke, but the lack of NAV lights is what helped me realise it was a meteor. That and the bits breaking off as it went.

[DrCaleb]

Canadian_Mind Canadian_Mind:

DrCaleb DrCaleb:

Green is given off by many elements when they burn; Copper, Tungsten, Boron just to name a few. Yellow can be sodium, but nearly anything can burn yellow if hot enough.

I was wondering if the green was the meteor causing an aurora as it went through.

No, Aurora are charged solar particles interacting with Earths magnetic field. By the time a meteor starts to emit plasma, it's already in the atmosphere and a long way from the magnetic field.

The plasma meteors emit is from the friction of the atmosphere.

Canadian_Mind Canadian_Mind:

DrCaleb DrCaleb:

Did you hear popping and fizzling of the meteor at the same time? That's pretty rare event, if you think of how far away the meteor is.

And I was driving south on highway 17. Wouldn't have heard it. It had to be very far away, in the 5 seconds it only moved across about 2 or 3 degrees of the sky.

It's a very rare phenomenon, and I've only experienced it once. What normally happens is the meteor gives off plasma as it creates friction with the atmosphere. Since meteor is hundreds of miles away, you may hear the roar but it will be delayed minutes or seconds later because of the speed of sound. Once in a while, the plasma the meteor creates can create a magnetic field and create powerful radio waves that end up interacting with things in the environment. It sounds like trees and grass and even your eyeglasses are 'echoing' the sound of the meteor, but really they are transmitting these radio waves back as sound!

So the light from meteor and the sound it makes both travel at the same speed, and you hear it the same time as you see it! It seems pretty normal at first, until you realize you couldn't have heard and seen something so far away at the same time.

[DrCaleb]

$1:

Rare images of red sprites captured at ESO

At the ESO's observatories located high in the Atacama Desert of Chile, amazing images of distant objects in the Universe are captured on a regular basis. But in January 2015, ESO photo ambassador Petr Horálek captured some amazing photos of much closer phenomena: red sprites flashing in the atmosphere high above distant thunderstorms.

The photo above was captured from ESO's Paranal Observatory. A few days earlier during the early morning hours of Jan. 20 Petr captured another series of sprites from the La Silla site, generated by a storm over Argentina over 310 miles (500 km) away.

So-named because of their elusive nature, sprites appear as clusters of red tendrils above a lighting flash, often extending as high as 55 miles (90 km) into the atmosphere. The brightest region of a sprite is typically seen at altitudes of over 40-45 miles (65-75 km).

Because they occur high above large storms, only last for fractions of a second and emit light in the portion of the spectrum to which our eyes are the least sensitive, observing sprites is notoriously difficult.

These furtive atmospheric features weren't captured on camera until 1989. Continuing research has since resulted in more images, including some from the International Space Station. When they are spotted, sprites – and their lower-altitude relatives blue jets – can appear as bright as moderate aurorae and have also been found to emit radio noise. It has even been suggested that looking for sprite activity on other planets could help identify alien environments that are conducive to life.

Find out more about sprite research from the University of Alaska Fairbanks, and check out the PBS NOVA program "At the Edge of Space" below about a sprite hunt in the skies over Denver, CO conducted by a team of American scientists and Japanese filmmakers.

http://phys.org/news/2015-02-rare-image ... tured.html

The PBS show is here, and on Netflix. I encourage people interested to watch it!

http://www.pbs.org/wgbh/nova/earth/edge-of-space.html

[Canadian_Mind]

DrCaleb DrCaleb:

Canadian_Mind Canadian_Mind:

DrCaleb DrCaleb:

Green is given off by many elements when they burn; Copper, Tungsten, Boron just to name a few. Yellow can be sodium, but nearly anything can burn yellow if hot enough.

I was wondering if the green was the meteor causing an aurora as it went through.

No, Aurora are charged solar particles interacting with Earths magnetic field. By the time a meteor starts to emit plasma, it's already in the atmosphere and a long way from the magnetic field.

The plasma meteors emit is from the friction of the atmosphere.

Canadian_Mind Canadian_Mind:

DrCaleb DrCaleb:

Did you hear popping and fizzling of the meteor at the same time? That's pretty rare event, if you think of how far away the meteor is.

And I was driving south on highway 17. Wouldn't have heard it. It had to be very far away, in the 5 seconds it only moved across about 2 or 3 degrees of the sky.

It's a very rare phenomenon, and I've only experienced it once. What normally happens is the meteor gives off plasma as it creates friction with the atmosphere. Since meteor is hundreds of miles away, you may hear the roar but it will be delayed minutes or seconds later because of the speed of sound. Once in a while, the plasma the meteor creates can create a magnetic field and create powerful radio waves that end up interacting with things in the environment. It sounds like trees and grass and even your eyeglasses are 'echoing' the sound of the meteor, but really they are transmitting these radio waves back as sound!

So the light from meteor and the sound it makes both travel at the same speed, and you hear it the same time as you see it! It seems pretty normal at first, until you realize you couldn't have heard and seen something so far away at the same time.

Well that would have been neat. I'm sorry I missed out on the audio spectacle.

[Jabberwalker]

I run a little freebee astronomy program on my laptop called Stellarium. What do you think of it? Would you recommend anything better?

Also, what would you recommend for an Android tablet? I haven't tried Stellarium on it yet.

[DrCaleb]

Jabberwalker Jabberwalker:

I run a little freebee astronomy program on my laptop called Stellarium. What do you think of it? Would you recommend anything better?

Also, what would you recommend for an Android tablet? I haven't tried Stellarium on it yet.

I've never tried any programs. I just used to use a star chart that I've had for decades and a flashlight with red plastic on it.

I thought about getting one of those new computer controlled telescopes, but put it on the 'want' list with all the other stuff.

Has anyone tried them?

[Jabberwalker]

We had a bunch of Cubs out under a winter sky and we used an Apple tablet with a star chart program to orient ourselves and the kids a bit beyond the usual "Ursa Major-Polaris" bit that we do first. It was kind of cool and useful for beginners such as ourselves. The kids are also seriously tuned to using that sort of technology.

[DrCaleb]

Jabberwalker Jabberwalker:

We had a bunch of Cubs out under a winter sky and we used an Apple tablet with a star chart program to orient ourselves and the kids a bit beyond the usual "Ursa Major-Polaris" bit that we do first. It was kind of cool and useful for beginners such as ourselves. The kids are also seriously tuned to using that sort of technology.

I imagine they would be. I'm oldschool though, one of these and a compass, and I can usually find my way around the galaxy.



At least, as much as my old telescope can let me see.

[Zipperfish]

Gunnair Gunnair:

I love that photo of Hyperion!

Have you sued those loser Jupiter Ascending people yet for stealing your title?

[DrCaleb]

$1:

Strange Stars Pulsate According to the "Golden Ratio"

Astronomers have discovered variable stars that periodically dim and brighten at frequencies close to the famed golden mean

Scholars have seen the golden ratio in nautilus shells, the Parthenon, da Vinci paintings and now in stars. A new study of variable stars observed by the Kepler space telescope found four stars that pulsate at frequencies whose ratio is near the irrational number 0.61803398875, known as the Greek letter phi, or the golden ratio (which is also sometimes referred to as the inverse of that number, 1.61803398875…).

The golden ratio had not turned up in the celestial sphere before astronomer John Linder of The College of Wooster in Ohio and his colleagues analyzed the Kepler data. The researchers looked at a class of stars called RR Lyrae that are known for their variability. Unlike the sun, which shines at a near constant brightness (a good thing for life on Earth!), these stars brighten and dim as their atmospheres expand and contract due to periodic pressure changes. Each star pulses with a primary frequency and also shows smaller brightness fluctuations occurring on a secondary frequency. The ratios between these two frequencies “are very important,” says astronomer Róbert Szabó of the Konkoly Observatory in Hungary, who was not involved in the study, “because they are characterized by the inner structure of stars—and if a star exhibits many modes, then observation of the frequencies gives very strict constraints to stellar models.” For four of the six RR Lyrae stars the researchers analyzed, the ratio of the primary to secondary frequencies was near the golden mean—within 2 percent of its value in the case of the star KIC 5520878, for example.

http://www.scientificamerican.com/artic ... den-ratio/