So why is 67P "singing" at 40-50 millihertz?

[MrAmsterdam]

Just missed watching a BBC documentary about asteroids and they speak of photon propulsion:

http://www.bbc.co.uk/programmes/b00vv0w8

Famed for their ability to inflict Armageddon from outer space, asteroids are now revealing the secrets of how they are responsible for both life and death on our planet.

Armed with an array of powerful telescopes, scientists are finding up to 3,000 new asteroids every night. And some are heading our way.

But astronomers have discovered that it's not the giant rocks that are the greatest danger - it's the small asteroids that pose a more immediate threat to Earth.

Researchers have explained the photon propulsion that send these rocks across space, and have discovered that some asteroids are carrying a mysterious cargo of frost and ice across the solar system that could have helped start life on Earth.

So it's rock, sometimes (?) carrying frost and ice with a photon propulsion engine ?

Do working models of "photon propulsion engines" already exist ? Do you need plasma for it ?

[paladin17]

Just missed watching a BBC documentary about asteroids and they speak of photon propulsion:

http://www.bbc.co.uk/programmes/b00vv0w8

Famed for their ability to inflict Armageddon from outer space, asteroids are now revealing the secrets of how they are responsible for both life and death on our planet.

Armed with an array of powerful telescopes, scientists are finding up to 3,000 new asteroids every night. And some are heading our way.

But astronomers have discovered that it's not the giant rocks that are the greatest danger - it's the small asteroids that pose a more immediate threat to Earth.

Researchers have explained the photon propulsion that send these rocks across space, and have discovered that some asteroids are carrying a mysterious cargo of frost and ice across the solar system that could have helped start life on Earth.

So it's rock, sometimes (?) carrying frost and ice with a photon propulsion engine ?

Do working models of "photon propulsion engines" already exist ? Do you need plasma for it ?

I think it's just that the guy who wrote this, well, wasn't too smart.
My best guess would be that someone explained him the Yarkovsky effect, and through some really wicked pathways inside his head it become what we can see in this piece of text.

[seasmith]

~

EGU.eu news conference today gives explanation for "singing"
(Rosetta scientist Glassmeier speaking at around minute 15).

Paraphrasing here; ion/plasma emissions from the comet, intersecting the solar magnetic field, are creating a 100 amp current, and humming at a ~ 50Mhz pitch
(later slowed down to audible frequency for singing effect).

Please, it's only a very rough first-take, listening to a non-english speaker.
Will have to listen a couple more times or read the transcript...

http://blogs.esa.int/rosetta/2015/04/13 ... -14-april/

http://client.cntv.at/EGU2015/PC1

[seasmith]

doofydangdecimals, guess that was Millihertz,, so ~ audible..
still, 100 Amps from that pipsqueak. Image the current associated with those "braided plasma streams" in the sun...

[seasmith]

~

4-14-2015 EGU/Rosetta news conference blogified:

http://blogs.esa.int/rosetta/2015/04/14 ... agnetised/




(see news-conf link for electro-magnetic oscillation expln):
http://client.cntv.at/EGU2015/PC1