Anyone watching the comet landing?

[fromderinside]

Thought. deploy artificial spider web to capture the comet. Then send down a robotic spider on the web to sample things. Avoids the dynamic problems associated with controlling two bodies. All we have to do is pretest how spider web acts in space, develop some that works at near absolute zero, and deploy it around the asteroid. Since the web originates at the orbiter that can be the point at which the spider begins its crawl to the captured object. With the addition of stable web the spider can essentially avoid all those object gravity problems.

So, from my vantage point the mission was a huge success.

 

[HellFire]

About how large is the comet?

If the comet were sitting on Earth,what would it weigh?

The comet is a dirty ice ball then? How does an ice ball form in space?

Just curious really.

Thank Yu.

 

[dystopian]

About how large is the comet?

If the comet were sitting on Earth,what would it weigh?

The comet is a dirty ice ball then? How does an ice ball form in space?

Just curious really.

Thank Yu.

This could be googled really quickly.

http://en.wikipedia.org/wiki/67P/Churyumov–Gerasimenko

 

[blastula]

I would very much call it a success, especially given that this is the first time anything like this has ever been attempted. A very long journey with lots of things that have to happen just right, or the craft doesn't even get to the comet in the first place. I think it exceeded expectations of the scientists and engineers involved. Very interesting to see a comet close up. I was expecting it to look more like a typical egg shaped meteor, with a few pock marks here and there. Had no idea there was so much interesting terrain and features to it.

Kinda shitty, though, that the SJWs had to turn a joyous technical achievement for scientist Dr. Matt Taylor into silly, tear-filled shaming episode just because the shirt he wore got a few uptight people offended.

http://www.theguardian.com/science/...lor-breaks-down-apology-offensive-shirt-video

Yeah, because somebody can do some math, means they're excused of any social responsibility to their community.

 

[Togo]

I would very much call it a success, especially given that this is the first time anything like this has ever been attempted. A very long journey with lots of things that have to happen just right, or the craft doesn't even get to the comet in the first place. I think it exceeded expectations of the scientists and engineers involved. Very interesting to see a comet close up. I was expecting it to look more like a typical egg shaped meteor, with a few pock marks here and there. Had no idea there was so much interesting terrain and features to it.

Kinda shitty, though, that the SJWs had to turn a joyous technical achievement for scientist Dr. Matt Taylor into silly, tear-filled shaming episode just because the shirt he wore got a few uptight people offended.

http://www.theguardian.com/science/...lor-breaks-down-apology-offensive-shirt-video

Yeah, because somebody can do some math, means they're excused of any social responsibility to their community.

Can anyone explain to me what was wrong with the shirt?

 

[Angry Floof]

Yeah, because somebody can do some math, means they're excused of any social responsibility to their community.

Can anyone explain to me what was wrong with the shirt?

It was images of sexy women in shiny, tight suits shooting guns.
I'm a Harry Harrison fan, so I thought it was cool.

 

[blastula]

Yeah, because somebody can do some math, means they're excused of any social responsibility to their community.

Can anyone explain to me what was wrong with the shirt?

If you don't already know, then, no, nobody probably could explain it to your satisfaction..

 

[Speakpigeon]

Can anyone explain to me what was wrong with the shirt?

If you don't already know, then, no, nobody probably could explain it to your satisfaction..

So now the debate has turned onto whether the guy with the shitty shirt scored alright or not!?
EB

 

[lpetrich]

Rosetta | rendezvous with a comet -- the spacecraft's home page at ESA
Rosetta - ESA's comet chaser -- ESA's blog about the spacecraft and its adventures

It looks like Philae bounced twice.

Philae spotted after first landing on 67P | Rosetta - ESA's comet chaser
OSIRIS spots Philae drifting across the comet | Rosetta - ESA's comet chaser after its first landing. OSIRIS is a high-resolution camera that Rosetta has, high-resolution enough to resolve Philae at Rosetta's distance from the comet at the time.

Homing in on Philae’s final landing site | Rosetta - ESA's comet chaser -- looks like some spot near the smaller lobe's cliffs at the neck.

Our lander's asleep | Rosetta - ESA's comet chaser but Pioneering Philae completes main mission before hibernation / Rosetta / Space Science / Our Activities / ESA

Not completely successfully, it seems. Some of the experiments did not work properly.
ESA Science & Technology: Shape model of comet 67P/C-G

Which you can load into your favorite 3D-modeling software. I've been looking for a voxelizer, some software that will convert a 3D model into a 3D-pixel or voxel representation. I can then use it to try to calculate its gravity.

 

[fromderinside]

Can anyone explain to me what was wrong with the shirt?

It was images of sexy women in shiny, tight suits shooting guns.
I'm a Harry Harrison fan, so I thought it was cool.

Taylor's got you, babe.

 

[Speakpigeon]

Weighty news! H2O found on Philea is different from that found on Earth (hydrogen is deuterium). So, mostly, our water wouldn't come from comets after all.

Maybe it's a bit too fast a conclusion but it's very important to me that the water I am drinking should come from, say, meteorites rather than dusty comets. The coffee would taste different I fear.

And, otherwise, Philae might have left 67P definitely on the first rebound?

Anyone wants to water down this news? Or put more weight on the significance of it?
EB

 

[thebeave]

The "water came from comets" theory was around when I was in college, but the more plausible theory, in my mind, has always been from volcanoes. I don't think anyone has proposed that earth's water has come from meteorites, have they? They're just a hunk or iron/rock.

 

[fromderinside]

Weighty news! H2O found on Philea is different from that found on Earth (hydrogen is deuterium). So, mostly, our water wouldn't come from comets after all.

Maybe it's a bit too fast a conclusion but it's very important to me that the water I am drinking should come from, say, meteorites rather than dusty comets. The coffee would taste different I fear.

And, otherwise, Philae might have left 67P definitely on the first rebound?

Anyone wants to water down this news? Or put more weight on the significance of it?
EB

The comet is the remains of an ancient nuclear site.......

 

[Mageth]

Weighty news! H2O found on Philea is different from that found on Earth (hydrogen is deuterium). So, mostly, our water wouldn't come from comets after all.

Maybe it's a bit too fast a conclusion but it's very important to me that the water I am drinking should come from, say, meteorites rather than dusty comets. The coffee would taste different I fear.

And, otherwise, Philae might have left 67P definitely on the first rebound?

Anyone wants to water down this news? Or put more weight on the significance of it?
EB

To be correct, the indication is that the water on 67P contains about 3x the deuterium than water on Earth, not that "H2O found on Philea is different from that found on Earth (hydrogen is deuterium)." But it's been known for a while that the water in Oort cloud objects/comets tends to contain more deuterium than Earth water (see first link below). So this is not new news.

Also, a link, which is always a nice thing to include in such a post. Two actually; the first links to the second...

http://www.esa.int/spaceinimages/Images/2014/12/Deuterium-to-hydrogen_in_the_Solar_System

"The horizontal blue line shows the value of the ratio [deuterium-to-hydrogen ratio (D/H)] in Earth's oceans, which has been determined to be 1.56 ×10–4. Rosetta’s ROSINA instrument measured the water vapour emanating from Comet 67P/Churyumov–Gerasimenko and found it to be 5.3 x 10–4, more than three times greater than for Earth’s oceans."

Also see, for more details:
http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_fuels_debate_on_origin_of_Earth_s_oceans

 

[Speakpigeon]

Ok, thanks Mageth. So, based on what you explained about hydrogen, deuterium and water, I'm proposing that the water on our planet comes originally from a mix of sources. Contributions from asteroids would seem to be right in terms of D/H but maybe not in terms of the quantity of water on Earth. So, possibly, other contributions might have been necessary, with the proper mix to produce the observed ratio on Earth, for example other contributions from both comets from the Oort cloud (I think it's a much bigger reserve in mass overall that the asteroids between Mars and Jupiter?) and whatever came originally from the "protosolar nebula", i.e. from which I guess came the material that together initially formed the Earth itself.

What strikes me, though, is that the D/H ratio of objects seems to be nicely correlated to their relative proximity (Jupiter/Saturn, Uranus/Neptune, Earth/Asteroids, objects in the Oort cloud). So 67P and the "jupiter family" might both come from the Oort cloud for example.

Also, given that presumably everything in the solar system comes from the protosolar nebula, which has a D/H ratio different from most objects in the solar system and in the Oort cloud, the whole significance of the ratio becomes problematic, i.e. the ratio is not stable over long periods of time in the conditions of the solar system.
EB

 

[Speakpigeon]

The "water came from comets" theory was around when I was in college, but the more plausible theory, in my mind, has always been from volcanoes. I don't think anyone has proposed that earth's water has come from meteorites, have they? They're just a hunk or iron/rock.

ESA - Herschel

(5 October 2011) The origin of Earth's water is hotly debated. Our planet formed at such high temperatures that any original water must have evaporated. Yet today, two-thirds of the surface is covered in water and this must have been delivered from space after Earth cooled down.

Comets seem a natural explanation: they are giant icebergs travelling through space with orbits that take them across the paths of the planets, making collisions possible. The impact of comet Shoemaker-Levy 9 on Jupiter in 1994 was one such event. But in the early Solar System, when there were larger numbers of comets around, collisions would have been much more common.

That was 2011, not 50 years ago.

They still say here that water on Earth must have come from the outside once the Earth had already been formed but that asteroids, and therefore meteorites, are now better candidates than comets...
EB

 

[fromderinside]

ESA - Herschel

(5 October 2011) The origin of Earth's water is hotly debated. Our planet formed at such high temperatures that any original water must have evaporated. Yet today, two-thirds of the surface is covered in water and this must have been delivered from space after Earth cooled down.

Comets seem a natural explanation: they are giant icebergs travelling through space with orbits that take them across the paths of the planets, making collisions possible. The impact of comet Shoemaker-Levy 9 on Jupiter in 1994 was one such event. But in the early Solar System, when there were larger numbers of comets around, collisions would have been much more common.

That was 2011, not 50 years ago.

They still say here that water on Earth must have come from the outside once the Earth had already been formed but that asteroids, and therefore meteorites, are now better candidates than comets...
EB

... from outer space, my arse.

Way back in the day when things were very hot on earth there is no evidence of water in the geological record. that is because the water, as vapor, was permanently held in the atmosphere so rock effects were recorded./sheesh

 

[Speakpigeon]

... from outer space, my arse.

Any evidence of that?
EB

 

[Bomb#20]

ESA - Herschel

(5 October 2011) The origin of Earth's water is hotly debated. Our planet formed at such high temperatures that any original water must have evaporated. Yet today, two-thirds of the surface is covered in water and this must have been delivered from space after Earth cooled down.

Comets seem a natural explanation: they are giant icebergs travelling through space with orbits that take them across the paths of the planets, making collisions possible. The impact of comet Shoemaker-Levy 9 on Jupiter in 1994 was one such event. But in the early Solar System, when there were larger numbers of comets around, collisions would have been much more common.

That was 2011, not 50 years ago.

They still say here that water on Earth must have come from the outside once the Earth had already been formed but that asteroids, and therefore meteorites, are now better candidates than comets...
EB

Whatever the source of Earth's water was, it supplied the water 4 billion-odd years ago. So why do people appear to be assuming that current deuterium concentrations of various objects are a good indication of what the concentrations were billions of years ago? Everything but Jupiter and Saturn has a whole lot more deuterium than the cosmos at large; that can't be because they made deuterium. So it has to be because they lost light hydrogen. If comets now have three times as much deuterium as Earth has, why would that mean Earth's water didn't come from comets? Why wouldn't it instead mean that comets have spent four billion years losing light hydrogen faster than Earth?

 

[fromderinside]

... from outer space, my arse.

Any evidence of that?
EB

Yes. Rock effects of water presence are only there when water was on the planet. The very fact that the earth was hot on the surface then cool enough on the surface for surface water is very suggestive. The incidence of comets and meteors striking the earth don't seem to be increasing, rather they have been decreasing as the earth and planets and sun of solar system have with their gravity syncs swept them up. So meteors don't seem a likely source.