Welcome to a comet

http://www.esa.int/spaceinimages/Images/2014/11/Welcome_to_a_comet

by jbogp • 12 years ago

387 78 12 years ago

jbogp3• 12 years ago

That's a great achievement in any case. I'm just slightly worried from the looks of this picture that Philae actually stabilized on its side.

Also the large amount of shadow in the area is worrisome for the solar panels to function properly.

Press conference with the release of a full panorama (which will hopefully not confirm the side landing) is scheduled for 1400 CET.

mhandley2• 12 years ago

The sunlight appears to be coming from behind and to the left of Philae in this picture, at a fairly low angle, so the back of it should (I hope) be reasonably illuminated at the moment.

It's definitely not clear from this picture which way is "up". It looks to me like up may be towards the top right of the picture, in which case Philae may be at a 45 degree angle. But I'm probably wrong - the full panorama should tell all.

mhandley2• 12 years ago

After staring at the image a lot more, I realised I'm completely wrong. The leg reveals which way the lighting is coming from - above, slightly to the left, and probably slanting slightly into the camera. So my original interpretation of the orientation cannot be correct.

The real question is whether the picture should be rotated 90+ degrees clockwise.

smoyer• 12 years ago

The lander's leg is very well lit and there is clearly nothing underneath it. The antenna appears (based on it's end converging with it's own shadow) to be resting against either a rock or the surface.

I'm not a rocket scientist ... I hope I'm grossly misinterpreting this image!

jbogp3• 12 years ago

Also very interesting, if you look at the high-res picture and zoom at the bottom right, you'll notice some sort of cable on the ground/boulder.

This could be the cable from one of the harpoons that may have fired but didn't anchor themselves, or it could be a feature attached to Philae that's in the field of vision.

Luc• 12 years ago

It looks like it's resting on one of the antennae. You can see its shadow underneath it.

andrewd18• 12 years ago

That's one of the audio cables from the sound stage. If you look closely you can see the shadow of a boom mic on one of the rocks.

mirkules• 12 years ago

My first thought was: "Why would they need a mic? There's no sound in space" and then I felt the whoosh over my head. Well done.

lentil_soup2• 12 years ago

Curious question, is the light in the picture all from the Sun or do they use something artificial?

jbogp3• 12 years ago

All from the sun.

binarymax• 12 years ago

The sheen coming from the surface where light hits is indicative of some interesting materials on that comet. Looking forward to more photos and especially analysis of the surface composition!

Lrigikithumer3• 12 years ago

You know I have some bad days some times, but seeing shit like this just makes me think "What a fucking time to be alive!" It's truly incredibly and is sometimes that kick in the pants I need to keep on going. We are living in a golden age of humanity right now, at no point before in human history have so many people had such an incredible quality of life and never before has man been doing such incredible feats and have the ability to reach a worldwide audience almost instantaneously. The fact that just a few hours ago a human designed space craft landed on a comet, after decades of work and I can receive the images fresh from the great minds that brought us this feat, while laying in bed dicking about on my phone, it's just pure and simply astounding.

For all our flaws I love humans and I am so excited to see what the future holds.

Back to the comet, any word on what happened to the harpoons? I heard there was a misfire or they didn't fire or something? Any idea how that's affected the landing as of yet?

kissickas• 12 years ago

I don't think we've gotten any further details than the fact that they didn't fire when they should have. There's a press conference at 2 pm CET.

vital101• 12 years ago

I'm not sure about that status of the harpoons, but I generally use http://reddit.com/r/space to keep up with all of my space related news. Article quality is generally very high and there are a lot nice folks over there who answer questions in the comments.

Lrigikithumer3• 12 years ago

Thanks, I'll be sure to keep my eye on that sub

badname2• 12 years ago

Yes it is golden age as long as you disregard percentages and trend.

"Some 805 million people in the world do not have enough food to lead a healthy active life. That's about one in nine people on earth." http://www.wfp.org/hunger/stats

Economy seems like a boiler ready to explode, rich-poor chasm is widening like hell.

Global peace doesn't look very rosy either.

Not to mention what's happening on the environmental front.

All in all, sorry but I cannot feel the joy of "us humans doing well". We don't. Some technical sectors are doing well - that's all. Socially, ethically, politically we're still at middle ages and speeding backwards.

My 2 cents (which is most than millions of people can spare ;-) )

Tepix• 12 years ago

805 million means the number is down more than 100 million over the last decade, and 209 million lower than in 1990–92. In the same period, the prevalence of undernourishment has fallen from 18.7 to 11.3 percent globally and from 23.4 to 13.5 percent for developing countries.

Source: http://www.fao.org/publications/sofi/en/

maccard2• 12 years ago

I'm not well versed enough in world hunger problems to talk about it, but on the Global Peace side, we are currently in the least violent period in the last 2000 years.

Lrigikithumer3• 12 years ago

I think you should look at these things in perspective, by no means is our society perfect, in relation to literally any point in history before maybe the fall of the Soviet Union, this world was objectively worse. Global conflicts are operating on much smaller scales, the environmental front has a hell of a lot of people fighting to improve current conditions, the economy isn't a boiler ready to explode. We are NOT in the middle ages in ANY of those sectors, to even suggest that tells me you've actually got 0 idea of what this world or what historically we looked like. We aren't burning witches or beheading people, we aren't accusing mentally ill people of being possessed by the devil. We have medicine, we have food, we can communicate with people around the world instantaneous. People are moving away from separated communities and becoming a global entity.

Look buddy, in the end our perspective on the world is what you decide it is and while we aren't living in the Garden of Eden our world is pretty top notch presently and in relation to any point in human history the world is great and only getting better.

So remove your pessimist spectacles and try and enjoy life and think optimistically, you only get one whip around and would you rather spend it disappointed and grumpy at the world or hopeful and excited?

My 2 cents (which is most than millions of people can spare ;-) )

Also that was probably the snarkiest smug comment and it makes me think you like the smell of your own farts

afoot2• 12 years ago

The wealth gap can be misleading too, since the quality of life for those at the 'bottom' is often better than it ever has been on just about every metric you care to consider.

gpvos• 12 years ago

Of those things, especially if you compare it with, say, a century ago, only the environment is really in trouble. Which is bad enough, of course, but when looking at hunger and peace, we are actually doing pretty well.

Igglyboo• 12 years ago

Yes the world isn't perfect and theres still a shit ton wrong, regardless we're better off than we've ever been before except perhaps on the environment.

knowaveragejoe2• 12 years ago

Actually, the statistics today are largely better than at any point in history we have statistics for.

Here's a nice aggregate:

http://daeken.com/2014-04-16_Spoiler__The_World_Isn_t_On_Fir...

There is a shitload of good things going on in the world. You just have to pull your head out of the negativity echochamber present in a lot of Internet communities, most notably parts of reddit.

tjradcliffe• 12 years ago

Every age has its little people whose entire contribution to public discourse is to complain about how dreadful everything is. They add nothing good to the world. They don't feed the hungry or clothe the homeless the way creative people operating within the framework of capitalism, the rule of law and global trade have been doing for the past several hundred years. They just complain about how awful everything is.

I'm not sure why they consider this a worthwhile thing. Clearly they are capable of identifying problems, but aren't capable of doing anything about them. As such, they should get out the way of the people who are actually solving them. A hundred years ago such people were complaining that capitalism and global trade were evil and destructive, and they and their fellow-travelers attempted several more-or-less violent approaches to overthrowing them, which held back human development by decades and destroyed tens of millions of lives.

Despite those abject failures, the same anti-empirical wingnuts are back today, when capitalism, the rule of law and global trade have created an era of unprecedented peace and prosperity--exactly as their irrational predecessors predicted would never and could never happen. But they don't let anything so Enlightened as mere empirical reality prevent them from continuing their litany of complaint and opposition to progress.

weavie• 12 years ago

To get an idea of the scale of the thing, here is a picture of the comet relative to the size of London :

http://www.esa.int/spaceinimages/Images/2014/11/Comet_over_L...

I had no idea the thing was so small. To get something to intercept an object that size traveling at 1000's mph is an amazing feat!

mapimopi• 12 years ago

Textbook comment right here.

muyuu• 12 years ago

Does it have a colour camera? or maybe it's a bandwidth-saving decision to transmit only B&W? or because of the lighting?

wlievens2• 12 years ago

Apparently the visible light sensor has RGB color filters.

http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=PHILA...

I would guess these are probably not a Bayer filter pattern, but filters that are mechanically swapped.

narag• 12 years ago

I remember having read long time ago that superposing B&W images took with those filters gives an also B&W image that our brain perceives as coloured. Does anybody know if this is correct or what's the name of that effect?

Zeebrommer• 12 years ago

The pictures taken by Rosetta are BW. From [0]: "Some light contrast enhancements have been made to emphasise certain features and to bring out features in the shadowed areas. In reality, the comet is extremely dark -– blacker than coal. The images, taken in black-and-white, are grey-scaled according to the relative brightness of the features observed, which depends on local illumination conditions, surface characteristics and composition of the given area. Some slight vignetting can also be seen in the corners of some images." So possibly Philae has a similar system. [0] https://www.flickr.com/photos/europeanspaceagency/1573996637...

fit2rule• 12 years ago

Looks like a pretty rough place to land - I wonder though if this is one of the 'bounce' phases of the landing, and maybe what ended up happening was that it was more of a tumble, due to surface features snagging a leg, or something.. I must admit that during the approach, the landing site looked to me like it might have been 'pretty smooth', like it was a plane of material that didn't look too jagged and nasty, but this photo just looks like we landed in a pretty rough spot. Regardless, seems like some science is going to get done anyway, and that sure is exciting! Can't wait for 14:00 and see some new pics ..

IndianAstronaut• 12 years ago

Moon, Mars, Venus, Titan, and now comet 67p.

Absolutely amazing.

avian2• 12 years ago

Don't forget asteroid Itokawa. https://en.wikipedia.org/wiki/Hayabusa

NietTim• 12 years ago

I think he was talking about actual landings. Hayabusa/its lander MINERVA failed to land

jeffwass• 12 years ago

Space probe NEAR-Shoemaker landed on asteroid Eros in 2001!

What is amazing about this landing is that the probe had no landing gear, no shock absorbers, and was not designed in any way to land. NASA engineers tuned the orbit carefully and slowly and we're able to match velocities for a soft landing for what was otherwise supposed to be an orbiting spacecraft.

http://en.m.wikipedia.org/wiki/NEAR_Shoemaker

(Edit - fixed asteroid name)

afoot2• 12 years ago

That single image is quite impactful if you know the background to the project. It's like something out of a movie.

rurban• 12 years ago

So "Armageddon" was right. A comet looks much more interesting than the Moon or Mars. No boring dunes and flat sands, really rocky.

Lambdanaut• 12 years ago

I'd say this is a far-cry from that dramatization, but hey, they weren't as far off as we thought!

Comet 67P seems a lot more rugged than previous comets we've been to.

gokhan• 12 years ago

From Reddit[1]:

"Got fresh news from the team, they are broadcasting live right now on french TV ! Philae landed, and bounced slowly for (1-2-? hours), and travelled 1km away the targetted site. Yes 1000m. Then know this because of the datas from the radar. It's now stopped slanted, some cams are shooting the sky, other the ground, and other nearby rocks, as seen on the first photo. It's inside some kind of cave/hole, not much sun for the solar panels.

EDIT1: It landed on the core of the comet, it sees the light from the sun for about 1 to 2 hours per day. In the next days/week the angle of the comet will change/sun, and it very likely the solar panel will get more sunlight so more power for the probe.

EDIT2 : Many labs are performing right now and performed the whole night. For now they put the drilling on hold since they don't know if it's tied to the ground or not. Drilling op was also power hungry so it's kinda a good thing it's on hold since there's not much sun available for the panels. Battery life been re-estimated to 50-55hours due to the lack of sunlight. This time includes the 7 hours of descent.They are constantly adjusting missions goals, depending on conditions, power available, etc,

EDIT3 : The probe has been working to gather scientifict datas the whole time, including during the bounces. There's already a large amount of datas available, whatever happens next.

EDIT4 : It's resting on "hard" ground, with a layer of dust about 30cm, and that's good news because it allows measurements to proceed as planned. As in, it's not burried into soft soil.

EDIT5 : Solar panels are deployed, radio link is up and running, but the fact the probe is slanted/in a hole/random ground limits the time it can communicate with the orbiter, but that's not jeopardizing the mission. There's already a lot of datas transmitted successfully to the orbiter. Contact between the orbiter and the probe can be approximately done twice per day.

EDIT6 : The first place it touched the comet was exaclty where it was planned, flat and cosy, too bad it didn't harpoon there.

EDIT7 : Next contact will be near 19:30GMT, until 23:45GMT approx. This night they made contact with the probe (from the orbiter) at about 4:00GMT, and at 5:30GMT they had safely recovered all the datas from the first batch of tests."

[1] http://www.reddit.com/r/space/comments/2m63hd/first_civa_ima...

valevk• 12 years ago

travelled 1km away the targetted site. Yes 1000m.

Wow, I think this is great luck, that the probe is still on the comet, and even seems to work properly.

netcan3• 12 years ago

Does the comet have enough gravity to hold on to dust? How do these small space objects even stay together?

Osmium• 12 years ago

Does the comet have enough gravity to hold on to dust?

Yes. Philae's weight on the comet is roughly equivalent to a few ounces/100g* on Earth. It's why there's so much concern about it not being anchored correctly; deploy the wrong instrument and you might push it away from the surface and out into space. So there is a significant gravitational attraction from the comet, just not very much!

* I've seen a few different estimates for this, but it's of this order.

nitrogen• 12 years ago

The full panorama is available: http://www.esa.int/spaceinimages/Images/2014/11/Comet_panora...

TomGullen2• 12 years ago

I'm curious to know, how far will the landing affect it's orbit?

sp332• 12 years ago

The probe is very small compared to the comet, so probably hardly at all. http://www.esa.int/spaceinimages/Images/2014/09/Philae_s_pri...

flinty• 12 years ago

are you thinking if we can potentially deflect comets?

TomGullen2• 12 years ago

Yep :)

zachrose• 12 years ago

It almost seems like "landing" is too strong a word: Philae has a mass of 100kg and the gravity of Churyumov–Gerasimenko is estimated to be 10e−3 m/s2, which comes out to a weight of 3.5 ounces, or the equivalent of 100 grams on earth. Let's hope it holds!

stromgo• 12 years ago

10e-3 m/s^2 is hard to believe, as the lander would have to be ~250m away from the center of mass [1]. More likely it is 2500m away from the center of mass, giving 6.67e-11 * 1.0e13 / 2500 ^ 2 = 0.0001 m/s^2, so about 1 gram.

[1] I can't find a reliable estimate of the surface gravity online, but the mass estimate at http://blogs.esa.int/rosetta/2014/08/21/determining-the-mass... seems accurate.

ctdonath2• 12 years ago

Thanks to the sorta dumbbell shape, depending on where Philae landed the apparent gravity may be a LOT less, should a considerable amount of the comet's mass be "above" the lander. (Think "what's the pull of gravity in the center of a planet?")

netcan3• 12 years ago

This is exciting. I'm excited.

My reaction to this photo is a little funny. Basically: "Rocks! We have rocks too! Yours look a lot like ours."

I have this desire to find things in common. Like flirting.

harisamin• 12 years ago

This is pretty crazy and awesome!

jamesfisher• 12 years ago

Possibly stupid question: why are all the images greyscale? Could we not send a color camera? Or is the comet very grey? Or does color not work in space?

NeverEnough• 12 years ago

color works just fine

I know that sometimes, images are first sent in black and white to save on data, color is sent later.

Hubble apparently only does black and white. color images can be obtained using a technique involving two of its black and white images. But that is a telescope, probably not similar.

http://hubblesite.org/gallery/behind_the_pictures/meaning_of...

the comet could just be grey, not sure about that one.

mnw21cam• 12 years ago

Also, cameras are much more sensitive and higher resolution if they are B&W. A colour camera has to have a bayer matrix filter in front of the pixels (or some other weird trick) which throws away a load of the light.

Generally, when telescopes want colour images, they will take several pictures with different filters in front of the telescope, then combine them. This is useful because you can have a wide selection of filters, including ones for specific science-related wavelengths, like hydrogen alpha, or oxygen emissions. A normal colour camera is limited to three filters.

hahainternet• 12 years ago

The comet is in fact very very black, but pretty much all cameras are greyscale. Most 'colour' cameras are just a series of filters placed over the pixels to sense only light of the desired colour (usually RGB)

When science has to be done, it's easier to have a selectable set of filters you can put in front of the whole sensor at once. This way you can use the full sensor resolution and you can have a wider variety of filters. They also tend to bring along spectrometers of some description which are again much much more useful.

lostInComm• 12 years ago

Ok this has been bugging me...

What is a "CIVA Image"? Everyone is using the term - but not explaining what it is!

dennismp• 12 years ago

I think its referring to this: http://www.esa.int/Our_Activities/Space_Science/Rosetta/CIVA

Welcome to a comet

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