back to article We sent a probe SIX BILLION km to measure temperature of a COMET doing 135,000 km/h

The comet-chasing spacecraft Rosetta has got close enough to its target to start getting temperature readings. The results show that comet 67P/Churyumov–Gerasimenko isn't the snowball some boffins were expecting. Between 13 and 21 July Rosetta moved within 5,000 kilometers of the rapidly spinning comet and used its visible, …

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Anonymous Coward

Phelea lander?

Judging by how that sounds, someone got one past the censors :)

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Anonymous Coward

Being probed?

Let's hope that the Alien entities piloting the comet don't object to being probed, they may not like it up em you know.

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Impressive and I'd expected it to be *much* colder

The background temperature of deep space is usually described as being about 3-4K.

Which suggests solar heating bumps things up a lot, or the comet has some kind of internal process going on.

Thumbs up for field work, especially so far away.

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Pint

Re: Impressive and I'd expected it to be *much* colder

My thoughts exactly. We've recorded lower temperatures on the third rock from the Sun (~-90C). So it's interesting that this object, receiving a tenth of the solar radiation, is warmer.

Oh, and a nice cold beer for the boffins involved.

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Alien

Re: Impressive and I'd expected it to be *much* colder

It's being heated up ready for its passengers to come out of stasis - just in time for an invasion next year.

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Re: Impressive and I'd expected it to be *much* colder

Indeed, they say the comet always precedes them.

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Re: Impressive and I'd expected it to be *much* colder

"...the comet has some kind of internal process going on."

I'd put my money on some amount of radio isotopes in the inside. It could even have a liquid core and some primitive life.*

What puzzles me more is the crust of dust, as every time the comet goes near the Sun said crust should be ablated. I hope Rosetta carries some means to ascertain the composition of said crust.

*Both these hypotheses have been stolen'borrowed' from some of Gregory Benford's books. ;-)

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Re: Impressive and I'd expected it to be *much* colder

The lower levels of glaciers here on Earth end up looking pretty murky because of the dust in the ice concentrating on the surface as the ice sublimates and melts. Might possibly be something similar on comets.

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Re: Impressive and I'd expected it to be *much* colder

> The background temperature of deep space is usually described as being about 3-4K.

To be pedantic, according to the article, the ...

> 4-kilometre-wide space rock moves around the Sun between the orbits of Jupiter and Earth at up to 135,000 kilometres per hour

Earth to Jupiter orbit isn't deep space, of course. Picking Mars as a handy 'somewhere in the middle point', night time low temperatures on Mars are -120C so the asteroid warming up to -70C isn't nearly such an unlikely jump as going from 3-4K

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Re: Impressive and I'd expected it to be *much* colder

Interesting, since I just finished reading an old copy of Heart of the Comet (Benford/Brin collaboration)

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Pint

Hurrah for Boffins.

Just arriving 'alongside' and getting ready for orbit around a comet is mind boggling. Sticking a box of tricks on one will be sheer fun for us spectators wot don't have to do all the hard work. Well done Boffins, you're a credit to humanity.

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Re: Hurrah for Boffins.

Yep, not bad for a bunch of ape-descended life-forms who think that iPhones are a pretty neat idea.

Makes you proud to be human.

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Happy

Re: "..... who think that iPhones are a pretty neat idea....."

Happily for the reputation of the human race not all of us share that opinion.

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Happy

Re: "..... who think that iPhones are a pretty neat idea....." @Artic Fox

Ah come on! Your not still into digital watches are you?

Oh wait, they are about to come back into fashion aren't they.

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Shouldn't the mother ship be called Pequod ?

"Philae will detach from Rosetta and power down towards the surface at one metre per second, and fire harpoons .."

And it's commander Ahab.

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Re: Shouldn't the mother ship be called Pequod ?

Oblig XKCD:

http://xkcd.com/1402/

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Re: Shouldn't the mother ship be called Pequod ?

Also: http://xkcd.com/1297/

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major lag

"... it would take about 22 minutes for a signal from the rock to reach home."

So I guess Call of Duty is out of the question then.

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Re: major lag

For your average Samsung user that's not that impressive.

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Anonymous Coward

Celsius?

Sorry to be pedantic, but the measured temperature is in Centigrade not Celsius. Celsius can only be used if the temperature has been measured in Kelvin by a constant volume gas thermometer, and then converted. Temperature in Celsius is defined by the absolute temperature scale.

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Re: Celsius?

Celsius and Centigrade agree to within 0.1 degree. So if you know one, you know the other to within 0.1 degree.

Since the level of precision used in the article is either 1 or 10 degrees, either label is accurate.

NO international standard of measure requires the use of specific equipment or methodology to use, as you wrongly claim. There are specific standards against which any equipment or methodology must be calibrated and proven, but once properly calibrated any equipment and methodology which has been proven can be used.

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Re: Celsius?

Never contemplated the difference before I have now read a little about and I am not making it fit with what you are saying. It seems that they are just two different names for the same scale. Where centigrade is the old one, centigrade, defined by water freezing and boiling and the new one is defined by that, but has moved the reference point to absolute zero in addition. It is however the same scale, just a new better definition technically giving a small difference. But that can also be said for all other units of measurements that change definition from time to time. The meter is still a meter even though we are not considering a platina staff or the distance between the poles and equator the definition anymore.

Further more as of any measurement you can never make them absolute accurate. Thus the unit is never tied up to the tool you are measuring with. I do not need to time light to measure the meter and I do not a constant volume gas thermometer to measure degrees Celsius. I can use any thermometer.

What am I missing?

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Re: Celsius?

Celsius and Centigrade agree to within 0.1 degree. So if you know one, you know the other to within 0.1 degree.

I thought it was 0.01 degree.

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Headmaster

Re: Celsius?

@mr.K - You are missing the fact that a Metre is a unit of measure and a meter is a device to measure with.

I will just get my coat out of the meter cupboard :-)

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Headmaster

Re: Celsius?

Actually and Pedantically mr.K, Celsius is both the older and the newer name, but not for the same scale. Those of us with long enough memories will recall that Anders Celcius proposed a temperature scale on which water boiled at 0 and froze at +100 degrees. Thanks to the botanist Carl Linnaeus Centigrade became the name for a reciprocal scale based on Anders' degree and used for several hundred years. The new Celcius scale popped into existence mere moments ago (sometime in 1948 apparently, but much later in most people's consciousnesses).

Take home message: Will Kelvin catch on and become the universal temperature scale, or will an independant Scotland bring the Rankine to prominence?

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Re: Celsius?

I thought it was 0.01 degree.

You are correct. I'm not sure if I misread or mistyped it. But the point is that Celsius and Centigrade differ by a known, constant quantity which is less than the precision used in the article. So for the purposes of this discussion, they are interchangeable.

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Re: Celsius? @cosymart

Would you look at that, I actually didn't know that. Any chance that you native English speakers could switch them around? It would comply with how we write it in Norwegian and I wouldn't have to adapt.

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obligatory

http://xkcd.com/1402/

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Forcast for the next 10 days: cold

-70 C and that is not considering the wind chill. The wind is at least 135,000 km/h but it is likely a dry cold.

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Headmaster

Speed trap.

I know The author wants to put the speed in a form that makes it relevant, however no one experiences speeds of that magnitude. The speed in km/s is 37.5, this is far more understandable to me. Example: it's about 40km from my house to the local mall. And it takes me (with traffic) around 15min to get there, so this comet makes it in one second or less.

The fine for speeding like that would be huge!! That is a measurment I CAN relate to!!

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Anonymous Coward

Re: Speed trap.

Why has speed got to be published in format that your tiny mind can comprehend? Modifying a measure to make it human scale is irrelevant. Do you want your quarks measured fractions of thumb widths, or light speed in how long it takes for your reflection to be seen in a mirror. What are you, a child?

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Headmaster

Re: Speed trap.

"Modifying a measure to make it human scale is irrelevant"

In that case, what's so wrong with it? Is making things more comprehensible somehow a bad thing?

That said, this is el Reg, so speed should be expressed as a percentage of the maximum speed of a sheep in a vacuum. (1.2508% for those keeping track at home).

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Headmaster

Re: Speed trap.

Measure to human scale is irrelevant?

I was taught (and sincerely believe) Man is the measure of all things.

If you disagree, take it up with Protagoras.

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Boffin

Re: Speed trap.

>> The fine for speeding like that would be huge!!

At ~40 kilometers per second, I suspect that most of the technology employed by your average "safety camera partnership" would struggle to detect the speeding. (Don't try this at home kids)

Edit: Corrected units

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Coat

Re: Speed trap.

(If you are a politician,) you could always say it was your wife driving

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