Page 1 of 2

APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 5:10 am
by APOD Robot
Image Huygens Lands on Titan

Explanation: Delivered by Saturn-bound Cassini, ESA's Huygens probe touched down on the ringed planet's largest moon Titan, ten years ago on January 14, 2005. These panels show fisheye images made during its slow descent by parachute through Titan's dense atmosphere. Taken by the probe's descent imager/spectral radiometer instrument they range in altitude from 6 kilometers (upper left) to 0.2 kilometers (lower right) above the moon's surprisingly Earth-like surface of dark channels, floodplains, and bright ridges. But at temperatures near -290 degrees F (-180 degrees C), the liquids flowing across Titan's surface are methane and ethane, hydrocarbons rather than water. After making the most distant landing for a spacecraft from Earth, Huygens transmitted data for more than an hour. The Huygens data and a decade of exploration by Cassini have shown Titan to be a tantalizing world hosting a complex chemistry of organic compounds, dynamic landforms, lakes, seas, and a possible subsurface ocean of liquid water.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 5:19 am
by Wolfi
The description says "... But at temperatures near -290 degrees C...". Isn't that below the lowest temperature possible?

Best regards,
Wolfgang from Austria

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 5:26 am
by Chris Peterson
Wolfi wrote:The description says "... But at temperatures near -290 degrees C...". Isn't that below the lowest temperature possible?
Yes. The surface temperature on Titan is -290°F (-180°C, 94 K).

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 5:32 am
by geckzilla
I mailed the editors.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 10:48 am
by hoohaw
Wolfi wrote:The description says "... But at temperatures near -290 degrees C...". Isn't that below the lowest temperature possible?

Best regards,
Wolfgang from Austria
Hey, cool!

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 10:53 am
by hoohaw
I never could have imagined that in my own lifetime I would see the surface of Titan! Less than 400 years after Titan's discovery by Christian Huygens! http://www.esa.int/About_Us/Welcome_to_ ... r_of_Titan

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 12:20 pm
by BDanielMayfield
hoohaw wrote:I never could have imagined that in my own lifetime I would see the surface of Titan! Less than 400 years after Titan's discovery by Christian Huygens! http://www.esa.int/About_Us/Welcome_to_ ... r_of_Titan
But, consider how short a period it was between the invention of manned flight by the Wright brothers (1903) and people standing on the surface of our Moon (1969). In view of that, many have imagined that people would have reached at least Mars by now.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 1:23 pm
by strohschein
By international agreement, absolute zero is defined as precisely; 0 K on the Kelvin scale, which is a thermodynamic (absolute) temperature scale; and –273.15 degrees Celsius on the Celsius scale

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 1:39 pm
by henrystar
BDanielMayfield wrote:
hoohaw wrote:I never could have imagined that in my own lifetime I would see the surface of Titan! Less than 400 years after Titan's discovery by Christian Huygens! http://www.esa.int/About_Us/Welcome_to_ ... r_of_Titan
But, consider how short a period it was between the invention of manned flight by the Wright brothers (1903) and people standing on the surface of our Moon (1969). In view of that, many have imagined that people would have reached at least Mars by now.
Very good thought, that! My mother was born just before the Wright Brothers flew, and lived to after men walked on the moon. Absolutely flabbergasting, no doubt about it!

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 2:31 pm
by FloridaMike
henrystar wrote:
BDanielMayfield wrote:
hoohaw wrote:I never could have imagined that in my own lifetime I would see the surface of Titan! Less than 400 years after Titan's discovery by Christian Huygens! http://www.esa.int/About_Us/Welcome_to_ ... r_of_Titan
But, consider how short a period it was between the invention of manned flight by the Wright brothers (1903) and people standing on the surface of our Moon (1969). In view of that, many have imagined that people would have reached at least Mars by now.
Very good thought, that! My mother was born just before the Wright Brothers flew, and lived to after men walked on the moon. Absolutely flabbergasting, no doubt about it!

Compare and contrast this to how long it took the wheel to go from invention to traveling at 40 mph. Then from 40 mph to Mach 1. In your mothers grandmothers lifetime things would have barely changed at all.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 2:51 pm
by Steve Dutch
We can't commemorate Huygens without a huge shout out to Boris Smeds, an engineer who literally saved the mission more or less single-handedly. He realized they had never tested how Huygens and Cassini would communicate once separated. This is obviously not the sort of thing you can do in space. He finally pestered ESA to the point where they ran a test. They came up with a Rube Goldberg system whereby Huygens would transmit to Cassini, Cassini would send the signal to Earth, we'd process it to simulate Huygens' motion once detached, send it back, and Cassini would bounce it back again. To their horror, they got back gibberish. They'd correctly allowed for the Doppler shift between Huygens and Cassini, but failed to realize that would also affect the relative timing of the on-board computers. So they reconfigured the mission and separated Huygens much earlier to keep the timing issues manageable. And thus we have pictures from the surface of Titan. Yay Boris.

And to me, that certainly looks like standing liquid in the most famous picture from the surface. Not only is there a very flat surface but "rocks" within it are flattened as they would be by immersion in a liquid with higher refractive index.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 3:00 pm
by JRB
-290 is obviously F. even still, to say: " The Huygens data and a decade of exploration by Cassini have shown Titan to be a tantalizing world hosting a complex chemistry of organic compounds, dynamic landforms, lakes, seas, and a possible subsurface ocean of liquid water. Really!?

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 3:05 pm
by Chris Peterson
BDanielMayfield wrote:But, consider how short a period it was between the invention of manned flight by the Wright brothers (1903) and people standing on the surface of our Moon (1969). In view of that, many have imagined that people would have reached at least Mars by now.
Perhaps you overlooked the news. We have been to Mars many times in recent decades. And far beyond that.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 3:09 pm
by rstevenson
Chris Peterson wrote:
BDanielMayfield wrote:But, consider how short a period it was between the invention of manned flight by the Wright brothers (1903) and people standing on the surface of our Moon (1969). In view of that, many have imagined that people would have reached at least Mars by now.
Perhaps you overlooked the news. We have been to Mars many times in recent decades. And far beyond that.
You're being disingenuous, Chris. You know he was referring to humans going to Mars, as opposed to just sending devices there.

Rob

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 3:15 pm
by Chris Peterson
rstevenson wrote:
Chris Peterson wrote:
BDanielMayfield wrote:But, consider how short a period it was between the invention of manned flight by the Wright brothers (1903) and people standing on the surface of our Moon (1969). In view of that, many have imagined that people would have reached at least Mars by now.
Perhaps you overlooked the news. We have been to Mars many times in recent decades. And far beyond that.
You're being disingenuous, Chris. You know he was referring to humans going to Mars, as opposed to just sending devices there.
Indeed. But putting people on Mars is merely an engineering problem, entirely within the capabilities of the technology we have developed (and the real discussion here is technology). Because there isn't much reason to send humans there physically, we haven't done so. Nothing to do with technology. In fact, just getting to Mars isn't all that different from getting to the Moon. Old stuff. The real technological advances since going to the Moon have been in computers and robotics, which have allowed us to explore Mars and the rest of the Solar System in a way that would have been completely impossible in 1969, and indeed would still be impossible if we were dependent upon sending humans.

I would argue that our not having sent humans to Mars is a reflection of how advanced our technology is, not an indicator of any lack.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 4:03 pm
by Ron-Astro Pharmacist
I'd be curious to see a list (or to start a discussion) on what only humans could bring to a Mars mission. http://en.wikipedia.org/wiki/Human_mission_to_Mars
1.Describe with human senses what it feels like to be standing on Mars – eyes, ears, smell, feel, taste http://en.wikipedia.org/wiki/Sense Of course that would have to be mainly from the confines of a habitat but it would be possible once established and it would be different from anything a machine was able to do.
2.Real time geology – i.e. investigating leads that only a human's presence could see and determine for close follow-up
3.Other ideas ?

Everything else might be possible by machine. If the list comes up with enough real reasons, then humans should go. Of course, like in the Wanderers, maybe humans need to go to establish basic human fulfillment. I would bet "the human list" has already been discussed in NASA groups but I am not privy to those conversations.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 4:04 pm
by bystander

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 4:10 pm
by Chris Peterson
Ron-Astro Pharmacist wrote:I'd be curious to see a list (or to start a discussion) on what only humans could bring to a Mars mission. http://en.wikipedia.org/wiki/Human_mission_to_Mars
1.Describe with human senses what it feels like to be standing on Mars – eyes, ears, smell, feel, taste http://en.wikipedia.org/wiki/Sense Of course that would have to be mainly from the confines of a habitat but it would be possible once established and it would be different from anything a machine was able to do.
2.Real time geology – i.e. investigating leads that only a human's presence could see and determine for close follow-up
#1, for sure (outside the fact that smell, feel, and taste are likely to be quickly fatal). #2, doubtful that people could do better than machines.

All in all, I think we need to realize that you don't send people to Mars (or anywhere else) for science. It's about exploration, politics, glory... whatever. Whether these kinds of things justify the expense is a matter of opinion, but a pretty solid case can be made that we're not going to do very advanced science this way.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 4:41 pm
by Ron-Astro Pharmacist
I think we could look back to the human exploration of the moon and ask, "Are we happy with that effort and would we choose to do it again?" Many of us have lived through the excitement and fall-off the that enthusiasm many times now for many of our initial journeys to the various space environments. To have an overriding reason for humans to go is crucial, it seems, to keep our interest – as people versus individuals who would push on for their specific interests just as you pointed out.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 6:08 pm
by Boomer12k
Awesome pics.....reminds me of TOFFEE CANDIES!!! :lol2: :lol2:

:---[===] *

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 6:14 pm
by Boomer12k
My humble opinion....
As long as Robotics can do the science and exploration....we have no need to go....and indeed we ARE THERE...through our "little eyes".... :D We get data and knowledge with little to no risk.

BUT I WOULD GO IN A NEW YORK SECOND!!!! 8-)

:---[===] *

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 6:32 pm
by Ron-Astro Pharmacist
Boomer12k wrote:My humble opinion....
As long as Robotics can do the science and exploration....we have no need to go....and indeed we ARE THERE...through our "little eyes".... :D We get data and knowledge with little to no risk.

BUT I WOULD GO IN A NEW YORK SECOND!!!! 8-)

:---[===] *
Besides "what" humans would bring to a Mars mission, maybe a better point would be "why" humans might need to go:
1.To establish an alternate place, other than the Earth, for continuing human existence.
2.To establish an alternate place, other than the Earth, for every other life form that could be brought to sustain itself on Mars.
3.
Of course then that leads to the who, where and when parts too. Why are questions so much easier to ask then to answer? Like, "Should we go and mess it up too?" Lots to think about before we set out. "Clean" machines might be the most appropriate for now. Rarely has the human race "looked before it leaps" when it comes to ethical and moral issues. Mars might be a good time and place to start while we still have the luxury.
Hey – wait a minute. This is about Titan? I shouldn't be proselytizing about Mars. Or maybe it is the right time?? I'll join you Boomer. :wink:

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 6:41 pm
by Chris Peterson
Ron-Astro Pharmacist wrote:Besides "what" humans would bring to a Mars mission, maybe a better point would be "why" humans might need to go:
1.To establish an alternate place, other than the Earth, for continuing human existence.
Probably not something to consider for centuries yet. We totally lack the capacity to create a large enough colony on Mars to be self-sufficient. We are demonstrating an inability to survive on Earth. Finding another planet as a solution to that particular problem is pretty absurd.
2.To establish an alternate place, other than the Earth, for every other life form that could be brought to sustain itself on Mars.
Same response as above.

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 7:51 pm
by rstevenson
Chris Peterson wrote:
Ron-Astro Pharmacist wrote:Besides "what" humans would bring to a Mars mission, maybe a better point would be "why" humans might need to go:
1.To establish an alternate place, other than the Earth, for continuing human existence.
Probably not something to consider for centuries yet. We totally lack the capacity to create a large enough colony on Mars to be self-sufficient. We are demonstrating an inability to survive on Earth. Finding another planet as a solution to that particular problem is pretty absurd.
Establishing off-world colonies to protect ourselves from ourselves would indeed be absurd, if that was the only reason. Protecting our race from the universe is more to the point. We don't want to be watching the approach of the killer asteroid while thinking, "Gee, I guess we should have started a Mars colony years ago. Oh well, too late now!"

Rob

Re: APOD: Huygens Lands on Titan (2015 Jan 16)

Posted: Fri Jan 16, 2015 8:07 pm
by geckzilla
I wonder if an asteroid-stricken Earth would still be easier to survive than Mars?