Third Thursday Telecons

[jsmaje]

I couldn't join the Telecon, but am grateful for Evelyn's and Mike's summaries.

Re the dunes on 67P, this is from http://www.bbc.co.uk/news/science-environment-30931445:
The researchers report some fascinating behaviours over and above the expected sight of jets of gas and dust hurtling away from the comet as its ices warm and vaporise.
For example, these jets produce strong "winds" that appear to drive dust particles into dunes.
"It sounds highly improbable," commented Nic Thomas from Switzerland's University of Bern. "We see sand dunes on the Earth, on Mars and on Venus, but all of those objects have gravity and thick atmospheres.
"On the comet, you have almost no gravity and it's not an atmosphere we could breathe. So, it really is difficult to conceive how you can make sand dunes on a cometary nucleus. The trick we think is that there are very strong winds there - 300m/s - and that these winds can, even though the density of the gas is very low, push particles around to make the dunes."

As for the Ceres lights (of which I’ve read there were more of than just those prominent two, and were actually flickering rather than constant) - possibly volcanic eruptions? Has Dawn yet orbited sufficiently round again to check if they are still there and at the same luminosity?

Whatever the cause of both these phenomena, what extraordinary examples of the wonders to be revealed by space exploration, and worth every cent/penny/euro/yen of our money, via whichever nation's tax-funded budgets or private investment.

Exciting times!
John

[DanZ]

Hi John. Any chance you can join us for this week's telecon and ask some of your recent questions in that forum? You might get quicker answers!

Regarding Ceres, I just attended a presentation from the DAWN Mission PI (which will be available here fairly soon) and he barely mentioned the two reflective areas. But they plan to get closer and closer (and closer) to the dwarf planet over the coming months and take as many pictures as they can. Actually, they just came out of a no-contact period (as the craft descended lower in orbit) and have brand new photos released. You can follow the progress here: http://dawn.jpl.nasa.gov/news/

Otherwise, stay tuned for confirmation on this week's telecon with Dr. Westphal!

Dan

[DanZ]

Okay Everyone.

We are on for this Thursday at 11am Pacific Time and the call-in number remains the same - 1-866-740-1260. When prompted, please enter the passcode 6422969 followed by the # (pound) key. If you need a number from outside the US, please enter 6422969 at https://www.readytalk.com/account-admin ... al-numbers to retrieve the correct phone number to dial. You may also want to double check your corresponding timezone time here. If you haven't submitted a question, but would like to, you may do so until end of day tomorrow (14 Apr). Also, please help us spread this info to any other dusters you know.

Thanks - we look forward to speaking with you soon!

Dan

[caprarom]

Dan, if I understand correctly, we might soon be examining some foils as well as aerogel. If so, will there be any instruction on the website as what to look for in the foils? Perhaps that will be intuitive enough, just wondered. TTY Thursday. Mike

[DanZ]

Dan, if I understand correctly, we might soon be examining some foils as well as aerogel. If so, will there be any instruction on the website as what to look for in the foils? Perhaps that will be intuitive enough, just wondered. TTY Thursday. Mike

We actually just had a meeting about this today! One of the reasons it has stalled is because we have to setup a totally separate site for this, and today we discussed some of the training needs (yes, there will be a test!), and needs for calibrated movies so that we can do some scoring, just like we currently do for the aerogel site. More news to come! Dan

[DanZ]

As luck would have it, Dr. Westphal just got access to the local synchrotron machine (which is very limited), and of course, it's for Thursday. Nevertheless, Dr. Zack Gainsforth, a longtime and critical member of the Stardust research team, has agreed to step in. Thus the telecon for this Thursday is still on! See my post yesterday for when/how to join. For more on Dr. Gainsforth, see http://berkeley.academia.edu/ZackGainsforth/ Until Thursday! Dan

[SmithES]

DanZ, We will miss Dr. Westphal tomorrow. I am excited that Zack Gainsforth will host the Telecon since we discussed the difficulty of extracting tracks from the gel without destroying or damaging them, on our last Telecon. I googled Dr. Gainsforth and found that he, along with Dr. Westphal and others, is working on that problem right now! I copied this excerpt from google: Here we report on the successful implementation of infrared near-field imaging, spectroscopy and analysis techniques capable of sub-micron scale mineral identification within natural samples, including . . . a cometary dust grain (Iris) from NASA's Stardust mission . . . this work . . . inaugurates a new era of infrared nano-spectroscopy applied to small and invaluable extraterrestrial samples. Hopefully, these men will be able to, in a non-destructive manner, extract and examine a dust particle close at hand! Looking forward to Telecon tomorrow. ERSTRS- Evelyn

[caprarom]

Dan, it was a real pleasure to "meet" Dr. Gainsforth yesterday. His enthusiasm is contagious and being able to see the slides really enhanced the discussion. It was very educational and you were both most gracious in answering all our questions - I was beginning to worry we might keep you 'overtime.' Thanks again for hosting the telecon. Hope Andrew had a very productive day on the synchrotron. Mike

[SmithES]

(Friday, April 17, 2015) Hey, Dan,and fellow Dusters, It was such a privilege to hear Dr. Zack Gainsforth yesterday! The full-color slides he had prepared, helped me to (partly) understand the information given. My hubby Ted was listening, too, so he helped interpret most of it for me after the Telecon. That there is now International cooperation in furthering the "Real Heart of Interstelar- microscopic dust," is encouraging. In 2006, when the spacecraft from Comet Wild-2 returned to Earth, Dr. Westphal conceived the brilliant idea that humans using microscopes downloaded onto their computers, would be able to recognize bits of stardust. Stardust@Home was born! I remember that 4,000 or so dusters joined up that first year. I was one of them. We have grown and matured over the past nine years,and we dusters are still looking for extraterrestrial space particles from Comet Wild-2. That is exciting enough. But the renowned Dr. Zack Gainsfoth said yesterday that new technology is being developed to "catch up" with the needs of Stardust@Home Team. For example, if I understood him right, we currently have no way to measure Isotopes. But, instruments to do this "are just over the horizon." My invitation to my fellow dusters is that you come aboard for the Third Thursday Telecons! The trip ahead for Dusters gets more and more exciting! Evelyn, ERSTRS

[DanZ]

So glad you could join us Mike and Evelyn, and Ted too! We're very happy that you find value in these discussions. And you are correct Evelyn, much of what we want to do with these samples can't be done yet. In fact, proposals are in the works as I write to devise new technologies and techniques for more in-depth investigations of these rare particles. Finding more definitely helps!

Note: I'm trying to find time to post the recordings of these presentations on the Stardust@home website, and once done, I'll make the announcement here. In the meantime, we look forward to having you (and anyone else) join us again (live) next month!

All the best.

Dan

[caprarom]

Thanks for the link to the "Science" article, Dan. It made more sense after the background information Dr. Gainsforth provided. It also raised a question that has nagged at me before. Assuming the seven particles are indeed all ISD particles, and the only ones, I had to wonder what the odds were that four of the seven would impact the foils when the foils make up only 15% of the target area. I dusted off my old probability book and came up with a probability of 1.09%*. Does that bother anyone else? Perhaps we can address it next month. Mike

* P(x=4) = (7!/4!3!)(0.15)exp4(0.85)exp3
Of course, even lower odds result if one uses the actual areas mentioned in the paper, 250sqcm aerogel and 5sqcm foil, but I don't know how the foil sample was selected, probably not at random. If it was at random, then P(x=4) = (7!/4!3!)(5/255)exp4(250/255)exp3 = .000005 or .0005%.

[jsmaje]

Today, April 20, 2015, at Ceres_bright_spots_come_back:
“The two brightest spots on dwarf planet Ceres, which have fascinated scientists for months, are back in view in the newest images from NASA's Dawn spacecraft”.
They look just as prominent as before to me, but still no clues yet as to their cause. However, Dawn’s orbit will soon be closing in:
“On May 9, Dawn will begin to make its way to lower orbits to improve the view and provide higher-resolution observations”.

[eagle]

Hi all,

it is very important that the Telecons reports is published here.

Thank you so much for all those unable to attend to them.

[DanZ]

Thanks for the link to the "Science" article, Dan. It made more sense after the background information Dr. Gainsforth provided. It also raised a question that has nagged at me before. Assuming the seven particles are indeed all ISD particles, and the only ones, I had to wonder what the odds were that four of the seven would impact the foils when the foils make up only 15% of the target area. I dusted off my old probability book and came up with a probability of 1.09%*. Does that bother anyone else? Perhaps we can address it next month. Mike

* P(x=4) = (7!/4!3!)(0.15)exp4(0.85)exp3
Of course, even lower odds result if one uses the actual areas mentioned in the paper, 250sqcm aerogel and 5sqcm foil, but I don't know how the foil sample was selected, probably not at random. If it was at random, then P(x=4) = (7!/4!3!)(5/255)exp4(250/255)exp3 = .000005 or .0005%.

Hi Mike. I just chatted with Dr. Westphal and he's wondering if you wouldn't mind taking his answer during the next Thursday Telecon, so he can better explain the details. Is that okay? Dan

[caprarom]

Absolutely, Dan. That was what I meant when I said we might address it "next month." I should have specifically said at the telecon.