WEBVTT 00:00:03.376 --> 00:00:08.040 🎵 [music] 🎵 00:00:11.226 --> 00:00:14.671 KIDS: Our World! 00:00:14.673 --> 00:00:18.083 EVAN: Hold on Globey, just one more cut should do it. 00:00:18.085 --> 00:00:22.738 Here we go... and Ta Dah!!! 00:00:22.740 --> 00:00:25.758 It’s a snowflake!! Snowflakes are a beautiful part of our 00:00:25.760 --> 00:00:28.670 world and they also very fascinating. 00:00:28.671 --> 00:00:32.498 One place that’s no stranger to snow is Lake Placid, New York. 00:00:32.500 --> 00:00:36.068 Once a year NASA Goddard Space Flight Center co hosts a 00:00:36.070 --> 00:00:39.205 program called the History of Winter. It’s there that 00:00:39.206 --> 00:00:41.306 students and teachers can study... 00:00:41.308 --> 00:00:44.710 You guessed it, snow! Let’s visit some experts there and 00:00:44.711 --> 00:00:47.013 find out why NASA has such an interest in the 00:00:47.015 --> 00:00:49.348 science of snow. TIM MCCOLLUM: The idea was that 00:00:49.350 --> 00:00:54.086 the students would become engaged in scientific research. 00:00:54.088 --> 00:00:56.588 It wouldn’t be a word problem in a book. It would be 00:00:56.590 --> 00:00:59.058 something that they could literally be outside looking at 00:00:59.060 --> 00:01:01.293 something that they could analyze. Something they could 00:01:01.295 --> 00:01:03.530 study. They’d have to dress, they’d have to prepare for the 00:01:03.531 --> 00:01:08.066 elements. When students look at a snowflake, because of what 00:01:08.068 --> 00:01:11.436 they’ve learned and what we’ve learned about the structure and 00:01:11.438 --> 00:01:14.073 everything that goes into forming a snowflake as it’s 00:01:14.141 --> 00:01:17.071 falling from the sky and the different changes that it goes 00:01:17.140 --> 00:01:19.745 through. That a snowflake represents a history of what 00:01:19.813 --> 00:01:22.315 happened to that snowflake on the way down. 00:01:22.316 --> 00:01:25.318 EVAN: So if I stare at a snowflake and find out exactly 00:01:25.320 --> 00:01:28.621 what it’s been through, you could call me a snow detective! 00:01:28.623 --> 00:01:31.891 But what causes snow and where does it come from? 00:01:31.893 --> 00:01:34.960 TIM: Snow is not rain that freezes on the way down. 00:01:34.961 --> 00:01:38.163 That’s how we end up with sleet. Snow is basically 00:01:38.165 --> 00:01:41.701 something that forms directly from water vapor in the air. 00:01:41.703 --> 00:01:43.836 PETE WASILEWSKI: The cloud conditions first of all have to 00:01:43.838 --> 00:01:46.973 be cold enough and then you need a little bit of 00:01:46.975 --> 00:01:52.345 dust to nucleate a little tiny ice crystal. 00:01:52.346 --> 00:01:56.783 TIM: Then as those snowflakes fall, as they pass through 00:01:56.785 --> 00:01:59.385 different layers of temperature, and different 00:01:59.386 --> 00:02:02.188 percentages of humidity, and as the wind blows them around and 00:02:02.190 --> 00:02:04.356 as they bump into other snowflakes on their way down- 00:02:04.358 --> 00:02:07.860 all of those factors go into the actual shape and you wind 00:02:07.861 --> 00:02:10.496 up getting more of these star like pattern that we’re 00:02:10.498 --> 00:02:13.766 familiar with. Looking at a snowflake really does tell so 00:02:13.768 --> 00:02:16.601 much about its history as it’s falling. 00:02:16.603 --> 00:02:19.405 EVAN: So if no two snowflakes are alike, then what are the 00:02:19.406 --> 00:02:22.541 different types of snowflakes? TIM: That is what the students 00:02:22.543 --> 00:02:25.111 are most interested in. And they see there is such a wide 00:02:25.113 --> 00:02:28.146 variety. Most snowflakes, or many snowflakes don’t look at 00:02:28.148 --> 00:02:32.085 all like what most people think in terms of a snowflake. 00:02:32.086 --> 00:02:35.455 Some of them look like bullets. They literally have a pointy 00:02:35.456 --> 00:02:38.323 end. And when you walk into a driving snowstorm, and it’s 00:02:38.325 --> 00:02:41.160 hitting your face and it kind of stings and you look at the 00:02:41.161 --> 00:02:43.763 shape of those crystals, well that makes sense. Or they’ll 00:02:43.765 --> 00:02:47.200 look like hourglasses, we call hollow columns. Or capped 00:02:47.201 --> 00:02:50.503 columns which almost look like spools of thread. And there’s 00:02:50.505 --> 00:02:55.275 such a wide variety, but they’re still all ice crystals. 00:02:55.276 --> 00:02:58.076 EVAN: At the “History of Winter” event, teachers and 00:02:58.078 --> 00:03:01.013 students look at the shape of snowflakes then record the 00:03:01.015 --> 00:03:04.050 weather conditions. They’re building a huge database of 00:03:04.051 --> 00:03:07.335 crystals and weather conditions to discover connections. 00:03:07.336 --> 00:03:09.921 But why do all this research? 00:03:09.923 --> 00:03:13.225 TIM: As much as we’ve learned about the Earth’s system and 00:03:13.226 --> 00:03:16.796 what a complex system it is, the more we realize there’s so 00:03:16.798 --> 00:03:20.233 much we don’t’ know. And as we learn more about something as 00:03:20.235 --> 00:03:23.168 simple as a snowflake, and the conditions it takes to form a 00:03:23.170 --> 00:03:26.205 snowflake, it helps all of us have a better understanding of 00:03:26.206 --> 00:03:30.076 the way the atmosphere works. Hopefully we will learn more 00:03:30.078 --> 00:03:34.065 about the conditions that change our climate. 00:03:34.066 --> 00:03:37.283 EVAN: Who knew you could learn so much from something as small 00:03:37.285 --> 00:03:40.386 as a snowflake? I think I’m going outside and be a snow 00:03:40.388 --> 00:03:43.623 detective too. Come on Globey! 00:03:43.625 --> 00:03:47.260 You can be a snow detective too, just go to the History of 00:03:47.261 --> 00:03:50.833 Winter website and download the forms. 00:03:53.341 --> 00:03:57.441 ? [music] ? 00:04:02.466 --> 00:04:06.755 KIDS: Our World!