1 00:00:00,000 --> 00:00:02,000 Welcome, Mars Explorers. 2 00:00:02,000 --> 00:00:04,000 I see you finished your terrarium. 3 00:00:04,000 --> 00:00:08,000 Yes, I'm really pleased with it. I think the terrarium is very close to being in equilibrium. 4 00:00:08,000 --> 00:00:10,000 What's in equilibrium? 5 00:00:10,000 --> 00:00:12,000 It means that everything is in balance. 6 00:00:12,000 --> 00:00:16,000 For example, in a balanced system, the amount of carbon dioxide consumed by the plants 7 00:00:16,000 --> 00:00:19,000 is equal to the carbon dioxide produced by everything else. 8 00:00:19,000 --> 00:00:23,000 My completed, sealed-off terrarium is a self-sufficient system. 9 00:00:23,000 --> 00:00:27,000 That's great, Dr. D. We think we've found the solution to our Mars habitat problem. 10 00:00:27,000 --> 00:00:30,000 We first had to learn a lot about the Mars environment. 11 00:00:30,000 --> 00:00:33,000 Yes, we learned that it's a pretty harsh environment. 12 00:00:33,000 --> 00:00:36,000 Cold, with a sparse atmosphere, and hardly any oxygen. 13 00:00:36,000 --> 00:00:40,000 That meant that our habitat had to be entirely self-contained, except for sunlight. 14 00:00:40,000 --> 00:00:42,000 That's a major source of energy. 15 00:00:42,000 --> 00:00:46,000 Don't forget that gravity on Mars is only one-third as strong as that on Earth. 16 00:00:46,000 --> 00:00:49,000 And we had to watch out for wind storms and meteors. 17 00:00:49,000 --> 00:00:54,000 Since there's almost no oxygen on Mars, we decided we had better have lots of plants. 18 00:00:54,000 --> 00:00:57,000 They not only provide us with food, but also oxygen. 19 00:00:57,000 --> 00:01:00,000 That's right. We had to meet the basic needs of the astronauts. 20 00:01:00,000 --> 00:01:03,000 Food, water, shelter, and oxygen. 21 00:01:03,000 --> 00:01:07,000 And we checked into alien environments, and how plants can grow in them. 22 00:01:07,000 --> 00:01:11,000 I learned that I need to acquire a taste for vegetables, since there won't be any meat. 23 00:01:11,000 --> 00:01:14,000 One of our modules was a trash management facility. 24 00:01:14,000 --> 00:01:17,000 There are a lot more than the four basic needs that need to be met in our habitat. 25 00:01:17,000 --> 00:01:21,000 With our module, we also noticed that we had to take into account the adaptations 26 00:01:21,000 --> 00:01:23,000 that astronauts will have to make to live on Mars. 27 00:01:23,000 --> 00:01:27,000 That's great. Hayley, have you found any more information about your fish problem? 28 00:01:27,000 --> 00:01:33,000 I talked to Mrs. Stewart's class, and they said that migratory patterns are usually consistent. 29 00:01:33,000 --> 00:01:35,000 So I don't think the fish have migrated. 30 00:01:35,000 --> 00:01:38,000 Probably correct. Otherwise, fish would be missing every year. 31 00:01:38,000 --> 00:01:41,000 They suggested I talk to the Virginia Marine Science Committee. 32 00:01:41,000 --> 00:01:44,000 And they said there had been an algal bloom in the bay back home. 33 00:01:44,000 --> 00:01:46,000 But I'm not sure what that is. 34 00:01:46,000 --> 00:01:48,000 Well, let's do an internet search. 35 00:01:48,000 --> 00:01:50,000 Okay, let's pull up a search engine. 36 00:01:51,000 --> 00:01:54,000 Type in the words algal and bloom. 37 00:01:54,000 --> 00:01:57,000 Here's a site that says harmful algae page. 38 00:01:57,000 --> 00:02:00,000 Okay, click on it and see what they have to say. 39 00:02:00,000 --> 00:02:03,000 How does an algal bloom make all the fish disappear? 40 00:02:03,000 --> 00:02:06,000 It says that algae use the nutrients to quickly multiply. 41 00:02:06,000 --> 00:02:11,000 It also says that some algae are toxic to fish. That means that the fish die. 42 00:02:11,000 --> 00:02:15,000 They can last up to a few days, and in some cases over a year. 43 00:02:15,000 --> 00:02:17,000 I hope it doesn't last that long. 44 00:02:17,000 --> 00:02:18,000 Me too. 45 00:02:18,000 --> 00:02:22,000 Guys, we better get back to the treehouse if we want to see our presentation on KSNN. 46 00:02:22,000 --> 00:02:25,000 I'm proud of you guys. I can't wait to see the presentation. 47 00:02:25,000 --> 00:02:28,000 I've got a present for you. Here's a terrarium for your treehouse. 48 00:02:28,000 --> 00:02:30,000 Try to give it lots of indirect sunlight. 49 00:02:30,000 --> 00:02:32,000 Thanks, Dr. D. Bye. 50 00:02:32,000 --> 00:02:33,000 Bye-bye.