{"id":1234,"date":"2019-06-13T17:32:58","date_gmt":"2019-06-13T17:32:58","guid":{"rendered":"https:\/\/wstsm.drmeganargo.net\/?p=1234"},"modified":"2019-07-29T14:59:17","modified_gmt":"2019-07-29T14:59:17","slug":"science-activity-edible-comets","status":"publish","type":"post","link":"https:\/\/wstsm2.drmeganargo.net\/?p=1234","title":{"rendered":"Science Activity: Edible Comets"},"content":{"rendered":"\n<p style=\"text-align:center\"><a href=\"#summary\">Summary<\/a> | <a href=\"#concept\">Key concept<\/a> | <a href=\"#scistory\">Science Story<\/a> | <a href=\"#science\">Background Science<\/a> | <a href=\"#activity\">Activity<\/a> | <a href=\"#curlinks\">Curriculum links<\/a> | <a href=\"#actlinks\">Linked Activities<\/a><\/p>\n\n\n\n<div style=\"text-align: center;\">\n<a href=\"\/resources\/activities\/word\/EdibleComets.docx\"><span style=\"color: Grey;\"><i class=\"far fa-file-word fa-5x\"><\/i><\/span><\/a>&nbsp;&nbsp; &nbsp;&nbsp;\n<a href=\"\/resources\/activities\/pdf\/EdibleComets.pdf\"><span style=\"color: Grey;\"><i class=\"far fa-file-pdf fa-5x\"><\/i><\/span><\/a><br><br>\n<em>Download this activity as Word or PDF &#8211; click on the links above<\/em><\/div>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<div style=\"background-color: #d8d8d8;\">\n<ul class=\"infobox\">\n<li>Suggested Age Range: 7 &#8211; 8 years <\/li>\n<li>UK Primary Curriculum: Key Stage Two (lower)<\/li>\n<li>Suggested UK Year Group: Year 3<\/li>\n<li>UK Primary Curriculum Link: Rocks<\/li>\n<li>Science Subject: Space rocks; Meteors, asteroids and comets<\/li>\n<li>Science Question: What are comets?  What are meteors?  What are asteroids?<\/li>\n<li>Activity type: small groups\n<li>Suggested linked stories: <a href=\"https:\/\/wesharethesamemoon.org\/?p=713\">Dancing with the Stars<\/a><\/li><\/ul><\/div>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><span id=\"summary\"><strong>Brief summary:<\/strong><\/span> Our Solar System contains the Sun, the eight planets, as well as numerous dwarf planets, many asteroids, and an unknown number of comets.\u00a0\u00a0Comets have often featured in historical accounts as portents of doom or disaster (one features in the Bayeux Tapestry, for example), but the reality is that they are giant dirty snowballs.\u00a0\u00a0As they get close to the Sun they begin to warm, and some of the ice begins to turn to gas, creating the spectacular tails visible from Earth.\u00a0\u00a0This activity helps students to understand what comets are made of, and why they look the way they do in the sky.<\/p>\n\n\n\n<p><span id=\"concept\"><strong>Key concept:<\/strong><\/span> comets are made of ice, dust, rock, and traces of simple organic materials.<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"alignleft\"><a href=\"https:\/\/wstsm.drmeganargo.net\/wp-content\/uploads\/2019\/06\/comet_752px-Iss030e015472.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"220\" height=\"300\" src=\"https:\/\/wstsm.drmeganargo.net\/wp-content\/uploads\/2019\/06\/comet_752px-Iss030e015472-220x300.jpg\" alt=\"Comet Lovejoy photographed from the International Space Station.  Credit: NASA\/Dan Burbank.\" class=\"wp-image-1250\" srcset=\"https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/06\/comet_752px-Iss030e015472-220x300.jpg 220w, https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/06\/comet_752px-Iss030e015472.jpg 752w, https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/06\/comet_752px-Iss030e015472-676x921.jpg 676w\" sizes=\"auto, (max-width: 220px) 100vw, 220px\" \/><\/a><figcaption>Comet Lovejoy as seen from the International Space Station. Image credit:&nbsp;<a href=\"https:\/\/spaceflight.nasa.gov\/gallery\/images\/station\/crew-30\/html\/iss030e015472.html\">NASA\/Dan Burbank<\/a>.<\/figcaption><\/figure><\/div>\n\n\n\n<p>Left: a photograph of Comet Lovejoy, as seen from the International Space Station, orbiting roughly 200 kilometres above the surface of the Earth.&nbsp;&nbsp;The comet is seen against a background of stars.&nbsp;&nbsp;The dark area at the bottom of the photograph is the surface of the Earth.&nbsp;The fuzzy green line is a phenomenon known as air glow.&nbsp;&nbsp;Between the ground and the green air glow lies our atmosphere.&nbsp;&nbsp;The comet is a long way from the Earth and so, although it looks as though it is heading into the atmosphere, it is actually in the background. <\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"684\" src=\"https:\/\/wstsm.drmeganargo.net\/wp-content\/uploads\/2019\/07\/meteor-1024x684.jpg\" alt=\"\" class=\"wp-image-1586\" srcset=\"https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/07\/meteor-1024x684.jpg 1024w, https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/07\/meteor-300x200.jpg 300w, https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/07\/meteor-768x513.jpg 768w, https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/07\/meteor-676x451.jpg 676w, https:\/\/wstsm2.drmeganargo.net\/wp-content\/uploads\/2019\/07\/meteor.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption><strong>Above:&nbsp;<\/strong>this is a photograph of a shooting star.&nbsp;&nbsp;These look different to comets \u2013 they are much thinner, and they move much faster.&nbsp;&nbsp;Comets can stay in the sky for many weeks, whereas meteorites pass through the atmosphere in less than a second.<br><strong>Image source:&nbsp;<\/strong><a rel=\"noreferrer noopener\" href=\"https:\/\/www.flickr.com\/photos\/joshuatreenp\/20713070995\/in\/album-72157651261832459\/\" target=\"_blank\">https:\/\/www.flickr.com\/photos\/joshuatreenp\/20713070995\/in\/album-72157651261832459\/<\/a><\/figcaption><\/figure>\n\n\n\n<p><span id=\"scistory\"><strong>The Science Story:<\/strong><\/span> <em>Have you ever noticed that it gets cold at night?\u00a0\u00a0Why do you think that is?<\/em>\u00a0\u00a0It gets cold because the Sun goes down, the Sun is what keeps the Earth warm.\u00a0\u00a0<em>What do you think, would it be warmer or colder if we lived further away from the Sun?<\/em>\u00a0\u00a0It would be colder.\u00a0\u00a0Just like when you sit close to a radiator or a bonfire, it is very hot close to the Sun, but if you go far away it gets much colder.\u00a0\u00a0Imagine if we travel in a rocket and go four thousand times further from the Sun, out where it gets very, very cold indeed.\u00a0\u00a0Out here, in the edge of the Solar System where it is cold and dark, this is where comets live most of the time.\u00a0\u00a0<em>Has anyone ever seen a comet?\u00a0What does a comet look like?<\/em>\u00a0Comets are fuzzy blobs in the sky, a comet looks like a tiny cloud when you look at it through a telescope.\u00a0\u00a0Sometimes they have tails (illustrate with a photograph, or a model \u201c<a href=\"https:\/\/wesharethesamemoon.org\/?p=1297\">Comet on a Stick<\/a>\u201d, see linked activities, below) that can stretch across the sky, some comets look spectacular!\u00a0\u00a0They only look like this when they get close to the Sun though.\u00a0\u00a0<em>What do you think comets are made of?<\/em>\u00a0\u00a0Comets are made of ice, dust, and smalls bits of rock, all mashed together to make a giant dirty-snowball.\u00a0\u00a0Imagine a snowball as big as a city!\u00a0\u00a0Far away from the Sun they stay frozen, just like ice cream does in the freezer.\u00a0\u00a0<em>But if a comet is unlucky and comes close to the Sun, what happens?<\/em>\u00a0\u00a0If a comet gets too close to the Sun it begins to melt, just like a snowman in the spring.\u00a0\u00a0As it melts some of the ice and dust gets left behind as it travels around the Sun, and those bits that are left behind are what makes the spectacular tails.\u00a0When the Earth passes through these tails, some of the rocks fall though the atmosphere and hit the ground \u2013 these are known as meteorites.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><span id=\"science\"><strong>The Science:<\/strong><\/span> Comets are made of the material left over from the formation of our Solar System, roughly 4.5 billion years ago.\u00a0\u00a0They mostly consist of ice, dust, rocks of various sizes, and traces of organic compounds.\u00a0\u00a0There is a lot of scientific interest in studying comets because they formed so long ago, the hope is that by studying their chemistry we can better understand the formation of the Solar System and test models of how the Solar System has evolved over the last 4.5 billion years.\u00a0\u00a0Comets spend the majority of their time in the outer Solar System where it is very cold, many thousands of times further from the Sun than the Earth.<br><br>Comets are made of the material left over from the formation of our Solar System, roughly 4.5 billion years ago.\u00a0\u00a0They mostly consist of ice, dust, rocks of various sizes, and traces of organic compounds.\u00a0\u00a0There is a lot of scientific interest in studying comets because they formed so long ago, the hope is that by studying their chemistry we can better understand the formation of the Solar System and test models of how the Solar System has evolved over the last 4.5 billion years.\u00a0\u00a0Comets spend the majority of their time in the outer Solar System where it is very cold, many thousands of times further from the Sun than the Earth.<br><br>Unlike planets, comets do not move in circular orbits around the Sun, instead they travel in very elongated elliptical orbits.\u00a0\u00a0These elliptical orbits mean that, from time to time, one of them comes close to the Sun.\u00a0As a comet moves closer to the Sun, the temperature rises and the ice on the surface starts to sublimate \u2013 it passes from a solid to a\u00a0gas without passing through the liquid state (this can happen at low pressures such as those in the near-vacuum of space).\u00a0\u00a0As the water turns to vapour, it can take some of the dust with it.\u00a0\u00a0This forms a cloud around the comet nucleus, known as a coma \u2013 this is what makes comets appear fuzzy through binoculars or a telescope.\u00a0The comet keeps moving in its orbit while this process happens, and as it does so it leaves behind a debris trail of gas and dust behind it.\u00a0\u00a0This debris that is left behind is what causes meteors \u2013 when the Earth passes through this left-behind debris, the bits of rock fall into the Earth\u2019s atmosphere and become meteors.<br><br>The Sun is continuously shining, but it is also producing a constant \u201cwind\u201d of particles and gas moving out through the Solar System at hundreds of kilometres per second.\u00a0\u00a0This wind pushes the material in the debris trail of the comet, just like a hairdryer would blow away the steam from a pan of boiling water.\u00a0\u00a0The consequence of this is that the tail of a comet always points directly away from the Sun.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><span id=\"activity\"><strong>The activity:<\/strong><\/span> This is best done in small groups.\u00a0\u00a0Supervision is recommended as it can get messy, and it is best to use ice straight from the freezer if you can (warmer ice does not work as well).\u00a0\u00a0If you have access to liquid nitrogen, this works really well for this activity, freezes the comets much faster, and is a bit of a \u201cwow\u201d factor, but MUST be done by an adult with appropriate safety equipment.<\/p>\n\n\n\n<p style=\"color:#ff0000\" class=\"has-text-color\"><strong>Safety note<\/strong>: It may be necessary to substitute some items in this activity in case of allergies, intolerances or dietary requirements of anyone participating.&nbsp;&nbsp;Dairy-and gluten-free alternatives are available.&nbsp;&nbsp;Check the ingredients carefully.<\/p>\n\n\n\n<p><strong>Props required:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Large resealable food bags<\/li><li>Small resealable food bags<\/li><li>Lots of ice<\/li><li>Whole milk (low-fat versions do not work as well)<\/li><li>Cookies, crushed (for the dust)<\/li><li>Chocolate chips (for the rocks)<\/li><li>Vanilla essence (for the organic material)<\/li><li>Gloves for handling the ice<\/li><li>Small paper cups and spoons for eating the comets!<\/li><li><\/li><\/ul>\n\n\n\n<ol class=\"wp-block-list\"><li>You are going to make a model of a comet &#8211; unlike real comets, this one will be good enough to eat!&nbsp;&nbsp;First you need to collect your ingredients (see above).<\/li><li>Place about 100ml of milk in the small sandwich bag \u2013 this is the ice that makes up the main part of a comet body.<\/li><li>Break up your cookie and add it to the milk.&nbsp;&nbsp;The cookie pieces represent the dust and loose rocks in the comet.<\/li><li>Add the chocolate chips to represent the rocks.<\/li><li>Add a couple of drops of vanilla essence to represent the organic materials.<\/li><li>Ensure the small bag is sealed shut, and give it a bit of a shake to mix the ingredients.<\/li><li>One person in your group should put on the gloves and put lots of ice in the large bag, the more the better but leave some space for the comet.<\/li><li>Place the comet bag inside the bag with the ice and shake it a bit.&nbsp;&nbsp;Keep it moving so that all the milk starts to turn to ice.<\/li><li>When the milk has started to freeze, remove the smaller bag and discard the ice somewhere safe.\u00a0\u00a0Spoon the comet into the cups and enjoy!<\/li><\/ol>\n\n\n\n<p><strong>Extension<\/strong>: This activity can be extended by making edible asteroids such as in this activity from the <a href=\"https:\/\/www.lpi.usra.edu\/education\/space_days\/activities\/spaceRocks\/makeAtHome.pdf\">Lunar and Planetary Institute<\/a> and doing a \u201ccompare and contrast\u201d exercise, looking at the similarities and differences between comets and asteroids.<\/p>\n\n\n\n<p><strong>Common misconceptions:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Comets are often confused with shooting stars (also known as meteors).&nbsp;&nbsp;Comets are long-lived objects that can be visible in the night sky for many weeks when near to the Sun, meteors are small bits of rocks that are only visible very briefly (typically for less than a second) as they burn up in our own atmosphere.<\/li><li>\u201cOrganic compounds\u201d means there is life \u2013 organic compounds do not automatically mean that there is life, an organic compound is just a compound that contains the element carbon.<\/li><li>Comet tails always show you which direction the comet came from \u2013 the tails are made up of material that is so light that the solar wind is strong enough to push it around.&nbsp;As a result of this, comet tails always point directly away from the Sun.<\/li><\/ul>\n\n\n\n<p><span id=\"curlinks\"><strong>Curriculum links<\/strong>:<\/span> <\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Rocks KS2 (lower) \u2013 can be used in conjunction with an activity comparing the characteristics of different rocks and\/or looking at different meteorites.<\/li><li>Light KS2 (lower) \u2013 notice that light is reflected from surfaces, we see comet tails because light from the Sun reflects from the particles of ice and rock.<\/li><li>States of matter KS2 (lower) \u2013 observe that some materials change state when heated or cooled.<\/li><li>Earth and space KS2 (upper) \u2013 describe the movements of objects in the Solar System.<\/li><li>Forces KS2 (upper) \u2013 gravity keeps the planets (and comets) in orbit around the Sun, and the solar wind produces a force that creates comet tails.<\/li><\/ul>\n\n\n\n<p><span id=\"actlinks\"><strong>Linked activities<\/strong>:<\/span> <\/p>\n\n\n\n<p>Craft activity: \u201ccomet on a stick\u201d from NASA \u2013 can be used to make a classroom display.<br><a href=\"https:\/\/spaceplace.nasa.gov\/comet-stick\/en\/\">https:\/\/spaceplace.nasa.gov\/comet-stick\/en\/<\/a><\/p>\n\n\n\n<p>A more complex version of this activity from NASA.<br><a href=\"https:\/\/www.nasa.gov\/sites\/default\/files\/546138main_ESS8_Eat-A-Comet_C2.pdf\">https:\/\/www.nasa.gov\/sites\/default\/files\/546138main_ESS8_Eat-A-Comet_C2.pdf<\/a><\/p>\n\n\n\n<p><strong>Other resources<\/strong>:<\/p>\n\n\n\n<p>STFC\u2019s Borrow the Moon &#8211; borrow some space rocks to use in the classroom!<br><a href=\"https:\/\/stfc.ukri.org\/public-engagement\/activities-for-schools\/borrow-the-moon\/\">https:\/\/stfc.ukri.org\/public-engagement\/activities-for-schools\/borrow-the-moon\/<\/a><br><\/p>\n\n\n\n<p><strong>Copyright: Megan Argo 2019<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Our Solar System contains the Sun, the eight planets, as well as numerous dwarf planets, many asteroids, and an unknown number of comets.  Comets have often featured in historical accounts as portents of doom or disaster (one features in the Bayeux Tapestry, for example), but the reality is that they are giant dirty snowballs.  As they get close to the Sun they begin to warm, and some of the ice begins to turn to gas, creating the spectacular tails visible from Earth.  This activity helps students to understand what comets are made of, and why they look the way they do in the sky.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20,5,7],"tags":[91,90,32,70,30,79],"class_list":["post-1234","post","type-post","status-publish","format-standard","hentry","category-ks2-science-activity","category-resources","category-science-activity","tag-comets","tag-edible","tag-make-your-own","tag-rocks","tag-science","tag-solar-system","post-preview"],"_links":{"self":[{"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=\/wp\/v2\/posts\/1234","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1234"}],"version-history":[{"count":7,"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=\/wp\/v2\/posts\/1234\/revisions"}],"predecessor-version":[{"id":1854,"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=\/wp\/v2\/posts\/1234\/revisions\/1854"}],"wp:attachment":[{"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1234"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1234"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wstsm2.drmeganargo.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1234"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}