WATER BEARS: THE ANIMAL THAT SURVIVED SPACE! Meet a hardy little organism called the water bear Water bears, also known as tardigrades, are a wonder! They are tiny eight-legged creatures, known for their virtual indestructibility on Earth They can survive almost anything: extreme temperatures, tons of radiation, the pressures of the deep sea, starvation, and nearly a decade without water Now their legendary toughness has been put to the ultimate test They've been sent into space! In the past, some biologists have suggested that tardigrades may be the only animal to come back alive after a trip in real space Scientists now decided to send them into space to find out if that is true Once in space, all the water bears were exposed to the vacuum of space, and some were even exposed to solar and cosmic radiation After 10 days of exposure to space, the satellite returned to Earth The water bears were rehydrated to see how their reproductive abilities were affec ted Task Label the paragraphs with their topic Significance of water bears The Experiment Objective of Experiment Who Are Tardigrades Results of Experiment Task Find synonyms in the text for the phrases the force of pushing The vacuum itself seemed to have little effect on the creatures But ultraviolet radiation , which can damage cellular material and DNA, did take its toll Yet, a handful of animals even survived full exposure to the Sun's UV light, which is more than 1000 times stronger in space than on the Earth's surface Water bears are a mystery They have an unparalleled ability to cope with the extremely dry conditions of deep vacuum and the harmful solar and cosmic radiation up there, which has piqued scientific curiosity Still, no one quite understands how they can be as resistant as they are Besides, they are also challenging our traditional concepts of life, for instance that life depends on water, or that life is a continuous process 10 11 12 13 14 15 16 17 18 a lot of UV waves ability to create children being faced with certain conditions harm to sg to excite scientists’ interest having a second name having eight legs having no rivals idea impossibility to destroy having nothing to eat ten years the best or the biggest to question that sg is true to be influenced by sg to be soaked in water to face certain conditions TARDIGRADE QUIZ I Are water bears bacteria or animals? A They have claws and eyes They are real animals B They are bacteria C Neither, they are the largest known viruses II How big are they? A Tardigrades are about the size of a fly B Bigger adults are visible to the naked eye, reaching about 1,5 mm in length C They can only be seen under a microscope III How many legs they have? A Tardigrades are six-legged B Tardigrades are seven-legged C Tardigrades are eight-legged IV Where they live? A They are found throughout much of Asia and Africa B Tardigrades occur over the entire world, from the high Himalayas (above 6,000 m), to the deep sea (below 4,000 m) and from the polar regions to the equator C They can only be found inside active volcanos in Peru V How did they get their name? A The name water bear comes from the way they walk, reminiscent (=reminding) of a bear's B The name is a reminder of their distant genetic relationship with bears C The name reflects their ability to go into hibernation to survive extremes VI How hot is too hot for them? A They can survive temperatures between -50 and 90 °C for a few minutes B They can survive temperatures between -150 and 125 °C for a few minutes C They can survive being chilled to –272 °C (absolute zero is −273.15 °C), or being heated to 151 °C for a few minutes VII How long can they go without water? A Tardigrades can go without water for nearly one year B Tardigrades have been shown to survive nearly one decade in a dry state C Tardigrades can survive nearly one hundred years in a dry state VIII How much radiation can they survive? A They can withstand (=survive) 17,000 rads of x-ray radiation (1,000–2,000 rads could be fatal to a human) B They can withstand 57,000 rads of x-ray radiation C They can withstand 570,000 rads of x-ray radiation IX How they survive extreme conditions? A They're capable of halting (=stopping) their metabolisms (=life functions) during times of extreme privation (=a lack of basic things), and can repair DNA damage caused by extraordinary doses of radiation B They are supposed to be alien organisms that landed on Earth with an incoming meteor Their native planet must have been much closer to the Sun, making them evolve resistance toward extreme heat and radiation C They survive extremes by having a tremendously resilient (=resistant) shield that reflects heat and radiation Source URLs: http://tardigradesinspace.blogspot.com/ http://blog.wired.com/wiredscience/2008/09/invertebrate-as.html http://www.newscientist.com/article/dn14690?DCMP=ILChmts&nsref=news1_head_dn14690 http://en.wikipedia.org/wiki/Tardigrade http://x1brettstuff.blogspot.com/2007/10/tardigrades-in-space.html TARDIGRADE QUIZ SOLUTIONS I Are water bears bacteria or animals? A They have claws and eyes They are real animals II How big are they? B Bigger adults are visible to the naked eye, reaching about 1,5 mm in length III How many legs they have? C Tardigrades are eight-legged IV Where they live? B Tardigrades occur over the entire world, from the high Himalayas (above 6,000 m), to the deep sea (below 4,000 m) and from the polar regions to the equator V How did they get their name? A The name water bear comes from the way they walk, reminiscent of a bear's VI How hot is too hot for them? C Tardigrades can survive being chilled to –272 °C (absolute zero is −273.15 °C), or being heated to 151 °C for a few minutes VII How long can they go without water? B Tardigrades have been shown to survive nearly one decade in a dry state VIII How much radiation can they survive? C They can withstand 570,000 rads of x-ray radiation (1,000–2,000 rads could be fatal to a human) IX How they survive extreme conditions? A They're capable of halting their metabolisms during times of extreme privation, and can repair DNA damage caused by extraordinary doses of radiation Source URLs: http://tardigradesinspace.blogspot.com/ http://blog.wired.com/wiredscience/2008/09/invertebrate-as.html http://www.newscientist.com/article/dn14690?DCMP=ILChmts&nsref=news1_head_dn14690 http://en.wikipedia.org/wiki/Tardigrade http://x1brettstuff.blogspot.com/2007/10/tardigrades-in-space.html COMPREHENSION QUESTIONS ARTICLE & QUIZ Why did scientists send water bears into space? …………………………………………………………………………………………………………………… What was more difficult for water bears to survive: vacuum or cosmic radiation? …………………………………………………………………………………………………………………… How does the existence of water bears inform our understanding of what “life” is? …………………………………………………………………………………………………………………… How long can water bears go without water? …………………………………………………………………………………………………………………… How did tardigrades get their names? …………………………………………………………………………………………………………………… Are tardigrades real animals? …………………………………………………………………………………………………………………… What scientists understand about how these creatures can survive such extremes that no other animal can? …………………………………………………………………………………………………………………… VOCABULARY PRACTICE a force of pushing ……………………………………………… a lot of UV waves ……………………………………………… ability to create children ……………………………………………… being faced with certain conditions ……………………………………………… decade ……………………………………………… harm to sg ……………………………………………… having a second name ……………………………………………… having eight legs ……………………………………………… having no rivals ……………………………………………… 10 having nothing to eat ……………………………………………… 11 idea ……………………………………………… 12 impossibility to destroy ……………………………………………… 13 the best or the biggest ……………………………………………… 14 to be influenced by sg ……………………………………………… 15 to be soaked in water ……………………………………………… 16 to excite scientists’ interest ……………………………………………… 17 to face certain conditions ……………………………………………… 18 to find the answer ……………………………………………… 19 to question that sg is true ……………………………………………… 20 to survive ……………………………………………… 21 to tackle sg ……………………………………………… 22 to test ……………………………………………… 23 tough (2.) 24 tough ……………………………………………… ……………………………………………… 25 very famous ……………………………………………… SOLUTIONS Task Label the paragraphs with their topic Who Are Tardigrades Objective of Experiment The Experiment Results from Experiment Significance of water bears Task Find synonyms in the text for the phrases Vocabulary 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 a force of pushing: pressure a lot of UV waves: tons of radiation ability to create children: reproductive abilities being faced with certain conditions: exposure to decade: 10 years harm to sg: take its toll having a second name: also know n as having eight legs: eight=legged having no rivals: unparalelled having nothing to eat: starvation idea: concept impossibility to destroy: indestructibility the best or the biggest: ultimate to be influenced by sg: be affected to be soaked in water: rehydrate to excite scientists’ interest: piqued scientific curiosity to face certain conditions: be exposed to to find the answer: find out if … to question that sg is true: challenge to survive: come back alive to tackle sg: cope with to test: put to the test tough: hardy tough (2.): resistant very famous: legendary