여기에 있는 활동들은 주로 천문학의 여러 내용 중에 태양계의 태양 및 다른 행성과 관련되어 있는 중요한 물리량에 대한 것으로, 천문학자들의 과학보다는 중등과학 수준의 학교 과학(school science) 수준에서 태양계와 관련된 의문 혹은 문제들을 해결하는 방식을 취하였다. 활동의 첫 시작은 중학교 과학 교육과정에 있는 ‘지구의 반지름 구하기’이다. 그러나 우리는 이 활동을 다루면서 왜 ‘지구의 반지름 구하기’ 활동이 중요한가에 대하여는 생각해 보지 않았다. 따라서 본서의 첫 장은 바로 이러한 질문을 바탕으로 전개하여 과거 인류가 어떻게 이와 관련된 활동들을 하였는지를 다루었다. 이제 지구와 가까운 달의 물리량을 어떻게 구하였는지에 대한 질문이 자연스럽게 일어난다. 당연히 지구에서 관측할 수 있는 천문 현상들이 이용되어야 할 것이다. 달과 관련되어 쉽게 관측되는 자연 현상이 달의 위상 변화이다. 그리고 더 나아가 월식과 일식 현상이다. 이렇게 달과 관련된 자연 현상을 관측하여 얻을 수 있는 몇 개의 물리량은 달의 거리와 크기를 구할 수 있게 해 준다. 물론 이때 중등학교 교육과정에서 배운 수학 내용이 이용된다. 수학은 자연의 현상을 묘사하는 언어이고, 이를 잘 사용하면 여러 가지 과학적 사실을 알아 낼 수 있다. 이러한 활동을 하다 보면 때로는 적절한 가정도 필요하고, 모르는 물리량이지만 꼭 필요한 물리량을 알아야 문제를 해결할 수가 있다. 따라서 이 모르는 물리량은 어떤 방법으로 해결해야 하는지를 학교과학의 수준에서 고안해 볼 필요가 있다. 이렇듯 본서는 질문과 문제 해결, 그리고 새롭게 일어나는 질문들과 이 질문들을 다시 학교 과학의 수준에서 해결하는 방식으로 기술하였다. 따라서 여기서 제시하는 활동들은 모두 연결되어 한 덩어리로 되어 있지만 개별 활동의 연계성을 파악한 교수자(敎授者)가 학습자(學習者)에게 개별적으로 수행하게 하여도 좋은 과학 활동이다. 전체를 다 수행하면 하나의 커다란 과학프로젝트도 될 수 있다. 본서에서는 계산의 편이를 위하여 컴퓨터 프로그램인 Excel을 사용하였다. Fortran 언어, C 언어, Java 언어들과 같은 컴퓨터프로그램 언어를 모르더라도, 이 프로그램에서 사용되는 스프레드시트(spreadsheet)에서 모든 계산을 하고 그래프를 완성할 수 있다. 그리고 이러한 언어를 사용하여 계산하기 위하여 코딩(coding)을 하게 되는데, Excel의 스프레드시트를 이용하면 이러한 코딩과정을 어느 정도 익힐 수 있다. 더구나 빠른 시간 안에 계산 결과를 이용할 수 있기에 중등학교 교육과정에서 ‘과학하기’를 수행하는 데 많은 도움이 된다. 이렇게 과학에서의 Excel 이용을 어느 정도 훈련할 수 있는 것이 본서의 특징 중에 하나이다. 또 하나의 다른 특징은 학교에서 쉽게 접할 수 있는 망원경과 DSLR 사진기를 이용하여 천문 현상을 촬영할 수 있고, 더구나 천문 현상 관측 자료를 생성해 낼 수 있다는 것이다. 이러한 관측 자료를 바탕으로 본서에 제시된 활동들을 수행할 수 있기에, 본서를 가지고 천문에서의 관측 관련 연구를 수행하는 훈련을 할 수 있다.

머리말 ········································································································· 3 01 태양, 지구, 달의 크기와 거리 사이와의 관계 ··············································· 9 1) 태양과 달 ································································································ 9 2) 아리스타코스의 측정 실험 ······································································· 12 3) 태양-달 반경 사이의 관계 ······································································· 14 4) 각 천체의 거리와 반경과의 관계 ······························································ 15 5) 또 다른 관측과 측정의 필요 ···································································· 16 6) 지구의 크기 ··························································································· 18 7) 결과 ····································································································· 20 8) 지구-태양의 거리를 알아낸 또 다른 방법 ·················································· 20 9) 달에서 본 지구와 태양은? ······································································· 22 02 지구와 달 사이의 거리 ··········································································· 25 활동 1 지구의 반지름 구하기 ······································································· 28 활동 2 달까지의 거리 구하기 ······································································· 31 03 달의 시직경 측정 ··················································································· 35 활동 3 달의 각지름 구하기 ·········································································· 39 활동 4 태양의 각지름 구하기 ······································································· 43 활동 5 태양의 자전주기 구하기 ···································································· 46 04 금성의 태양면 통과를 이용하여 1AU 구하기 ············································· 53 활동 6 태양과 지구 사이의 거리 구하기 ························································ 60 05 행성의 궤도 ·························································································· 65 1) 기반이 되는 과학 이론 배경 ···································································· 65 2) 기초 학습 ······························································································ 65 3) 중등 교육과정에서 다루는 행성의 궤도 결정 ·············································· 66 4) 심화 학습 ······························································································ 70 5) 프로젝트 학습 ························································································ 77 활동 7 위상 변화를 이용한 달의 궤도 ··························································· 80 06 지구의 궤도는 타원궤도인가? ·································································· 89 활동 8 달의 크레이터 높이 구하기 ······························································· 98 활동 9 달의 공전주기 ················································································ 103 활동 10 지구의 공전궤도 이심률 구하기 ······················································ 110 활동 11 달의 공전궤도 이심률 ··································································· 116 07 케플러의 법칙 찾아내기 ········································································ 125 실험 1. 수성과 금성의 공전궤도 그리기(5장 참조) ········································ 126 실험 2. 케플러 제1법칙 찾아내기 ································································ 130 실험 3. 지구는 원운동을 할까? 타원운동을 할까? ········································· 134 실험 4. 엑셀을 이용한 행성의 운동 시뮬레이션하기 ······································ 139 실험 5. 케플러 제3법칙은 어떻게 발견할 수 있을까? ···································· 146 실험 6. 확장된 케플러 법칙 ······································································· 150 08 행성의 운동: 수치해석학적인 방법 ························································· 151 활동 12 엑셀을 이용하여 그래프 그리기 ······················································ 157 09 목성의 질량 구하기 ·············································································· 165 1) 목성의 관찰 ························································································· 166 2) 조화의 법칙 이용 ·················································································· 167 3) 건판 척도(s) ························································································ 167 활동 13. 목성의 질량 구하기 ······································································ 169 10 태양의 광도 측정하기 ··········································································· 179 1) 양초 광도계를 이용하는 방법 ································································· 179 2) 구리통 광도계를 이용하는 방법 ······························································ 180 3) 두 실험의 차이 ····················································································· 182 4) 태양 관측 ···························································································· 183 부록1 태양크기(SOHO) 자료 ······································································ 185 부록2 천체망원경 설치 및 극축 맞추기 ························································ 201 활동 14 DSLR 사용방법 ············································································ 211 활동 15 고정 촬영법 ················································································· 221 활동 16 직초점 촬영법 ·············································································· 234 부록3 별자리의 움직임과 행성 관측 ···························································· 243 실험 결과 및 토의 정답 및 해설 ································································· 252