Want to Form a Planet? Learn to Accrete!

Andrea Wilford
Big History Teacher, 9th Grade
Muscatine, IA

Ever hear the story about the little engine that could?  Think about that story and apply it to a rock.  Call that rock, “the little rock that could”…that could become a planet some day, and there you have the story of accretion.  In Big History, the students learn about the concept of accretion in Unit 4 when learning about the origins of the planets and stars.  Some of the most fun we have had this year was “practicing” accretion!  Big History provides a lesson plan that our students found very engaging.  We practiced “accreting” several times–the students begin their rotation around the sun as individual dust particles that slowly accrete, creating larger and larger objects from chondrule, to meteoroid, to asteroid, to planetoid, until at last, under gravitational pull, a planet is born!  It was a fun, engaging way to master yet another Big History concept. Check out the BHP Activity here, and our student video below!

Check out all the BHP activities and resources at http://school.bighistoryproject.com.

BHP Experts – David Christian

BHP Team

BHP has partnered with leading Big Historian David Christian to develop and refine the curriculum. He oversees the strategy for the course and leads the main lecture. David is a professor of history at Macquarie University, Sydney, Australia. Christian is by training a historian of Russia and the Soviet Union, but since the 1980s he has become interested in world history on very large scales. He has written on the social and material history of the 19th-century Russian peasantry, in particular on aspects of diet and the role of alcohol. In 1989, he began teaching courses on “Big History,” surveying the past on the largest possible scales, including those of biology and astronomy.


Hear insights from all the experts that have contributed to BHP at http://school.bighistoryproject.com.