If you are old enough, you may remember a time when we thought Pluto was a planet. In 2006 the International Astronomical Union (IAU) adopted a standardized definition of what is and isn't a planet. Unfortunately Pluto no longer made the cut. However, the IAU also adopted a new term: "dwarf planet." A dwarf planet is a planet that orbits the sun, has enough mass for its gravity to form it into a nearly round shape, has not cleared other large objects from the region it crosses during its orbit, and is not a satellite of another object in space. Pluto fits this definition perfectly. 

Exhibitions

Learning Resources

Activity/Lab Video

Flights of Fancy Story Time: "Pluto’s Secret"

In this special author session, Margaret Weitekamp reads the book, Pluto’s Secret: An Icy World’s Tale of Discovery

More Flights of Fancy Story Time: "Pluto’s Secret"
Less Flights of Fancy Story Time: "Pluto’s Secret"
Grade Level
Grade PK, Grade K, Grade 1, Grade 2 and Grade 3
Topics
Dwarf planets, People, Science, Small solar system bodies and Solar System
Leader
Student, Teacher and Parent/Caregiver
Rights
cc-by-nc
Activity/Lab Video

My Path: "Don't Be Afraid of Who You Are." Hannah Wakeford, Astronomer

Dr. Hannah Wakeford is on the cutting edge researching and hunting for exoplanets. Many of these newly discovered planets are in the Goldilocks Zone where conditions may be right to support life.

More My Path: "Don't Be Afraid of Who You Are." Hannah Wakeford, Astronomer
Less My Path: "Don't Be Afraid of Who You Are." Hannah Wakeford, Astronomer
Grade Level
Grade 5, Grade 6, Grade 7, Grade 8 and Grade 9
Topics
Astronomy, Dwarf planets, Exoplanets, People, Solar System and Spaceflight
Leader
Student
Rights
cc-by-nc
Lecture Video

What’s New in Aerospace: Inside the First Epic Mission to Pluto (Alan Stern) or Chasing New Horizons

A conversation with New Horizons principal investigator Alan Stern and astrobiologist David Grinspoon about their new book, Chasing New Horizons: Inside the Epic First Mission to Pluto.

More What’s New in Aerospace: Inside the First Epic Mission to Pluto (Alan Stern) or Chasing New Horizons
Less What’s New in Aerospace: Inside the First Epic Mission to Pluto (Alan Stern) or Chasing New Horizons
Grade Level
Grade 3, Grades 15-16, Grades 17-20, Grades 13-14, Grade 12, Grade 11, Grade 10, Grade 9, Grade 8, Grade 7, Grade 6, Grade 5 and Grade 4
Topics
Dwarf planets and Uncrewed spaceflight
Leader
Student, Teacher, Parent/Caregiver and Other
Rights
cc-by-nc
Lecture Video

What’s New in Aerospace: New Horizons at Pluto

Alan Stern, principal investigator of NASA’s New Horizons mission, shows the exciting images and science results yielded from the New Horizons mission as the spacecraft flew through the Pluto system

More What’s New in Aerospace: New Horizons at Pluto
Less What’s New in Aerospace: New Horizons at Pluto
Grade Level
Grade 6, Grade 7, Grade 8, Grade 9, Grade 10, Grade 11, Grade 12, Grades 13-14, Grades 15-16 and Grades 17-20
Topics
Astronomy and Dwarf planets
Leader
Student, Teacher, Parent/Caregiver and Other
Rights
cc-by-nc
Activity/Lab Video

Flights of Fancy Story Time: Pluto’s Secret

In this special author session; Margaret Weitekamp reads the book; Pluto’s Secret: An Icy World’s Tale of Discovery

More Flights of Fancy Story Time: Pluto’s Secret
Less Flights of Fancy Story Time: Pluto’s Secret
Grade Level
Grade PK, Grade K, Grade 1, Grade 2 and Grade 3
Topics
Dwarf planets, People, Science, Small solar system bodies and Solar System
Leader
Student, Teacher and Parent/Caregiver
Rights
cc-by-nc
Activity/Lab Video

E.Z. Science: Exploring the X-ray Universe

By studying X–rays in deep space, we can learn about some of the most violent and extreme objects in the universe, such as black holes and the remains of stars that have exploded

More E.Z. Science: Exploring the X-ray Universe
Less E.Z. Science: Exploring the X-ray Universe
Grade Level
Grade 3, Grade 5, Grade 6, Grade 4, Grade 7, Grade 8, Grade 9, Grade 10, Grade 11 and Grade 12
Topics
Dwarf planets, Exoplanets, Solar System, Stars, Sun, Telescopes and Spaceflight
Leader
Student, Teacher and Parent/Caregiver
Rights
cc-by-nc