Amazing Space—Overview of Star Witness news story: Xena: The Tenth Planet?

Description:

Star Witness news story: Xena: The Tenth Planet? explains how the Hubble Space Telescope was used to measure the size of object 2003 UB313, nicknamed "Xena." Xena is just a little larger than Pluto. Based on size alone, Xena might be considered a planet, but there are other factors to consider. This selection is an adaptation of the HubbleSite press release: Hubble Finds that the 'Tenth Planet' is Slightly Larger than Pluto. NOTE: This article was published before the August 2006 International Astronomical Union decision to reclassify Pluto as a "dwarf planet," thereby changing the number of solar system planets to eight. In addition, after publication, Xena was formally named Eris.

Format(s) available: Printer-friendly web page; also, downloadable PDF including story and images

Grades: 5-8, but the material can be adapted for use in other grades at the teacher’s discretion

• A content reading selection. Teachers should discuss the meaning of unfamiliar vocabulary prior to having students read this selection.

• An engagement activity. Have students read the selection. Ask them whether they think Xena should be called a planet.

• An inquiry tool. Propose a question, such as "What have astronomers learned by studying Xena with the Hubble Space Telescope?" Have students read the selection and write down questions they would like answered as a result of the reading.

• A source of information. Have students read the selection. Conduct a class discussion using the questions associated with the reading to clarify student understanding and expand on the information provided.