| Little Pluto, formerly the solar system’s smallest planet, has been stripped of its status by the International Astronomical Union, reducing the number of planets to eight.
The new guidelines — introduced in Prague on Thursday after a week of debate by the 2,500 astronomers at the organization’s conference — define what is a planet and what is not. Pluto didn’t make the cut. Pluto has been considered a planet since its discovery in 1930. Pluto is now considered a “dwarf planet,” and the eight others — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune — are now called “classical planets.” Among other implications, Thursday’s new definition means students will have to find a new way of remembering how the planets are arranged in order from the sun. The old mnemonic device of “Mark’s Very Extravagant Mother Just Sent Us Ninety Parakeets” helped them recall that the order was Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. |
As a former teacher, I offer this alternative:
Mark’s Very Extravagant Mother Just Sent Us Ninety (dwarf) Parakeets
That way students will only have to drop dwarf when the definition changes again.
Plus it reminds them of the good old days.
Plus it drives home the point that Pluto is still classed as a planet, albeit a dwarf.
You’re welcome.