By Jorge Casuso

July 22, 2016 -- It was first thought to be a moon, then a planet, but Pluto has been downgraded to the status of a dwarf planet, and not even the most massive in the solar system.

The show will survey the results published to date, which include "spectacular images that transformed our concept of Pluto from a dot of light or pixelated smudge in an image to a newly-surveyed small world," organizers said.

About one-sixth the mass of the Moon, Pluto was discovered in 1930 and was initially thought to be the size of Earth. In 1992, its status as a planet came under fire when it was discovered that Pluto was part of a population of objects called the Kuiper belt.

But Pluto -- once known as Planet X -- has been coming into sharper focus, thanks to New Horizons, which was launched on January 19, 2006.

Last July, after a nine-and-a-half year journey through the solar system, the spacecraft made its closest approach to the dwarf planet, taking spectacular photographs of its five moons, "flowing glaciers and blue skies," according to Sci-News.

It also photographed methane snow capping its mountains, "jagged ice shorelines and snowy pits," Sci-News reported.

Last week, on New Horizon's first anniversary flyby of Pluto, the mission's principal investigator Alan Stern wrote, "The capstone exploration of Pluto that completed humankind's first era of reconnaissance of the planets in our solar system is now behind us."

Stern noted that the mission will continue with another flyby of a small object called 2014 MU69, which lies about 1 billion miles beyond Pluto.

"We are also excited to explore further," Stern said, "and to see what knowledge and inspiration that exploration will bring just 2.5 years from now."

"New Horizons at Pluto" takes place at 8 p.m. and is preceded by “The Night Sky Show” at 7 p.m., offering the latest news in astronomy and space exploration, a family-friendly “tour” of the constellations, and the chance to ask astronomy-related questions, organizers said.

The John Drescher Planetarium, which features a Digistar projection system, is located near the elevators on the second floor of Drescher Hall, 1900 Pico Boulevard.

Tickets are available at the door and cost $11 ($9 seniors and children) for the evening’s scheduled “double bill,” or $6 ($5 seniors age 60 and over and children age 12 and under) for a single Night Sky or feature show or telescope-viewing session.

For information, call (310) 434-3005 or visit www.smc.edu/eventsinfo or www.smc.edu/planetarium. All shows subject to change or cancellation without notice.