SCIENCE LAB SPECIAL : NATURE'S PLAN

 

Not According To Plan

A dwarf planet's ring 

just doesn't add up.

A small icy world far beyond Neptune possesses a ring like the ones around Saturn. Perplexingly, the ring is at a distance where simple gravitational calculations suggest there should be none.

''That's very strange,'' said Bruno Morgado, a professor in Brazil. Dr. Morgado is the lead author of a paper published in the journal Nature the describes the ring encircling Quaoar, a planetary body about 700 miles in diameter [1,100 Kms] that orbits the sun at a distance of about four billion miles.

Given its distance from Quaoar, the ring should long ago have coalesced into small moon, according to the standard calculations.

Quaoar [ pronounced KWA-wahr, the name of the creator god for the Indigenous Tongva people in the Los Angeles area ]  is a little less than half the diameter of Pluto and about a third of the diameter of Earth's moon.

It is likely to be big enough to qualify as a dwarf planet, pulled by its gravity into a round shape. It has a moon, Weywot [the son of a Quaoar in Tongva's belief].

Quaoar orbits the sun in the Kuiper belt, a region of frozen debris beyond Neptune that includes Pluto.

The ring is not visible in telescope images. Rather, astronomers found it indirectly, when distant stars happened to pass behind Quaoar, blocking the starlight. [ Kenneth Chang ]