To Pluto… and Beyond

Listen 0:07:58

A 10th dwarf planet has been discovered out beyond the orbit of Pluto. The newest one V774104 is less than half Pluto’s size and is about 9.5 billion miles out, 2-3 times the distance to Pluto. Other objects in that region are Eris, Makemake, Haumea, Sedna, Quaoar, Orcus, Ixion, Varuna, AW197 and now V774104. Eris may even be larger than Pluto. The others are smaller.

Speaking of which, UCLA professor Jean-Luc Margot suggests a simpler, mathematical way to classify what makes a planet is to use estimates of the star’s mass, the planet’s mass and its orbital period to calculate the critical mass needed to clear its orbit of other stuff . . .

The upshot? Pluto’s still a dwarf but our moon qualifies as a planet!

Heading out-of-doors ? All about the pre-dawn planets are still available to be seen this week.

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