Pluto at Opposition

StarDate

Pluto is at its best now. It’s lining up opposite the Sun. It rises around sunset and is in the sky all night. It’s brightest for the year as well. Don’t bother looking for it, though, unless you have a good-sized telescope.

Clyde Tombaugh was using a good-sized telescope when he discovered Pluto, in 1930. He’d been searching for a possible planet beyond Neptune for about a year, from Lowell Observatory in Arizona. When he found it, the little world was moving through Gemini.

Almost a century later, Pluto has advanced only a third of the way around the sky. That’s because Pluto is so remote that it takes 248 years to orbit the Sun – and to complete a single loop through the constellations. Today, it’s in the southwestern corner of Capricornus.

Pluto doesn’t move evenly across the sky. Its distance from the Sun varies from about 30 to almost 50 times Earth’s distance – a difference of 1.8 billion miles. It moves a lot faster when it’s closest to the Sun, so it crosses more of the starry background.

Pluto won’t complete its first orbit since its discovery until the year 2178 – when it will once again appear in Gemini.

For now, although you can’t see it, you can at least see its location. It’s between the handle of the “teapot” formed by the constellation Sagittarius, and the wide triangle that marks Capricornus. Tonight, that puts it not far to the upper right of the Moon.

Script by Damond Benningfield