What is the date of Neptune's next perihelion?

Question

I wanted to know because apparently Triton is warming, and no one knows why (http://science.nationalgeographic.com/science/space/solar-system/neptune-article.html).

I know that Neptune has a nearly circular orbit, but its orbit still has a difference of a little more than a third of an AU between aphelion and perihelion, which is about the same as the orbit of Mercury, and more than the distance from Mercury to Venus. Maybe a small distance for a giant planet like Neptune that far out, but given that Triton is geologically active and outgassing nitrogen, I wondered about the effect of even a minor change in mean temperature caused by being closer to the sun.

I know; it's not likely. But sometimes the obvious answer actually can be the right one.

Interestingly, although I found a b'zillion sites that gave me Neptune's aphelion and perihelion *distances*, I couldn't find the blinkin' *dates* for them. Frustrating.

Answer 1

I've set up an ephemeris for you at this website (http://ssd.jpl.nasa.gov/horizons.cgi#res...

The column you'll be interested in is "delta," which is range to Neptune.

I found 29.0261279706921 on August 18, 2008

Answer 2

I'd like to know this too.

When you are studying planetary orbits you like to know everything about them.

Answer 3

Using JPL's HORIZONS system I found the next perihelion of Neptune to be in 2045 at a distance of 29.81 AU relative to the barycenter of the Solar System