Planets Tonight computes where the planets are and which sky events are coming, for Japan and the world.

It is an independent site. All values are calculated, not observed; weather and terrain are not taken into account.

Computed with Skyfield (MIT) and JPL DE421; city data: GeoNames (CC BY 4.0).

How this site works

Once a day an automated job downloads the latest public data from the sources listed below, checks it and rebuilds these static pages. Nothing is invented or estimated by us: every number comes from a cited source.

Data sources

• JPL planetary ephemeris DE421 (NASA/JPL) — U.S. government work
• Skyfield (Brandon Rhodes) — MIT licence
• GeoNames — CC BY 4.0

Languages

The interface is available in 14 languages and was translated by hand. Where free text from a source is translated, it is done by offline machine translation and labelled as such.

Independence

Independent site, not affiliated with the data providers named here. For information only. Figures are reproduced from the cited sources, may be delayed or contain errors, and are not advice of any kind. Always check the original source.

Using the data

Please follow each source's own terms when reusing the data and credit the original publisher.

Affiliate links

Some Japanese pages include Rakuten Affiliate and (when enabled) Amazon Associates search links. They are separate from the price data on this site and do not show store prices. See the privacy policy for details.

As an Amazon Associate I earn from qualifying purchases.

Image credits

Image: NPS / Jeremy M. White · Public domain