TPE Web 4.8 is now available. Two additions so far:
- Declination range limit visualization – this makes using Visual Search easier
- Open in Google Maps – as requested
Declination Range Limits
One challenge when using Visual Search has always been knowing where in the sky your target can possibly appear. If you search for the Moon in the northern sky, you’ll likely get no results unless you live in the southern hemisphere, for example.
We now show the range limits of the selected target when Visual Search is enabled so can you avoid fruitless searches that will never generate any results.
Additionally, if you do attempt a search that includes areas of the sky outside the range limits, the search will complete much more quickly than before (early return).
Sun
For the Sun, this concept is familiar: it is the range of movement achieved across a 1-year period and bounded by the Sun’s path on the winter and summer solstices.
We show the range limit as a translucent band, in the body color, bounded by dashed lines
Moon
For the Moon, the situation is a little more complex. Shown above, the inner range limits (longer dashed lines) show the range of motion of the Moon in the given location over the coming 1-year.
However, over a longer time, the range of motion is wider, the widest being during the Major Lunar Standstill, when lunar declination reaches its extrema. We show this as a fainter range (shorter dashed lines) so you know that even if an alignment is not possible in the coming year, if you search on a longer time horizon, it may occur.
Planets
We show range limits for the planets too. Similarly to the Moon, you may see shorter and longer-term range limit. The longer term range limit considers a 20-year period – the longest that can be selected for a single Visual Search run at this time.
Open in Google Maps
Using the Share button (bottom right) to access the Open in Google Maps feature:
A new button at the far right offers the option to open just the pin in a separate tab in Google Maps, or to obtain directions from your current location:
If the secondary pin is enabled, you’ll separate menu options for that in addition to the primary pin.
I’d appreciate your feedback on this new functionality. Please report any issues or bugs you find!
Stephen






