Alert Title ×
Help! ×

This page shows how to display graphical components in background, always present, even if other elements are displayed on top.

Use the Background Parameters link in the menu to configure the globe.

Use the Show/Hide Computed Data button to display the computed data in the foreground.

Select the bodies you want to display the cones for (for the date YOU've set).
You can also set the observed altitude for each body, to see how it affects the cone.
Based on those cones, the intersection will be calculated, to find the observer's position.
You can click on the Reverse link to calculate what the observed altitude should be for that body, from the user's position.
For a better precision, the bearing of the selected bodies shpuld be as close to 120° as possible, just like with an hand bearing compass.

The Marquee panel (available from the hamburger ≡ menu) will show the same data, formatted, in a dialog, on top of others.

Featuring:

Credits:
All celestial calculations are based on Hening Umland's remarkable work.

Background Parameters... ×
Center on: User Position
Sun Position
    Real Time
Auto-refresh the date every second.
Simulate Pressure and Heading
Transparent Globe
Display Polar Grid
Display Sun
Display Moon
Display Sun Light
Display Moon Light
Wandering Bodies
Display Stars
With Constellations
Tropics & Polar Circles
Solar Date Foreground
Astro Data Marquee ×
Sun Path ×
Sky Map(s) ×
Type:
Stars. Const. Star Names. Const Names. Visible sky. Sky grid. Wandering bodies. Aries LHA.
× Help!
Background parameters Toggle foreground Marquee Panel
Sun Path Sky Map
More links here, some day... ☎

  ≡ Celestial Computer - MPS for real

all in ES6, no REST back-end

Last code update Oct 25, 2025, 08:30 CET
MPS Data
  • MPS Data goes here...
All renderings happen only in the browser, it generates absolutely NO network traffic,
even MPS cones related calculations are done on the client.
Guaranteed 0% external libraries (100% pure organic HTML5/CSS3/ES6), no GMO.
► Help !
How-to: Use the hamburger (≡) at the top left to set the background parameters (Wandering bodies, Sunlight, Real Time...)
Then you can show or hide the computed data... And you can use the "Help" in the sliding menu.

MPS Cones Computing

Select the bodies you want to display the cones for (for the date YOU've set).
You can also set the observed altitude for each body, to see how it affects the cone.
Based on those cones, the intersection will be calculated, to find the observer's position.
You can click on the Reverse link to calculate what the observed altitude should be for that body, from the user's position.
For a better precision, the bearing of the selected bodies shpuld be as close to 120° as possible, just like with an hand bearing compass.
► User's Position on Earth
Latitude:   Longitude:   
Enable GeoLocation
► Select the bodies for MPS Cones
Select the bodies, and provide the observed altitude and observation (UTC) time.
Enable Reverse Calculation
► UTC Date, and options
Enter UTC date and time, then click the Compute button (in the background parameters).
at : : UTC
Skip planets calculations
Skip stars calculations
Console verbose