Yes, it is possible to get a scene ID from a Planet Mosaics. There are several methods to identify the contributing source scenes for a specific location in a Planet Mosaics:

1. Using Planet GIS integrations: The inspector tool in Planet's ArcGIS and QGIS integrations allows you to identify which scene intersects a specific point in a Planet Mosaic.
2. Using the Basemap API: You can use the Planet Basemaps API to programmatically retrieve the contributing source scenes for a specific location or region in a mosaic.
3. The Mosaics in the Planet Insights Platform web application allows you to visually inspect and identify contributing scenes for a mosaics.

For a detailed guide on how to identify contributing scenes using the Basemap Viewer, you can refer to the How to Identify Contributing Scenes documentation.

It's important to note that while you can identify the contributing scenes, the source scenes themselves are not directly accessible in some integrations like Google Earth Engine. However, if you have the appropriate access permissions, you can use the scene ID to retrieve more information or potentially order the full scene through Planet's data services.

Search and preview also provides tools for searching and analyzing geospatial imagery, which can be useful for working with basemaps and their contributing scenes.