Using Clear Outside, find the estimated sky quality (Magnitude, Bortle Class, Brightness) for 'London, UK'. Then, confirm that an annual darkness chart is available for this location and describe its purpose.
Navigate to clearoutside.com. In the 'Lookup Address / Town / Postcode' field, enter 'London, UK'. Click the 'Get Forecast' button. Identify the 'Est. Sky Quality' details (Magnitude, Bortle Class, and Brightness) for London, UK. Locate the link or section related to the 'Annual Darkness Chart' for this location. Describe the purpose of the annual darkness chart as explained on the website.
Successfully navigate to a forecast page for 'London, UK' on clearoutside.com. State the 'Est. Sky Quality' (Magnitude, Bortle Class, and Brightness) for London, UK. Confirm the presence of a link or section for the 'Annual Darkness Chart' for London, UK. Accurately describe the purpose of the annual darkness chart based on the website's explanation (e.g., 'See how the sun’s rise/set times for your location change over the course of a year. Shows civil, nautical and astronomical darkness.').