This event comes after the solar eclipse, which happened at the beginning of the month and can be seen all over the country during its first phase.

As shown by the data obtained from the astronomical monitoring service The Sky Live, the phenomenon starts at 2:23 am, the moment when the Earth begins to cast its shadow onto the Moon. Yet the peak stage of the eclipse, which is due at 05:12, will not be visible in the country since at that time the Moon is below the horizon.

In order to observe the development of the phenomenon—this involving the division of the Earth's shadow into the umbra and penumbra areas—the Centro Ciência Viva de Constância is holding a special observation session during the night at the Astronomy Park in the town of Santarém; entry is contingent upon making a prior reservation.