Moon eclipse and noctilucent cloud summer festival, 25 & 27 July

We arrived in Mariehamn, Åland, on 27 July, just in time to witness the moon eclipse from the marina. Moonrise was at 22:15, but we could not see any moon rising at the time. We would realise after that the moon was so faint that it was not visible along the horizon through the atmosphere. It is only around 23:30 that the moon start appearing when it reach higher elevation over the horizon. By then, it was a remarkable show!

The blood moon in Mariehamn, Åland, 27 July, 23:30 and 23:55

Twenty-five minutes later, the sun started highlighting again the moon. The shape of the highlighted area differed from the normal moon crescent that we are used too, as it is the shadow of the earth on the surface of the moon and not the areas of the moon in the shadow when receiving the light from the sun sideways.

There were lots of boat in the Mariehamn Österhamn bay watching the eclipse from there to avoid the light pollution in the city.

By contrast, this is a picture of the moon taken from Belisama in the evening of the 25 July, in Brändö, Åland Archipelago.

Near full moon, Brändö, Åland, 27 July 2018

On the night of the 25 July in Brändö, we observed a blooming of noctilucent clouds in the North direction around 12:30 in the night. These cloud like phenomenons are rare and tenuous. They are mainly observed between 50° and 70° of latitude (we are currently at 60° in the Åland Archipelago). They appear after the sun set, when the lower part of the atmosphere is in the shadow of earth, but the upper part, the mesosphere around 80,000 metres, still receives sun light. The small ice crystals in the mesosphere are then highlighted and become visible against the darker layers beneath them.

Noctilucent clouds over Belisama, Brändö, 25 July 2018.

Noctilucent clouds, Brändö, 25 July 2018

 This is the second time I observe such clouds in the Baltic sea. In July 2012, I witnessed such clouds while sailing to Gotland. The picture below was taken from the boat sailing at night and is therefore quite fuzzy.

A few days later, from land, I saw a couple more noctilucent clouds (23 July 2012)

Scientistsn are still studying the meaning of such clouds. They were first reported in 1885, two years after the eruption of the Krakatoa volcano, but it is not proven that they resulted from the eruption. Their occurrence seems to increase and is believed to be related to farming development and climate change.