The phenomenon is the second of the type in the month – the star may appear up to 30% larger and 14% brighter than normal
Another superlum is coming to light up the skies of January – this time, on the 31st, last day of the month. The same phenomenon also appeared on the night of January 1, making the welcome to 2018 even more special. The show of the end of the month must be seen all over Brazil.
Superlight events occur when the Moon is in perigee, which is the point of its trajectory closest to Earth. During its passage, the star can appear up to 30% larger and 14% brighter than normal. In addition, the phenomenon promises to be even more special this time, as it is the second full moon of the month. When this happens, it is called the Blue Moon. And although it does not go physically blue, it is interesting to note that this phenomenon is relatively rare – astronomers believe that after that, the next Blue Moon will only appear in 2020.
If the celestial phenomenon already promises an incredible spectacle here in Brazil, in the Northern Hemisphere the expectations are even higher. This is because, in addition to a “Blue SuperLue”, they will still be able to see a total lunar eclipse (when the Moon is completely covered by the Earth’s shadow) and the so-called “Blood Moon” phenomenon in which the star acquires a reddish color.
“The ‘blood moon’ is an effect generated by sunlight in our atmosphere,” explains astronomer Daniel Mello, of the Valongo Observatory, Federal University of Rio de Janeiro (UFRJ). According to him, this type of event only happens when there is a lunar eclipse. During this phenomenon, the Earth is positioned between the Sun and the Moon – that is why the light beams flow through our atmosphere before it affects the Moon and, due to the presence of the gases, leave it with a reddish appearance. But since there will be no eclipse here in Brazil, the blood moon will also not be visible on national territory.
Even so, it is still possible to admire the superlum, which will be the last of the year. Mello says that the star can be observed with the naked eye – as it will be very large, it is possible that we see more details than usual – or even with binoculars or telescopes.