Full Moon tonight will be bigger and brighter - Digital Journal

The Full Moon today will be bigger and brighter than usual, a phenomenon which only return to again and again, under the same conditions, within 18 years, according to the Lisbon Astronomical Observatory (OAL).

If the sky is clear, the “Super Moon” may be visible between 21h06 (Lisbon time) when born and 6:14 a.m. on Monday, when it sets.

phenomenon happens once a year, when the phase of the Moon occurs near perigee point of moon’s orbit closest to Earth. Under these conditions, the full moon is bigger and brighter.

However, on Sunday the size and brightness of the Moon will be even greater, since the Moon is closest to the orbital perigee, 21 minutes away, Lusa said today the director of the OAL, Rui Agostinho , adding that the “Super Moon” 2013 will only come to pass within 18 years.

According to the OAL, the Moon will, on Sunday, a size 14 percent larger and 30 percent will be brighter than the full moon in apogee, the moon’s orbit farthest from Earth.

Without these features, the Moon back to be closer to perigee, in 2014, but a different date, August 10, as the moon’s orbit is not constant, assuming the shape of an ellipse.

On Sunday, the “Super Moon” as any full moon can be seen with the naked eye, but also with the aid of binoculars and telescopes. The Lisbon Astronomical Observatory organizes, from 20.30, a special session of observation, with free entry.

During Full Moon, when the Moon is fully illuminated, are visible with a telescope, craters, valleys, seas and mountains, although certain details to the surface, as the shadow of the mountains on the Moon , the transition from dark to bright condition, can only be observed in the phase Waxing Crescent, pointed Rui Agostinho.

Earth is distant, on average, 384,400 kilometers from the moon perigee On average, the distance decreases to 363 100 kilometers and apogee average increases to 405 700 kilometers, according to the OAL.

The Observatory said that on Sunday, when the “Super Moon” will be closer to the horizon, from 21h06 (Lisbon time), the size of the Moon meets the eye will be larger than they actually are , is not real.

“It is an optical effect, a construction of the brain,” said Rui Agostinho.

To demonstrate this, the director of the Lisbon Astronomical Observatory uses a little experiment: if you look at the Moon when it is born and cover up under half a sheet of paper, “the brain reduces the size the Moon. “

Diary Digital / Lusa