The Super moon tonight will be joined by a special guest, presenting the last scene in a three-act cosmic play.
National Geographic is reporting that though the moon was closest to the Earth over 22 hours ago, the moon will reach full phase Monday, September 8 at 9:39 p.m. Eastern Standard Time. At the earlier phase, the moon on September 7th at 11:38 p.m. Eastern Standard Time was just 222,698 miles (358,398 kilometers) from Earth. Of the two Super moons that have happened already this year, the Super moon on August 10 was the closest and brightest, passing just 221,765 miles (356,896 kilometers) from the Earth. The Super moon and the Harvest moon will join and become one.
The whole show begins with perigee. The moon orbits the Earth every 28 days in an egg-shaped orbit. The Earth is a bit off-center. At one point every month, the moon reaches the point where it is the closest to the Earth, known as its perigee. At perigee, the moon looks to have its largest diameter.
At the same time, the moon is also at the point in its 28-day-long orbit around the Earth that it passes opposite the Sun. When viewed from the Earth, the moon will be fully illuminated, or “full.”
Since the Earth revolves around the sun, however, the point of perigee changes. When the positions coincide, we have what astronomers call the perigee full moon, or Super moon, in the common vernacular.
Discovery News is reporting that some confusion regards the Harvest moon itself, where the Harvest moon occurs in October. However, since this the last of the full moons, it is regarded as a Harvest moon. It’s a rarity that a Harvest moon occurs so early, which makes its occurrence simultaneously with this Super moon so special.
Many people feel that the Harvest moon stays out longer than normal moons. In fact, the Harvest moon rises a little later during this phase, making it seem like its out later, giving farmers more time and light to harvest their crops, hence the name Harvest moon.
Weather permitting, a full moon is visible all night long. There really is no exact time of perigee and fullness, just pick a time suitable for you during the night and hope the weather is clear so you can watch it. One recommendation for viewers: Look at the moon while it is on or near the horizon, recommends Geza Gyuk, astronomer at the Adler Planetarium in Chicago. “Try and look for the moon when it is near the horizon, that’s when it gives an extra thrill, as it appears larger and more colorful than when it is overhead.”