Prepare to be dazzled with the luminous light of a supermoon as it ascends into the sky tonight (Nov. 13), marking the closest a full moon has been to Earth in almost 69 years, according to NASA.
This month's supermoon will appear up to 14 percent larger and 30 percent brighter than the year's smallest full moon, said NASA scientist Noah Petro. He advised people hoping to catch an eyeful of the supermoon to find a dark place far from city lights, as well as away from tall buildings and trees, which might obstruct a view of the moon, especially when it is low in the sky.
But what exactly makes a supermoon so super? And will its difference in brightness and size actually be noticeable to the average skywatcher? [Supermoon Photos: Full Moon Rises Across the Globe]
Supermoons happen when a full moon coincides with the closest point in the moon's orbit to Earth. Picture the moon's oval-shaped orbit around Earth: When the moon is farthest away, at its apogee, which is about 252,088 miles (405,696 kilometers) away, a full moon will appear smaller and slightly dimmer than usual, according to Live Science's sister website, Space.com.
However, when the moon is at its perigee — that is, its closest point to Earth — the satellite is slightly more than 26,000 miles (41,800 km) closer than at its apogee, making it appear larger and brighter than normal, Petro said.
The upcoming supermoon is expected to reach perigee at 6:22 a.m. EST on Monday morning, NASA reported. However, the full moon itself lasts only for a moment, and this will happen about 2 hours later, at 8:52 a.m. EST on Monday, a time when the moon will no longer be visible for most of the United States, NASA said.
But people can still admire the extra-large moon even if they don't stay up late (or wake up early). The moon will appear larger than usual as it ascends Sunday night and waxes, or increases in illumination. Then, after the moon reaches peak fullness, it will begin to wane and decrease in illumination, but will still appear mostly full on Monday night, Petro said.
However, unless a person is an avid moonwatcher or photographer, it may be hard to notice the moon's super brightness and size, Petro said.
"They may not necessarily notice, especially if they haven't looked at the moon regularly, that it's much larger," Petro told Live Science. "But if you start looking at the moon starting Sunday, and look at it regularly over the next few weeks, months and even longer, you may start appreciating the difference in size of the moon as it goes in its orbit around the Earth."
The last time a supermoon passed this close to Earth was in January 1948, when gas cost only 16 cents a gallon, NASA said. The next supermoon to whirl this close to the planet will be in November 2034.
Original article on Live Science.