In 2018, the month of February had no full moon at all.
But this year’s February presents the biggest full moon supermoon of 2019. From around the world, the moon will look plenty full to the eye on both February 18 and February 19 as it parades across the nighttime sky. It reaches the crest of its full phase on February 19 for much of the world. What’s a supermoon? It’s a popularized term for what astronomers call a perigean full moon. In other words, it’s a full moon near perigee, or closest to Earth for this month. This February 2019 full moon reaches its exact full phase closer to the time of perigee than any other full moon this year. Hence the year’s closest supermoon.
Will you be able to discern with your eye that this full moon is larger than an ordinary full moon? Experienced observers say they can do it, but – for most of us – the difference is too small for the eye to notice.
On the other hand, photographic techniques can illustrate the difference!
And there are other factors that make a supermoon special. For example, if you look outside tonight – assuming your sky is clear – you might be able to discern with your eye that the landscape is more brightly lit than usual by moonlight. Supermoons are substantially brighter than ordinary full moons.
Also, the moon’s gravity affects earthly tides, and a supermoon – full moon closest to Earth – pulls harder on Earth’s oceans than an ordinary full moon. That’s why supermoons create higher-than usual tides, which tend to come a day or two after the full moon.
By the way, that bright star accompanying the February supermoon is none other than Regulus, the brightest star in the constellation Leo the Lion. See the sky chart below.
Although the moon appears full for a few to several nights in succession, the moon is only truly full for a fleeting instant – when the moon lies 180 degrees opposite the sun, from the vantage point of Earth.
This full moon moment arrives on February 19, 2019, at 15:53 Universal Time. At North American and US time zones, that means the moon turns full at 11:53 a.m. AST, 10:53 a.m. EST, 9:53 a.m. CST, 8:53 a.m. MST, 7:53 a.m. PST, 6:53 a.m. AKST and 5:53 a.m. HST.
This February full moon ushers in the second in a series of three full moon supermoons occurring on January 21, February 19 and March 21, 2019. All of these full moons are less than 362,000 km (225,000 miles) distant as measured from the centers of the Earth and moon. (In contrast, the year’s farthest full moon on September 14, 2019, will reside at a distance of 406,248 km or 252,431 miles.) The full moons of January, February and March 2019 are regarded as supermoons because of their relative nearness to Earth.
2019 Jan 21 full moon: 357,715 km (222,274 miles)
2019 Feb 19 full moon: 356,846 km (221,734 miles)
2019 Mar 21 full moon: 360,772 km (224,173 miles)
The full moon on February 19, 2019, counts as the most “super” of these full supermoons because it’s the full moon that most closely aligns with perigee – the moon’s closest point to Earth in its monthly orbit:
Perigee: 2019 Feb 19 at 9:06 UTC (356,761 km or 221,681 miles)
Full Moon: 2019 Feb 19 at 15:53 UTC (356,846 km or 221,734 miles)
The February full moon gives us the closest of this year’s 12 full moons, plus the February lunar perigee showcases the closest of this year’s 13 perigees.
Amazingly enough, 14 returns to full moon almost exactly equal 15 returns to perigee, a period of about 413 days (approximately one year plus one month and 18 days). So next year, in 2020, the year’s closest full moon and closest lunar perigee will coincide in April 2020. We elaborate below.
Perigee: 2020 Apr 7 at 18:08 UTC (356,907 km or 221,772 miles)
Full Moon: 2020 Apr 8 at 2:35 UTC (357,035 km or 221,851 miles)
Of course, it’ll be three-peat supermoon performance in the year 2020, as well. The preceding full moon of March 9, 2020, and the following full moon on May 7, 2020, will make up the supermoon “season” of 2020.
2020 Mar 9 full moon: 357,404 km (222,081 miles)
2020 Apr 8 full moon: 357,035 km (221,851 miles)
2020 May 7 full moon: 361,184 km (224,429 miles)
Then we’ll have another three-peat production in the following year, 2021:
2021 Apr 27 full moon: 357,615 km (222,212 miles)
2021 May 26 full moon: 357,462 km (222,117 miles)
2021 Jun 24 full moon: 361,558 km (224,662 miles)
But this year, in 2019, the biggest full moon of the year happens on February 19, 2019, at a distance of 356,846 km (221,734 miles). Each full moon for the next 7 months will occur farther away than the one in the previous month. Seven full moons later, on September 14, 2019, this full moon will be the one to most closely align with lunar apogee – the moon’s most distant point from Earth in its orbit. Thereby, September 2019 will stage the most distant full moon of 2019.
Apogee: 2019 Sept 13 at 13:32 UTC (406,377 km or 252,511 miles)
Full Moon: 2019 Sept 14 at 4:33 UTC (406,248 km or 252,431 miles)
The year’s closest full moon on February 19, 2019, swings a whopping 49,402 km (30,697 miles) closer to Earth than does the year’s farthest full moon (or micro-moon) on September 14, 2019. Hence, the diameter of the February full moon is about 14 percent greater than that of the September full moon. But the disk size and brightness of this February supermoon exceed those of the September micro-moon by about 30 percent. To make the difference more concrete, perhaps, the size difference between the year’s largest and smallest full moons is comparable to that of a U.S. quarter versus a U.S. nickel. See the above illustration.
Bottom line: Enjoy the grand and glorious full moon supermoon on both February 18 and February 19, 2019, as this brilliant celestial lamp lights up the nighttime from dusk until dawn!