January 19, 2019 - NASA/JPL reports a total Lunar Eclipse and Supermoon will occur on Sunday, January 20, 2019. Totality at 9:12 P.M. PST
The total eclipse will be visible in North and South America and western parts of Europe and Africa
Overview:
Viewers in North and South America, as well as those in western parts of Europe and Africa, will be able to watch one of the sky's most dazzling shows on Jan. 20, 2019, when the Sun, Earth and Moon align at 9:12 p.m. PST (12:12 a.m. EST), creating a total lunar eclipse. The full moon will also be at its closest point to Earth in its orbit, called perigee. While at perigee, the Moon appears slightly bigger and brighter from our perspective on Earth, so it's often referred to as a "supermoon." But does it really look as super as some say?
Check out these Teachable Moments from NASA/JPL Edu to find out how to watch a lunar eclipse and see what causes them to occur – plus learn more about supermoons and what to expect when one comes around.
What’s a Supermoon and Just How Super Is It?
The term “supermoon” has been popping up a lot in the news and on social media over the past few years. But what are supermoons, why do they occur and how can they be used as an educational tool. Plus, are they really that super?
There’s a good chance you’ll hear even more about supermoons in the new year. There will be two supermoons in a row in January 2018! Now is a great time to learn about these celestial events and get students exploring more about Earth’s only natural satellite.
Lessons About the Moon
Explore our collection of standards-aligned lessons for grades 1-12.
How it Works
As the Moon orbits Earth, it goes through phases, which are determined by its position relative to Earth and the Sun. When the Moon lines up on the opposite side of Earth from the Sun, we see a full moon. The new moon phase occurs when the Moon and the Sun are lined up on the same side of Earth.
The Moon doesn’t orbit in a perfect circle. Instead, it travels in an ellipse that brings the Moon closer to and farther from Earth in its orbit. The farthest point in this ellipse is called the apogee and is about 405,500 kilometers from Earth on average. Its closest point is the perigee, which is an average distance of about 363,300 kilometers from Earth. During every 27-day orbit around Earth, the Moon reaches both its apogee and perigee.
Full moons can occur at any point along the Moon’s elliptical path, but when a full moon occurs at or near the perigee, it looks slightly larger and brighter than a typical full moon. That’s what the term “supermoon" refers to.
What makes a supermoon super? Watch this short animation to find out. Credit: NASA/JPL-Caltech
Because supermoon is not an official astronomical term, there is no definition about just how close to perigee the full moon has to be in order to be called “super." Generally, supermoon is used to refer to a full moon 90 percent or closer to perigee. (When the term supermoon was originally coined, it was also used to describe a new moon in the same position, but since the new moon isn’t easily visible from Earth, it’s rarely used in that context anymore.)
A more accurate and scientific term is “perigee syzygy.” Syzygy is the alignment of three celestial bodies, in this case the Sun, Moon and Earth. But that doesn’t quite roll off the tongue as easily as supermoon.
Why It’s Important
Make a Moon Phases Calendar
Use this Moon "decoder wheel" to see where and where to view the Moon all year!
As the largest and brightest object in the night sky, the Moon is a popular focal point for many amateur and professional astronomers pointing their telescopes to the sky, and the source of inspiration for everyone from aspiring space scientists to engineers to artists.
The supermoon is a great opportunity for teachers to connect concepts being taught in the classroom to something students will undoubtedly be hearing about. Students can practice writing skills in a Moon journal, study Moon phases and apply their math skills to observing the supermoon. (Click here for related activities from JPL’s Education Office.)
Incorrect and misleading information about the Moon (and supermoons) can lead to confusion and frustration. It’s important to help students understand what to expect and be able to identify inaccurate info.
What to Expect
Size
As with anything that moves closer to the person viewing it, the supermoon will appear bigger than an average full moon. At its largest, it can appear 14% larger in diameter than the smallest full moon. Keep in mind that a 14% increase in the apparent size of something that can be covered with a fingernail on an outstretched arm won’t seem significantly bigger. Unlike side-by-side comparisons made in science and everyday life, students will not have seen the full moon for at least 30 days, and won’t see another for at least 30 more days. Comparing a supermoon with a typical full moon from memory is very difficult.
While they make for great photographs, images like this one that rely on a special photographic technique aren't an accurate representation of what the supermoon will look like to the naked eye. Credit: NASA/Bill Ingalls | Full image and caption on Flickr
A supermoon looks bigger than a "micromoon" (when the full moon is at apogee) because it's about 40,000 kilometers closer to Earth on average. Credit: NASA/JPL-Caltech
It's nearly impossible to compare the apparent size of the supermoon with a micromoon from memory, but when seen side-by-side as in this graphic, it becomes clear. Credit: NASA/JPL-Caltech
Leading up to a supermoon, there are often misleading images on popular media. A technique that involves using a long telephoto lens to take photographs of the Moon next to buildings or other objects makes the Moon look huge compared with its surroundings. This effect can make for great photographs, but it has nothing to do with the supermoon. In fact, these photos can be taken during any Moon phase, but they will likely be used in stories promoting the supermoon.
There are also images that have been edited to inaccurately dramatize the size of the supermoon. Both of these can lead students, and adults, taking pictures with their cell phone to think that they’ve done something wrong or just aren’t cut out for observing the sky, which isn’t true!
Your students may have noticed that when they see a full moon low on the horizon, it appears huge and then seems to shrink as it rises into the night sky. This can happen during any full moon. Known as the Moon Illusion, it has nothing to do with a supermoon. In fact, scientists still aren’t sure what causes the Moon Illusion.
Brightness
The full moon is bright and the supermoon is even brighter! Sunlight reflecting off the Moon during its full phase is bright enough to cast shadows on the ground. During a supermoon, that brightness can increase up to 30 percent as a result of the Moon being closer to Earth, a phenomenon explained by the inverse square law. (Introduce students to the inverse square law with this space-related math lesson for 6th- through 8th-graders.) As with the size of the Moon, students may not remember just how bright the last full moon was or easily be able to compare it. Powerful city lights can also diminish how bright a supermoon seems. Viewing it away from bright overhead street lights or outside the city can help viewers appreciate the increase in brightness.
What Not to Expect
A supermoon will not cause extreme flooding, earthquakes, fires, volcanic eruptions, severe weather, nor tsunamis, despite what incorrect and non-scientific speculators might suggest. Encourage your students to be good scientists and research this for themselves.
Source: NASA/JPL
