In the News
Looking up at the Moon can create a sense of awe at any time, but those who do so on the evening of January 20 will be treated to the only total lunar eclipse of 2019. Visible for its entirety in North and South America, this eclipse is being referred to by some as a super blood moon – “super” because the Moon will be closest to Earth in its orbit during the full moon (more on supermoons here) and “blood" because the total lunar eclipse will turn the Moon a reddish hue (more on that below). This is a great opportunity for students to observe the Moon – and for teachers to make connections to in-class science content.
How It Works
Eclipses can occur when the Sun, the Moon and Earth align. Lunar eclipses can happen only during a full moon, when the Moon and the Sun are on opposite sides of Earth. At that point, the Moon can move into the shadow cast by Earth, resulting in a lunar eclipse. However, most of the time, the Moon’s slightly tilted orbit brings it above or below Earth’s shadow.
The time period when the Moon, Earth and the Sun are lined up and on the same plane – allowing for the Moon to pass through Earth’s shadow – is called an eclipse season. Eclipse seasons last about 34 days and occur just shy of every six months. When a full moon occurs during an eclipse season, the Moon travels through Earth’s shadow, creating a lunar eclipse.
Unlike solar eclipses, which require special glasses to view and can be seen only for a few short minutes in a very limited area, a total lunar eclipse can be seen for about an hour by anyone on the nighttime side of Earth – as long as skies are clear.
What to Expect
The Moon passes through two distinct parts of Earth’s shadow during a lunar eclipse. The outer part of the cone-shaped shadow is called the penumbra. The penumbra is less dark than the inner part of the shadow because it’s penetrated by some sunlight. (You have probably noticed that some shadows on the ground are darker than others, depending on how much outside light enters the shadow; the same is true for the outer part of Earth’s shadow.) The inner part of the shadow, known as the umbra, is much darker because Earth blocks additional sunlight from entering the umbra.
At 6:36 p.m. PST (9:36 p.m. EST) on January 20, the edge of the Moon will begin entering the penumbra. The Moon will dim very slightly for the next 57 minutes as it moves deeper into the penumbra. Because this part of Earth’s shadow is not fully dark, you may notice only some dim shading (if anything at all) on the Moon near the end of this part of the eclipse.
At 7:33 p.m. PST (10:33 p.m. EST), the edge of the Moon will begin entering the umbra. As the Moon moves into the darker shadow, significant darkening of the Moon will be noticeable. Some say that during this part of the eclipse, the Moon looks as if it has had a bite taken out of it. That “bite” gets bigger and bigger as the Moon moves deeper into the shadow.
At 8:41 p.m. PST (11:41 p.m. EST), the Moon will be completely inside the umbra, marking the beginning of the total lunar eclipse. The moment of greatest eclipse, when the Moon is halfway through the umbra, occurs at 9:12 p.m. PST (12:12 a.m. EST).
As the Moon moves completely into the umbra, something interesting happens: The Moon begins to turn reddish-orange. The reason for this phenomenon? Earth’s atmosphere. As sunlight passes through it, the small molecules that make up our atmosphere scatter blue light, which is why the sky appears blue. This leaves behind mostly red light that bends, or refracts, into Earth’s shadow. We can see the red light during an eclipse as it falls onto the Moon in Earth’s shadow. This same effect is what gives sunrises and sunsets a reddish-orange color.
A variety of factors affect the appearance of the Moon during a total lunar eclipse. Clouds, dust, ash, photochemical droplets and organic material in the atmosphere can change how much light is refracted into the umbra. Additionally, the January 2019 lunar eclipse takes place when the full moon is at or near the closest point in its orbit to Earth – a time popularly known as a supermoon. This means the Moon is deeper inside the umbra shadow and therefore may appear darker. The potential for variation provides a great opportunity for students to observe and classify the lunar eclipse based on its brightness. Details can be found in the “Teach It” section below.
At 9:43 p.m. PST (12:43 a.m. EST), the edge of the Moon will begin exiting the umbra and moving into the opposite side of the penumbra. This marks the end of the total lunar eclipse.
At 10:50 p.m. PST (1:50 a.m. EST), the Moon will be completely outside the umbra. It will continue moving out of the penumbra until the eclipse ends at 11:48 p.m (2:48 a.m. EST).
What if it’s cloudy where you live? Winter eclipses always bring with them the risk of poor viewing conditions. If your view of the Moon is obscured by the weather, explore options for watching the eclipse online, such as the Time and Date live stream.
Why It’s Important
Lunar eclipses have long played an important role in understanding Earth and its motions in space.
In ancient Greece, Aristotle noted that the shadows on the Moon during lunar eclipses were round, regardless of where an observer saw them. He realized that only if Earth were a spheroid would its shadows be round – a revelation that he and others had many centuries before the first ships sailed around the world.
Earth wobbles on its axis like a spinning top that’s about to fall over, a phenomenon called precession. Earth completes one wobble, or precession cycle, over the course of 26,000 years. Greek astronomer Hipparchus made this discovery by comparing the position of stars relative to the Sun during a lunar eclipse to those recorded hundreds of years earlier. A lunar eclipse allowed him to see the stars and know exactly where the Sun was for comparison – directly opposite the Moon. If Earth didn’t wobble, the stars would appear to be in the same place they were hundreds of years earlier. When Hipparchus saw that the stars’ positions had indeed moved, he knew that Earth must wobble on its axis!
Lunar eclipses are also used for modern-day science investigations. Astronomers have used ancient eclipse records and compared them with computer simulations. These comparisons helped scientists determine the rate at which Earth’s rotation is slowing.
Ask students to observe the lunar eclipse and evaluate the Moon’s brightness using the Danjon Scale of Lunar Eclipse Brightness. The Danjon scale illustrates the range of colors and brightness the Moon can take on during a total lunar eclipse, and it’s a tool observers can use to characterize the appearance of an eclipse. View the lesson guide below. After the eclipse, have students compare and justify their evaluations of the eclipse.
Evaluating a Lunar Eclipse
Students use the Danjon Scale of Lunar Eclipse Brightness to illustrate the range of colors and brightness the Moon can take on during a total lunar eclipse.
Time 30 mins - 1 hr
Use these standards-aligned lessons and related activities to get your students excited about the eclipse, Moon phases and Moon observations:
Observing the Moon
Students identify the Moon’s location in the sky and record their observations over the course of the moon-phase cycle in a journal.
Time 30 mins - 1 hr
Students learn about the phases of the moon by acting them out.
Time 30 mins - 1 hr
Whip Up a Moon-Like Crater
Whip up a moon-like crater with baking ingredients as a demonstration for students.
Time 30 mins - 1 hr
Teachable Moment: What’s a Supermoon and Just How Super Is It?
Are supermoons as super as they're made out to be? Learn what causes them and explore related activities for teachers and students.
Measuring the Supermoon
Students use analog and digital tools to measure the Moon’s apparent size and brightness.
Time 30 mins - 1 hr
Modeling the Earth-Moon System
Students learn about scale models and distance by creating a classroom-size Earth-Moon system.
Time 30 mins - 1 hr
Make a Moon Phases Calendar and Calculator
Like a decoder wheel for the Moon, this calendar will show you where and when to see the Moon and every moon phase throughout the year!
- Try these related resources for students from NASA’s Space Place:
- Lunar Eclipses and Solar Eclipses – This guide for kids provides an overview of lunar and solar eclipses.
- Why Does the Moon Have Craters? – Check out NASA’s Space Place for the answer, written just for kids.
- NASA Moon Website – Find out more about the Moon along with the NASA robots and humans who have visited it.
When Lean Teodoro was growing up on the remote island of Saipan in the middle of the Pacific Ocean, her dream of one day working for NASA always seemed a bit far-fetched to those around her. Now, a geophysics student on the premed track at the University of Hawaii and a summer 2018 intern at NASA’s Jet Propulsion Laboratory, Teodoro is making her dream a reality. This summer, she took a short break from her internship searching for asteroids with NASA’s NEOWISE team to tell us about her career journey so far, what inspired her to study STEM and how she hopes to play a role in human space exploration of the future.
What are you working on at JPL?
I work with the NEOWISE team, the Near-Earth Object Wide-field Infrared Survey Explorer. My focus is on near-Earth asteroids. I do a lot of image analysis and processing. Not all of the time do asteroids get detected through our automated system, so my job is to look at archives to find previously undetected asteroids.
What is a near-Earth object and how do you look for them?
Near-Earth objects are objects [such as asteroids and comets] that are very near to Earth's orbit. There are other asteroids that are located roughly between the orbits of Mars and Jupiter, but my focus is on those that are closer to Earth. The way that we detect them is we have this [space telescope called NEOWISE] that surveys the sky in two wavelengths. It senses the heat of asteroids. So I look at images from NEOWISE and, if I see a red dot that is bright, then that's usually an asteroid. But I go through several search techniques to see if the signal-to-noise ratio is good. So there are several processes that work.
What is the ultimate goal of the project?
My ultimate goal is to try to increase the number of known near-Earth objects so that, in the future, we can get more precise measurements for their positions and movements -- just in case they pose a risk to Earth.
What's an average day like for you?
I go through, I'd say, hundreds of images per day. I also took part in a side project where I had to get the measurements of an asteroid that was observed 39 years before it was officially discovered. We looked at this astronomical plate from the 1950s. You can see a very small arrow pointing to an asteroid. Positions for the asteroid hadn’t been discovered yet, so my job was also to find those. It had a lot to do with coding and I had very little experience with coding, so it was nice.
What other skills have you been able to pick up at JPL?
My major is geophysics, so I had little knowledge about astronomy. My whole research team exposed me to an exciting world of astronomy, so that was really nice. They were very encouraging. I've learned so much more about astronomy this summer than I did throughout my whole undergrad career. I mean, there is some connection between geophysics and astronomy, in a way, but this summer, I really learned so much.
Meet JPL Interns
Read stories from interns pushing the boundaries of space exploration and science at the leading center for robotic exploration of the solar system.
You grew up on the remote island of Saipan in the Northern Mariana Islands. How did you get exposed to STEM and what got interested in pursuing it as a career?
When I was young, my dad would always make us go fly kites at night on the beach. There was this one night where I was just looking at the Moon. I was like, "Oh my god, I really want to learn more about astronomy.” I think since then, I've been interested in STEM. But when you're coming from a really small island, you feel very limited. So I didn't have that strong foundation in STEM. And that's the reason why I wanted to move off the island -- because I knew that I couldn't get the opportunities if I stayed. That's the reason I moved to the University of Hawaii. They have a strong geology and geophysics program, and it's a great research university. Since I started there, I've been doing research related to NASA -- like the NASA Hawaii Space Grant Consortium. I feel like if I didn't move to the University of Hawaii, I wouldn't be where I am today, interning at JPL.
So you moved from one island to another?
[Laughs.] Yeah, I couldn't leave the island vibe, I guess. I think it's just a little closer to home. I feel more at home when I'm in Hawaii. Not only that, but also they have a great program, so that was a plus, too. And they have close affiliations with NASA, so that was really great, because my goal was to work for NASA.
Was it a challenge to move away from the island where you grew up?
It was definitely a challenge leaving family and friends behind. I was there on my own. The reason why I chose the University of Hawaii is because of their program. I had a really hard time choosing my major because I was interested in health, but I was interested in geology as well. I'm doing premed as well [as geology and geophysics]. I'm really interested in how humans or organisms can adapt to extreme environments and in learning about geology – for example on Mars – and health, and seeing how we can combine those two fields to contribute to future human space exploration.
What do your family and people back home think of your career path?
It's so funny because I remember, in middle school, I would always tell my friends and family how I wanted to work for NASA, and they would laugh about it because I don't think anyone back home has ever done something big like that. Having them see me working here -- it just kind of opened their eyes, like, “Wow, it's possible,” you know? Most of the time, people back home just stay for financial reasons. It was really expensive moving to Hawaii. But I really wanted to do it. So here I am, and I'm so happy.
Did you know that we have a group of student teachers from the Northern Mariana Islands that has come to NASA’s MUREP Educator Institute at JPL the past couple summers?
Yeah! So three weeks ago, I was walking to my office, and I saw a few friends from back home. I was like, “Oh my god, what are you guys doing here?” We all went to the same high school and everything! They were telling me about that whole program. I was like, “Oh my god, I feel so happy. That's so great.” The chances -- it was mind-blowing. I'm so happy for them. I'm really excited for the future of Saipan and the whole Northern Mariana Islands.
What's the most JPL- or NASA-unique experience you've had so far?
Of all the internships I've had in the past, JPL is really unique because everyone is just so passionate about the work that they do, so it really rubs off on you. Not only that, but also the intern community here is just amazing. And not only the interns, but also my mentors and the other scientists and engineers I've met. I've made so many friends throughout my summer here from all over the nation and all over the world, which is nice because I'm from this small island, and it just makes me realize how big the world is.
I feel like interning at JPL builds a foundation for me. And with my mentors here at JPL and in Hawaii, I do feel more confident in being a minority and a woman in STEM. I feel more driven to be successful and to inspire people from back home to go and pursue what they want to do. Don't let the confinements of your environment stop you from what you want to do.
What’s your ultimate career goal?
My ultimate goal is to try and contribute to future human space exploration. That's what I really want to do. I'm still trying to figure out how I can pave my path by combining health and geosciences. We'll see how it goes.
Explore JPL’s summer and year-round internship programs and apply at: https://www.jpl.nasa.gov/edu/intern
The laboratory’s STEM internship and fellowship programs are managed by the JPL Education Office. Extending the NASA Office of Education’s reach, JPL Education seeks to create the next generation of scientists, engineers, technologists and space explorers by supporting educators and bringing the excitement of NASA missions and science to learners of all ages.
Looking for a stellar 2018 calendar? Try this new Moon Phases Calendar and Calculator DIY from the Education Office at NASA’s Jet Propulsion Laboratory!
Download the free, decoder-ring style calendar and assemble it to see when and where to view the Moon every day of the year. The calendar features daily moon phases, moonrise, moonset and overhead viewing times, a listing of Moon events including supermoons and lunar eclipses, plus graphics depicting the relative positions of Earth and the Moon during various moon phases. Use it to teach students about the phases of the Moon, for sky-gazing or simply as a unique wall calendar.
In the classroom, it makes a great addition to this Teachable Moment and related lessons about supermoons – two of which will ring in the new year in January 2018.
Explore these and more Moon-related lessons and activities from NASA/JPL Edu at the links below:
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?
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.
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
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.
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.
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.
The excitement and buzz surrounding a supermoon is a great opportunity to teach a variety of Moon topics with these lessons from JPL’s Education Office:
- *NEW* Observing the Moon (Grades K-6) – Students identify the Moon’s location in the sky and record their observations over the course of the moon-phase cycle in a journal.
- *NEW* Measuring the Supermoon (Grades 5-12) – Students take measurements of the Moon during its full phase over multiple Moon cycles to compare and contrast results.
- *NEW* Moon Phases Calendar and Calculator – Like a decoder wheel for the Moon, this calendar will show you where and when to see the Moon and every moon phase throughout the year!
- *NEW* Look at the Moon! Journaling Project – Draw what you see in a Moon Journal and see if you can predict the moon phase that comes next.
- Moon Phases (Grades 1-6) – Students learn about the phases of the Moon by acting them out. In 30 minutes, they will act out one complete Moon cycle.
- Whip Up a Moon-Like Crater (Grades 1-6) – Whip up a Moon-like crater with baking ingredients as a demonstration for students.
- Modeling the Earth-Moon System (Grades 6-8) – Using an assortment of playground and toy balls, students will measure diameter, calculate distance and scale, and build a model of the Earth-Moon system.
- Learn more about the Moon on NASA's Moon website.
For the record: This story originally stated a supermoon would be visible in January and February 2018. The two supermoons of 2018 are both in January.
Find out how one student's far-fetched dream landed her an internship at JPL. Astronomy intern Alyx Stevens shares what it's like to work at the leading center for robotic exploration of the solar system.
Today, successful women in science all contribute to a "little piece of the puzzle." Farisa Morales makes her contribution as an astronomer at NASA's Jet Propulsion Laboratory studying other planetary systems, observing the sky through the Spitzer Space Telescope and analyzing the dust around distant stars outside our solar system in search of new planets. But she didn't discover this passion until she was in college.
At the start of her college experience, Morales was majoring in mathematics and decided on taking an internship at JPL for engineering. She was later introduced to Spitzer Project Scientist Michael Werner, who asked her to take on huge task far from her comport zone: help take in data from the giant space telescope. This would range from searching for baby star formations to discovering distant galaxies at the edges of the universe. Farisa found her calling and she wanted to be exposed to even more. She switched her major to astrophysics and now has her PhD. "Life just takes you places and you are the main force pushing through," said Morales.
As part of the University of Southern California's Organization of Women in Physics, Morales takes an active role in encouraging women to be a part of the science field. Over the years she's juggled raising two kids, working and studies, but she says, "If I can do it, why can't others?" hoping to see a rise in the number of women in science.
days, she spends her time writing proposals, programming downloaded
images from Spitzer, learning about a specific telescope or publishing a
recent finding. Even teaching astronomy at Cerritos College, Los
Angeles Mission College, Pierce College and California State University,
Northridge adds to her busy schedule. In five to ten years she sees
herself at a full-time job teaching at a university while still
maintaining her research activities at JPL. She's earned a few awards
including an American Astronomical Society Chambliss award. To Morales,
the work itself is satisfying. "My life has not been in vain because I'm
providing the answers to one little tiny piece of the cosmic puzzle,"
she said. "I came into this world, and I worked and solved a little tiny
piece of the puzzle. And when I leave, that is my legacy. The
realization of knowing you're a productive human being and you're
leaving something positive for humanity to continue to build upon is