The Solar Eclipse Experience

On Oct. 14, 2023, and April 8, 2024, the entire United States and millions around the world will be able to view a solar eclipse.

 

A map showing where the Moon’s shadow will cross the U.S. during the 2023 annular solar eclipse and 2024 total solar eclipse.
A map showing where the Moon’s shadow will cross the U.S. during the 2023 annular solar eclipse and 2024 total solar eclipse. (NASA SVS)

There are three different kinds of solar eclipses: total, annular, and partial. When the Moon is far from the Earth, its size is too small to completely cover the Sun, thus an annular eclipse is observed, like what is expected on Oct. 14, 2023. When the Moon is close to the Earth, its larger size completely covers the Sun, causing a total eclipse, which will occur on April 8, 2024. A partial eclipse occurs when the Earth, Moon, and Sun are not perfectly aligned so only a part of the Sun will appear to be covered, giving it a crescent shape. During a total or annular solar eclipse, people outside the totality/annularity paths will see a partial solar eclipse.

From left to right, this image shows a total solar eclipse, annular solar eclipse, and partial solar eclipse.
From left to right, this image shows a total solar eclipse, annular solar eclipse, and partial solar eclipse.

The Eclipse Experience

Mitzi Adams, NASA Marshall Space Flight Center​ Heliophysics and Planetary Science Branch Assistant Chief, shares her observations during the five total eclipses she has experienced. “It is like nothing you’ve ever experienced before. It’s sort of like somebody puts a bowl on top of Earth right above where you’re standing. In the middle of the day, it gets darker, but you can still see light around the rim.” Adams explains. “You can essentially observe a sunrise or sunset. The temperatures cool. The wind picks up. The birds may go to roost, or the coyotes may howl.”

During an annular eclipse like the one coming up on Oct. 14, even with the sun covered up to 90%, the sky remains fairly bright. Those in the path of annularity will have a chance to observe the famed “ring of fire” effect, but it is important to manage your expectations and to remember that solar viewing glasses will be needed during the event’s entirety.

Bill Cooke, NASA’s Meteoroid Environment Office Lead and eclipse enthusiast, says he is most looking forward to the 2024 total eclipse because totality, when the sun is covered 100%, will last much longer than the last total eclipse in 2017 – up to nearly four and a half minutes.

In any of the upcoming eclipse events, in our technology-fueled world, you may also experience some electronic changes as the moon moves across Earth and the ionosphere cools.

The ionosphere forms the boundary between the Earth’s lower atmosphere – where we live and breathe – and the vacuum of space. It is formed when particles are charged, or ionized, by solar radiation. A total solar eclipse effectively “turns off” the ionosphere’s primary charging mechanism, mimicking nighttime conditions, so the many communications signals passing through the ionosphere could be disrupted.

GPS signals could produce location errors. Radio waves could change, sometimes even allowing Ham Radio operators to send or receive transmissions over longer distances.

The ionosphere is also home to many NASA satellites, including the International Space Station.

Solar Eclipse Science

Experiencing an eclipse is one way that everyone can participate in NASA Science. Depending on your access to different types of technology (phones, laptops, telescopes), there are several NASA Citizen Science projects you can participate in that relate to the Sun’s corona and the effects of the Moon’s shadow on Earth’s upper atmosphere.

Regardless of how you plan to experience a solar eclipse, or any solar viewing for that matter, remember to always do so safely. https://solarsystem.nasa.gov/eclipses/safety/

Lauren Perkins
NASA Marshall Space Flight Center

Welcome June with a Full Strawberry Moon and Summer Solstice

Sky enthusiasts, start off summer by witnessing two extraordinary celestial events in June – the Full Strawberry Moon and the summer solstice. These events hold both historical and cultural significance.

The Moon rises as a Metrorail car crosses the Potomac river in Washington
The Moon rises as a Metrorail car crosses the Potomac river in Washington 50 years to the day after astronauts Neil Armstrong, Michael Collins, and Buzz Aldrin launched on Apollo 11, the first mission to land astronauts on the Moon, Tuesday, July 16, 2019. Photo Credit: NASA/Bill Ingalls

The Full Strawberry Moon, depending on one’s time zone, will illuminate the night sky on June 3. Although the exact moment of full moon occurs when the Moon is opposite the Earth from the Sun, its full appearance will extend for about a day before and after the event. Remember to bring binoculars or a telescope to see all of the details of the Moon’s craters and other lunar features.

The name “Full Strawberry Moon” originated from the Algonquin tribes in the northeastern United States. This full moon occurred during the month of June when strawberries were ripening and ready to be harvested. The name “Strawberry Moon” has been passed down through generations and continues to be used by many today.

Diagram of the Earth’s alignment with the Sun for the June and December solstices.
Diagram of the Earth’s alignment with the Sun for the June and December solstices. (NASA)

Later in the month on June 21, the summer solstice will mark the beginning of the astronomical summer and the longest day in the Northern Hemisphere, and the start of winter and the shortest day in the Southern Hemisphere. This change in season is due to the 23.5-degree tilt of the Earth’s axis compared to its orbit around the sun, allowing the most direct sunlight to reach the Northern Hemisphere this month.

Throughout history, this celestial event has played a crucial role in various civilizations, shaping their calendars, traditions, and agricultural practices. Farmers would rely on the June Solstice to determine when to plant and harvest crops. The solstice’s timing influenced the development of many calendars, such as the ancient Roman calendar and the modern Gregorian calendar.

Enjoy the seasonal change as you watch the skies!

By Eben Boothby

May’s Sky Show: Top Planetary Events to Observe in May

May is a great month for stargazing with a host of celestial events happening in the morning and evening skies.

On May 17, a slim crescent moon will rise about an hour before the Sun. From much of the United States and Canada, you’ll be able to see Jupiter appearing very close to the Moon. In some southern U.S. states, Jupiter will pass behind the Moon as the pair rises in morning twilight. From western states, Jupiter will be behind the Moon, in occultation, as the duo rise. Jupiter will start to emerge from behind the Moon as the Sun comes up. To observe this event, you’ll need a clear view of the horizon, and a pair of binoculars will be essential as many locations in the U.S. will be in daylight during this occultation.

The image reveals Earth's Moon, Venus, Jupiter, and Earth's crescent, arranged from bottom to top.
Astronaut Scott Kelly observes three planets and Earth’s Moon in an impressive display while conducting long-duration space flight research aboard the International Space Station. The image reveals Earth’s Moon, Venus, Jupiter, and Earth’s crescent, arranged from bottom to top. Credit: NASA/Scott Kelly

Following sunset from May 22 through 24, you’ll be able to witness a close grouping of the Moon, Venus, and Mars in the western sky. The Moon will sit between the two planets on the 23rd. Venus has been rising higher in the sky each evening for the past few months, but in May, it’ll reach its highest point in the western sky.

For those stargazing from the Southern Hemisphere, there are some key differences in the night sky compared to the Northern Hemisphere. For instance, there’s no counterpart to the North Star in the Southern Hemisphere, and the seasonal star patterns that a northern observer are familiar with appear flipped upside down when viewed in southern skies.

A photo of the Southern Hemisphere with stars and two Magellanic Clouds
Some celestial objects are only visible from Earth’s Southern Hemisphere, such as central portions of our Milky Way galaxy, left, plus the two Magellanic Clouds above and to the left of the observatory dome, as shown in this photo taken at Cerro Paranal in Chile’s Atacama Desert. Credits: ESO / Y. Beletsky

Two entire galaxies, the large and small Magellanic Clouds, can be easily observed in the southern sky with the unaided eye. These are dwarf galaxies that orbit our own Milky Way galaxy.

If you are interested in what else is in the sky for May, check out the latest “What’s Up” video from Jet Propulsion Laboratory:

Enjoy these stellar spectacles as you watch the skies!

By Eben Boothby

August 2021 Brings Rare Seasonal ‘Blue Moon’

This month we’ll get to see a Full Moon on Aug. 22, 2021, known by some early Native American tribes of the northeastern United States, as the Sturgeon Moon. The name was given to the Moon because the large sturgeon fish of the Great Lakes, and other major lakes, were more easily caught at this time of year. But that’s not all! We also get to see a Blue Moon!

We’ve all heard the phrase “once in a Blue Moon,” which usually refers to something that rarely happens. Blue Moons do sometimes happen in Earth’s night sky, giving rise to this phrase. But what is a Blue Moon?

One way to make a Blue Moon is by using a blue filter.
One way to make a Blue Moon is by using a blue filter. Credit: NASA

Well, we have two kinds of Blue Moons – monthly and seasonal.

A monthly Blue Moon is the second Full Moon in a calendar month with two Full Moons. Then, there’s a seasonal Blue Moon – the third Full Moon of an astronomical season that has four Full Moons.

In astronomy, a season is the period of time between a solstice and equinox, or vice versa. Each season – winter, spring, summer or fall – lasts three months and usually has three Full Moons, occurring about 30 days apart. Because June’s Full Moon came just a few days after the June (Summer) solstice, we will see four Full Moons in the current summer season, which ends at the September equinox on Sept. 22.

The third Full Moon – our seasonal Blue Moon – will happen on Aug. 22.  All Full Moons are opposite the Sun, as viewed from Earth, rising fully illuminated at local time around sunset and setting around sunrise.

Perhaps you’re wondering if the Moon ever actually takes on a blue color. Well, Blue Moons that are blue in color are extremely rare and have nothing to do with the calendar or the Moon’s phases; they don’t have to be Full Moons either. When a blue-colored Moon happens, the blue color is the result of water droplets in the air, certain types of clouds, or particles thrown into the atmosphere by natural catastrophes, such as volcanic ash and smoke. Also, blue-colored Moons in photos are made using special blue filters for cameras or in post-processing software.

In 1883, an Indonesian volcano called Krakatoa produced an eruption so large that scientists compared it to a 100-megaton nuclear bomb. Ash from the Krakatoa explosion rose as high into the atmosphere as 80 kilometers (50 miles). Many of these ash particles can be about 1 micron in size, which could scatter red light and act as a blue filter, resulting in the Moon appearing blue.

Blue-colored Moons appeared for years following the 1883 eruption. Many other volcanoes throughout history, and even wildfires, have been known to affect the color of the Moon. As a rule of thumb, to create a bluish Moon, dust or ash particles must be larger than about 0.6 micron, which scatters the red light and allows the blue light to pass through freely. Having said all of that, what we call a Blue Moon typically appears pale grey, white or a yellowish color – just like the Moon on any other night.

Generally, Blue Moons occur every 2 to 3 years. Our last Blue Moon was on Oct. 31, 2020 – the night of Halloween. Mars was red and very large, since it was closer to Earth, and it was seen in the sky near the Blue Moon. Coincidently, this year’s Blue Moon will appear near planets again, but this time Jupiter and Saturn! We won’t see another Blue Moon until August 2023.

Learn more about Earth’s Moon here.

by Lance D. Davis

‘Once in a Blue Moon’ Coming Soon

by Lauren Lambert

There’s an extra special treat coming Earth’s way – a Blue Moon on the night of Oct. 31 for Halloween.

What is a Blue Moon?

According to modern folklore, it is a phenomenon where a Full Moon appears twice in one calendar month. Typically, each month has only one, as Full Moons occur about 29 days apart.

Our first Full Moon of the month – known as a Harvest Moon – occurred on Oct. 1. This is a name given to the Full Moon happening closest to the autumnal equinox – the first day of fall. The Blue Moon coming up is respectively known as the Hunter’s Moon.  Rising in the early evening, the Hunter’s Moon was given its name because it provided plenty of moonlight for hunters to gather meat for the long winter ahead.

One way to make a Blue Moon is by using a blue filter. That's what a photographer did back in 2004 when he photographed this Full Moon rising over Brighton, Massachusetts. Credit: Kostian Iftica
One way to make a Blue Moon is by using a blue filter. That’s what a photographer did back in 2004 when he photographed this Full Moon rising over Brighton, Massachusetts. Credit: Kostian Iftica

While the informal phrase “once in a Blue Moon” refers to something that rarely happens, the same definition rings true for the skies this Halloween. These moons are of significance because they only come every two or three years. In fact, the last Blue Moon occurred on March 31, 2018.

Contrary to its name, a Blue Moon has nothing to do with the Moon having a blue hue. However, very rarely there are actual blue-tinted Moons due to particles thrown into the atmosphere by natural catastrophes. In 1883, an Indonesian volcano called Krakatoa had an eruption so large that it was compared by scientists to a 100-megaton nuclear bomb. Lots of ash from the Krakatoa explosion rose into the atmosphere. Many of these ash particles were about 1 micron in size, which could scatter red light and act as a blue filter. This resulted in the Moon appearing blue.

Blue-colored Moons appeared for years following the 1883 eruption. Many other volcanos and even wildfires throughout history have been known to affect the color of the moon. As a rule of thumb, in order to create a bluish Moon, dust or ash particles must be larger than ~0.6 microns, which is the wavelength of red light. Having said that, what we call a Blue Moon appears pale grey and white – just like the Moon on any other night. Having a second Full Moon in one given month does not change its color.

October’s Blue Moon, however, will be the first Blue Moon to appear on Halloween since 1944. This moon occurred one month following the introduction of the Aggregat 4, or the V-2 rocket. This rocket was the first vehicle capable of reaching the edge of space. In years following, the Apollo Saturn V became its direct descendant.

As we approach October 2020’s Blue Moon, the Artemis Generation prepares to explore the Moon’s surface from a lunar base. NASA’s Artemis program is named after the twin sister to Apollo, the Sun god in Greek mythology, and she is known as the goddess of the Moon. There hasn’t been this much momentum to return to the Moon’s surface since the Apollo missions.

The next Halloween Blue Moon will occur in 2039. By then, the Artemis Generation will hopefully look at Mars from that same lunar base – perhaps passing the torch to an Ares Generation bound for the Red Planet.

Sky Watching Highlights for October 2020

There’s plenty to see in the sky for October! The Moon will be full not once, but twice this month. It’s also a great time for viewing Mars and trying to spot the galaxy of Andromeda. Learn more from the video below produced by NASA’s Jet Propulsion Laboratory.

International Observe the Moon Night 2020

by Lance D. Davis

International Observe the Moon Night is a worldwide public event encouraging observation, appreciation and understanding of our Moon and its connection to NASA exploration and discovery.

This is a great time to celebrate the Moon with enthusiasts and curious people all over Earth as excitement grows about NASA’s Artemis program, which will send the next man and first woman to the Moon.

International Observe the Moon Night 2020
Image Credit: NASA/Jennifer Baer

Since 2010, the celebration has occurred annually in September or October when the Moon is around first quarter – a great phase for excellent viewing opportunities.

You can join NASA’s Marshall Space Flight Center for a live planetarium show Saturday, Sept. 26 at 6:30 p.m. CDT – available online to everyone via YouTube and Facebook. Interviews with planetary and citizen scientists will also be included.

This virtual event is brought to you by the Planetary Missions Program Office at Marshall and U.S. Space & Rocket Center.

Whether it’s outdoors, at home, online, or wherever you may be, you are encouraged to be a part of International Observe the Moon Night. Please remember to follow your local health and safety guidelines.

Learn more and find other events here.

Sky Watching Highlights for September 2020

This month spot the Moon together with Mars and Venus, along with the flickering star Fomalhaut, which had itself a planet…until it didn’t! Check out the video below produced by NASA’s Jet Propulsion Laboratory to learn more.

International Observe the Moon Night 2019

Heads up, skywatchers! Did you know there’s a night set aside each year to celebrate and observe our Moon? International Observe the Moon Night has been held annually since 2010. This year it’s Saturday, Oct. 5.

This year also offers an opportunity to celebrate lunar exploration at a time when we are preparing to land American astronauts, including the first woman and the next man, on the Moon by 2024. Through the NASA’s Artemis lunar exploration program, we will use innovative new technologies and systems to explore more of the Moon than ever before, and use that knowledge to take the next giant leap, sending astronauts to Mars.

If you live in or near Huntsville, Alabama, you can join our local Moon celebration Saturday, from 5:30-8:30 p.m. CDT at the U.S. Space & Rocket Center’s Davidson Center for Space Exploration. The event is organized and hosted by the Planetary Mission Program Office at NASA’s Marshall Space Flight Center. This year’s event will include lunar and solar system exploration exhibits and more hands-on activities than ever. Members of the public are invited to attend, and it is free! Don’t live in Huntsville? No worries! There are events held worldwide and you can find a list of them here.

Can’t get to an event this weekend? You can still go outside no matter where you live and look at our incredible neighbor. For a list of Moon phases and other cool Moon facts, check out the NASA Science Earth’s Moon page.

And happy Moon-gazing, skywatchers!