Earth Day: NASA Celebration, Lyrids to Peak

Earth Day – also known as the birth of the modern environmental movement – is Thursday, April 22, 2021. It began in 1970, giving a voice to an emerging public consciousness about the state of our planet. The celebration is widely recognized as the largest secular observance in the world, with more than a billion people participating annually in support of preserving the health and beauty of our planet.

In observance of Earth Day, NASA will host a virtual event April 21-24 to show how we are #ConnectedByEarth with a week of online events, stories, and resources. The event platform will feature live presentations by NASA scientists, as well as interactive chats with Earth science experts. Visitors can explore the connections between Earth’s atmosphere, water cycle, forests, fields, cities, ice caps, and climate through videos and interactive science content, a kid-friendly fun zone, a scavenger hunt, hundreds of downloadable resources, and more. Some content also will be available in Spanish.

Earth Day
This Earth Day, NASA highlights science and technology that is helping us all live more sustainably on our home planet and adapt to natural and human-caused changes. Credits: NASA

On Earth Day at 11 a.m. EDT, NASA will host a special live conversation with Grammy-nominated singer-songwriter Shawn Mendes and five people living and working in space: NASA astronauts Mike Hopkins, Victor Glover, Dr. Shannon Walker, and Mark Vande Hei; and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi. The event will air live on NASA Television, the NASA app, and the agency’s website. Learn more about NASA’s Earth Day plans and free online registration.

After several months of a meteor drought in 2021, we also have the annual Lyrid meteor shower coming up on Earth Day. The Lyrids will peak in the predawn hours of Earth Day (April 22). If you miss the peak, the wee hours of the following morning (April 23) offer another chance to see this shower, though the number of meteors will be down about 30% from the night of the 21st/22nd.

Lyrid and not-Lyrid meteors over New Mexico
Composite image of Lyrid and not-Lyrid meteors over New Mexico from April, 2012. Credits: NASA/ MSFC/ Danielle Moser

Observers in the Northern Hemisphere will see the most Lyrids, with the best time to watch between midnight and dawn. Although you’ll see a fairly bright Moon in the evening sky, it will set before the shower peaks near dawn. Peak rates for the Lyrids are around 10-20 meteors per hour. The meteors will appear to radiate from the constellation Lyra, but they can appear anywhere in the sky, which is why it is important to lie on your back and take in as much sky as possible.

The Lyrids is among the oldest of known meteor showers, with records going back for 2,700 years or more. It is produced by dust particles left behind by Comet C/1861 G1 Thatcher, which was discovered in 1861. The shower runs annually from April 16-25.

For more on meteor showers, visit the NASA Meteor Watch Facebook page.

Happy Earth Day and meteor watching!

by Lance D. Davis

Jupiter-Saturn Great Conjunction: Watch Best View Since Middle Ages!

by Lance D. Davis


Stargazers get ready for a nice treat as we are about to witness a super-rare planetary alignment not seen for almost 800 years!

Our solar system’s two biggest worlds – the mighty Jupiter followed by the glorious ringed Saturn – will appear in the sky next to each other at their closest since 1623 and closest visible from Earth since the Middle Ages in 1226. This will happen on Dec. 21, 2020, during an event called a “great conjunction.”

Astronomers use the word conjunction to describe close approaches of planets and other objects on our sky’s dome. They use great conjunction specifically for Jupiter and Saturn because of the planets’ top-ranking sizes.

view of the 2020 great conjunction through the naked eye just after sunset
A graphic made from a simulation program, showing a view of the 2020 great conjunction through the naked eye just after sunset at approximately 5:15 p.m. (EST) on Dec. 21.
Credit: NASA

Great conjunctions between Jupiter and Saturn happen every 20 years, making the planets appear to be close to one another. This closeness occurs because Jupiter orbits the Sun every 12 years, while Saturn’s orbit takes 30 years, causing Jupiter to catch up to Saturn every couple of decades as viewed from Earth.

The last conjuction between these planets took place on May 28, 2000. This year’s conjunction occurs on Dec. 21, which coincidentally is also the date of the winter solstice in the Northern Hemisphere. The 2020 conjunction is unique because of how close Jupiter and Saturn will appear. In most conjunctions, Jupiter and Saturn pass within a degree of each other. This year, they will pass 10 times closer to each other – the closest in nearly 400 years.

view of the 2020 great conjunction through a telescope
A graphic made from a simulation program, showing the view of the 2020 great conjunction
through a telescope at approximately 5:15 p.m. (EST) on Dec. 21. Credit: NASA

Currently, you can watch Jupiter and Saturn get closer in Earth’s sky each evening until their grand finale on Dec. 21. Just look for them shortly after sunset, shining brightly and low in the southwestern sky. Also, tune in to NASA Science Live or NASA Facebook on Dec. 17 at 3:00 p.m. EST (2:00 p.m. CST) and learn how to see Jupiter and Saturn’s great conjunction.

During the great conjunction, the giant planets will appear just a tenth of a degree apart – that’s about the thickness of a dime held at arm’s length! This means the two planets and their moons will be visible in the same field of view through a small telescope. Truly, this is a once-in-a-lifetime event!

Some astronomers suggest the pair will look like an elongated star and others say the two planets will form a double planet. To know for sure, we’ll just have to look and see. Either way, take advantage of this opportunity because Jupiter and Saturn won’t appear this close in the sky until 2080!

Additional Information & Resources:

Learn how to photograph the Jupiter-Saturn conjunction.
Read about mission visits to Jupiter and Saturn.
Find an astronomy club or event near you!

Total Solar Eclipse to Cast Shadow on South America

by Lauren Lambert

What is a Solar Eclipse?

A solar eclipse is a natural phenomenon that occurs when the Moon passes between the Sun and Earth. This event happens when the Moon completely blocks the Sun and the Moon’s shadow falls onto a portion of the Earth’s surface.

There are three types of solar eclipses: total, partial and annular. During a total solar eclipse, observers can witness daytime twilight because the disk of the Moon blocks 100% of the Sun. During a partial solar eclipse, the Moon is not entirely covering the Sun and you will likely not notice any difference in light intensity. You may only notice a subtle difference if the partial eclipse is close to total and you go outside at maximum eclipse.  Lastly, an annular eclipse can be observed when the Moon is at apogee, or the farthest from Earth within its elliptical orbit. This causes a ring of light, or annulus, to be visible around the Moon, which is sometimes referred to as the “ring of fire.”

total solar eclipse image
During the total solar eclipse, the Sun’s visible-light corona (meaning crown), only visible at maximum eclipse from within the path of totality, is seen here as a crown of white light extending from around the edge of the eclipsing Moon. The red loops of material also seen around the edge, are called prominences, in which magnetic fields enclose hot solar material. Credit: NASA/Armstrong’s Gulfstream III.

Total eclipses are of particular interest to solar scientists, because with the Moon blocking the bright light of the Sun, you can see the Sun’s atmosphere from the ground.  Solar scientists at Marshall Space Flight Center, and around NASA, make use of telescopes called coronagraphs that block the Sun so they can see the dim atmosphere, the corona, around it. But — given how perfectly the Moon lines up with the Sun — you can see the atmosphere closer to the surface of the Sun than we even can with our telescopes in space.

The shadow of the Moon on a planet during an eclipse can be described using three terms: umbra, antumbra and penumbra. The umbra is the shadow that is cast when the Moon completely covers the Sun and is where the path of totality falls. If the Moon is further away from the Earth, it is unable to block the Sun entirely. The Sun appears as a ring of light around the Moon. In this case, the shadow is known as the antumbra, or path of annularity, and occurs during an annular eclipse. Similarly, a partial solar eclipse can be observed when only a portion of the Moon blocks the Sun and creates a shadow referred to as the penumbra. The penumbra also occurs surrounding the umbra during a total eclipse, effectively covering those regions on the planet that only have a view of a partial eclipse.

Crescents of light from solar eclipse
Crescents of light are projected onto the ground during the partial phases of a solar eclipse due to light from the Sun passing through gaps between the leaves of trees, a pinhole effect. This is a safe and indirect way to view a solar eclipse. Credit: NASA/Johnson Space Center

Solar eclipses happen at least twice per calendar year, with total solar eclipses occurring about once every year and a half. But the possibility of seeing them is rare if you’re not in the right place at the right time. Additionally, since Earth is made up of mostly water, the path of totality, or the area receiving total blockage of the Sun, may not necessarily fall on land.

The year of 2020 sees two solar eclipses. The first occurred on June 21 and was an annular solar eclipse, visible from the continents of Africa and Asia. The second will be a total solar eclipse, occurring on Dec. 14, visible from South America. The path of totality crosses over Chile and Argentina, but some of their areas outside of the path of totality will experience a partial solar eclipse. The total eclipse will also be visible in Antarctica, South Africa, as well as the Pacific, Atlantic, and Indian Oceans. Observers will be able to witness the total solar eclipse for about 2 minutes.

If you are not within the path of totality, watching the total solar eclipse from a virtual location is an option as well. You can view it on NASA TV and the agency’s website, beginning at 10:30 a.m. EST on Dec. 14.  Be sure to check it out, as the next total solar eclipse won’t be happening until Dec. 4, 2021.

Top 5 Solar Eclipse Viewing Tips:

  1. Do not stare directly at the Sun. Wear safety approved, protective solar eclipse-viewing glasses to directly view the event or use some indirect means (see below). For more information here are some NASA Safety tips.
  2. To indirectly view the eclipse, create a pinhole camera or box projector. Learn how to build your own here.
  3. Stand under a tree and look at the ground. The trees act as pinhole projectors and will project hundreds of crescent shapes right at your feet.
  4. To capture an eclipse with binoculars, a telescope, or a camera, you must use a safety-approved, protective solar filter on your lens.
  5. Keeping with the theme of 2020 Observe the eclipse virtually! It will be streamed live here.

Sky Watching Highlights for December 2020

In the month of December, stargazers get ready for some excitement in the sky! Catch the year’s best meteor shower, the Geminids, in the middle of the month. Then, witness an extremely close pairing of Jupiter and Saturn that won’t be repeated for decades. And mark the shortest day of the year on the northern winter solstice. Check out the video below produced by NASA’s Jet Propulsion Laboratory to learn more!

‘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.

It’s All About Mars in October

by Lance D. Davis

NASA is developing a path for an exciting journey to Mars – a rich destination for scientific discovery and human exploration as we expand our presence into the solar system. This month of October brings an amazing night-sky view of the Red Planet.

Mars is currently visible, reaching its highest point in the sky around midnight. Earth’s closest neighbor is also at its brightest and will remain that way well into November.

Two illustrations contrasting Mars’ position when it reaches opposition and conjunction. During opposition, like in October 2020, Earth passes near Mars – which is easily visible and bright. During conjunction, Mars and Earth are far from each other, so Mars appears small and faint.
Two illustrations contrasting Mars’ position when it reaches opposition and conjunction. During opposition, like in October 2020, Earth passes near Mars – which is easily visible and bright. During conjunction, Mars and Earth are far from each other, so Mars appears small and faint. Credit: NASA

Right now, Mars is the third brightest object in Earth’s night. The Moon and Venus are the two brightest objects, and usually Jupiter is third. But for this season, Mars is passing close enough to Earth to outshine Jupiter. This great visibility of Mars coincides with an event known as opposition, which happens every two years and two months.

Opposition occurs when the orbit of a planet, such as Mars, takes it near the Earth. Just like runners passing each other on a track, the faster, inner planets, such as Earth, can approach and overtake slower-moving outer planets like Mars. When the planets pass each other during this opposition, Mars’ proximity means it will appear larger and brighter in our sky. Because the Sun, Earth, and Mars are lined up during this passing, Mars will rise at sunset, having a high overhead at midnight. This is the closest the Red Planet will come to Earth for the next 15 years, or until September 2035.

At its furthest, Mars reaches about 250 million miles (400 million km) from Earth. During the October opposition, it will be as close as 40 million miles (60 million km) – nearly seven times closer. Although Mars will still look like a bright star to the unaided eye, it will grow dramatically in size when seen in a telescope. This year, Mars’ closest approach to Earth happens just a week before the opposition on Oct. 13, giving the Red Planet its biggest, apparent size of the 2020’s.

When it comes to observing Mars around opposition, telescopes will show more of the planet’s details, such as dark and light regions on Mars’ surface, and the prominent south polar ice cap, which will be tilted towards the Earth. Due to the turbulence of our atmosphere, these details can be hard to see, especially in smaller telescopes.

Many amateur astronomers use a color video camera attached to their telescope, running special software that selects the best frames to stack into a single image. This helps in negating the blurring caused by the air.

The most striking thing about Mars’ appearance – whether seen with the naked eye or through a telescope – is its red color. This color is caused by iron in the rocks on Mars’ surface – the same thing that causes the red color in sandstone formations in the southwestern US.

So, when you spot Mars, keep your eye on it and enjoy its fiery, red brightness!

 

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.

Perseids Peak: Watch Best Meteor Shower of the Year!

By Emily Clay

The Perseid meteor shower is here! With Comet NEOWISE making its way out of the solar system, it is time for a celestial show caused by a different comet. Perseid meteors, caused by debris left behind by the Comet Swift-Tuttle, began streaking across the skies in late July and will peak in the pre-dawn hours of Aug. 12.

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Friday, Aug. 12, 2016 in Spruce Knob, West Virginia. The Perseids show up every year in August when Earth ventures through trails of debris left behind by an ancient comet. Image
In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Friday, Aug. 12, 2016 in Spruce Knob, West Virginia. The Perseids show up every year in August when Earth ventures through trails of debris left behind by an ancient comet. Image Credit: NASA/Bill Ingalls

The Perseid meteor shower is often considered to be one of the best meteor showers of the year due to its high rates and pleasant late-summer temperatures. This year’s shower, however, has the unfortunate circumstance of the Moon phase—last quarter—impeding the view of the shower peak, reducing the visible meteors from over 60 per hour down to 15-20 per hour. But the Perseids are rich in bright meteors and fireballs, so it will still be worth going out in the early morning to catch some of nature’s fireworks.

WHEN SHOULD I LOOK?

Make plans to stay up late the night of Aug. 11 or wake up early the morning of Aug. 12. The Perseids are best seen between about 2 a.m. your local time and dawn. The Moon rises at around midnight, so its brightness will affect the peak viewing window. However, even though the Moon’s phase and presence will keep the frequency of visible meteors lower, there is still nearly one meteor every two minutes during the peak!

If those hours seem daunting, not to worry! You can go out after dark, around 9 p.m. local time, and see a few Perseids. Just know that you won’t see nearly as many as you would had you gone out during the early morning hours.

How can you see the Perseids if the weather doesn’t cooperate where you are? A live broadcast of the meteor shower from a camera at NASA’s Marshall Space Flight Center in Huntsville, Alabama, (if our weather cooperates!) will be available on the NASA Meteor Watch Facebook starting around 8 p.m. CDT on Aug. 11 and continuing until sunrise on Aug. 12. Meteor videos recorded by the NASA All Sky Fireball Network are also available each morning; to identify Perseids in these videos, look for events labeled “PER.”

WHY ARE THEY CALLED PERSEIDS?

All meteors associated with one particular shower have similar orbits, and they all appear to come from the same place in the sky, called the radiant. Meteor showers take their name from the location of the radiant. The Perseid radiant is in the constellation Perseus. Similarly, the Geminid meteor shower, observed each December, is named for a radiant in the constellation Gemini.

HOW TO OBSERVE PERSEIDS

If it’s not cloudy, pick an observing spot away from bright lights, lay on your back, and look up! You don’t need any special equipment to view the Perseids – just your eyes.  (Note that telescopes or binoculars are not recommended because of their small fields of view.) Meteors can generally be seen all over the sky so don’t worry about looking in any particular direction.

While observing this month, not all of the meteors you’ll see belong to the Perseid meteor shower. Some are sporadic background meteors. And some are from other weaker showers also active right now, including the Alpha Capricornids, the Southern Delta Aquariids, and the Kappa Cygnids. How can you tell if you’ve seen a Perseid? If you see a meteor try to trace it backwards. If you end up in the constellation Perseus, there’s a good chance you’ve seen a Perseid. If finding constellations isn’t your forte, then note that Perseids are some of the fastest meteors you’ll see!

Pro tip:  Remember to let your eyes become adjusted to the dark (it takes about 30 minutes) – you’ll see more meteors that way. Try to stay off of your phone too, as looking at devices with bright screens will negatively affect your night vision and hence reduce the number of meteors you see!

Happy viewing!

See Comet NEOWISE! A Once-in-a-Lifetime Event

For Comet Vocabulary, please read to the end of the post.


For most, early July is when most people living in the United States look to the skies to watch dazzling firework shows. However, this month there is a different kind of show happening in the sky.

Comet Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) was only discovered a few months ago on March 27 by NASA’s NEOWISE telescope and has quickly become a popular solar system visitor. Its popularity is warranted, however, as it is the brightest comet since Comet Hale-Bopp that passed by Earth 23 years ago in 1997.

The graphic shows the comet as seen from Huntsville, Friday, July 17 at 9 PM. Look almost due northwest, 15 degrees above the horizon. The comet will be below the stars in the bowl of the Big Dipper, and about as bright (magnitude 3). Binoculars should give a really spectacular view!
The graphic shows the comet as seen from Huntsville, Friday, July 17 at 9 PM. Look almost due northwest, 15 degrees above the horizon. The comet will be below the stars in the bowl of the Big Dipper, and about as bright (magnitude 3). Binoculars should give a really spectacular view!

Comet nuclei are cosmic snowballs of frozen gases, rock and dust that orbit the sun. They can range in size from a few miles to tens of miles wide, and the nucleus of NEOWISE measures about 3 miles across. When these comets approach the sun, their frozen bodies start to sublimate, and they spew dust and gasses in a tail that can span millions of miles.

Comet NEOWISE made its harrowing close approach to the sun, known as its perihelion, on July 3, and it is now zooming past the Earth on its way back out of the solar system. NEOWISE will make its closest approach (64 million miles) to Earth on July 22, but the best viewing window is happening right now until July 19.

NEOWISE can be seen with the naked eye, but for an even better viewing experience, binoculars or even a telescope is recommended. As for which to choose, binoculars are your current best option. “Definitely use binoculars for now – the tail of NEOWISE is at least 7 degrees long, which is much bigger than the field of view of most telescopes,” said Bill Cooke, lead of NASA’s Meteoroid Environment Office at Marshall Space Flight Center. “Binoculars will allow you to see the whole thing, whereas a telescope only shows a tiny part.”

To see NEOWISE, start looking in the northwestern sky about an hour after sunset. The comet will be below the stars that make up the bowl of the Big Dipper and shining nearly as brightly at a magnitude 3. If you are an early riser, you can still see NEOWISE about an hour before sunrise in the northeastern horizon until the end of the week.

You need a clear view of the horizon to see this comet. Beaches, fields, and areas with higher elevations are all great observation spots. In areas with more light pollution, binoculars may be necessary for viewing. This is definitely a once-in-a-lifetime event, as NEOWISE won’t be visiting again for 6,800 years!

Learn more about comets at NASA’s Solar System Exploration website.

For comet-related, kid-friendly activities, visit NASA Science Space Place.

Top 5 viewing tips for Comet NEOWISEComet Vocabulary

Comet – Made up of ice, dust and gas which form a coma and sometimes a visible tail when it is orbiting close to the sun

Nucleus – The head of the comet, which is made up of ice and frozen gas that vaporizes to form the coma and the tail

Sublimate – The transition of a substance directly from the solid to the gas state, without passing through the liquid state

Perihelion – The point where an object orbiting the sun is closest to the sun

Magnitude – The units used to describe brightness of astronomical objects. The smaller the numerical value, the brighter the object is