MSFC Meteoroid Environment Office

Ancient Oort Cloud Comet to Make First Documented Pass By Earth in Mid-October

An ancient celestial traveler will make its first close pass by Earth in mid-October. Mark those calendars – because it might not be back.

The Oort Cloud comet, called C/2023 A3 Tsuchinshan-ATLAS, was discovered in 2023, approaching the inner solar system on its highly elliptical orbit for the first time in documented human history. It was identified by observers at China’s Tsuchinshan – or “Purple Mountain” – Observatory and an ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in South Africa. The comet was officially named in honor of both observatories.

NASA astronaut Matthew Dominick captured this timelapse photo of Comet C/2023 A3 (Tsuchinshan-ATLAS) from the International Space Station as it orbited 272 miles above the South Pacific Ocean southeast of New Zealand just before sunrise on Sept. 28, 2024. At the time, the comet was about 44 million miles away from Earth. (NASA/Matthew Dominick)

The comet successfully made its closest transit past the Sun on Sept. 27. Scientists surmised it might well break up during that pass, its volatile and icy composition unable to withstand the intense heat of our parent star, but it survived more or less intact – and is now on track to come within approximately 44 million miles of Earth on Oct. 12.

“Comets are more fragile than people may realize, thanks to the effects of passing close to the Sun on their internal water ice and volatiles such as carbon monoxide and carbon dioxide,” said NASA astronomer Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Comet Ison, for example, reached the inner solar system in 2013, but failed to survive the Sun’s intense heat and gravity during perihelion in 2013.”

A bright green blur streaks across the black sky. — Comets traveling through the inner solar system aren’t uncommon, but many never survive a close pass by the Sun. Icy comet ISON, photographed here on Nov. 19, 2013, reached solar perihelion later that month – but couldn’t endure the punishing heat and gravity so close to Earth’s parent star and disintegrated. (NASA/MSFC/Aaron Kingery)

Though Comet Tsuchinshan-ATLAS will be ideally positioned to view from the Southern Hemisphere, spotters above the equator should have a good chance as well. Peak visibility will occur Oct. 9-10, once the half-moon begins to move away from the comet.

Choose a dark vantage point just after full nightfall, Cooke recommended. Looking to the southwest, roughly 10 degrees above the horizon, identify the constellations of Sagittarius and Scorpio. Tsuchinshan-ATLAS should be visible between them. By Oct. 14, the comet may remain visible at the midway point between the bright star Arcturus and the planet Venus.

“And savor the view,” Cooke advised – because by early November, the comet will be lost to the unaided eye, perhaps gone forever.

Comet light, comet bright

It’s highly unlikely Tsuchinshan-ATLAS will be visible in daylight hours, except perhaps at twilight, Cooke said. In the past 300 years of astronomical observation, only nine previous comets have been bright enough to spot during the day. The last were Comet West in 1976 and, under ideal conditions, Comet Hale-Bopp in 1997.

The brightness of comets is measured on the same scale we use for stars, one that has been in use since roughly 150 B.C., when it was devised by the ancient scholar Hipparchus and refined by the astronomer Ptolemy. Stellar magnitude is measured on a logarithmic scale, which makes a magnitude 1 star exactly 100 times brighter than a magnitude 6 star. The lower the number the brighter the object, making it more likely to be clearly seen, whether by telescope or the naked eye.

“Typically, a comet would have to reach a magnitude of –6 to –10 to be seen in daylight,” Cooke said. “That’s extremely rare.”

At peak visibility in the northern hemisphere, Tsuchinshan-ATLAS’s brightness is estimated at between 2 and 4. In comparison, the brightest visible star in the night sky, Sirius, has a magnitude of –1.46. At its brightest, solar reflection from Venus is a magnitude of –4. The International Space Station sometimes achieves a relative brightness of –6.

Comets are often hard to predict because they’re extended objects, Cooke noted, with their brightness spread out and often dimmer than their magnitude suggests. At the same time, they may benefit from a phenomenon called “forward scattering,” which causes sunlight to bounce more intensely off all the gas and debris in the comet’s tail and its coma – the glowing nebula that develops around it during close stellar orbit – and causing a more intense brightening effect for observers.

“If there is a lot of forward scattering, the comet could be as bright as magnitude –1,” Cooke said. That could make it “visible to the unaided eye or truly spectacular with binoculars or a small telescope.”

What will become of Comet Tsuchinshan-ATLAS? Cooke said it could be flung out of the solar system – like a stone from a sling – due to the gravitational influence of other worlds and a “jetting” effect caused by the comet’s offgassing during its solar transit.

But the hardy traveler likely still has miles to go yet. “I learned a long time ago not to gamble on comets,” Cooke said. “We’ll have to wait and see.”

Learn more about comets here.

Lane Figueroa
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
lane.e.figueroa@nasa.gov

Editor’s Note: The orbits of comets are continuously revised as new observational data becomes available. An earlier version of this article cited a period of 80,000 years for C/2023 A3 Tsuchinshan-ATLAS, which is no longer accurate based on newly available data. As of Oct. 14, the comet’s path may take it out of the solar system altogether.

Smith, an Aeyon employee, supports the Marshall Office of Communications.

Eta Aquariids Outburst This Weekend – Next One in 2046

The eta Aquariid meteor shower should put on a spectacular sky show this year with meteor rates up to one per minute! The typical peak viewing time would normally be the night of May 4 into the morning of May 5. However, due to the outburst, May 2-6 could provide excellent skygazing opportunities.

According to Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, many of the shooting stars we see this year are actually caused by material from Halley’s Comet that is around 3,000 years old. As Earth runs into that debris, we can see streaks of light across the sky. When our planet moves through concentrated clumps of material, we can get a meteor outburst. The next time the eta Aquariids will outburst is about 20 years from now.

A sky full of falling meteors. — Grains of cosmic dust streaked through night skies in early May 2023. Swept up as planet Earth plowed through the debris streams left behind by periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids. Credit: Petr Horalek / Institute of Physics in Opava

Explanation: Grains of cosmic dust streaked through night skies in early May. Swept up as planet Earth plowed through the debris streams left behind by periodic Comet Halley, the annual meteor shower is known as the eta Aquariids. In 2022, the eta Aquariids peak was visually hampered by May’s bright full Moon. But early morning hours surrounding last May’s shower of Halley dust were free of moonlight interference. In exposures recorded between April 28 and May 8 in 2022, this composited image shows nearly 90 eta Aquariid meteors streaking from the shower’s radiant in Aquarius over San Pedro de Atacama, Chile.

To really top off this year’s event, the new Moon aligns with the peak nights, therefore there will be no light interference to obscure the fainter meteors. There’s only one catch with this shower in particular – the best viewing time is from 4 a.m. to dawn. You will be able to see the glowing in the early evening, as the constellation Aquarius does not rise until around 4 a.m. local time. Set the alarm, grab the coffee, and settle in for what should be a magnificent meteor shower experience.

By Lauren Perkins
NASA’s Marshall Space Flight Center

Enjoy the Warming Weather Under These 3 Upcoming Meteor Showers

Still basking in that post-eclipse celestial glow? We’ve got great news – there is plenty of reasons to look up again and we are here to share in the skywatching excitement as meteor showers top the upcoming headlines.

It’s been a quiet few months for meteors, but the Lyrid meteor shower peaks overnight April 21-22. Unfortunately, the Moon will be at greater than 90% waxing gibbous so a lot of light interference will outshine the fainter meteors. Even under perfect conditions – dark, away from city lights, open view of the sky – only a few meteors per hour are expected to be visible to the naked eye because of the bright Moon. For a dedicated observer, it may still be worth spotting members of one of the oldest known meteor showers – the Lyrids have been observed for 2,700 years!

The Eta Aquarids meteor shower peaks during early May each year. These meteors are known for their speed, which can leave glowing “trains” (incandescent bits of debris in the wake of the meteor) which last for several seconds to minutes. This is expected to be an outburst year, exclaims Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Visual rates could be as high as one per minute in the Southern Hemisphere, with just slightly less in the Northern.” The moon will be a waning crescent during its peak overnight May 4-5, so there will not be much moonlight interference.

Cooke is most excited for the Perseid meteor shower in mid-August, “The Perseids are always a stunner and this year, there will be no moonlight to spoil the show.” During its peak overnight August 12-13, about 50 to 100 meteors per hour can be seen! Perseids are also known for their fireballs. Fireballs are larger explosions of light and color that can persist longer than an average meteor streak.

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower, Wednesday, Aug. 11, 2021, in Spruce Knob, West Virginia. Credit: NASA/Bill Ingalls

Happy skywatching!

By Lauren Perkins
NASA’s Marshall Space Flight Center

Spooky Season of the Skies

The NASA All-sky Fireball Network is a network of cameras set up by the NASA Meteoroid Environment Office (MEO) with the goal of observing the brightest meteors called fireballs.

However, sometimes creepy, crawly, spooky, strange, and mysterious images also get picked up by their cameras.

Do you see the jack-o-lantern in the clouds?

Long-legged creepy crawler.

Hooded visitor of the night?

Not all tree frogs live in trees.

Broomstick convention or birds?

I bet those talons could grab a lot of candy.

Images and video of fireballs from the cameras are available for anyone to download from NASA’s All-Sky Fireball Network.

By Lauren Perkins
NASA’s Marshall Space Flight Center

The 2022 Geminids Meteor Shower Is Approaching

The cosmos’ annual gift to sky watchers, the Geminids Meteor shower, will peak on Dec. 13-14 this year.

During peak activity and perfect weather conditions, which are rare, the Geminids produce approximately 100-150 meteors per hour for viewing. However, this year a waning gibbous moon will make it harder to view most of the shower, resulting in only 30-40 visible meteors per hour at the peak in the Northern Hemisphere, depending on sky conditions. But the Geminids are so bright that this should still be a good show.

Bill Cooke, lead of NASA’s Meteoroid Environments Office at Marshall Space Flight Center in Huntsville, Alabama, suggests sitting in the shade of a house or tree while also maintaining a view of the open sky to alleviate moonlight interference.

The meteor shower is coined the Geminids because the meteors appear to radiate from the constellation Gemini. According to Cooke, meteors close to the radiant have very short trails and are easily missed, so observers should avoid looking at that constellation. However, tracing a meteor backwards to the constellation Gemini can determine if you caught a Geminid (other weaker showers occur at the same time).

Gemini does not appear very high above the horizon in the Southern Hemisphere, resulting in viewers only seeing approximately 25% of the rates seen in the Northern Hemisphere, which is between 7-10 meteors per hour. Sky watchers from the Southern Hemisphere are encouraged to find areas with minimal light pollution and look to the northern sky to improve their viewing opportunities.

A black circle has a series of white streaks which represent the geminid meteor shower. — Over 100 meteors are recorded in this composite image taken during the peak of the Geminid meteor shower in 2014. Credit: Jacobs Space Exploration Group/ESSCA

The Geminids start around 9 or 10 p.m. CST on Dec. 13, making it a great viewing opportunity for any viewers who cannot be awake during later hours of the night. The shower will peak at 6 a.m. CST on Dec. 14, but the best rates will be seen earlier around 2 a.m. local time. You can still view Geminids just before or after this date, but the last opportunity is on Dec. 17 – when a dedicated observer could possibly spot one or two on that night.

For prime viewing, find an area away from city and streetlights, bundle up for winter weather conditions, bring a blanket or sleeping bag for extra comfort, lie flat on your back with your feet facing south, and look up. Practice patience because it will take approximately 30 minutes for your eyes to fully adjust and see the meteors. Refrain from looking at your cell phone or other bright objects to keep your eyes adjusted.

The show will last for most of the night, so you have multiple opportunities to spot the brilliant streaks of light across our sky.

So where does this magnificent shower come from? Meteors are fragments and particles that burn up as they enter Earth’s atmosphere at high speed, and they usually originate from comets.

The Geminid shower originates from the debris of 3200 Phaethon an asteroid first discovered on Oct. 11, 1983, using the Infrared Astronomical Satellite. Phaethon orbits the Sun every 1.4 years, and every year Earth passes through its trail of debris, resulting in the Geminids Shower.

Phaethon is the first asteroid to be associated with a meteor shower, but astronomers debate its exact classification and origins. Phaethon lacks an icy shell (the staple characteristic of a comet), but some consider it a “dead comet” – suggesting it once had an icy shell that melted away. Other astronomers call it a “rock comet” because Phaethon passes very close to the Sun during its orbit, which theoretically results in heating and cracking that creates debris and dust. The bottom line is Phaethon’s exact origins are still a mystery, but we do know it’s the Geminids parent body.

Geminids travel 78,000 miles per hour, over 40 times faster than a speeding bullet, but it is highly unlikely that meteors will reach the ground – most Geminids burn up at altitudes between 45 to 55 miles.

An info graphic showing the altitude of the geminids based on 2019’s meteor camera data for the Geminids. — An info graphic based on 2019’s meteor camera data for the Geminids. Credit: NASA

In addition to sky watching opportunities, meteor videos recorded by the NASA All Sky Fireball Network are available each morning to identify Geminids in these videos – just look for events labeled “GEM.”

And, if you want to know what else is in the sky for December, check out the video below from Jet Propulsion Laboratory’s monthly “What’s Up” video series:

Happy stargazing!

by Lane Figueroa

Fireball lights up the sky over Salt Lake City

A bright meteor flew through the skies over northern Utah on Saturday morning, later raining down meteorites over the Great Salt Lake.

Residents of the Salt Lake City area were startled by loud booms at 8:30 a.m. MDT on Saturday, Aug. 13, 2022. Eyewitnesses saw a fireball in the sky, 16 times brighter than the full Moon.

GOES 17 Geostationary Lightning Mapper detection of the Aug. 13, 2022, fireball over northern Utah. Credits: NOAA

Approximately 22,000 miles out in space, NOAA’s Geostationary Lightning Mappers (GLM) onboard the Geostationary Operational Environmental Satellites (GOES) 17 and 18 detected the meteor, which was first seen 50 miles over West Valley City. However, it is difficult to pinpoint its exact trajectory.

“Daytime fireballs are very tough to analyze,” said Bill Cooke, lead of NASA’s Meteoroid Environments Office at Marshall Space Flight Center in Huntsville, Alabama. “There are few eyewitness sightings of the fireball and videos posted on social media are difficult to calibrate without stars in the background.”

The meteor was first seen 50 miles over West Valley City, Utah, moving to the northwest at 39,000 miles per hour. The object broke apart above the eastern shore of the Great Salt Lake. Credits: NASA

After traveling northwest at 39,000 miles per hour, the object – a piece of an asteroid about 2 feet across – broke apart above the eastern shore of the lake. “One meteorite has been recovered from the lake shore,” said Cooke. “There are probably more, but I would expect the vast majority fell into the water.”

NASA studies meteoroid environments in space to protect astronauts and satellites in space. NASA’s Meteoroid Environment Office prepares meteoroid forecasts for missions like Artemis I, the first integrated test of NASA’s deep space exploration systems: the Orion spacecraft, Space Launch System rocket, and the ground systems at Kennedy Space Center in Cape Canaveral, Florida. The Artemis I launch is currently targeted for Aug. 29.

For more information on NASA’s All Sky Fireball Network, visit:

https://fireballs.ndc.nasa.gov

To follow and share meteor updates, visit:

https://www.facebook.com/NasaMeteorWatch

By Hannah Maginot

Perseids Meteor Shower on the Way

The Perseids are back! Well… sort of.

Usually bringing one of the most vivid annual meteor showers visible in Earth’s night sky, commonly delivering 50-100 “shooting stars” per hour at its height, the Perseids will peak Aug. 12 and 13. There’s just one problem: the full Moon.

A shower of Perseid meteors lights up the sky in 2009 in this NASA time-lapse image. (NASA/JPL)

“Sadly, this year’s Perseids peak will see the worst possible circumstances for spotters,” said NASA astronomer Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Most of us in North America would normally see 50 or 60 meteors per hour,” he said, “but this year, during the normal peak, the full Moon will reduce that to 10-20 per hour at best.”

The Moon is so much brighter than anything else in the night sky, and it will wash out all, but the very brightest Perseids as they streak through our atmosphere and burn up far overhead.

As the full Moon subsides, the Perseids will begin to wane Aug. 21-22 and cease completely by Sept. 1. They’re the debris remnants of Comet Swift-Tuttle, a lumbering “snowball” composed of ice, rock, and dust, which orbits our Sun every 133 years. The comet itself was last visible to us in 1992 and won’t pass our way again until 2125.

How far back sightings of the Perseids actually go remains a matter of some contention, Cooke said. The comet itself wasn’t identified until 1862, but the meteor shower was seen over medieval Europe. The annual event came to be known as “the Tears of St. Lawrence,” named for the last of seven Roman church deacons martyred by the emperor Valerian in August of the year 258.

So, this is probably not the best year to make a special trip in order to see the Perseids, but, if you find yourself outside between midnight and dawn on Aug. 13, don’t forget to look up anyway. Because you never know – you might just catch one of the bright Perseid meteors that defies the glare of the Moon. Also, the occasional early Perseid can streak across the sky as much as a week beforehand.

If you want to know what else is in the sky for August, check out the latest “What’s Up” video from Jet Propulsion Laboratory:

by Rick Smith

Meteor Showers to Bookend Overnight Skywatching Opportunities in May

As the spring season continues, May could prove to be of great interest for stargazers and space enthusiasts – with a pair of potentially active meteor showers opening and closing the month.

“Meteors aren’t uncommon,” Bill Cooke said, who leads NASA’s Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Earth is bombarded every day by millions of bits of interplanetary detritus speeding through our solar system.”

A meteor mosaic comprised of 99 images, using a blue filter, of the Eta Aquariids observed during the early morning hours from April 30 to May 8, 2013.
Credits: NASA All Sky Fireball Network

Most particles are no bigger than dust and sand. Hitting the upper atmosphere at speeds up to 45 miles per second, they flare and burn up. On any given night, the average person can see from 4 to 8 meteors per hour. Meteor showers, however, are caused by streams of comet and asteroid debris, which create many more flashes and streaks of light as Earth passes through the debris field.

“It’s a perfect opportunity for space enthusiasts to get out and experience one of nature’s most vivid light shows,” Cooke said.

Eta Aquariids (May 5-6)

First up, on the night of May 5 and early hours of May 6, around 3:00 am CDT, is the eta Aquariid shower, caused by the annual encounter with debris from Halley’s comet – remnants of the comet’s tour through the solar system once every 75 or 76 years. Its radiant – or the point in the night sky from which the meteor shower appears to originate – is the constellation Aquarius. The shower is named for the brightest star in that constellation, eta Aquarii.

A 2013 eta Aquariid composite from a camera used in New Mexico.
Credits: NASA Meteoroid Environment Office

Until Halley’s comet is next visible from Earth in 2061, only the eta Aquariids – and their fall counterpart, the Orionid meteor shower, which is visible each October – mark the passage of this solar system visitor.

“It will be interesting to see if the rates are low this year, or if we will get a spike in numbers before next year’s forecast outburst,” Cooke said.

The annual meteor shower has the best rates for those in the Southern Hemisphere, but even in the Northern Hemisphere, if weather conditions are right, there is a possibility of seeing up to 30 meteors per hour. The waxing crescent Moon will set before the eta Aquariid radiant gets high in the sky, leaving dark skies for what should be an excellent show. Best viewing happens after 3 AM local time, so get up early.

Tau Herculids (May 30-31)

A possible newcomer this year is the tau Herculid shower, forecast to peak on the night of May 30 and early morning of May 31.

Back in 1930, German observers Arnold Schwassmann and Arno Arthur Wachmann discovered a comet known as 73P/Schwassmann-Wachmann, or “SW3, which orbited the Sun every 5.4 years. Being so faint, SW3 wasn’t seen again until the late 1970s, seeming pretty normal until 1995, when astronomers realized the comet had become about 600 times brighter and went from a faint smudge to being visible with the naked eye during its passage. Upon further investigation, astronomers realized SW3 had shattered into several pieces, littering its own orbital trail with debris. By the time it passed our way again in 2006, it was in nearly 70 pieces, and has continued to fragment further since then.

If it makes it to us this year, the debris from SW3 will strike Earth’s atmosphere very slowly, traveling at just 10 miles per second – which means much fainter meteors than those belonging to the eta Aquariids. But North American stargazers are taking particular note this year because the tau Herculid radiant will be high in the night sky at the forecast peak time. Even better, the Moon is new, so there will be no moonlight to wash out the faint meteors.

“This is going to be an all or nothing event. If the debris from SW3 was traveling more than 220 miles per hour when it separated from the comet, we might see a nice meteor shower. If the debris had slower ejection speeds, then nothing will make it to Earth and there will be no meteors from this comet,” Cooke said.

Learn more about meteors and meteorites. Also, if you want to know what else is in the sky for May, check out the latest “What’s Up” video from Jet Propulsion Laboratory:

Enjoy all this month has to offer as you watch the skies!

by Rick Smith

December Solstice Brings Winter, Summer Seasons

In meteorology, Earth’s winter season for the Northern Hemisphere and summer season for the Southern Hemisphere began on Dec. 1, 2021. However, the December solstice brings in the astronomical winter and summer seasons, respectively, for the two hemispheres of our planet. This will happen on Dec. 21 at 15:59 UTC, which is 9:59 a.m. CST in the United States.

Summer solstice explanation — During the solstices, Earth reaches a point where its tilt is at the greatest angle to the plane of its orbit, causing one hemisphere to receive more daylight than the other. Credits: NASA/Genna Duberstein

Solstices come twice a year. For the Northern Hemisphere, the summer (June) solstice occurs around June 20-21, and the winter (December) solstice happens around Dec. 21-22. At the solstice, the Sun’s path appears farthest north or south, depending on which half of the planet you’re on. Seasons change on Earth because the planet is slightly tilted on its axis as it travels around the Sun.

Earth’s axis may be imagined as an imaginary pole going right through the center of our planet from “top” to “bottom.” Earth spins around this pole, making one complete turn each day. That is why we have day and night.

Earth's seasons — Click to view larger. Credit: NASA/Space Place

Although the tilt of the Earth as compared to the plane of its orbit around the Sun is more or less constant (23.5˚), at the December solstice, the Northern Hemisphere receives the most indirect sunlight, causing cooler temperatures. The Southern Hemisphere receives the most direct sunlight, causing warmer temperatures, so it is summer there. At the June solstice, this effect reverses and the Northern Hemisphere receives the most direct sunlight, causing warmer temperatures, and the Southern Hemisphere receives the most indirect sunlight, causing cooler temperatures.

The December solstice brings the shortest day and longest night of the year for locations in the northern half of the globe, like the U.S., while the southern half of the globe is experiencing its longest day and shortest night. Therefore, all locations north of the equator see daylight shorter than 12 hours and all locations south see daylight longer than 12 hours.

After the winter solstice in the Northern Hemisphere, the days will get longer and the nights shorter until the summer solstice on June 21, 2022, when things reverse. The March equinox on March 20, 2022, will mark the beginning of the astronomical spring season and the September equinox on September 22, 2022, will mark the beginning of astronomical fall.

The ancient cultures knew that the Sun’s path across the sky, length of daylight, and location of the sunrise and sunset all shifted in a regular way throughout the year. Additionally, people built monuments, like Stonehenge in England and the Torreon in Machu Picchu, Peru, to follow the Sun’s annual progress and predict its movements.

Today, we have even more information about the universe, and we celebrate the solstice as an astronomical event caused by Earth’s tilt on its axis and its motion in orbit around the Sun.

No matter where you are on Earth’s globe – this is your time to celebrate this seasonal change!

by Lance D. Davis

Geminid Meteor Shower: NASA to Livestream Annual Highlight of December Skies

Every December we have a chance to see one of our favorite meteor showers – the Geminids. The shower is currently active until Dec. 17 and will peak on the night of Dec. 13 into the morning of Dec. 14, making those hours the best time for viewing the meteor shower.

The Geminids are caused by debris from a celestial object known as 3200 Phaethon, whose origin is the subject of some debate. Some astronomers consider it to be an extinct comet, based on observations showing some small amount of material leaving Phaethon’s surface. Others argue that it has to be an asteroid because of its orbit and its similarity to the main-belt asteroid Pallas.

Whatever the nature of Phaethon, observations show that the Geminids are denser than meteors belonging to other showers, enabling them to get as low as 29 miles above Earth’s surface before burning up. Meteors belonging to other showers, like the Perseids, burn up much higher.

The Geminids can be seen by most of the world. Yet, it is best viewed by observers in the Northern Hemisphere. As you enter the Southern Hemisphere and move towards the South Pole, the altitude of the Geminid radiant – the celestial point in the sky where the Geminid meteors appear to originate – gets lower and lower above the horizon. Thus, observers in these locations see fewer Geminids than their northern counterparts.

Besides the weather, the phase of the Moon is a major factor in determining whether a meteor shower will have good rates during any given year. This is because the moonlight “washes out” the fainter meteors, resulting in sky watchers seeing the fewer bright ones. This year, the Moon will be almost 80% full at the peak of the Geminids, which isn’t ideal for our highly regarded meteor shower. Nevertheless, that bright Moon is expected to set around 2:00 a.m. wherever you are located, leaving a couple of hours for meteor watching until twilight.

“Rich in green-colored fireballs, the Geminids are the only shower I will brave cold December nights to see,” said Bill Cooke, lead for NASA’s Meteoroid Environment Office, located at Marshall Space Flight Center in Huntsville, Alabama.

NASA will broadcast a live stream of the shower’s peak Dec. 13-14 via a meteor camera at NASA’s Marshall Space Flight Center in Huntsville, Alabama, (if our weather cooperates!), starting at 8 p.m. CST on the NASA Meteor Watch Facebook page.

Meteor videos recorded by the All Sky Fireball Network are also available each morning to identify Geminids in these videos – just look for events labeled “GEM.”

Learn more about the Geminids below:

Why are they called the Geminids?

All meteors associated with a shower have similar orbits, and they all appear to come from the same place in the sky, which is called the radiant. The Geminids appear to radiate from a point in the constellation Gemini, hence the name “Geminids.”

How fast are Geminids?

Geminids travel 78,000 mph (35 km/s). This is over 1000 times faster than a cheetah, about 250 times faster than the swiftest car in the world, and over 40 times faster than a speeding bullet!

How to observe the Geminids?

If it’s not cloudy, get away from bright lights, lie on your back, and look up. Remember to let your eyes get adjusted to the dark – you’ll see more meteors that way. Keep in mind, this adjustment can take approximately 30 minutes. Don’t look at your cell phone screen, as it will ruin your night vision!

Meteors can generally be seen all over the sky. Avoid watching the radiant because meteors close to it have very short trails and are easily missed. When you see a meteor, try to trace it backwards. If you end up in the constellation Gemini, there’s a good chance you’ve seen a Geminid.

Observing in a city with lots of light pollution will make it difficult to see Geminids. You may only see a handful during the night in that case.

When is the best time to observe Geminids?

The best night to see the shower is Dec. 13/14. Sky watchers in the Northern Hemisphere can go out in the late evening hours on Dec. 13 to see some Geminids, but with moonlight and radiant low in the sky, you may not see many meteors.

Best rates will be seen when the radiant is highest in the sky around 2:00 a.m. local time, including the Southern Hemisphere, on Dec. 14. The Moon will set around the same time. Therefore, observing from moonset until twilight on Dec. 14 should yield the most meteors.

You can still see Geminids on other nights, before or after Dec. 13-14, but the rates will be much lower. The last Geminids can be seen Dec. 17.

How many Geminids can observers expect to see Dec. 13/14?

Realistically, the predicated rate for observers in the northern hemisphere is closer to 30-40 meteors per hour. Observers in the Southern Hemisphere will see fewer Geminids than those in the northern hemisphere – perhaps 25% of rates in the Northern Hemisphere.

Although this year’s conditions are not the best for viewing the Geminid meteor shower, it will still be a good show to catch in our night skies.

And, if you want to know what else is in the sky for December, check out the video below from Jet Propulsion Laboratory’s monthly “What’s Up” video series:

Happy viewing stargazers!

by Lance D. Davis