Ahh, fall is almost upon us. Autumn officially begins Sept. 23 and for many, it will mean cooler temperatures – a welcome reprieve from the summer heat.
Fall also brings football, pumpkins, and a Harvest Moon to watch for in the sky. Save the date of Tuesday, Sept. 17. With a clear sky, people in the Northern Hemisphere will see a partial lunar eclipse, making the full supermoon on Sept. 17 extra super.
When only a part of the moon enters Earth’s shadow, the event is called a partial lunar eclipse. Image Credit: Brad Riza
In a partial lunar eclipse, the umbra – the shadow’s darkest part – “takes a bite out” of just a fraction of the Moon. The dark bite grows larger, and then recedes, never reaching the totality phase. In a total lunar eclipse, by comparison, the Earth’s full shadow falls across the face of the Moon. Learn more information about lunar eclipses here.
“From Huntsville, the penumbral phase will begin around 7:41 p.m., and people should start noticing a ‘reddish bite’ being taken out of the top part of the Moon around 9:12 p.m.,” said Bill Cooke, who leads NASA’s Meteoroid Environment Office at the agency’s Marshall Space Flight Center in Huntsville, Alabama. “The maximum eclipse will be at 9:44 p.m., and the partial phase will be over at 10:15 p.m.. The penumbral phase will end about an hour and a half later, at 11:47 p.m..”
The September full Moon is often called the Harvest Moon due to its association with autumn harvests in the Northern Hemisphere. So, bring on fall and the pumpkin spice. As Neil Young sang in his song “Harvest Moon” – “Let’s go out and feel the night.” And perhaps take a sweater. And skywatchers, grab your cameras!
Times will vary by location in the U.S., with only Alaska and Hawaii missing out on the event.
Visit here for more September skywatching tips from NASA.
Lane Figueroa
Marshall Space Flight Center, Huntsville, Ala.
256.544.0034
lane.e.figueroa@nasa.gov
Everyone everywhere is invited to join fellow sky-watchers Saturday, Sept. 14, for International Observe the Moon Night – a worldwide public event encouraging observation, appreciation, and understanding of the Moon and its connection to NASA exploration and discovery.
This celebration of the Moon has been held annually since 2010, and this year NASA’s Planetary Missions Program Office will host an event at the U.S. Space & Rocket Center (USSRC) in Huntsville, Alabama.
This free event will be held Sept. 14 from 5:30 p.m. to 8 p.m. CDT at the Davidson Center at the USSRC. Attractions will include hands-on STEM activities, telescope viewing from the Von Braun Astronomical Society, a live DJ, face painting, a photo booth, a science trivia show, and much more.
Headline entertainment will be provided by The Science Wizard, David Hagerman. The Science Wizard has appeared on national television and will perform two different science-based stage shows at the event. Learn more about what to expect on the .
It’s the perfect time to universally celebrate the Moon as excitement grows about NASA returning to our nearest celestial neighbor with the Artemis missions. Artemis will land the first woman and first person of color on the Moon, using innovative technologies to explore areas of the lunar surface that have never been discovered before.
Learn more and find other events here. Happy International Observe the Moon Night!
Stargazers seeking familiar points of interest in the night sky are likely to point out Betelgeuse, the red supergiant star sometimes identified as “the shoulder of Orion.” Even some 400-600 light-years distant, it’s typically one of the brightest stars visible in the night sky, and the brightest of all in the infrared spectrum.
Fewer space enthusiasts may know that Betelgeuse’s nickname may have been mistranslated from the Arabic phrase Ibṭ al-Jauzā’ in the 13th century. Depending on the nuances of pronunciation, Betelgeuse actually might be “the armpit of Orion.”
Betelgeuse is part of the Orion constellation. Credit: NASA
What may come as a surprise is that the star that inspired the naming of a ghostly movie menace is doing some hurtling of its own. Betelgeuse is actually a runaway star in the process of bidding a big galactic adios to its birthplace – the hot star association that includes Orion’s Belt – and speeding away at approximately 18.6 miles per second.
That’s an awesome prospect, said Dr. Debra Wallace, Marshall’s Deputy Branch Chief of Astrophysics. Betelgeuse is a pulsating star with an uncertain distance of roughly 548 light-years and changing luminosity. We estimate its radius is approximately 724 times larger than our Sun. If it sat at the center of our solar system, it would swallow the orbits of Mercury, Venus, Earth, and Mars. Its bow shock – the “wave” generated by its passage through the interstellar medium – is roughly four light-years across.
What cosmic force caused Betelgeuse to go on the interstellar lam from its point of origin?
“Typically, stars don’t become runaways without receiving a big kick,” Wallace said. “What’s most likely is that the competing gravity of other nearby stars ejected it outward or something else blew up in its proximity. There was a change in the dynamic interactions of the star grouping, and Betelgeuse was sent packing.”
Betel-BOOM!
Betelgeuse is only 10 million years old, but already in the twilight of its life. Given that our own small star is nearly 5 billion years, roughly halfway through its own estimated lifespan, why is Betelgeuse expected to be here today and gone tomorrow – give or take 100,000 years?
“Think about setting a fire in your back yard,” Wallace said. “The more fuel you throw on it, the faster and hotter it burns. It’s visually impressive – but gone in a flash.”
That’s because stars ignite a powerful chain of nuclear fusion reactions to counter their own intense gravity, which is always striving to collapse the star in on itself. For supergiants such as Betelgeuse, that delicate balance requires it to burn extremely hot and bright – but that also means it consumes its fuel supply far faster than our own modest young star.
Wallace said Betelgeuse likely started its life at least 20 times the mass of Earth’s Sun. It’s been visible to us for millennia. Ancient Chinese astronomers would have identified it as a yellow star which has since evolved to the right, per the Hertzsprung-Russell stellar evolution diagram and a 2022 study of the star’s color evolution. When the Egyptian astronomer Ptolemy saw Betelgeuse some 300 years after the earliest Chinese observations, it had gone orange. Today, the star has taken on a fierce red color that makes it easy to find in the night sky.
“Betelgeuse likely will burn for another 100,000 years or so, depending on its mass loss rate, then could end up a blue supergiant – like Rigel, the star that serves as Orion’s right knee – before it explodes,” Wallace said. That supernova event, she noted, will release as much energy in a split-second as our Sun generates in its entire lifetime, though Betelgeuse is far too distant to have any effect on our solar system.
This four-panel illustration reveals how the southern region of the red supergiant Betelgeuse suddenly may have become fainter for several months in late 2019 and early 2020. In the first two panels, as seen in ultraviolet light by NASA’s Hubble Space Telescope, a bright, hot blob of plasma is ejected from a convection cell on the star’s surface. In panel three, the expelled gas rapidly expands outward, cooling to form an enormous cloud of obscuring dust grains. The final panel reveals the huge dust cloud blocking the light from a quarter of Betelgeuse’s surface, as seen from Earth. Credits: NASA, ESA, and E. Wheatley (STScI)
Which isn’t to say the red supergiant doesn’t have any surprises left. In October 2019, Betelgeuse abruptly darkened, as much as half of its luminosity draining away in an event astronomers dubbed “the Great Dimming.”
Researchers began speculating about an early supernova, but by early 2020, Betelgeuse had brightened once more. Studies using NASA’s Hubble Space Telescope suggested a slightly less explosive cause. An upwelling of a large convection cell on Betelgeuse – perhaps in honor of its flatulent namesake – had expelled a titanic outburst of superhot plasma, yielding a dust cloud that dramatically blocked the star’s light for months.
“We’re still figuring out the mechanisms which cause massive star evolution, and the advent of new telescopes has been tremendously helpful,” Wallace said. “We’ve only realized in the last 20 or 30 years that most massive stars are products of binary evolution.”
Was Betelgeuse part of a binary star system, and did its demise – or a cataclysmic split – turn it into a runaway? Is it possible it’s still there, having merged with or still locked in a fatal dance with its fugitive partner? New studies suggest those may be possibilities, though Wallace notes that further intensive study is needed.
Will Betelgeuse ultimately go out with a bang or a whimper? Time will tell. But don’t write off the red giant just yet.
Stargazers in the Northern Hemisphere seeking to spot Betelgeuse should scan the southwestern sky. Those south of the equator should look in the northwestern sky. Find a line of three bright stars clustered together, representing Orion’s belt. Two brighter stars just to the north mark Orion’s shoulders; the very bright left one is Betelgeuse.
They may not attract as much attention as last month’s daylight fireball over New York City, but stargazers can still anticipate seeing some shooting stars with the upcoming Perseid meteor shower. Caused by Earth passing through trails of debris left behind by Comet Swift-Tuttle, the shower has become famous over the centuries because of its consistent display of celestial fireworks.
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. Photo Credit: (NASA/Bill Ingalls)
“The Perseids is the best annual meteor shower for the casual stargazer,” said Bill Cooke, who leads NASA’s Meteoroid Environment Office at the agency’s Marshall Space Flight Center in Huntsville, Alabama. “Not only is the shower rich in bright meteors and fireballs – No. 1 in fact – it also peaks in mid-August when the weather is still warm and comfortable. This year, the Perseid maximum will occur on the night of Aug. 11 and pre-dawn hours of Aug. 12. You’ll start seeing meteors from the shower around 11 p.m. local time and the rates will increase until dawn. If you miss the night of the 11th, you will also be able to see quite a few on the night of the 12th between those times.”
The best way to see the Perseids is to find the darkest possible sky and visit between midnight and dawn on the morning of Aug. 12. Allow about 45 minutes for your eyes to adjust to the dark. Lie on your back and look straight up. Avoid looking at cell phones or tablets because their bright screens ruin night vision and take your eyes off the sky.
Perseid meteors travel at the blistering speed of 132,000 mph – or 500 times faster than the fastest car in the world. At that speed, even a smidgen of dust makes a vivid streak of light when it collides with Earth’s atmosphere. Peak temperatures can exceed 3,000 degrees Fahrenheit as they speed across the sky. The Perseids pose no danger to people on the ground as practically all burn up 60 miles above our planet.
The first Perseid captured by NASA’s All Sky Meteor Camera Network was recorded at 9:48 p.m. EDT on July 23. The meteor – about as bright as the planet Jupiter, so not quite bright enough to be considered a fireball – was caused by a piece of Comet Swift-Tuttle about 5 millimeters in diameter entering the atmosphere over the Atlantic and burning up 66 miles above St. Cloud, Florida, just south of Orlando.
NASA’s All Sky Meteor Camera Network captured its first Perseid at 9:48 p.m. EDT on July 23.
Rare Fireball in New York, New York Not Perseids
It wasn’t part of the Perseids, but a rare daylight fireball streaked across the sky over New York City at 11:15 a.m. EDT on Tuesday, July 16. The event gained national attention and was reported in media outlets across the U.S.
The fireball, defined as a meteor brighter than the planet Venus, is estimated to have soared over New York City before traversing a short path southwest and disintegrating about 31 miles above Mountainside, New Jersey. Cooke said the meteor was likely about 1 foot in diameter, which would have made the rock bright enough to see during the day. Seeing a meteor of this size is rarer than catching sight of the smaller particles a few millimeters in size typically seen in the night sky.
“To see one in the daytime over a populated area like New York is fairly rare,” Cooke said during an interview with ABC 7 in New York.
The Meteoroid Environments Office studies meteoroids in space so that NASA can protect our nation’s satellites, spacecraft and even astronauts aboard the International Space Station from these bits of tiny space debris.
For more skywatching highlights in April, check out Jet Propulsion Lab’s What’s Up series.
Lane Figueroa Marshall Space Flight Center, Huntsville, Ala.
256.544.0034
lane.e.figueroa@nasa.gov
Most casual skywatchers know the bright, busy Perseids meteor shower arrives in late July and peaks in mid-August. Fewer are likely to name-drop the Southern delta Aquariids, which overlap with the Perseids each summer and are typically outshone by their brighter counterparts, especially when the Moon washes out the Southern delta Aquariids.
This year, with the Southern delta Aquariids set to peak on the night of July 28, the underdog shower isn’t likely to deliver any surprises. Unless you’re below the equator, it’ll take a keen eye to spot one.
Perseids meteors – which coincide with the Southern Delta Aquariids at the tail end of July – streak over Sequoia National Forest in this 2023 NASA file photo. (NASA/Preston Dyches)
“The Southern delta Aquariids have a very strong presence on meteor radars which can last for weeks,” said NASA astronomer Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Sadly, for most observers in the Northern Hemisphere, they’re difficult to spot with the naked eye, requiring the darkest possible skies.”
Meteor watchers – particularly those in the southern United States and points south – will be best served to check out the night sky July 28-29 before moonrise at 2 a.m.
During peak shower activity, under ideal viewing conditions with no Moon in the sky, casual watchers may see 2-5 meteors per hour, flashing into view at speeds of 25 miles per second. A small percentage of these may leave glowing, ionized gas trails that linger visibly for a second or two after the meteor has passed. But most of the noticeable activity for the Southern delta Aquariids occurs over a couple of days around its peak, so don’t expect to see any past the end of July.
You can distinguish Southern delta Aquariids meteors from the Perseids by identifying their radiant, or the point in the sky from which a meteor appears to originate. Southern delta Aquariids appear to come from the direction of the constellation of Aquarius, hence the name. The Perseids’ radiant is in the constellation of Perseus in the northern sky.
Most astronomers agree the Southern delta Aquariids originate from Comet 96P/Machholz, which orbits the Sun every 5.3 years. Discovered by Donald Machholz in 1986, the comet’s nucleus is roughly 4 miles across – about half the size of the object suspected to have wiped out the dinosaurs. Researchers think debris causing the Southern delta Aquariid meteor shower was generated about 20,000 years ago.
On June 3, stargazers will have an opportunity to look for six planets in Earth’s solar system. Mercury, Mars, Jupiter, Saturn, Uranus, and Neptune will appear, from some dark, weather-free vantage points on Earth, to form a more-or-less straight line in the night sky – but it’ll take some optical assistance to see them all.
The alignment is a bit of an illusion, astronomers are quick to point out, given the widely varying elliptical path of each planet’s orbit around the Sun. But the uncommon arrangement could prove captivating indeed – if local weather does not interfere.
Astronomers and stargazers around the world should be on the lookout before dawn on June 3 for a “planetary parade,” a loose alignment of six of our neighboring worlds: Mercury, Mars, Jupiter, Saturn, Neptune, and Uranus – though the latter two will require high-powered binoculars or a telescope to spot. (NASA/Night Sky Network)
The planetary alignment is likely to be most visible 30-60 minutes before sunrise, looking east from a dark, high vantage point with minimal light pollution and an unobstructed view of the complete horizon.
“If you were somewhere out in space other than on Earth, these planets would not appear aligned at all,” said Dr. Alphonse Sterling, astrophysicist at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “It is not unusual to see two or three lined up, but to have six of them line up like this is uncommon.”
Mars and Saturn will be identifiable with the naked eye, and Mercury and Jupiter may also be spotted close to the horizon. To add Neptune and Uranus to the lineup, however, will require the use of a telescope or high-powered binoculars.
“You can see it basically anywhere there isn’t a ton of light pollution,” Sterling said. “You just need a clear view looking east. Jupiter and Mercury will be the last to join, rising just above the horizon. You won’t see six bright dots lined up. In the best circumstances, you can see Jupiter, Mercury and Mars and Saturn. You’ll need binoculars or a telescope for the others.”
Alignments of six planets happen infrequently, depending on the orbit and position of each planet as seen from Earth. Indeed, we may see an encore performance later this year. The same rough alignment of six planets could be visible in the pre-dawn hours of Aug. 28 and again on Jan. 18, 2025.
That’s certainly more common than a full planetary alignment, in which all eight planets in our solar system would appear to fall into approximate formation on the same side of the Sun. Given all the factors involved, including the orbital plane, speed, and distance of each planet, estimates suggest it would take more than 300 billion years to happen just once.
That’s longer than the estimated lifetime of our parent star, so don’t wait up.
The planetary alignment is the latest skywatching event in a recent period rife with them. Space enthusiasts enjoyed a total solar eclipse April 8 and a rare sighting in May of the aurora borealis over parts of the continental United States – the result of an uncommonly large geomagnetic storm.
Comet 12P/Pons-Brooks is one of the brightest known periodic comets. It earned the nickname of “devil comet” in 2023 when an outburst caused the comet to have an asymmetrical appearance, like having horns. It comes around every 71 years and is currently getting brighter as it flies toward the Sun.
As spring approaches for northern skygazers, Comet 12P/Pons-Brooks is growing brighter. Currently visible with small telescopes and binoculars, the Halley-type comet could reach naked eye visibility in the coming weeks. Seen despite a foggy atmosphere, the comet’s green coma and long tail hover near the horizon in this well-composed deep night skyscape from Revuca, Slovakia recorded on March 5. M31, also known as the Andromeda galaxy, and bright yellowish star Mirach, second brightest star in the constellation Andromeda, hang in the sky above the comet. The Andromeda galaxy is some 2.5 million light-years beyond the Milky Way. Image Credit & Copyright: Petr Horálek / Institute of Physics in Opava
In the Northern Hemisphere, the comet is best viewed with binoculars or a small telescope – right after the Sun dips below the horizon, look West just beneath the Moon, and just right of Jupiter. An hour after sunset, the comet drops so low, it will be difficult to see without a perfectly clear view of the horizon. The comet then sets an hour later.
Sky chart showing the crescent Moon above Jupiter and Comet 12P in the western sky following sunset on April 10. Credit: NASA/JPL-Caltech
Bill Cooke, who leads the Meteoroid Environment Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, encourages viewers to have more realistic expectations about what they might see. “Many images depict a bright comet with a long green tail,” Cooke said. “That’s not going to happen.”
By July, it will be too dim to view even with binoculars.
As for viewing this comet with the naked eye, it might be possible in the coming days, but by mid-April, it will be too close to the Sun and then growing fainter as it makes its way away from the Sun.
The brightest stars are a magnitude 1, the faintest are a magnitude 6. Comet 12P will peak around a magnitude 5 unless an outburst occurs.
However, Cooke warns that outbursts are unpredictable. “There have been minor outbursts roughly once a month but it’s impossible to predict them,” he said. “The last one was on Leap Day, Feb. 29.”
It is certainly a possibility. If Comet 12P remains around a magnitude 5, it would only be visible in binoculars during the few minutes of totality. Consider enjoying the main spectacle instead of using that time to locate Comet 12P and attempt to view it at another time.
For more skywatching highlights in April, check out Jet Propulsion Lab’s What’s Up series.
By Lauren Perkins
NASA’s Marshall Space Flight Center
April’s solar eclipse has stolen the headlines for many months now, and rightfully so with millions of Americans in the path of totality.
But did you know there is also a lunar eclipse before the solar eclipse?
As the full moon rises during the late evening of March 24 into the early morning hours of March 25, it will travel through the Earth’s penumbra, or the faint outer part of its shadow. This is called a penumbral eclipse.
When the moon passes through the Earth’s shadow, it causes the Moon to look very unusual for a short period of time. This event is called a lunar eclipse, and it occurs roughly twice a year. Learn more about how lunar eclipses work in this video!
Credit: NASA Video
The lunar eclipse will be visible to all of North and South America. The Moon will dim very slightly over those few nighttime hours, which can make for an interesting timelapse, even if it can be difficult to notice by just a glance at the sky.
Happy skywatching!
By Lauren Perkins
NASA’s Marshall Space Flight Center
A star system, located 3,000 light-years away from Earth, is predicted to become visible to the unaided eye soon. This could be a once-in-a-lifetime viewing opportunity as the nova ouburst only occurs about every 80 years. T Coronae Borealis, or T CrB, last exploded in 1946 and astronomers believe it will do so again between February and September 2024.
A red giant star and white dwarf orbit each other in this animation of a nova. The red giant is a large sphere in shades of red, orange, and white, with the side facing the white dwarf the lightest shades. The white dwarf is hidden in a bright glow of white and yellows, which represent an accretion disk around the star. A stream of material, shown as a diffuse cloud of red, flows from the red giant to the white dwarf. The animation opens with the red giant on the right side of the screen, co-orbiting the white dwarf. When the red giant moves behind the white dwarf, a nova explosion on the white dwarf ignites, filling the screen with white light. After the light fades, a ball of ejected nova material is shown in pale orange. A small white spot remains after the fog of material clears, indicating that the white dwarf has survived the explosion. Credit: NASA’s Goddard Space Flight Center
The star system, normally magnitude +10, which is far too dim to see with the unaided eye, will jump to magnitude +2 during the event. This will be of similar brightness to the North Star, Polaris.
Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years.
As we wait for the nova, become familiar with the constellation Corona Borealis, or the Northern Crown — a small, semicircular arc near Bootes and Hercules. This is where the outburst will appear as a “new” bright star.
A conceptual image of how to find Hercules and his mighty globular clusters in the sky created using a planetarium software. Look up after sunset during summer months to find Hercules! Scan between Vega and Arcturus, near the distinct pattern of Corona Borealis. Once you find its stars, use binoculars or a telescope to hunt down the globular clusters M13 and M92. If you enjoy your views of these globular clusters, you’re in luck – look for another great globular, M3, in the nearby constellation of Boötes. Credit: NASA
This recurring nova is only one of five in our galaxy. This happens because T CrB is a binary system with a white dwarf and red giant. The stars are close enough that as the red giant becomes unstable from its increasing temperature and pressure and begins ejecting its outer layers, the white dwarf collects that matter onto its surface. The shallow dense atmosphere of the white dwarf eventually heats enough to cause a runaway thermonuclear reaction – which produces the nova we see from Earth.
Follow @NASAUniverse for updates about the outburst.
By Lauren Perkins NASA’s Marshall Space Flight Center
February is a great month for the early rising skygazers. Venus has been bright in the morning sky all year, rising just before the Moon.
In the minutes before dawn this week, Venus will rise to the upper left of the waning crescent Moon and will be joined by Mars.
This graphic shows Venus, Earth and its Moon, and Mars. Credit: NASA/JPL-Caltech/ESA
Over the coming weeks, Venus will shift towards Mars until they appear to merge into one another, just a half a degree apart, on Feb. 22.
To view this planetary illusion, you’ll need to find a place with a clear view of the western horizon – few to no tall trees or buildings.
For more skygazing opportunities, including observing spiral galaxy M81, check out the video below from Jet Propulsion Laboratory’s monthly “What’s Up” video series:
By Lauren Perkins
NASA’s Marshall Space Flight Center
