How many Perseids will I see in 2021?

By Bill Cooke, NASA Meteoroid Environments Office

Many Perseid-related news stories and social media posts state that the maximum rate is about 100 meteors per hour, which is a lot. So, folks get excited and go out on the peak night, braving mosquitos and other nightly hazards. But they are often disappointed; we routinely hear, “I went out and only saw a few meteors. Not even 20, much less 100!” And they would be right. The problem is that the 100 per hour is a theoretical number used by meteor scientists and does not convey what people are actually going to see.

In the 1980’s, meteor researchers were searching for a way to compare the meteor shower rates observed by various individuals and groups across the globe. People were reporting the rates, but the differences in sky conditions, radiant altitude and observer eyesight made getting a comprehensive view of shower activity difficult.

So, the meteor researchers put their heads together and came up with the concept of a ZHR, or Zenithal Hourly Rate. The ZHR is what you get after you correct the observed rates for the sky conditions, the altitude of the radiant above the horizon and observer biases. In other words, it is basically what a perfect observer would see under perfect skies with the meteor shower radiant straight overhead – which never happens!

The often-quoted ZHRs overestimate the meteor rates people actually see – sometimes by a lot. Fortunately, we can take the ZHR and invert things to get the hourly rates for certain locations and circumstances – it’s only math, after all. We have done this for select locations in the United States, producing the following maps.

These maps show the hourly rates that can be expected on the night of the Perseid shower’s peak, provided there are no clouds in the sky. (It’s hard to account for partial cloud cover.)

These rates assume you are out in the country, where lots of stars and the Milky Way are visible and no clouds, of course:

Perseids in CountrySo, instead of 100 Perseids per hour, people in the U.S. can reasonably expect to see around 40-ish Perseids in the hour just before dawn on the peak nights. That’s about one every couple of minutes – not bad. However, we are assuming you are out in the country, well away from cities and suburbs.

What rates can you expect if you want to do your Perseid watching from the neighborhood? We also computed that:

Perseids in SuburbsThe brighter skies of the suburbs greatly cut down the rates. We have gone from a Perseid every couple of minutes to one every 6-7 minutes – a factor of three reduction. This explains the great disappointment expressed by many casual Perseid watchers; they go outside, expecting to see at least a meteor a minute and end up with 10 or less in an hour. The brightness of your sky is everything in meteor observing – you have to get away from the lights!

But what about those in cities? The rates are close to zero:

Perseids in CityUgh! City dwellers might see a Perseid or two in an hour. Not very inspiring. Perhaps the only good news is that, if someone in a city sees a Perseid, it has to be really, really bright and spectacular.

Want to see Perseids? Then head out into the dark – it’s worth it!

Check out our previous blog post, The Perseids are on the Rise, for more information on the Perseids and tips on how to observe them.

The Perseids are on the Rise!

It’s time again for one of the biggest meteor showers of the year! The Perseids are already showing up in our night skies—and when they peak in mid-August, it’s likely to be one of our most impressive skywatching opportunities for a while.

Perseid Meteor image
In this 30 second exposure taken with a circular fish-eye lens, a meteor streaks across the sky during the annual Perseid meteor shower on Friday, Aug. 12, 2016 in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)

Our meteor-tracking cameras spotted their first Perseid on July 26, but your best chance to see them will start the night of Aug. 11. With the crescent moon setting early, the skies will be dark for the peak viewing hours of midnight (local time) to dawn on Aug. 12.

Perseid activity
This chart shows expected levels of Perseid activity for July and August 2021, relative to the peak on Aug. 11-13, ignoring the effects of the Sun, Moon, and clouds. All times are in UTC. Credits: (NASA/MEO/Bill Cooke)

If you’re in the Northern Hemisphere, and far away from light pollution, you might spot more than 40 Perseids an hour! (If you’re in a city, you may only see a few every hour; skywatchers in the Southern Hemisphere will also see fewer Perseids, with none visible below about 30 degrees south latitude.) The night of Aug. 12-13 will be another great opportunity to see the Perseids: with a full Moon (and lower meteor activity) during the Perseids’ peak in 2022 and a waning crescent high in the sky for 2023, this might be your best chance to do some summer skywatching for a few years.

Find somewhere comfortable, avoiding bright lights as much as possible (yes, including your phone), and give your eyes some time to adjust to the dark—up to half an hour if you can. The Perseids will appear as quick, small streaks of light: they get their name because they look like they’re coming from the direction of the constellation Perseus (near Aries and Taurus in the night sky), but Perseids in that area can be hard to spot from the perspective of Earth. So just look up and enjoy the show!

If you can’t see the Perseids where you live, join NASA to watch them on social media! Tune in overnight Aug. 11-12 (10 PM–5 AM CDT; 3–10 AM UTC) on Facebook, Twitter and YouTube to look for meteors with space fans from around the world. If skies are cloudy the night of Aug. 11, we’ll try again the same time on Aug. 12-13. Our livestream is hosted by the Meteoroid Environment Office at NASA’s Marshall Space Flight Center, which tracks meteors, fireballs, and other uncommon sights in the night sky to inform the public and help keep our astronauts and spacecraft safe.

Where do the Perseids *actually* come from?

The Perseids are fragments of the comet Swift-Tuttle, which orbits between the Sun and beyond the orbit of Pluto once every 133 years. Every year, the Earth passes near the path of the comet, and the debris left behind by Swift-Tuttle shows up as meteors in our sky. (Don’t worry, there’s no chance that we’ll run into the actual comet anytime soon.)

Where can I go to learn more?

We’ve got some great space-rock lessons for students, starting with the biggest question: what’s the difference between an asteroid and a meteor? Our NASA Space Place site also has a kid-friendly introduction to meteor showers in general. If you’re looking for something a little more hands-on, try this asteroid-building classroom activity—or, for an older audience, learn how to describe rocks like a NASA scientist.

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

Happy skywatching!

by Brice Russ

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!

Perseids Meteor Shower Peaks This Weekend

A live broadcast of the meteor shower from a camera in Huntsville, AL (if our weather cooperates!) will be available on NASA TV and the NASA Meteor Watch Facebook starting around 9 p.m. Eastern time (8 p.m. CT) and continuing until the early hours of August 13.

The Perseid meteor shower is here! Perseid meteors, caused by debris left behind by the Comet Swift-Tuttle, began streaking across the skies in late July and will peak on August 12.

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 peak, however, has the added bonus of dark skies courtesy of an early-setting crescent Moon. Combine these ideal observing conditions and high rates (an average of 60 meteors per hour at the peak) with the fact that the best nights for viewing – August 11 to 12 and August 12 to 13 – occur on a weekend and you have a recipe for successfully viewing some celestial fireworks!

A Perseid meteor over Daytona Beach, FL.
A Perseid meteor over Daytona Beach, FL. Perseids are known for being bright and fast, traveling 132,000 mph. Image Credit: NASA/MEO.

When Should I Look?

Make plans to stay up late or wake up early the nights of August 11 to 12 and August 12 to 13. The Perseids are best seen between about 2 a.m. your local time and dawn.

If those hours seem daunting, not to worry! You can go out after dark, around 9 p.m. local time, and see 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 in Huntsville, AL (if our weather cooperates!) will be available on the NASA Meteor Watch Facebook starting around 8 p.m. CT and continuing until the early hours of August 13. 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.

Most of the meteors seen in this composite are Perseids.
Most of the meteors seen in this composite are Perseids. Notice how they all appear to be streaking from the same direction? The Perseids appear to radiate from a point in the constellation Perseus. Image Credit: NASA/MEO.

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.) 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!

The Greatest Meteor Show of All Time

By Bill Cooke

At NASA, we get very excited about many astronomical events — to name just a few, the return of Halley’s Comet back in 1985/86; the impact of the fragments of Comet Shoemaker-Levy 9 with Jupiter in 1992; the Leonid meteor storms of 1998, 1999, 2001 and 2002; and, of course, the upcoming total solar eclipse on Aug. 21 of this year.

Some of these events get blown a bit out of proportion. A classic example is that every time Mars comes to opposition (closest approach to Earth), the internet reverberates with the very false statement that Mars will appear as large as the Moon at that time. Nothing could be farther from the truth, as Mars, at its very closest to Earth, appears only 1/70th the apparent diameter of the Moon.

This year we have a new one — reports are circulating that this year’s Perseids will be the “brightest shower in recorded human history,” lighting up the night sky and even having some meteors visible during the day. We wish this were true… but no such thing is going to happen.

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Thursday, Aug. 13, 2015, in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)

For one thing, the Perseids never reach storm levels (thousands of meteors per hour). At best, they outburst from a normal rate between 80-100 meteors per hour to a few hundred per hour. The best Perseid performance of which we are aware occurred back in 1993, when the peak Perseid rate topped 300 meteors per hour. Last year also saw an outburst of just over 200 meteors per hour.

This year, we are expecting enhanced rates of about 150 per hour or so, but the increased number will be cancelled out by the bright Moon, the light of which will wash out the fainter Perseids. A meteor every couple of minutes is good, and certainly worth going outside to look, but it is hardly the “brightest shower in human history.” The Leonid meteor storms of the late 1990’s and early 2000’s were much more spectacular, and had rates 10 times greater than the best Perseid display.

So, if not this year’s Perseid shower, what was the greatest meteor show of all time? I think many meteor researchers would give that award to the 1833 Leonids, which had rates of tens of thousands, perhaps even 100,000, meteors per hour. During a good Perseid shower under ideal conditions, you can see about one meteor per minute. Now imagine yourself being back in 1833, on the night of Nov. 12. Looking outside, you would see something like 20 to 30 meteors PER SECOND. No wonder we read accounts like this one from South Carolina (Chambers, A Handbook of Descriptive and Practical Astronomy, Volume 1, 1889):

“Upwards of 100 lay prostrate on the ground…with their hands raised, imploring God to save the world and them. The scene was truly awful; for never did rain fall much thicker than the meteors fell towards the Earth; east, west, north and south, it was the same.”

Now, THAT’s a meteor shower. The 1833 storm had a profound effect on those that witnessed it; it also gave birth to modern meteor science. Those of us who study meteors dream of such a display happening sometime within our lifetimes.

But it won’t be caused by this year’s Perseids.

Cooke leads NASA’s Meteoroid Environment Office at the agency’s Marshall Space Flight Center.

 

Perseids Are Already Appearing in the Huntsville Sky

This composite image shows the meteors detected by the NASA All Sky Fireball Network station here in Huntsville, Alabama this morning.   The majority of the meteors are Perseids, but a handful belong to the Northern Delta Aquariid, Southern Delta Aquariid, Alpha Capricornid, and Southern Iota Aquariid meteor showers that are also active.

HuntsvilleComposite

This Perseid meteor was observed by the NASA Wide-field Meteor Camera Network in the skies over Huntsville, Alabama on the morning of August 12.

ev_20150812_100322A_07A

Perseid Fireball Over New Mexico

This Perseid fireball was observed by the NASA All Sky Fireball Network in the skies over New Mexico on the morning of August 12.

ev_20150812_101552A_06A

Join Us For the May Camelopardalids!

Step outside and take a look at the skies on the evening of May 23 into the early morning of May 24. Scientists are anticipating a new meteor shower, the May Camelopardalids. No one has seen it before, but the shower could put on a show that would rival the prolific Perseid meteor shower in August. The Camelopardalids shower would be dust resulting from a periodic comet, 209P/LINEAR.

“Some forecasters have predicted a meteor storm of more than 200 meteors per hour,” said Bill Cooke, lead for NASA’s Meteoroid Environment Office. “We have no idea what the comet was doing in the 1800s. The parent comet doesn’t appear to be very active now, so there could be a great show, or there could be little activity.”

The best time to look is during the hours between 06:00 and 08:00 Universal Time on May 24, or between 2-4 a.m. EDT. That’s when forecast models say Earth is most likely to encounter the comet’s debris. North Americans are favored because their peak occurs during nighttime hours while the radiant is high in the sky.

On the night of May 23-24, NASA meteor expert Bill Cooke will host a live web chat from 11 p.m. to 3 a.m. EDT. Go to this page to learn more about the May Camelopardalids, to get information about the live chat and to view the live Ustream view that will be available during the chat.

 camel

NASA All Sky Fireball Network Cameras Catch Perseids

The annual Perseid meteor shower peaked on Aug. 12 and 13, 2013, filling the sky with streaks of light caused by the meteoroids burning up in Earth’s atmosphere. Big meteor showers like the Perseids, are caused when Earth travels through a region of space filled with debris shed by a comet. The Perseids have been observed for at least 2,000 years and are the small fragments from comet Swift-Tuttle. These bits of ice and dust wander in space for centuries, finally burning up in the Earth’s atmosphere to create one of the best meteor showers of the year.

Compilation of Perseid meteors taken by the NASA All Sky Fireball Network cameras. Video credit: NASA/MSFC/MEO

iotd

This Perseid fireball meteor was observed in the skies over Chickamauga, Ga., on Aug. 11, 2013, at 2:14:49 a.m. EDT. It was also recorded by four other cameras in the NASA All Sky Fireball Network. Image Credit: NASA/MSFC/MEO

Perseids Already Lighting Up The Night

Here is a video of a bright Perseid seen by our all-sky camera located at PARI (NC) in the early morning hours of July 30. Several Perseids have already been detected and they are not set to peak for over a week! The nights of August 11-12 and 12-13 will be the best time to observe, but check out fireballs.ndc.nasa.gov regularly to see how many have already been detected by our all-sky cameras!