A total solar eclipse is coming to North America. On 8 April, the moon will pass between Earth and the sun, aligning perfectly to block out the sun’s entire disc in an event called totality. It will be visible from a thin strip of land spanning from Mexico across the US to Canada.

The eclipse will commence in the Pacific Ocean about halfway between North America and New Zealand, and it will begin to be visible on Mexico’s west coast at 9.51am local time. It will start as a partial eclipse, with the moon slowly moving to cover more and more of the sun. Totality will first be visible on Mexico’s west coast at 11.07am local time.

As the sun and moon move across the sky, the eclipse will become visible in the US above a swathe of land about 185 kilometres (115 miles) wide, known as the path of totality. It will pass over 13 states, from Texas up through Maine, before crossing into southern Ontario in Canada. The last place on land from which the eclipse will be visible will be Newfoundland, and totality will end there at 5.16pm local time.

The duration of totality will vary by location, from less than 2 minutes to nearly 4.5 minutes. This is because the moon’s orbit around Earth isn’t perfectly circular – nor is Earth’s orbit around the sun – so the distances between the three celestial bodies will change throughout the day.

How dark will it get?

During a total solar eclipse, the moon’s shadow travels across the ground at speeds in excess of 2400 kilometres per hour, creating a dark spot that rushes along the ground. Temperatures in this shadow drop dramatically. Totality is as dark as dawn or dusk, within about half an hour before sunrise or after sunset. It’s dark enough to see the brightest stars and planets, but not quite as dark as nighttime because some sunlight does still shine around the edges of the moon. The brightness of that sunlight depends on the exact orientations of the sun and moon in their orbits, which affect the size of the moon’s shadow on Earth.

Free newsletter

Sign up to Launchpad

Sign up to newsletter

Total eclipses are important for scientists because they provide a rare opportunity to take measurements of the outermost layer of the sun, called the corona. This tenuous layer is difficult to observe normally, because it is so much dimmer than the sun’s disc. Viewers in the areas just outside of the path of totality will still be able to see a solar eclipse, but it will only be partial, with the moon covering a smaller portion of the sun. The partial eclipse will last around 3 hours.

��

How to view the eclipse safely

Looking directly at a solar eclipse is only safe for a short period for those in the path of totality. Partial solar eclipses – including the period of a total eclipse just before and after totality – must be viewed through special solar filters. Such filters are available in the form of eclipse glasses; however, regular sunglasses cannot protect viewers’ eyes sufficiently. Do not look directly at the sun without a solar filter, even during a partial eclipse.

If you don’t have eclipse glasses, there is no need to despair. You can still see the partial eclipse, just not directly. Any object with holes in it, such as a colander or even a piece of paper with a pinhole, can be used to project an image of the eclipse’s shape on a screen or the ground. Even the spaces between leaves on the trees will speckle the ground with strange, shifting crescents of sunlight.

Solar Eclipse 2024

On 8 April a total solar eclipse will pass over Mexico, the US and Canada. Our special series is covering everything you need to know, from how and when to see it to some of the weirdest eclipse experiences in history.

Read more

How to make an eclipse viewer

Eclipse viewers can be made with a few basic items. To make a pinhole camera that shows a projection of the sun, all you need is some paper, aluminium foil, scissors and a pen. Add a cardboard box into the mix and you could make yourself a box eclipse viewer. We've got full instructions on how to do both of these here.

Which eclipse glasses should I get?

When buying eclipse glasses, make sure that they are from a trusted source and that they satisfy the ISO 12312-2 international standard, which means they can be used for looking directly at the sun. See our full article on this topic here.

Across North America, solar scientists will be studying April’s total solar eclipse to view the strangest part of the sun:��the corona.

Seen fleetingly as a bright halo that appears only during totality, it is a million times dimmer than the rest of the sun in visible light. The corona is also a million degrees hotter than the sun’s surface, or photosphere, which reaches only about 6000°C, and it extends millions of kilometres into the solar system.

The corona is where the sun’s magnetic fields act on charged particles to form complex shapes, known as streamers, loops and plumes, among other names. Understanding the corona will help us predict the solar wind, the stream of charged particles hurled from the sun into space. This is what causes��aurorae, but it is also a��potential threat to astronauts, satellites and electricity grids.

Expectations are sky high for the total solar eclipse on 8 April because totality – when the sun is entirely covered – will last up to 4 minutes and 27 seconds – the longest such period on land for over a decade. Here are a few of the experiments that will be taking place.

The solar wind sherpas

, a solar researcher at the University of Hawaiʻi Institute for Astronomy, has been chasing solar eclipses for almost 30 years, using special filters and cameras to measure the temperatures of the particles from the innermost part of the corona.

Habbal’s group, now known as the Solar Wind Sherpas, has travelled to places as far afield as the Marshall Islands, Kenya, Mongolia, the Norwegian archipelago of Svalbard, Antarctica and Libya. At each eclipse, some of which last just a few seconds, Habbal and her team image the corona using their filters. Studying the different wavelengths of light emitted by charged iron particles in the corona lets them tease out temperatures.

Eclipse 2024: When is it and where can I see it?

North America will have a total solar eclipse on 8 April – here is where, when and how to view it safely

Most of the time, solar physicists studying the corona rely on coronagraphs from space-based observatories, which use a disc on a telescope to block the sun. But these devices cover up the innermost part of the corona, the source of towers of plasma called prominences and eruptions called coronal mass ejections.

“Observations during totality are critical,” says Habbal. There is no other way to see the part of the sun’s atmosphere that extends from its surface out to at least 5 solar radii in a continuous manner. “That’s fundamental to understanding how the solar atmosphere starts at the sun and then extends into interplanetary space,” she says. Only then can accurate computer models be devised that simulate the corona and help in the prediction of space weather.

In the past couple of years, Habbal’s group has made an astonishing discovery. Right now, the sun is heading towards solar maximum in 2025, the most active point in its 11-year cycle, when the solar wind intensifies. Since the corona looks much larger during total solar eclipses at solar maximum, it was thought that the solar cycle and the temperature of the corona are inextricably linked. But it might not be so simple.

In 2021, Habbal and her colleagues published research from observations taken during 14 total solar eclipses that suggests��. The lines of the sun’s magnetic field can be open, travelling outwards with the solar wind, or closed, which are hotter and form loops. “We found open field lines everywhere regardless of the cycle,” says Habbal. This means the corona has a roughly constant temperature.

The high fliers

Bad weather has prevented observations since 2019. “We had rain in Chile in 2020, clouds at sea in Antarctica in 2021 and there was no eclipse in 2022,” says Habbal. It was during the expedition to Antarctica that team member suggested that next time they could fly a kite equipped with a spectrometer, which separates light into its component wavelengths.

The NASA-funded kite, which has a 6.5-metre wingspan, was successfully tested in Western Australia during a total solar eclipse in April 2023. It was launched on a kilometre-long tether attached to a vehicle. “It was pretty miraculous,” says Habbal. Bad weather meant that the team flew it for the first time just 45 minutes before totality. “It was thrilling.”

If the technology works well at the upcoming eclipse, the kite will be deployed more in future, probably with cameras added. “It’s much easier and cheaper than using balloons,” says Habbal. But if it doesn’t work, there is always a backup.

During the total eclipse, two WB-57 planes will follow each other at 740 kilometres per hour, about a quarter of the speed of the moon’s shadow, just south-west of the maximum point of the eclipse. At that speed, totality increases from the 4 minutes 27 seconds for those viewing it from the ground to over 6 minutes. “The WB-57 is perfect for this because in its nose cone is a camera and telescope system that can rotate to point at anything… no matter which way the aircraft is flying,” says at the Southwest Research Institute in Boulder, Colorado, who is in charge of an experiment in the second WB-57 to study the corona in a different way.

Using a stabilised platform, Caspi and his team will capture images of the eclipse using both a visible-light camera and a higher-resolution mid-infrared camera developed by NASA. The latter will capture seven different wavelengths of light and help determine which structures in the corona emit their own light and which merely scatter light from the sun’s surface. “We need to be above as much of the atmosphere as we can get to make those observations,” says Caspi. Infrared light is absorbed by Earth’s atmosphere and is hard to observe from ground level.

The live streamers

Caspi is also part of the Citizen Continental-America Telescopic Eclipse (CATE) project, an attempt to make a continuous 60-minute high-resolution movie using 35 teams of citizen scientists in the path of totality, from Texas to Maine, each with the same cameras, telescopes and training so they can make exactly the same kinds of observations. “The teams will be spaced out so that every station is overlapped by its neighbours,” says Caspi. “If one station doesn’t get data, because of clouds or broken equipment, it’s OK.”

He is hopeful the equipment will work, since it was successfully tested last year in Western Australia. “That was the first eclipse I’ve seen,” says Caspi, who only got to see a few brief seconds because he was busy live streaming it on YouTube. “Our equipment couldn’t get online, so I spent the whole time holding my phone in front of my face.”

Solar Eclipse 2024

On 8 April a total solar eclipse will pass over Mexico, the US and Canada. Our special series is covering everything you need to know, from how and when to see it to some of the weirdest eclipse experiences in history.

Read more

The movie will hopefully allow scientists to study the corona’s complexities, notably its shape and how it changes over a short time. It builds on a CATE project from 2017, which used 68 cameras throughout the path. This time, it will use more sophisticated cameras that are sensitive to different types of polarised light.

“Most of the light that you see during totality is actually light from the surface of the sun that goes up into the corona to scatter off electrons,” says Caspi. This is the K corona, the bright inner part, which overwhelms the light coming only from the corona itself. As the light scatters, it becomes angled, a property called polarisation. “If you can measure the angle of polarisation, then that gives you a 3D structure of the corona, its density and how that changes over time,” he says.

Time is in short supply during a total solar eclipse, so a continuous hour-long video makes it possible to capture processes that take seconds or minutes, like a solar flare or coronal mass ejection, as well as other details. “The corona is permeated by a complicated magnetic field,” says Caspi. “During totality, we don’t see the magnetic field, but instead the hot plasma trapped along it – just like being able to see iron filings around a magnetic field around a magnet.”

How to photograph a total solar eclipse using your smartphone

Discovery Tours: Eclipses

Explore our tours and cruises designed to help you make the most of experiencing awe-inspiring solar eclipses in handpicked locations around the world.

Find out more

How to photograph a total solar eclipse using a camera

How to photograph a partial solar eclipse

There is no experience in life like witnessing a total eclipse of the sun. For a few moments, the sky goes dark, the air gets cold and the stars come out in the middle of the day. Some people will go through life never seeing one, but eclipse chasers like me can’t get enough.

The thrill of anticipating the next total eclipse comes from the fact that each one is totally unique. They can last anywhere from a single second to over 7 minutes, and they happen over varying types of geography and geology, usually over the sea.

Just before, during and after the magical minutes of totality, those in the path of the eclipse should look out for a range of phenomena. Clear skies allowing, here’s what to expect from a total solar eclipse:

Sunspots being covered by the moon

At the moment, the sun is in the most active part of its cycle, called solar maximum, which lasts between 11 and 17 years. This means magnetic activity is as high as it gets, causing visible sunspots on the sun’s surface. If these dark, cool, magnetically complex regions are large enough, they can be seen at any time through eclipse glasses. Watching them gradually being covered by the moon during an eclipse is an interesting sight, even for those outside the path of totality.

Shadow bands on the ground

Between a couple of minutes and about 30 seconds before the sun becomes totally eclipsed, the from its surface, called the photosphere, comes from only a slim crescent. When this happens, it is sometimes possible to see wavy lines moving swiftly across light-coloured surfaces. “A [bed] sheet or other white-ish surface placed on the ground may show shadow bands,” says at Villanova University in Pennsylvania. “These are due to that sliver of photospheric light that travels through our atmosphere and essentially ‘twinkles’ in roughly parallel bands.” Whether they become visible depends on the amount of turbulence in Earth’s atmosphere.

Free newsletter

Sign up to Launchpad

Sign up to newsletter

Discovery Tours: Eclipses

Explore our tours and cruises designed to help you make the most of experiencing awe-inspiring solar eclipses in handpicked locations around the world.

Find out more

Darkness, Baily’s beads and the first diamond ring

Just before totality, the final 0.1 per cent of the sun disappears and the light levels crash. Now come the beads. “In the few seconds before and after totality, one may see Baily’s beads as the last bits of the sun can be seen shining through the moon’s irregular surface,” says Maloney. The final bead shines like a jewel for a second, just as the sun’s corona appears, creating a brief “diamond ring” effect around the moon. It is safe to look at the diamond ring without eclipse glasses, but most observers miss it because they still have them on.

Solar corona

Here it comes – one of the most glorious sights in all of nature. “During totality, when the sun’s photosphere is eclipsed, the other parts of the sun’s atmosphere, the white corona and the pink-purple chromosphere, become visible,” says Maloney. Darkness has arrived and you can safely remove your eclipse glasses and look with your naked eyes at the corona, which is expected to be spiky and star-like because the sun is nearing its most active phase of its cycle. You will see wispy extended tendrils in the corona, if you have binoculars.

The ambitious plans to study the sun during April’s solar eclipse

Solar scientists have been preparing for years for a 4-minute window, during the total solar eclipse on 8 April, in which they will study the sun's corona

Pinkish-red chromosphere and prominences

At the onset and just before the end of totality, you will see the chromosphere, the lower region of the sun’s atmosphere, as a pinkish band that disappears mid-eclipse and remerges on the other side as the moon moves across the sun. You are also likely to see prominences, pinkish-red towers, or loops of plasma and magnetic field structures protruding from the corona visible around the moon.

The second diamond ring

The most impactful diamond ring effect comes at the end of totality. Tiny beads of sunlight appear between the moon’s mountains and valleys before merging into one bright diamond ring, the appearance of which marks the end of totality. It is safe to look at for a few seconds, but as daylight returns it is necessary to put eclipse glasses back on if you want to continue looking at the partial phases.

As totality ends, shadow bands can sometimes be seen again. You will have at least another hour to watch the sun, and any sunspots, slowly being uncovered – with your eclipse glasses back on, of course.

How to view the eclipse safely

Free newsletter

Sign up to Launchpad

Sign up to newsletter

Solar Eclipse 2024

On 8 April a total solar eclipse will pass over Mexico, the US and Canada. Our special series is covering everything you need to know, from how and when to see it to some of the weirdest eclipse experiences in history.

Read more

Which eclipse glasses should I get?