Researchers from the University of Warwick have observed signs of the rainbow-like ‘glory lights’ effect on a distant planet outside our Solar System for the first time.
Glory lights are colourful concentric rings of light that occur only under peculiar conditions.
They occur when light is reflected off clouds made up of a perfectly uniform, but so far unknown, substance.
The effect, similar to a rainbow, forms when light passes between a narrow opening, for example, between water droplets in clouds or fog, causing it to diffract and create ring-like patterns.
Data analysed by astronomers suggests this phenomenon is beaming from the hellish atmosphere of ultra-hot gas giant WASP-76b some 637 light-years away.
Glory lights could reveal crucial information about the distant planet
Observations from the European Space Agency’s Characterising Exoplanet Satellite (CHEOPS) suggest that between the unbearable heat and light of exoplanet WASP-76b’s sunlit face and the endless night of its dark side, there may be glory lights.
Although the effect is often seen on Earth, it has only been found once on another planet, Venus. If confirmed, this first glory outside the Solar System will reveal more about the nature of this puzzling distant planet.
Co-author Thomas Wilson from the University of Warwick commented: “Never before have we seen these colourful, concentric rings on an extrasolar body.
“This first exoplanetary glory, if confirmed with future studies, would make WASP-76b a truly unique body and give us a beautiful tool for understanding the atmospheres of distant exoplanets and their potential habitability.
“There’s a reason glory lights have never been seen outside our Solar System – it requires very peculiar conditions,” added Olivier Demangeon from the Institute of Astrophysics and Space Sciences, Portugal.
“First, you need atmospheric particles that are close to perfectly spherical, completely uniform, and stable enough to be observed over a long time. The planet’s nearby star needs to shine directly at it, with the observer at just the right orientation.”
Uncovering the mysteries of WASP-76b
WASP-76b is an ultra-hot Jupiter-like planet. While it has less mass than our striped cousin, it is almost double its size.
Tightly orbiting its host star twelve times closer than scorched Mercury orbits our Sun, the exoplanet’s large size is caused by it being ‘puffed up’ by intense radiation.
Since its discovery in 2013, WASP-76b’s bizarre environment has emerged. One side of the planet always faces the Sun, reaching temperatures of 2400°C. Here, elements that would form rocks on Earth melt and evaporate, only to condense on the slightly cooler night side, creating iron clouds that drip molten iron rain.
However, scientists have been puzzled by an apparent asymmetry, or wonkiness, in WASP-76b’s ‘limbs’ – its outermost regions seen as it passes in front of its host star.
Cheops intensively monitored WASP-76b as it passed in front of and around its Sun-like star. After 23 observations over three years, the data showed a surprising increase in the amount of light coming from the planet’s eastern ‘terminator’ – the boundary where night meets day. This allowed scientists to determine the origin of the glory lights.
Demangeon explained: “This is the first time that such a sharp change has been detected in the brightness of an exoplanet. This discovery leads us to hypothesise that this unexpected glow could be caused by a strong, localised and directionally dependent reflection – the glory effect.”
NASA’s James Webb Space Telescope (JWST) could now be used to officially confirm that these are glory lights.
Confirmation would imply that the temperature of WASP-76b’s atmosphere must be stable over time, enabling the presence of clouds made up of perfectly spherical water droplets crucial to glory lights formation.
If you live in the US and missed the last total solar eclipse in 2017, good news! You’re about to get another chance. There will be a total solar eclipse passing through Texas and the Midwest states on April 8. Remember that in a solar eclipse, the moon’s shadow falls on the Earth. If you’re in this shadow, it’s going to look really weird. But also awesome.
Even if you’re not in the path of totality, you can still see something. All of the continental states will get at least a partial eclipse. (Check out the map here at NASA’s eclipse page.) And do I need to tell you this? Never look at the sun without special glasses, even when it’s mostly blocked by the moon. You may still be able to get some safe solar viewers before the big event.
But there’s another way to view the solar eclipse without glasses: using a pinhole projector. It’s super simple to make and easy to use. All you need is something flat like a piece of cardboard. Then you poke a hole in it with a pin. That’s pretty much it. When light from the sun passes through the hole, it will project an image onto some flat surface (like a sidewalk).
If you did this on a normal day you’d see a circular dot of light. You might think that’s because the hole is round. But during the eclipse you will see a crescent shape caused by the moon passing in front of the sun. It’s both awesome and safe for your eyes.
Actually, you don’t even need to make a pinhole viewer—they already exist all around us. If you stand under a tree, the small spaces between the leaves will act as pinholes to project a bunch of little crescent images. Here’s a picture I took during the 2017 eclipse:
Images of a solar eclipse projected through the gaps in overhead leaves.
Courtesy of Rhett Allain
Fun With Pinholes
Just for fun, here’s a question for you. Most pinholes are round (because pins have cylindrical shafts). But what if you replaced the circular hole with a square one? What shape would a round sun project onto the ground? Would it be a circle? Would it be a square? Or maybe it would be a squircle! What about a triangular hole? What would happen then?
I actually have a card from PUNCH (Polarimeter to Unify the Corona and Heliosphere) that demonstrates this with three holes—circular, triangular and square. Check it out.
ON 8 APRIL, a total solar eclipse will be visible from various parts of North America. The path in which this will occur runs from Mexico, diagonally across the US and into the Atlantic region of Canada. Eclipses like this, where the moon moves directly between the sun and Earth and blocks out light, happen almost every 20 years. But our planet is a big place, and these events can’t be seen everywhere. Only about once every 400 years is one visible from any given spot on Earth. Which is to say, those of us in or near the…
A distant world is being stretched by the powerful gravity of its neighbouring planets and star to extremes never seen before in a rocky planet. The stretching is so intense that this strange world’s surface is probably entirely molten and so hot that it glows.
Stephen Kane at the University of California, Riverside, and his colleagues spotted this unusual planet in a system already known to have one larger world, a giant planet circling the star once every 55 days…
NASA’s WB-57 research jets will be used to study the eclipse
Amir Caspi
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
Shadia Habbal, 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.
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 corona’s temperature isn’t dependent on the solar cycle. 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 Benedikt Justen 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.”
This box-shaped kite will fly a NASA-funded scientific instrument to study the total solar eclipse
Klemens Brumann and Benedikt Justen
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 Amir Caspi 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.
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.”
It’s shadow time, baby! Soon, people living in North America will get to experience their first solar eclipse in almost a decade.
Even though the last solar eclipse in North America happened in 2017, the next one isn’t expected until August 2044, so seizing this moment is critical. More than just a peculiar shadow, the solar eclipse is a perfect opportunity to hang out with loved ones outside and meditate on humanity’s smallness compared to the vast universe.
What Is a Solar Eclipse?
“It’s an alignment of the sun, the moon, and the earth in such a way that the moon passes directly between the sun and the earth, blocking the sun’s rays from reaching the earth’s surface,” says Noah Petro, an Artemis III project scientist at NASA. If you’re in the path of totality, then you will see the moon completely cover the sun. Outside of the main path? You may still see a partial eclipse, where the moon covers a slice of the sun.
Despite the involvement of the moon, a solar eclipse is not to be confused with a lunar eclipse. During those, the moon passes into the shadow of Earth and turns a dark red color. Lunar eclipses are visible for most of the entire hemisphere that’s facing the moon at the time.
When Is the 2024 Solar Eclipse?
Passing through portions of North America, the total solar eclipse will occur on Monday, April 8. Depending on where you are in the path of totality, the solar eclipse will happen in the afternoon and potentially last around four minutes. For more specifics, refer to NASA’s map detailing the exact time different US cities will experience the eclipse.
Where Will It Be Visible?
While the total solar eclipse is primarily happening in Mexico and the United States, a small section of eastern Canada is also along the path of totality. To see what it might look like in different locations, check out this fantastic website created by a retired mathematician that simulates the solar eclipse.
Three major Mexican cities where you can see the total solar eclipse are Mazatlán, Durango, and Torreón.
There are numerous locations across the US where you can potentially experience totality. A few of the locations include Dallas, Texas; Russellville, Arkansas; Carbondale, Illinois; Greenwood, Indiana; and Buffalo, New York.
Finding somewhere you can avoid a cloudy overcast is crucial if you want to have the best viewing experience. “Particularly in northern New England, we can have colder, cloudy weather,” says Petro. “Through Mexico and Central Texas, you might be able to find places that are more likely to get clear skies.”
Want to travel somewhere within the path of totality? You might have to get creative at this point, since many hotels and campgrounds within the core path have been fully booked for months. Maybe consider finding a place to stay overnight that’s an hour or so outside of the main route and drive in for the afternoon to see the solar eclipse.
Do I Really Need to Wear Eclipse Glasses?
The answer is yes.
“Looking at any amount of sun is really dangerous,” says Matt Bothwell, a public astronomer at Cambridge’s Institute of Astronomy. “So you should be getting eclipse glasses to watch the progress of the moon over the face of the sun.” And just putting on a pair of typical sunglasses won’t do the trick—you want eye protection that is ISO-certified for direct sun observation.
A recent paper packed with delightful acronyms digs into where people report having seen UFOs, but finds no evidence of alien visitors, says Annalee Newitz
The giant volcano is located near the planet’s equator in the eastern part of Mars’ Tharsis volcanic province. It was discovered along with a possible sheet of buried glacier ice.
Imaged repeatedly by orbiting spacecraft around Mars since Mariner 9 in 1971 but deeply eroded beyond easy recognition, the giant volcano had been hiding in plain sight for decades in one of Mars’ most iconic regions.
Its discovery points to an exciting new place to search for life and a potential future destination for robotic and human exploration.
How did the researchers stumble upon a giant volcano on Mars?
The volcano’s gigantic size and complex modification history indicate that it has been active for a very long time.
In its southeastern part lies a thin, recent volcanic deposit beneath which glacier ice is likely still present.
“We were examining the geology of an area where we had found the remains of a glacier last year when we realised we were inside a huge and deeply eroded volcano,” said Dr Pascal Lee, a planetary scientist with the SETI Institute and the Mars Institute based at NASA Ames Research Center, and lead author of the study.
The central summit area is marked by several elevated mesas forming an arc, reaching a regional high and sloping downhill away from the summit area.
The gentle outer slopes extend out to 225 kilometres away in different directions.
Sourabh Shubham, a graduate student at the University of Maryland’s Department of Geology and the study’s co-author, explained: “This area of Mars is known to have a wide variety of hydrated minerals spanning a long stretch of Martian history.
“A volcanic setting for these minerals had long been suspected. So, it may not be too surprising to find a giant volcano here.”
A lot of the volcano’s history remains unknown
Much about the newly discovered giant volcano remains a mystery. Although it is clear that it has been active for a long time and began to build up early in Mars’ history, it is unknown how early exactly.
Similarly, although it has experienced eruptions even in modern times, it is unknown if it is still volcanically active and might erupt again.
If it has been active for a very long time, could the combination of sustained warmth and water from ice have allowed the site to harbour life?
As mysteries surrounding the giant volcano on Mars continue to puzzle scientists, the site is already emerging as an exciting new location to study Mars’ geologic evolution, search for life, and plan future robotic and human exploration.
Future human exploration in the region
The possible presence of glacier ice at shallow depths near the equator means that humans could potentially explore a less frigid part of the planet while still being able to extract water for hydration and manufacturing rocket fuel by breaking down H2O into hydrogen and oxygen.
Lee said: “It’s really a combination of things that makes the Noctis volcano site exceptionally exciting. It’s an ancient and long-lived volcano so deeply eroded that you could hike, drive, or fly through it to examine, sample, and date different parts of its interior to study Mars’ evolution through time.
“It has also had a long history of heat interacting with water and ice, which makes the giant volcano a prime location for astrobiology and our search for signs of life.”
He concluded: “Finally, with glacier ice likely still preserved near the surface in a relatively warm equatorial region on Mars, the place is looking very attractive for robotic and human exploration.”
THE 20th of March marks the vernal, or spring, equinox in the northern hemisphere, and the autumn equinox in the southern hemisphere. On this day, most places in the world will get around 12 hours of daylight. The days are getting shorter in the southern hemisphere, while many of us in the northern hemisphere are looking forward to signs of spring.
But wherever you are, this is a great time to spot a pattern of stars known as the Spring Triangle. It is worth looking for no matter where you live, even in areas with light pollution, because the three…
Black holes can go “dormant” if they aren’t actively feeding
Jurik Peter/Shutterstock
A black hole in the early universe has almost half the mass of its host galaxy despite no longer sucking in matter, raising questions about how black holes grow.
While Ignas Juodžbalis at the University of Cambridge and his colleagues were looking through data from the James Webb Space Telescope (JWST), they found something unusual. It was a faint galaxy, seen from our perspective as it was about 800 million years after the big bang, with a central black…
