The Sun May Have Swallowed a Planet
New research suggests that some unusual characteristics of the Sun may be explained if it swallowed a large planet sometime during the Solar System’s formation.
The study of our Sun
New research suggests that some unusual characteristics of the Sun may be explained if it swallowed a large planet sometime during the Solar System’s formation.
Our Sun is the very reason life exists on our small, blue planet. It provides solar radiation that warms the planet and ignites the intricate biochemical processes like photosynthesis producing oxygen for life to breathe. However, while the Sun is known for giving life, it can also potentially take it away with its solar flares, geomagnetic storms, and solar radiation storms, all of which are referred to as space weather. But how can space weather be forecasted so industries can better prepare and protect their assets, including Earth infrastructure, satellites, and even human safety?
Out in the solar system, there is a giant rippling curtain of charged particles that is actually the largest structure in our solar system. Known as the Heliospheric Current Sheet (HCS), it marks the spot where the sun flips its magnetic north and south poles, and grows directly out of giant, glowing loops of plasma on its surface called helmet streamers. However, so far, studies of it have only occurred near Earth, using space-based instruments such as SoHo and Wind. But now, a new paper from Keiichi Ogasawara of the Southwest Research Institute (SwRI) and his team used the joint ESA/NASA mission Solar Orbiter to capture the HCS at only about ⅓ the distance to Earth - before interactions with interstellar space and the solar wind change it. In other words, this paper represents the clearest ever picture of what the solar system’s largest coherent structure is actually made out of.
When we think of weather forecasts, we instinctively think of weather on Earth like rain or shine. However, we rarely consider weather forecasts from outside of the Earth, also called space weather. While space weather often results in the awe-inspiring aurora located at the northern and southern latitudes, we often forget the negative impacts of space weather on our everyday lives. This includes potential disruption of communication satellites or ground stations. The primary conundrum that has eluded researchers is being able to forecast incoming space weather so we can better prepare for its impact.
New research shows that extreme space weather can significantly raise radiation exposure on commercial flights and increase electronic faults in aircraft systems. A severe 1956 scale solar storm could expose passengers to a year's worth of radiation in a single flight, and the researchers point to last year's Airbus A320 grounding, triggered by a solar radiation linked flight computer fault, as proof this isn't theoretical. To address the gap, the team has proposed a new aviation specific radiation scale designed to give airlines clearer, more reliable guidance on when to monitor, reroute, or ground flights during severe events.
Every so often, the Sun hurls billions of tonnes of charged particles toward Earth in what are called coronal mass ejections and if a big one hits at the wrong moment, the consequences for satellites, power grids, and communications systems could be catastrophic. Our best defence is to predict them before they happen, and that means watching the Sun's magnetic fields constantly and precisely. Now, a component smaller than a shirt button could transform how we do exactly that.
The physics of neutron stars are almost too fantastic to believe. Something the weight of two Suns compacted to a sphere the size of a city. Each teaspoon of its material would weigh billions of tons. If you’ve done any reading on the topic, you’ve heard these facts before. But despite the intense interest these extreme objects hold, we are still actively learning lots about them. One of the most pertinent outstanding questions is where is the line between becoming a neutron star and becoming a black hole when a star dies. A new paper by researchers at the HUN-REN Wigner Research Centre for Physics in Hungary describes what they believe to be a definitive answer to that question - between 2.2 and 2.3 solar masses.
The Sun has a heartbeat. Every eleven years it swells with magnetic fury, hurling solar flares and charged particles into space, sparking auroral displays and threatening power grids, all before quietening down again. We've tracked this rhythm for centuries. But now, scientists listening to sound waves deep inside our local star have found something deeply unexpected, that heartbeat is changing. And nobody yet knows what it means.
Scientists have captured one of the most detailed observations ever of a failed solar eruption, a powerful blast from the Sun that built into what should have been a billion tonne plasma ejection, then stalled and collapsed back to the surface. Using data from five spacecraft simultaneously, the team identified a double magnetic process that strangled the eruption from both above and below.
New Mexico State University (NMSU) astronomy graduate student Khagendra Katuwal studied 70 coronal holes on the sun to better understand the connection between solar activity and space weather. His paper was recently published in The Astrophysical Journal.
For years, when something happened on the far side of the Sun, we didn't know much, if anything about it. Sunspots could form there, flares could lash out and the corona could send masses of material out to space. However, we didn't know about any of this until those active regions rotated around to our view. In the late 1900s, scientists came up with a technique called helioseismology to analyze sound waves created by such activity as they echoed through the Sun.
It has been a dream of astronomers and solar scientists for ages. A new mission gives solar researchers a powerful new tool in their arsenal: on-demand, total solar eclipses. Launched in 2024, The European Space Agency’s Proba-3 mission has proven the feasibility of a free-flying, space-based coronagraph. Now, first science results from the mission are giving us a view of the origin of space weather. The results were recently published in the Astrophysical Journal Letters.
Scientists at the Max Planck Institute for Solar System Research have produced the most detailed simulations ever of solar prominences. These vast clouds of cooler plasma suspended in the Sun's scorching outer atmosphere have often perplexed solar astronomers. Their research reveals that two separate processes work together to keep these structures alive, and could one day help us predict the violent eruptions that drive dangerous space weather here on Earth.
Using the eROSITA space telescope, MPE researchers have successfully isolated the X-ray glow from our Solar System, revealing its impact on the soft X-ray sky. The findings, published in Science, underscore the importance of considering Solar System processes when analyzing X-ray data and highlight eROSITA’s role in advancing not only astrophysics but also heliophysics.
The Sun is the most studied star in the universe, yet some of its most violent behaviour remains stubbornly out of reach. Solar flares, explosive eruptions that can disrupt satellites, knock out power grids and bathe astronauts in radiation release enormous bursts of X-rays that carry vital clues about what drives them. Now, a team of Japanese engineers has built the sharpest X-ray telescope ever to fly on a solar mission, and the technology it has pioneered could soon fit inside a satellite the size of a shoebox.
The Sun doesn't just pump out light and heat, it blasts a continuous stream of charged particles across the Solar System, and that solar wind is far more complex than it looks. Hidden within it are waves that act as invisible middlemen, constantly shuffling energy between particles as the wind expands outward. Now, thanks to the European Space Agency's Solar Orbiter spacecraft, we have our clearest picture yet of how those waves behave close to the Sun itself.
Space weather is a fascinating subject, but one we still have a lot to learn about. One of the main components of it is the active regions (ARs) of the Sun. These huge concentrations of magnetic fields show up throughout the Sun’s photosphere and are the primary source of solar flares and coronal mass ejections (CMEs). They can be simple pairings of magnetic flux or huge, magnetically complex tangles that spend weeks creating massive solar storms before dissipating. But tracking the longest lived of these ARs has been a headache for solar physicists, and a recent paper by Emily Mason and Kara Kniezewski, published in The Astrophysical Journal, both dives into this tracking problem and uncovers some interesting features of the Sun’s most persistent ARs.
It was an amazing sight witnessed by many during the April 2024 total solar eclipse. For a few precious moments, it seemed like a celestial dimmer switch was thrown, as the Moon eclipsed the Sun. It was one of the very few times you could actually see prominences and the pearly white corona of the Sun in person, without the aid of special equipment. Now, a recent study out of the University of Hawai’i has linked high resolution images taken during totality with observations from missions orbiting the Sun, in an effort to chronicle the evolution of space weather.
Our Sun didn't always call this quiet corner of the Milky Way home. New research using data from the European Space Agency's Gaia satellite has uncovered evidence that the Sun fled the chaotic heart of our Galaxy four to six billion years ago and it didn't go alone. A vast migration of stars almost identical to our own swept outward together, a great exodus that may have made life on Earth possible. The story of how astronomers pieced this together is as remarkable as the discovery itself.
The spacecraft changed the binary system’s orbit, confirming that a kinetic impactor can be an effective planetary defense technique for deflecting a near-Earth object.