You may have noticed that some weather forecasts have started mentioning the chances of seeing an aurora, also known as northern lights. Just as the atmosphere of the Earth gives us terrestrial weather, the nearby, vast atmosphere of the sun gives rise to space weather – triggering events such as auroras. Many weather institutes around the world now provide forecasts of the weather in space because of the hazard it poses to services we rely on, such as satellite positioning services, power distribution and communications.
Two tough, resilient, NASA spacecraft have been orbiting Earth for the past six and a half years, flying repeatedly through a hazardous zone of charged particles around our planet called the Van Allen radiation belts. The twin Van Allen Probes, launched in August 2012, have confirmed scientific theories and revealed new structures and processes at work in these dynamic regions. Now, they're starting a new and final phase in their exploration.
NASA's Solar Dynamics Observatory views our Sun in ten different wavelengths because each wavelength reveals different solar features. This Sept. 21, 2018, view of the Sun uses two selected images taken at virtually the same time but in different wavelengths of extreme ultraviolet light. The red-tinted image, which captures material not far above the Sun's surface, is especially good for revealing details along the edge of the Sun, like the small prominence at the ten o'clock position. The brown-tinted image clearly shows two large coronal holes (darker areas) as well as some faint magnetic field lines and hints of solar activity (lighter areas), neither of which are apparent in the red image. This activity is occurring somewhat higher in the Sun's corona. In a way it is like peeling away the layers of an onion, a little at a time.
How would you like to take an all-expenses-paid trip to the Sun? NASA is inviting people around the world to submit their names to be placed on a microchip aboard the Parker Solar Probe mission that will launch this summer. As the spacecraft dips into the blazing hot solar corona your name will go along for the ride. To sign up, submit your name and e-mail. After a confirming e-mail, your digital “seat” will be booked. You can even print off a spiffy ticket. Submissions will be accepted until April 27, so come on down!
The past summer has been a pretty terrible time in terms of weather. In addition to raging fires in Canada’s western province of British Columbia, the south-eastern United States has been pounded by successive storms and hurricanes – i.e. Tropical Storm Emily and Hurricanes Franklin, Gert, Harvey and Irma. As if that wasn’t enough, solar activity has also been picking up lately, which could have a serious impact on space weather.
My favourite science news is the stuff that changes the way I think about the world and our place in the universe. Many dinosaurs were covered in feathers; there’s a planet in the habitable zone around the nearest star in the night sky; the universe is expanding faster and faster but no one yet knows why.
From prayer and sacrifice to sunbathing, humans have worshipped the sun since time immemorial. And it’s no wonder. At around 150m km away, it is close enough to provide the light, heat and energy to sustain the entire human race. But despite the fact that our parent star has been studied extensively with modern telescopes – both from home and in space – there’s a lot we don’t know about it.
Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning — the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs.
New data from NASA’s Cassini mission, combined with measurements from the two Voyager spacecraft and NASA’s Interstellar Boundary Explorer, or IBEX, suggests that our sun and planets are surrounded by a giant, rounded system of magnetic field from the sun — calling into question the alternate view of the solar magnetic fields trailing behind the sun in the shape of a long comet tail.
Every so often the sun emits an explosive burst of charged particles that makes its way to Earth and often wreaks havoc on power grids, aircraft and satellite systems. When clouds of high-speed charged particles come racing off the sun, they can bathe spacecraft, astronauts and planetary surfaces in damaging radiation. Understanding why the sun occasionally emits these high-energy particles can help scientists predict space weather. Knowing when solar energetic particles may hit Earth can help people on the planet take precautions.
New research on solar storms finds that they not only can cause regions of excessive electrical charge in the upper atmosphere above Earth's poles, they also can do the exact opposite: cause regions that are nearly depleted of electrically charged particles. The finding adds to our knowledge of how solar storms affect Earth and could possibly lead to improved radio communication and navigation systems for the Arctic.
When it comes to dealing with the cosmos, we humans like to couch things in familiar terms. When examining exoplanets, we classify them based on their similarities to the planets in our own Solar System – i.e. terrestrial, gas giant, Earth-size, Jupiter-sized, Neptune-sized, etc. And when measuring astronomical distances, we do much the same.