Computer simulation of magnetic structures in solar-like conditions. Image: Jörn Warnecke
It’s almost impossible to over-emphasize the primal, raging, natural power of a star. Our Sun may appear benign in simple observations, but with the advanced scientific instruments at our disposal in modern times, we know differently. In observations outside the narrow band of light our eyes can see, the Sun appears as an enraged, infuriated sphere, occasionally hurling huge jets of plasma into space, some of which slam into Earth.
Jets of plasma slamming into Earth isn’t something to be celebrated (unless you’re in a weird cult); it can cause all kinds of problems.
NASA has created a video based on 133 days of observations by the Solar Dynamics Observatory. The hour-long video is a captivating look at four months of the Sun's approximately 10 billion year lifetime. Image Credit: NASA/Goddard Space Flight Center/SDO
NASA’s Goddard Space Flight Center has released an hour-long time-lapse video that shows 133 days of the Sun’s life. The video shows the Sun’s chaotic surface, where great loops of plasma arch above the star along magnetic field lines. Sometimes the looping plasma reconnects to the star, and other times it’s ejected into space, creating hazardous space weather.
NASA recently photographed the Sun "smiling" (Credit: NASA/Goddard Space Flight Center/Solar Dynamics Observatory)
Our Sun is the very reason we’re alive. It provides warmth and the energy our planet needs to keep going. Now you can add photogenic to its illustrious résumé, as NASA recently photographed our giant ball of nuclear fusion doing something quite peculiar.
Solar flares are complex phenomena. They involve plasma, electromagnetic radiation across all wavelengths, activity in the Sun’s atmosphere layers, and particles travelling at near light speed. Spacecraft like NASA’s Solar and Heliophysics Observatory (SOHO) and the Parker Solar Probe shed new light on the Sun’s solar flares.
But it was a Japanese-led mission called Yohkoh that spotted an unusual solar flare in 1999. This flare displayed a downward flowing motion toward the Sun along with the normal outward flow. What caused it?
A team of researchers think they’ve figured it out.
Precipitation is much more widespread throughout that solar system than commonly assumed. Obviously it rains water on Earth. But it snows carbon dioxide on Mars, rains methane on Titan, sulfuric acid on Venus, and could potentially rain diamonds on Neptune. The type of material falling out of the sky is almost as varied as the planets themselves. New research from a team led by Kaitlyn Loftus at Harvard found a similarity for all of the liquid materials that constitute rain throughout the solar system – all of the drops, no matter the material, are roughly the same size.
An artistic rendering of a series of powerful stellar flares. New research says that flaring activity may not prevent life on exoplanets.
CREDIT
NASA's Goddard Space Flight Center/S. Wiessinger
Red dwarf stars are the most common kind of star in our neighbourhood, and probably in the Milky Way. Because of that, many of the Earth-like and potentially life-supporting exoplanets we’ve detected are in orbit around red dwarfs. The problem is that red dwarfs can exhibit intense flaring behaviour, much more energetic than our relatively placid Sun.
So what does that mean for the potential of those exoplanets to actually support life?
A massive prominence erupts from the surface of the sun. Credit: NASA Goddard Space Flight Center
The sun constantly cycles between periods of activity and periods of inactivity, and a new technique allows scientists to better predict when things will start getting interesting.
Artist's impression of ESA's Solar Orbiter spacecraft. Credit: ESA/ATG medialab
On February 10th, 2020, the ESA’s Solar Orbiter (SolO) launched and began making its way towards our Sun. This mission will spend the next seven years investigating the Sun’s uncharted polar regions to learn more about how the Sun works. This information is expected to reveal things that will help astronomers better predict changes in solar activity and “space weather”.
Last week (on Thursday, Feb. 13th), after a challenging post-launch period, the first solar measurements obtained by the SolO mission reached its international science teams back on Earth. This receipt of this data confirmed that the orbiter’s instrument boom deployed successfully shortly after launch and that its magnetometer (a crucial instrument for this mission) is in fine working order.
A coronal mass ejection (CME) from the Sun on August 31, 2012, the event that caused a third ring to form in the Van Allen radiation belts. Credit: NASA
Solar storms powerful enough to wreak havoc on electronic equipment strike Earth every 25 years, according to a new study. And less powerful—yet still dangerous—storms occur every three years or so. This conclusion comes from a team of scientists from the the University of Warwick and the British Antarctic Survey.
These powerful storms can disrupt electronic equipment, including communication equipment, aviation equipment, power grids, and satellites.
The darker area on this image of the Sun's surface is the southern extension of the northern hemisphere polar corona. The coronal hole is a source of fast-moving streams of particles from the Sun, which can cause auroras here on Earth. Image: NASA/SDO
To the naked eye, the Sun puts out energy in a continual, steady state, unchanged through human history. (Don’t look at the sun with your naked eye!) But telescopes tuned to different parts of the electromagnetic spectrum reveal the Sun’s true nature: A shifting, dynamic ball of plasma with a turbulent life. And that dynamic, magnetic turbulence creates space weather.
Space weather is mostly invisible to us, but the part we can see is one of nature’s most stunning displays, the auroras. The aurora’s are triggered when energetic material from the Sun slams into the Earth’s magnetic field. The result is the shimmering, shifting bands of color seen at northern and southern latitudes, also known as the northern and southern lights.
This image of the northern lights over Canada was taken by a crew member on board the ISS in Sept. 2017. Image: NASA
There are two things that can cause auroras, but both start with the Sun. The first involves solar flares. Highly-active regions on the Sun’s surface produce more solar flares, which are sudden, localized increase in the Sun’s brightness. Often, but not always, a solar flare is coupled with a coronal mass ejection (CME).
A coronal mass ejection is a discharge of matter and electromagnetic radiation into space. This magnetized plasma is mostly protons and electrons. The CME ejection often just disperses into space, but not always. If it’s aimed in the direction of the Earth, chances are we get increased auroral activity.
The second cause of auroras are coronal holes on the Sun’s surface. A coronal hole is a region on the surface of the Sun that is cooler and less dense than surrounding areas. Coronal holes are the source of fast-moving streams of material from the Sun.
Whether it’s from an active region on the Sun full of solar flares, or whether it’s from a coronal hole, the result is the same. When the discharge from the Sun strikes the charged particles in our own magnetosphere with enough force, both can be forced into our upper atmosphere. As they reach the atmosphere, they give up their energy. This causes constituents in our atmosphere to emit light. Anyone who has witnessed an aurora knows just how striking that light can be. The shifting and shimmering patterns of light are mesmerizing.
The auroras occur in a region called the auroral oval, which is biased towards the night side of the Earth. This oval is expanded by stronger solar emissions. So when we watch the surface of the Sun for increased activity, we can often predict brighter auroras which will be more visible in southern latitudes, due to the expansion of the auroral oval.
This photo is of the aurora australis over New Zealand. Image: Paul Stewart, Public Domain, CC 1.0 Universal.
Something happening on the surface of the Sun in the last couple days could signal increased auroras on Earth, tonight and tomorrow (March 28th, 29th). A feature called a trans-equatorial coronal hole is facing Earth, which could mean that a strong solar wind is about to hit us. If it does, look north or south at night, depending on where your live, to see the auroras.
Of course, auroras are only one aspect of space weather. They’re like rainbows, because they’re very pretty, and they’re harmless. But space weather can be much more powerful, and can produce much greater effects than mere auroras. That’s why there’s a growing effort to be able to predict space weather by watching the Sun.
A powerful enough solar storm can produce a CME strong enough to damage things like power systems, navigation systems, communications systems, and satellites. The Carrington Event in 1859 was one such event. It produced one of the largest solar storms on record.
That storm occurred on September 1st and 2nd, 1859. It was preceded by an increase in sun spots, and the flare that accompanied the CME was observed by astronomers. The auroras caused by this storm were seen as far south as the Caribbean.
Sunspots are dark areas on the surface of the Sun that are cooler than the surrounding areas. They form where magnetic fields are particularly strong. The highly active magnetic fields near sunspots often cause solar flares. Image: NASA/SDO/AIA/HMI/Goddard Space Flight Center
The same storm today, in our modern technological world, would wreak havoc. In 2012, we almost found out exactly how damaging a storm of that magnitude could be. A pair of CMEs as powerful as the Carrington Event came barreling towards Earth, but narrowly missed us.
We’ve learned a lot about the Sun and solar storms since 1859. We now know that the Sun’s activity is cyclical. Every 11 years, the Sun goes through its cycle, from solar maximum to solar minimum. The maximum and minimum correspond to periods of maximum sunspot activity and minimum sunspot activity. The 11 year cycle goes from minimum to minimum. When the Sun’s activity is at its minimum in the cycle, most CMEs come from coronal holes.
NASA’s Solar Dynamics Observatory (SDO), and the combined ESA/NASA Solar and Heliospheric Observatory (SOHO) are space observatories tasked with studying the Sun. The SDO focuses on the Sun and its magnetic field, and how changes influence life on Earth and our technological systems. SOHO studies the structure and behavior of the solar interior, and also how the solar wind is produced.
Several different websites allow anyone to check in on the behavior of the Sun, and to see what space weather might be coming our way. The NOAA’s Space Weather Prediction Center has an array of data and visualizations to help understand what’s going on with the Sun. Scroll down to the Aurora forecast to watch a visualization of expected auroral activity.
NASA’s Space Weather site contains all kinds of news about NASA missions and discoveries around space weather. SpaceWeatherLive.com is a volunteer run site that provides real-time info on space weather. You can even sign up to receive alerts for upcoming auroras and other solar activity.
