Finding out more about the sun's atmosphere

Over the years, I have featured many articles about our sun, including sunspots, solar flares, cycles and its activity. Last week was a landmark occasion for NASA as a sophisticated solar probe plunged into the sun’s outer atmosphere with hopes of better understanding how this star works. On Dec. 24, the probe had its record-breaking approach as it became the only human-made object to get close or “touch” the sun.

Back in 2018, NASA launched the Parker Solar Probe and Dec. 24, the probe came within 3.8 million miles above the sun’s surface and survived the extreme temperatures and radiation. Scientists had to nervously await the probe’s reply for several days as the harsh conditions kept it from communicating with Earth.

The Parker Solar Probe is also the fastest human-made object that has ever been created. The speed was a whopping 430,000 miles per hour and it had to tolerate temperatures of over 1,800 degrees Fahrenheit. Despite the high temperatures that would literally destroy any onboard electronics, the probe was protected by a thick carbon-composite shield that could handle readings as high as 2,600 degrees. Also, with the probe’s incredible speed, it was able to essentially get in and out of the sun’s extreme environment very quickly.

The Parker Solar Probe had already moved around the sun 21 times previous to the one from Dec. 24. Although 3.8 million miles is a large distance, to put this into perspective, our planet is about 90 million miles from the sun at this time of year. Mercury, the closest planet to the star, is about 36 million miles with surface temperatures on that planet estimated to be as high as 800 degrees Fahrenheit. So, the probe’s encounter was very close.

The surface temperature of the sun is about 10,000 degrees Fahrenheit, which is estimated to be much cooler than a bolt of lightning here on Earth. The interior of the sun is believed to have a temperature of 27 million degrees Fahrenheit. Ironically, the sun’s corona, which is the outermost part of its atmosphere, can be as high as 3.6 million degrees. Scientists wanted to understand why the sun’s atmospheric temperature was much hotter than its surface. The Parker Solar Probe may help to answer that question as it quickly flew through the sun’s corona to take critical measurements.

According to an article by John Hopkins Applied Physics Laboratory, the probe may also help scientists to trace the origin of the solar wind. This is a constant flow of material that escapes the sun. It may also provide insight on how energetic particles ejected from the sun are accelerated to half of the speed of light and the structure of the magnetic fields.

Since the launch of the Parker Solar Probe in 2018, there have already been some significant discoveries. During the probe’s flybys, it has observed “switchbacks” in the sun’s solar wind. These are sudden changes in the direction of the sun’s magnetic field. It also provided data on the turbulence of the solar wind. With more data, scientists may be able to better understand and predict the solar flares and coronal mass ejections that could potentially severely damage critical communication systems across the globe.

The sun is about 109 times the size of our planet. Therefore, it’s estimated that about 1.3 million Earths would fit inside of it. The star is composed of around 74% of hydrogen and 24% of helium. The remaining elements include small amounts of iron, nickel, oxygen and others. It continuously creates energy by converting hydrogen to helium, a process known as nuclear fusion.

Scientists say that the sun is approximately 4.6 billion years old and a “middle-aged” star. Once the sun exhausts its hydrogen in 5 billion years from now, it’s expected to expand into a Red Giant and swell up that will consume Mercury, Venus and perhaps the Earth as well before it shrinks to a white dwarf, which is the core of the sun. Our star is too small to become a black hole as it would need to be at least 20 times more massive.

In terms of our local weather, moisture totals across the region have climbed to near-normal levels for December thanks to a series of Pacific storms. Unfortunately for those who have been waiting for snow in the Coeur d’Alene region, the air masses have been too warm. However, it has been cold enough to produce significant snowfalls in the higher mountains.

Most of the colder air and snowfall has been east of the Rockies. It does look like we’re going to have a good taste of winter in early January as the upper-level airflow will be ushering in much colder weather to our region with occasional snow. Then, the long-range computer models show the high-pressure ridge moving into our area with generally dry and cold conditions. More storms are expected around the middle of January, but we’ll have to wait and see if they will be cold enough for snow in the lower elevations.

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Contact Randy Mann at randy@longrangeweather.com.