This textual content was initially printed at The Dialog. The publication contributed the article to Space.com’s Educated Voices: Op-Ed & Insights.
Hannah Schunker, Lecturer of Physics, Faculty of Newcastle
David Pontin, Affiliate Professor of Physics, Faculty of Newcastle
Why is the photo voltaic’s setting hotter than its ground? — Olivia, age 9, Canberra
(Image credit score rating: The Dialog)
Good day Olivia, that’s an unbelievable question! In precise truth, it’s such an unbelievable question many scientists all around the world attempt to reply it.
The truth of the matter is — we don’t know! Nonetheless we do have some ideas in regards to the place the facility that heats the photo voltaic’s setting could also be coming from, and it has hundreds to do with the photo voltaic’s magnetic topic. Let me make clear what this suggests.
The temperature of the photo voltaic
Heat is created inside the very coronary heart of the photo voltaic, at its core, the place the temperature is a blistering 27 million ranges Celsius. And similar to strolling away from a campfire, the temperature will get cooler further away from the core.
The temperature of the photo voltaic’s ground is about 6,000 ranges C, which means it’s a lot cooler than the core. Moreover, it continues to relax down for a quick distance above the ground.
Nonetheless higher above the ground, inside the setting, the temperature abruptly shoots as a lot as higher than a million ranges! So there must be one factor that’s heating the photo voltaic’s setting. Nonetheless we won’t merely uncover out what it is.
Related: What’s contained within the photo voltaic? A star tour from the inside out
The key’s the photo voltaic’s magnetic topic
The principle idea amongst specialists is the photo voltaic’s magnetic topic is certainly bringing energy from contained within the photo voltaic up by way of its ground and into its setting.
Like Earth, the photo voltaic has a magnetic topic. We’re ready to consider a magnetic topic as invisible strains connecting the north and south poles of a star or planet.
We cannot see magnetic fields, nevertheless everyone knows they’re there on account of we now have objects that react to them. As an illustration, a compass needle on Earth will on a regular basis degree to the North Pole on account of it strains up with Earth’s magnetic topic.
(Image credit score rating: Shutterstock)
Whereas the photo voltaic moreover has a north and south pole, its magnetic topic behaves differently to Earth’s and seems hundreds messier. On the ground of the photo voltaic, the magnetic topic strains appear to be many loops rising up out of the ground into the setting — and these loops are altering regularly.
If the loops contact each other they will set off sudden explosions of big portions of energy that heat up the setting. We moreover know there are waves touring alongside the magnetic topic strains bringing energy up. Would possibly they be accountable for heating the setting?
Is it a combination of the waves and the explosions, or one factor else altogether? Being able to measure the photo voltaic’s magnetic topic would truly help us understand what’s going on on.
(Image credit score rating: NASA)
Measuring the magnetic topic
Magnetic fields may be invisible, nevertheless we are going to nonetheless measure them on account of they make small modifications to the sunshine that comes from the photo voltaic. The ground of the photo voltaic could also be very shiny, so it’s easy to see modifications inside the mild coming from the ground, and measure the magnetic topic there.
Nonetheless the photo voltaic’s setting is so scorching the sunshine there could also be not seen anymore. Reasonably it makes X-rays, which are a form of sunshine we won’t see! Even once we use specific X-ray telescopes, the X-rays from the photo voltaic’s setting are too dim for us to find out what the magnetic topic inside the setting seems to be like like.
The good news is there is a mannequin new satellite tv for pc television for computer, NASA’s Parker Photograph voltaic Probe, which is now orbiting close to the photo voltaic (nevertheless not too shut) and really flying by way of the magnetic topic to measure it. We must be receiving loads of thrilling new data from it over the next 5 years.
These magnetic topic measurements will convey us nearer to understanding what’s making the setting of the photo voltaic, and completely different stars, lots hotter than their ground.
(Image credit score rating: NASA)
Study additional: Curious Kids: how does the Photo voltaic make such pretty colours at sunsets and sunrises?
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