Solar spicule facts for kids
A spicule is a giant jet of hot gas, also called plasma, that shoots up from the Sun. You might also hear them called fibrils or mottles. These jets are found in the Sun's middle layer, called the chromosphere. Each spicule is about 300 kilometers (about 186 miles) wide.
Spicules burst upwards from the photosphere, which is the Sun's visible surface. They can move very fast, between 15 and 110 kilometers per second (9 to 68 miles per second). Each one lasts only a few minutes before it falls back into the Sun's atmosphere. A scientist named Angelo Secchi first saw spicules in 1877. Even today, scientists are still trying to figure out exactly how these amazing jets are formed.
How Spicules Look
Spicules usually last for about 15 minutes. When you see them at the edge of the Sun, called the solar limb, they look long and thin. If you see them on the main part of the Sun's disk, they look more like dark spots or lines. That's when they are known as "mottles" or "fibrils."
These jets are often found where the Sun's magnetic field is very strong. They shoot up at about 20 kilometers per second (about 12 miles per second). This means they travel incredibly fast, about 72,000 kilometers per hour (44,738 miles per hour)! Spicules can reach heights of several thousand kilometers before they disappear.
How Many Spicules Are There?
The Sun is always busy with spicules! At any given moment, there are about 3,000,000 active spicules on the Sun's chromosphere. Each individual spicule can reach an amazing height. They typically go up between 3,000 and 10,000 kilometers (1,864 to 6,213 miles) above the Sun's surface.
What Makes Spicules Form?
Scientists are still debating what causes spicules. In 2004, a team of scientists had an idea. Bart De Pontieu from the Lockheed Martin Solar and Astrophysics Laboratory, along with Robert Erdélyi and Stewart James from the University of Sheffield, suggested a theory.
They thought spicules might form because of something called "P-mode oscillations." These are like sound waves that travel through the Sun. These waves make the Sun's surface move up and down by hundreds of meters per second. This movement is similar to how a drum vibrates when you hit it.
They believe that if the Sun's magnetic field lines are tilted, they can help guide this moving material. The magnetic field acts like a funnel, pushing the rising gas up into the Sun's atmosphere. This creates the tall, thin spicules we see. However, not all solar scientists agree on this idea, and research continues.
