Following the success of Chandrayaan-3, India is all set to launch its solar mission, Aditya-L1, today. This mission is aimed at studying the Lagrangian Point 1 (L1) of the solar system, located approximately 1.5 million kilometers away from Earth. It is expected to take about four months for the mission to reach this distant point.
This solar mission has garnered significant interest not only in India but also worldwide, and people are eagerly awaiting its launch. In light of this, let’s explore some key questions related to the Sun:
What is the Sun?
In simple terms, the Sun is a massive, burning ball of gas. It primarily consists of hydrogen and helium and serves as the central star of our solar system. The Sun’s gravitational pull keeps the entire solar system bound together, with everything in our solar system orbiting around it.
How Big is the Sun?
The Sun is the largest object in our solar system, with a diameter of approximately 1.4 million kilometers. It contains about 99.86% of the total mass of our solar system. To put this into perspective, you could fit approximately 1.3 million Earths inside the Sun. The Sun is roughly 100 times larger in diameter than Earth and over 10 times wider than the largest planet, Jupiter.
How Hot is the Sun?
The core, or center, of the Sun is incredibly hot, with temperatures reaching about 15 million degrees Celsius. This extreme heat generates an immense amount of energy, which is eventually released as heat and light. As this energy travels from the core to the Sun’s surface, it takes about a million years. By the time it reaches the surface, the temperature drops to around 5,973 degrees Celsius. To put it in perspective, that’s hot enough to melt steel.
In the Sun’s outermost layer, called the corona, temperatures rise again to about 1 to 2 million degrees Celsius. This dramatic increase in temperature in the corona remains one of the biggest mysteries of our Sun. India’s Aditya-L1 mission aims to study this temperature variation among its objectives.
What is the Sun Made Of?
The Sun is primarily composed of gas and plasma. Approximately 91% of its mass is hydrogen gas. Due to its intense heat and gravitational pressure, hydrogen undergoes nuclear fusion, transforming into helium. When the plasma at the Sun’s core becomes hot enough, it releases energy in the form of heat and light, which eventually escapes into space. This is known as solar radiation, which, under certain conditions, interacts with Earth’s atmosphere, creating phenomena like the Northern Lights.
Apart from hydrogen and helium, scientists have identified at least 65 other elements in the Sun. These elements include oxygen, carbon, nitrogen, silicon, magnesium, neon, iron, and sulfur, among others.
Does the Sun Rotate?
Yes, the Sun rotates, although not in the same way as a solid object. The Sun’s rotation is differential, meaning that different parts of the Sun rotate at different speeds. At its equator, the Sun completes one full rotation approximately every 25 Earth days, while at its poles, it takes around 36 Earth days. This differential rotation is due to the Sun’s gaseous nature.
What are Sunspots?
Sunspots are cooler regions on the Sun’s surface and are observed in the photosphere, the visible layer of the Sun. These spots appear darker because they are cooler compared to the surrounding plasma. These cooler regions can extend up to 50,000 kilometers in diameter and are associated with the Sun’s magnetic activity. Sunspots often appear in pairs or groups and have a cyclical pattern, known as the solar cycle, which lasts roughly 11 years.
What are Solar Flares?
Solar flares are one of the most powerful explosive events in the solar system. They occur when magnetic fields associated with sunspots release energy, heating up and accelerating particles, which are then ejected into space. Solar flares emit various types of radiation, including ultraviolet, X-rays, and gamma rays. They can last from seconds to several minutes and are often accompanied by coronal mass ejections (CMEs), which are massive eruptions of solar material.
Can the Sun Explode?
No, the Sun cannot explode in the sense of a massive explosion like a supernova. While it will undergo significant changes in its later stages of life, the Sun will not explode. Instead, it will eventually expand into a red giant and then shed its outer layers, forming a white dwarf at its core.
What is a Solar Eclipse?
Occasionally, the Moon passes between the Sun and Earth, causing a solar eclipse. If all three celestial bodies align perfectly, the Moon can completely block out the Sun, casting a shadow on Earth and causing a total solar eclipse. However, total solar eclipses are rare events and occur roughly every two years at distant locations on Earth. They last only for a few seconds or minutes.
How Long Does it Take for Sunlight to Reach Earth?
Sunlight travels from the Sun to Earth in about eight minutes. This is because light from the Sun, which includes a stream of tiny particles called photons, travels at the speed of light, which is about 299,792 kilometers per second. The average distance from the Sun to Earth is about 150 million kilometers, which translates to roughly eight minutes for sunlight to reach us.
How Do We Study the Sun?
Due to the extreme temperatures, studying the Sun up close is extremely challenging. We rely on spacecraft and telescopes in Earth’s orbit to observe the Sun. In 2020, the European Space Agency (ESA) and NASA launched the Solar Orbiter, which will study the Sun’s outer atmosphere and its heliosphere. Similarly, India’s Aditya-L1 mission aims to study the Sun’s outermost layer, the corona, and explore various solar phenomena.
As we await the launch of the Aditya-L1 mission, it’s important to recognize the significance of studying our Sun, a celestial body that plays a fundamental role in our solar system and affects life on Earth in various ways.