Investigate the Sun's 11-year activity cycle, analyze real solar data, and explore how sunspots affect life on Earth.
Read the passage carefully, explore the interactive diagram, then answer all questions. You will need at least 60% to unlock Part 2.
The Sun may look like a solid glowing ball, but it is actually made up of distinct layers, each with its own temperature, pressure, and role in producing and moving energy. From its superheated center to its wispy outer atmosphere, every layer of the Sun plays a critical part in making it the star that powers life on Earth.
At the very center of the Sun lies the core. Temperatures here reach approximately 15 million °C — hot enough to force hydrogen atoms together in a process called nuclear fusion. Every second, the core fuses roughly 600 million tons of hydrogen into helium, releasing an almost incomprehensible amount of energy in the form of light and heat. This energy is the source of everything the Sun does — and everything life on Earth depends on.
Energy produced in the core doesn't travel directly to the surface. It first passes through the radiative zone, where it moves in the form of photons — tiny packets of light. The plasma in this zone is so dense that photons cannot travel in a straight line. Instead, they are constantly absorbed and re-emitted by particles, bouncing in random directions in a process sometimes called a "random walk." A single photon can take up to 100,000 years to cross the radiative zone — despite traveling at the speed of light.
Beyond the radiative zone lies the convective zone. Here, the plasma is less dense and energy is no longer carried by photons alone. Instead, hot plasma physically rises toward the surface, releases its energy, cools, and sinks back down — just like a pot of boiling water. This churning motion creates large convection cells visible on the Sun's surface as a pattern of granules. Importantly, the swirling plasma in the convective zone also generates and twists the Sun's magnetic field, which eventually leads to sunspot formation.
The photosphere is the layer we actually see when we look at the Sun. It is the Sun's visible "surface," though it is only about 500 km thick — remarkably thin for a star 1.4 million kilometers in diameter. The photosphere glows at approximately 5,500°C and emits most of the light that reaches Earth. Dark regions called sunspots appear here where concentrated magnetic fields disrupt the normal upward flow of plasma, creating patches that are cooler — and therefore darker — than the surrounding surface.
Surrounding everything is the Sun's outer atmosphere, called the corona. The corona extends millions of kilometers into space and can only be seen from Earth during a total solar eclipse. It presents one of the greatest mysteries in solar science: despite being farther from the Sun's energy source, the corona is far hotter than the photosphere below it — reaching temperatures of 1 to 3 million °C. Scientists are still investigating why. During periods of high solar activity, the corona releases powerful eruptions of plasma called coronal mass ejections (CMEs) that can travel toward Earth and disrupt technology.
| Sun's Layer | Information About Layer | Temperature |
|---|---|---|
| Photosphere | Observable layer — gives off electromagnetic energy | 6,700°F – 11,000°F (4,000 K – 6,500 K) |
| Convection Zone | Convection causes hot material to rise to surface and cool; creates sunspots and solar flares | 11,000°F – 2 million°F |
| Radiative Zone | Serves as a passage for radiation energy from core to surface | 7 million°F |
| Core | Nuclear reactions occur | 27 million°F (15 million K) |
Click the word chips in order to build a correct scientific sentence. Click a chip in the answer zone to remove it.
Click on each labeled zone of the Sun to learn more about it.
The Sun's energy influences the environment of all celestial objects in our solar system. Different forms of the hydrogen and helium atoms contained in the Sun's core, deuterium (²H) and the helium atom (³He), are under very high temperatures and pressures. These atoms combine to form helium (⁴He), while releasing tremendous amounts of energy. The model below shows some information about the Sun.
Scientists have tracked sunspot numbers for hundreds of years. Below is a graph of annual mean sunspot numbers from 1950–2023. Study the data carefully, complete the graph activities, then answer the questions below.
Hover over the graph to see values. Click peaks and valleys to record events in your data table below.
Total Solar Irradiance (TSI) measures the Sun's total energy output reaching Earth, in watts per square meter (W/m²). Compare this pattern to Graph 1 above.
Click directly on peaks (tall high points) in the graph to log a Solar Maximum. Click directly on valleys (low points near zero) to log a Solar Minimum. The graph auto-detects which type based on where you click — high on the graph = maximum, low on the graph = minimum.
Solar activity doesn't stay in space. High sunspot activity affects technology, communication, and even our atmosphere here on Earth. Read the news scenarios and complete all activities.
Scientists at NOAA's Space Weather Prediction Center issued a severe geomagnetic storm warning today after the Sun unleashed a powerful coronal mass ejection (CME) toward Earth. The ejection, linked to an active sunspot cluster, sent a massive cloud of charged particles on a collision course with Earth's magnetic field. Within 48 hours, the wave of particles disrupted satellite navigation systems, caused high-frequency radio blackouts for airline pilots, and triggered spectacular auroral displays visible as far south as Virginia and Texas.
"We're near the peak of Solar Cycle 25," said Dr. Sarah Chen, a solar physicist at NASA. "This kind of activity is expected. What makes this event notable is the strength and speed of the CME. Fortunately, power companies and satellite operators had advance warning and were able to take precautionary measures."
The event also offered scientists valuable data. By studying how Earth's magnetosphere and ionosphere respond to solar storms, researchers hope to improve space weather forecasting — protecting the infrastructure that modern society depends on. Aurora watchers, meanwhile, reported some of the most vivid skies in years, drawing comparisons to the famous 1989 event that caused a 9-hour blackout of the entire Quebec power grid.
You have been randomly assigned 10 questions from a 30-question test bank. These questions mimic the style of the NYS Regents Earth & Space Sciences exam. Answer all 10 to complete the lab.
Questions mirror the word bank fill-in, circle-one claim, table classification, and flowchart sequence formats from the August 2025 NYS Regents exam.