Question 1

What is Sunspots?

Accepted Answer

Sunspots is a free, real-time 3D visualization of solar activity built with WebGL. It displays live data from NASA's DONKI (Space Weather Database Of Notifications, Knowledge, Information) and NOAA's Space Weather Prediction Center (SWPC), including sunspot positions, solar flares, coronal mass ejections, solar wind conditions, and geomagnetic storm indices.

Question 2

Where does the solar data come from?

Accepted Answer

All data comes from two official U.S. government sources: NASA's Community Coordinated Modeling Center (CCMC) DONKI service for solar flare and CME events, and NOAA's Space Weather Prediction Center (SWPC) for solar wind plasma, magnetic field data, Kp indices, active region positions, daily sunspot numbers, NOAA space weather scales, and SUVI chromosphere imagery. No API keys are required — all endpoints are freely accessible.

Question 3

What are sunspots?

Accepted Answer

Sunspots are temporary dark areas on the Sun's photosphere caused by intense magnetic activity. They appear darker because they are cooler than surrounding regions (about 3,500K vs 5,800K). Sunspots are closely associated with solar flares and coronal mass ejections. Their number follows an approximately 11-year solar cycle. The Sunspots app displays real active region data from NOAA, showing each sunspot group's heliographic latitude, longitude, and area.

Question 4

What is a solar flare?

Accepted Answer

A solar flare is a sudden, intense burst of electromagnetic radiation from the Sun's surface, typically originating from active regions near sunspots. Flares are classified by X-ray intensity: A, B, C (minor), M (moderate), and X (extreme). M and X-class flares can disrupt radio communications, GPS signals, and power grids on Earth. The Sunspots app shows real-time flare events from NASA DONKI with their class, location, and timing.

Question 5

What is a coronal mass ejection (CME)?

Accepted Answer

A coronal mass ejection (CME) is a massive eruption of magnetized plasma from the Sun's corona into interplanetary space. CMEs can contain billions of tons of solar material traveling at speeds from 250 to over 3,000 km/s. When directed toward Earth, CMEs can trigger geomagnetic storms that produce auroras, disrupt satellite operations, and affect power infrastructure. The Sunspots app visualizes CME events as expanding rings from their source locations on the Sun.

Question 6

What is the Kp index?

Accepted Answer

The Kp index is a scale from 0 to 9 that measures geomagnetic disturbance in Earth's magnetic field, calculated from ground-based magnetometer stations worldwide. Kp 0-3 is quiet, Kp 4 is unsettled, Kp 5-6 indicates a minor to moderate geomagnetic storm (G1-G2), and Kp 7-9 indicates strong to extreme storms (G3-G5). Higher Kp values correlate with visible auroras at lower latitudes. The Sunspots app displays the current Kp value from NOAA's planetary K-index data.

Question 7

How often is the data updated?

Accepted Answer

Solar wind plasma and magnetic field data refresh every 1 minute. Solar flare events, CME events, Kp index, and NOAA space weather scales update every 5 minutes. Active solar region positions, daily sunspot numbers, and SUVI chromosphere imagery refresh every 15 minutes. All updates happen automatically when viewing in live mode.

Question 8

Can I view historical solar activity?

Accepted Answer

Yes. The Sunspots app includes a timeline scrubber and date picker that let you browse historical solar activity. Dragging the timeline or selecting a specific date switches from live mode to historical mode, fetching archived data from NASA DONKI for that time period. The timeline displays the past 30 days of flare activity with visual markers for significant events.

Question 9

Is Sunspots free to use?

Accepted Answer

Yes, Sunspots is completely free. It uses publicly available data from NASA and NOAA that requires no API keys or authentication. There are no usage limits, no accounts required, and no premium features.

Question 10

What do the NOAA R, S, and G scales mean?

Accepted Answer

NOAA uses three space weather scales: R (Radio Blackout) from R1-R5 measuring HF radio disruption from solar flares, S (Solar Radiation Storm) from S1-S5 measuring energetic particle flux dangerous to astronauts and satellites, and G (Geomagnetic Storm) from G1-G5 measuring geomagnetic disturbance from CME impacts. The Sunspots app displays current threat levels for all three scales.