Lead: India’s Aditya-L1, the country’s first dedicated solar observatory, is poised to observe the Sun as it reaches the expected activity peak in 2026. Placed into a halo orbit last year, the spacecraft will monitor increases in solar storms and coronal mass ejections (CMEs) that accompany the roughly 11-year solar cycle. Scientists expect daily CME rates to rise from a few per day in quiet periods to 10 or more during the maximum, making 2026 a critical year for both science and space-weather preparedness. The mission’s coronagraph and visible-light instruments give Aditya-L1 unique capabilities to track CME temperature, mass and trajectory in real time.
Key Takeaways
- Aditya-L1 is India’s first solar-observing mission and has been operating in halo orbit near the Sun–Earth L1 point since 2024.
- Solar activity peaks roughly every 11 years; the next maximum is expected in 2026 when the Sun’s magnetic poles flip.
- Typical quiet-phase CME production is two to three per day; researchers expect 10 or more CMEs per day during the 2026 peak.
- A single CME can contain up to a trillion kilograms of charged particles and reach speeds near 3,000 km/s, covering the 150 million km Sun–Earth distance in as little as 15 hours at top speed.
- Aditya-L1’s Visible Emission Line Coronagraph (VELC) can continuously block the photosphere and observe the faint corona 24/7, allowing temperature and energy measurements in visible light.
- Historical space-weather impacts include the 1859 Carrington Event, the 1989 Quebec blackout, and satellite disruptions reported in recent decades; NASA reported a large satellite loss event linked to solar activity in 2022.
- Data from a 13 September 2024 CME recorded by Aditya-L1 showed a mass of 270 million tonnes, source temperature ~1.8 million °C and energy ~2.2 million megatons of TNT, providing a benchmark for future comparisons.
Background
The solar activity cycle, driven by the Sun’s magnetic field, reverses polarity approximately every 11 years. During the reversal and the surrounding maximum, the frequency and intensity of eruptions on the solar surface rise markedly, producing more solar flares and coronal mass ejections. These CMEs are massive expulsions of magnetized plasma from the solar corona; their size, speed and direction determine whether and how strongly they affect near-Earth space.
Interest in continuous corona monitoring has grown because modern society depends on infrastructure that is vulnerable to space weather: nearly 11,000 satellites operate in near-Earth orbit, and terrestrial systems such as power grids and high-frequency communications can be disrupted by geomagnetic storms. India now fields 136 satellites in orbit, raising the strategic importance of domestic space-weather observational capability and timely warnings.
Main Event
Aditya-L1 carries seven scientific instruments; the Visible Emission Line Coronagraph (VELC) is central for CME science. Unlike instruments that must wait for natural eclipses to reveal the faint corona, VELC uses an occulting disk sized to simulate the Moon and continuously blocks the bright photosphere, giving nearly uninterrupted views of coronal structure and eruptions.
On 13 September 2024 at 00:30 GMT, Aditya-L1 recorded one of its largest CMEs to date. Investigators measured the ejection’s mass at 270 million tonnes and its source-region temperature at about 1.8 million °C. The team estimated the kinetic and thermal energy equivalent to roughly 2.2 million megatons of TNT—far larger than the 15–21 kiloton yields of the Hiroshima and Nagasaki weapons but still termed “medium-sized” by the project lead in the context of possible maxima.
Project scientists have used that September event, recorded while solar activity was still in a relatively normal phase, as a test case to calibrate models of CME heating, propagation and potential impact. By combining VELC visible-light thermometry with trajectory tracking, Aditya-L1 can estimate a CME’s energy budget and likely arrival time at Earth, enabling operational response options for satellite operators and infrastructure managers.
Analysis & Implications
Scientific value: Continuous visible-light measurements of the corona provide temperature and heat-energy diagnostics that are difficult to obtain from extreme-ultraviolet or coronagraphs positioned differently. These diagnostics help refine models of CME initiation and acceleration, improving our physical understanding of how eruptions are launched from the solar atmosphere.
Operational impacts: If Aditya-L1 can routinely detect and characterize CMEs early—measuring their initial temperature and trajectory—authorities could gain critical lead time to mitigate risks: powering down sensitive satellite subsystems, reorienting assets, or issuing grid-protection protocols. Even lead times of hours to a day matter for some defensive actions.
Economic and strategic effects: A sharp increase in CME frequency during 2026 could put more spacecraft and ground systems at risk, raising insurance and operational costs for satellite operators. For countries with growing space fleets, domestic monitoring and forecasting capability reduces reliance on foreign data streams and supports independent contingency planning.
Comparison & Data
| Metric | Typical/Example | Value |
|---|---|---|
| Daily CMEs (quiet) | Average low-activity rate | 2–3 per day |
| Daily CMEs (expected 2026) | Projected solar maximum | 10+ per day |
| Sample CME (13 Sep 2024) | Mass | 270 million tonnes |
| Sample CME (13 Sep 2024) | Temperature | ~1.8 million °C |
| Sample CME (13 Sep 2024) | Energy | ~2.2 million megatons TNT |
| Fastest CME speed | Observed upper range | ~3,000 km/s |
The table places the September 2024 event in context: even an event labeled “medium-sized” by investigators can contain enormous energy compared with human-made explosives, and projected daily CME counts at solar maximum represent a multiple of the quiet baseline. These comparisons show why 2026 will be an intense period of observation and operational testing for Aditya-L1.
Reactions & Quotes
“Our coronagraph is designed to behave like an artificial Moon so we can watch the corona continuously and measure the heat where eruptions begin,”
Prof R. Ramesh, Indian Institute of Astrophysics (Principal Investigator, VELC)
Prof Ramesh framed the September 2024 event as a calibration benchmark that will let teams judge how much stronger eruptions could be during the upcoming maximum and how to protect satellites.
“Solar maximum increases the frequency of space-weather events that can disrupt satellites and critical infrastructure; better early characterization improves preparedness,”
NASA spokesperson (space-weather science)
NASA and international partners are collaborating on data-sharing and model validation to turn solar observations into actionable forecasts.
Unconfirmed
- Exact daily CME counts during the 2026 maximum remain projections based on solar-cycle models and could be higher or lower than the current estimate of 10+ per day.
- Predicted energy and frequency of the strongest potential CMEs in 2026 are model-dependent; extreme worst-case scenarios remain uncertain.
- Operational impacts on specific satellites or power grids for any future CME depend on each asset’s hardening and response measures and are not predetermined by detection alone.
Bottom Line
Aditya-L1 arrives at the solar maximum with capabilities that uniquely position India to monitor the corona continuously and measure CME temperatures and energies in visible light. The 13 September 2024 event provided a real-world benchmark; 2026’s expected rise in eruptions will stress-test instruments and prediction systems and produce high-value science data.
For operators of satellites and critical infrastructure, improved early characterization of CMEs offers a meaningful opportunity to reduce damage through timely mitigation measures. International data sharing and model validation during 2026 will be essential to convert observations into reliable forecasts that protect assets on orbit and on the ground.