COSMO

The COronal Solar Magnetism Observatory (COSMO)  offers the potential to transform our fundamental understanding of magnetic fields in the Sun’s atmosphere. These magnetic fields drive the formation of solar eruptions and other space weather events that can affect technologies, and therefore the lives and livelihoods of people, on Earth.

Investigating the source of solar storms

“Magnetism is the force that sends mass from the corona, the outermost part of the Sun’s atmosphere, flying across the solar system,” said Sarah Gibson, senior scientist at the U.S. National Science Foundation's National Center for Atmospheric Research (NSF NCAR). “However, there is a crucial gap in our understanding of these coronal mass ejections, or CMEs. We have very little information about the magnetic fields in the lower and middle solar atmosphere — and that’s where the storms brew.“

CMEs can be very disruptive to life on Earth by interfering with power grids and satellite-based technologies including GPS, communications, and access to the internet. Understanding how and where CMEs develop will improve our ability to predict and prepare for solar storms, enhancing our ability to protect society. A CME can be seen as a large curve to the left of the Sun in this composite image of data taken on June 13, 2022, by (from center) SDO/AIA, MLSO/K-Cor, and SOHO/LASCO. COSMO will study the lower and middle solar atmospheres, represented here by the grayscale K-Cor image.

COSMO will be a suite of three instruments: the Large Coronagraph (COSMO‑LC), K‑Coronagraph (K-Cor), and the Chromospheric and prominence Magnetometer (ChroMag). No current instruments or suite of instruments in the U.S. or around the world study magnetic fields in the corona and catch the very beginning of a CME as COSMO will. The observatory will track energy buildup in the Sun’s magnetic field as well as changes in plasma conditions in the corona and the atmosphere just below the corona, which is called the chromosphere. These observations will be used to identify and track the physical processes that create solar storms and provide new information for space weather forecasting.

COSMO research data will be public, allowing scientists from universities, government agencies, and other organizations to access the information for their own research.

Protecting people and technology

CMEs endanger people on Earth because of damage to essential infrastructure and technologies. These include:

• Power grids, with the potential for outages
• Radio communications
• GPS, which affects navigation, agriculture, search and rescue, financial services, and other systems
• Other satellite-based technologies, including intelligence, internet, and entertainment

Radiation associated with solar storms also increases risks to airplane crews, frequent fliers, and in-space astronauts.

Scientists observe CMEs but cannot predict when they will happen. Once the CMEs erupt, it’s difficult to forecast whether and how severely they will affect the Earth. This reduces opportunities to prepare for their impacts and protect society.

Better space weather prediction capabilities will help protect and preserve access to the power grid and other technologies that people and communities rely on.

Current status

The U.S. National Science Foundation (NSF) awarded a grant to NSF NCAR to survey prospective locations and complete COSMO telescope design.

Six sites are being considered for COSMO and are being evaluated for the ability to observe the solar corona:

• Magdalena Ridge Observatory, New Mexico
• Wyoming Infrared Observatory, Jelm Mountain, Wyoming
• Barcroft Station, White Mountain Research Center, California
• Cerro Tololo Inter-American Observatory, Chile
• Observatorio Astronómico Félix Aguilar, Argentina
• Teide Observatory (Izaña), Spain

NSF NCAR has worked with existing facilities to place instruments at five sites to evaluate local weather and sky brightness; Teide Observatory already collects observations the team will use for these analyses.

Throughout the site selection process, the COSMO site survey team is engaging with local communities at each of the potential sites. In particular, the team is reaching out to Indigenous nations for whom these specific sites have meaning and connection. The team is committed to honoring the cultural context of each site, co-creating what successful engagement looks like with these nations, understanding whether there is interest in the project, and affirming the importance of the project’s impact on the land.

NSF NCAR will select three of the proposed sites for continued evaluation based on scientific viability, community feedback, and other considerations. We anticipate this will be in the third quarter of 2024. NSF NCAR will continue working with communities at those three sites as data assessment continues. In late 2025, NSF NCAR will recommend two sites to NSF and submit a grant proposal for construction funding.