According to Izabela Kowalska-Leszczyńska PhD, an astronomer at the Space Research Centre, the photometer will reach a point 1.5 million kilometres from Earth to study the structure of the solar wind.

The GLObal solar Wind Structure (GLOWS) instrument was designed and built at the Space Research Centre and will be part of NASA’s Interstellar Mapping and Acceleration Probe (IMAP) mission. NASA has scheduled the IMAP launch from the Kennedy Space Center in Florida ‘no earlier than September 23rd.’

“GLOWS is designed to detect photons… with a very narrow wavelength of 121.5 nanometers, called the Lyman-α line. This band of far ultraviolet light does not reach the Earth's surface because it is absorbed by the atmosphere, so observations of this wavelength must be conducted from space,” Kowalska-Leszczyńska, told the Polish Press Agency (PAP).

She said that interstellar hydrogen, the most common element in the universe, flows into the Sun’s vicinity from beyond the heliosphere, the bubble of ionised matter and magnetic fields surrounding the Solar System.

When hydrogen atoms are illuminated by ultraviolet radiation from the Sun, the electrons in the atoms are excited and then return to lower energy levels, radiating Lyman-α photons, which GLOWS is designed to observe.

“By observing how the glow's brightness changes in different directions, we can say something about the interstellar gas flowing into the heliosphere, how the Sun shines, and how the solar wind blows,” the astronomer said.

Kowalska-Leszczyńska added that the solar wind pushes interstellar hydrogen out of the heliosphere. The stronger the wind, the fewer glowing hydrogen particles GLOWS will detect.

“We are also interested in the so-called latitudinal structure of the solar wind. The wind blows differently over the Sun's equator than over its poles. There are many observations of what happens at the equator, but the solar wind from the Sun's poles is very little understood. We hope to change this,” she said.

The Polish team aims to determine the speed and density of the solar wind at different heliographic latitudes and to monitor changes over the solar cycle. “Although the nominal IMAP mission is scheduled for two years, we know from experience that, if all goes well, missions are usually extended. We are really hoping for this, because the solar cycle is 11 years, so it would be good to conduct observations throughout that period,” Kowalska-Leszczyńska said.

IMAP will operate at the L1 Lagrange point, about 1.5 million km from Earth and roughly 150 million km from the Sun, where the gravitational forces of the Sun and Earth balance. The spacecraft is expected to reach this point three to four months after launch, with first scientific data expected in February 2026.

The information from GLOWS will complement data from nine other instruments on IMAP, which will study phenomena ranging from high-energy solar particles to interstellar magnetic fields.

“GLOWS was entirely designed and built in Poland, with the help of companies from the Polish space sector. In terms of the global space industry, it may be a minor component, but for us it was a major challenge. And for me personally, it is a tremendous experience,” Kowalska-Leszczyńska said.

The IMAP mission is scientifically supervised by Princeton University professor David J. McComas, with development and spacecraft construction handled by the Johns Hopkins University Applied Physics Laboratory. Mission operations and the data center are based at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder, and the project involves additional partners in the US and the UK.

The GLOWS experiment is financed through the Polish state budget under an agreement between the Ministry of Science and NASA. (PAP)

PAP - Science in Poland

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