Solar storms will increase and accelerate the decline of Hubble

When charged solar particles hit the Earth’s atmosphere, it gives rise to superb northern lights. But the phenomenon can also damage our technological devices, and artificial satellites including the Hubble space telescope.

From May 10 to 12, our Earth was hit by the biggest solar storm in more than a decade, creating a magnificent spectacle: “The Sun is a plasma and these northern lights are due to an ejection of a solar flux of particles, mainly electrons and ions”, explains astrophysicist Corinne Charbonnel, professor in the astronomy department at the University of Geneva.

“They are ejected from the upper atmosphere of the Sun. There is a brutal and sudden recombination of the local magnetic field in certain regions of its surface: that is what a solar storm is,” she explains at the microphone of Forum, Monday.

External content

This external content cannot be displayed because it may collect personal data. To view this content you must authorize the category Social networks.

Accept More information

The variability of the Sun

“The intensity of the phenomenon varies with the activity of the Sun. The latter has an eleven-year cycle and, here, we are close to the solar peak.” Previous peaks were in 1992, 2003 and 2014; the following ones should arrive in 2025, or perhaps even early 2026, as indicated by the American astrophysicist Ethan Siegel in a article, specifying that the Sun is in its 25th cycle. The 26th cycle is planned for 2036 or 2037.

This activity was notably observed closely by the SOHO space satellite, from NASA and the ESA (read also boxed). This solar and heliospheric observatory is positioned between our planet and the Sun. He captured it spewing clouds of particles and emitting a particularly large burst toward Earth on May 11.

“The recent storm is associated with a strong eruption in a set of sunspots whose diameter is approximately 17 times that of the Earth. We could observe this eruption a few hours before the arrival of these particles: they only travel ‘at about three million kilometers per hour, while light travels much faster.’ Corinne Charbonnel notes that this is how astronomers were able to predict the arrival of these particles and, therefore, of the Northern Lights: “When these particles arrive at the level of the Earth’s orbit, the Earth’s magnetic field protects us. But billions of collisions occur between these particles ejected by the Sun at very high speed and the particles in the upper atmosphere.

A peak of solar activity at the origin of the recent northern lights: interview with Corinne Charbonnel / Forum / 3 min. / Monday at 6:00 p.m.

It is these interactions that generate light of different colors: “They will depend on the composition of the atmosphere. When you see greenish or red light, it comes from the oxygen in our atmosphere, if it is blue , it’s nitrogen.”

Solar flares are powerful bursts of energy that can impact radio communications, power grids, navigation signals and pose dangers to spacecraft and astronauts. “The main risks occur at high altitude”, notes Corinne Charbonnel: “A large part of the artificial satellites which orbit the Earth have modes which allow them to ‘batten down the hatches’ to protect the electronics from this great flux of Others do not have any and risk burning out.

The near end of the Hubble Space Telescope

As for the Hubble Space Telescope, it suffers from the Sun’s tantrums for another reason: solar activity increases the rate of orbital decay of satellites in low orbit. At this location, these machines also collide with atoms and molecules in the Earth’s atmosphere. Although tiny and at the atomic level, these impacts add up and contribute to a very slight frictional force: “Over time, satellites are pulled into lower and lower orbits, causing them to experience a greater atmospheric friction force over time, causing them to disappear much more quickly,” notes Ethan Siegel.

However, Hubble was launched in 1990 at an altitude of 620 kilometers, which is almost twice the altitude of the ISS. The star telescope has seen its orbit raised during each of the missions aimed at its maintenance – the last dating from 2009: it was then at an altitude of 570 kilometers.

“It is still in the Earth’s thermosphere [couche se trouvant juste avant l’exosphère, ndlr.]and its orbit not only declines, but declines more rapidly each time the solar cycle peaks, as is the case right now,” writes the astrophysicist. Because the particles ejected by the Sun are highly energetic. Hubble is expected to lose ten kilometers between January 1 and December 31, 2024, “which represents the largest degradation of the orbit in a single year in the 34 years of existence of the Hubble Space Telescope in space”.

>> The average altitude of the Hubble Space Telescope correlated with sunspots:

Sunspot data from the last 35 years (orange) and average altitude data from the Hubble Space Telescope (blue) over time. Note that servicing missions (SM) increase Hubble’s altitude, but the increase in solar activity corresponds to a rapid loss of altitude over time. [Ethan Siegel, Big Think – J.J. Hermes/Jonathan McDowell, Twitter]

Ethan Siegel predicts that in 2026, Hubble will be below 500 kilometers for the first time since its launch: “A more active Sun will accelerate its orbital decay.” And to summarize: “If we do not intervene, Hubble will not survive the peak of the 27th solar cycle.”

At 34 years old, the space telescope Hubble is far from obsolete and still contributes greatly to 21st century astronomy; he remains complementary to James Webb.

>> The planetary nebula M76an expanding shell of glowing gas ejected from a dying red giant star, captured by Hubble: