Proba-3 satellite duo to create artificial solar eclipse and study sun’s corona

Have you heard about the Proba-3 Satellite which has been launched of late. Well. the sun’s corona is a region that has baffled scientists for so many years, with the section being hotter than the sun’s surface. To delve deeper into the mysteries of the sun and to study the corona phenomena, a dual Proba-3 Satellite (Project for On-Board Autonomy) has been launched by the European Space Agency (ESA). The alignment known as ‘syzygy’ which is actually the alignment between the sun, moon and the earth during an eclipse, will be created in the same manner by the satellites.

The arrangement will assist in the understanding of the eclipse and thereby the coronal higher temperatures than the surface of the sun. Andrei Zhukov of the Royal Observatory of Belgium in Brussels says that the arrangement will for the first time, pave the way ‘to see an eclipse on demand.’

As per a further explanation of the mission, Ester Bastida, Proba-3 Satellite systems engineer, “Right now this [the corona] is a region of the sun that has been poorly investigated, and scientists nowadays don’t really understand some of the phenomenon that’s happening there.” Also, the mission will open up a way to demonstrate the capability of precise formation flying (PFF) as per Bastida.

Proba-3 Satellite launched from Satish Dhawan Space Center, India

Missed our Proba-3 mission this week? We've got you!

Proba-3 lifted off on @isro's PSLV-XL rocket from Satish Dhawan Space Centre in Sriharikota, India, on Thursday, 5 December.

Watch the launch highlights: https://t.co/aIZcVvYa6n

— European Space Agency (@esa) December 7, 2024

Launched from Satish Dhawan Space Centre in India, one of the world’s most-used space launch facilities, the two Proba-3 Satellites will be lofted up to 60,000 km (37,280 miles) above Earth in a lockstep manner. A precision of one millimeter will come into place to study the solar eclipse, which will come into effect by the blockage created by one of the satellites. A solar eclipse lasting for about six hours will give scientists enough time to study the solar corona.

Afterward, the Coronagraph Spacecraft (CSC) guiding the other spacecraft Occulter (OSC) to follow it, will cast shadow on the first one. High-resolution images of the sun’s innermost region will be sent from the observing spacecraft. A telescopic device called a coronagraph will be put before the lens which assists in blocking any incoming light from a nearby star, thereby effectively blocking interference to study the phenomenon with an accuracy. A technology called the Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun (ASPICCS), is utilized to create exact eclipse-like conditions.

Since an alignment of the sun, moon and the Earth are rare occurrence according to Zhukov again, lasting for a short span of time, a coronagraph eliminates any error that might creep in. Light bends in a method known as diffraction around sharp-edge disk, a process, with which the scientists observe the happenings in the coronal layer. This is where the role of a coronagraph comes into play.

Another important point that needs to be studied by Proba-3 Satellite is the extremely high temperature of the Sun’s corona at 1-3 million degrees Celsius, relative to its surface, with a temperature hovering around 5,500 degrees Celsius. Even at a larger distance, the Sun with its huge circumference of 2,717,000 miles affects the Earth with its coronal flares reaching almost 93 million miles away.

Owing to the low brightness of the corona normally, it is only during solar eclipses that the extreme brightness becomes visible. The moon blocks the sun’s light and scientists by observing the corona scientists are able to predict the weather patterns with accuracy. They can also study the geomagnetic storms causing disruptions in the satellite systems, apart from other devices on the earth, according to ESA in a recent video.  

Physicist Amir Caspi of the Southwest Research Institute in Boulder, Colorado has this to say about studying the eclipses. Caspi states that the distance between the two satellites not being an issue, is actually an advantage as diffracted light has more of a chance to spread out before another one.

Says Caspi “The cool thing about Proba-3 Satellite is they’re going to put the occulter much farther away than what you could reasonably do with a single spacecraft. That means that you can make the occulter exactly the right size, and you can see closer down to the solar surface.”

And if fuel is the issue due to the longer span of staying in an eclipse formation, it will mostly be impossible to do that. Yet scientists do hope for at least 1,000 eclipses in a two-year span of the mission.

Combining the observations from Proba-3 Satellite with other spacecraft is going to revolutionize solar science in general. Linking several telescopes acting as one unit, if that is done, will create a wide telescope increasing the range and power of the earth-based ones.

“It’s a very creative use of formation flying in space to achieve something that would be almost impossible, if not actually impossible, to do with a single spacecraft,” adds Caspi. “It opens up this new discovery space of observations that have been inaccessible until now.”