Satellites will create a “false solar eclipse” to study the Sun’s corona

Next Monday, April 8th, the total solar eclipse . The phenomenon, which will not be visible in Brazil, will highlight the brightness of stars and planets and will be an opportunity for astronomers to study the solar corona atmosphere that surrounds the Sun and is generally overshadowed by the star's intense brightness.

However, as the solar eclipse is an event that occurs once every 18 months and has a short duration, a deeper study of the solar corona will be possible with the creation of “fake solar eclipses “.

This is the idea behind Test-3 , new ESA (European Space Agency) mission. The objective is to produce events of Orbital solar eclipses “on demand” . To do this, the spacecraft Occulter will fly about 150 meters from a second spacecraft, the Coronagraph. The pair will align with the Sun so that the Occulter will cast a shadow on the face of Coronagraphmaking the solar corona more visible.

“The two spacecraft will function as if they were a huge instrument measuring 150 m long”, explains Dietmar Pilz, director of Technology, Engineering and Quality at ESA, in statement. “However, achieving this will be an extremely technical challenge, because at the slightest misalignment, [a missão] it won’t work”, he adds.

The objective of Proba-3 is to produce these artificial eclipses routinely through precise formation flying, for up to six hours, on each orbit of the mission — which lasts about 19 hours and 36 minutes. This will allow for a more in-depth study of the solar corona, as well as providing information about the Sun's glowing atmosphere.

Pobra-3's main instrument, ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Sun's Corona), will produce data “as if it were on board a single rigid spacecraft,” according to the statement. . Accuracy will be achieved through the combination of a suite of positioning technologists such as: satellite navigation, radio-based intersatellite links, LED-directed visible light cameras, and a laser beam reflected between the spacecraft.

In addition, the mission has a second instrument: a radiometer that measures the Sun's total energy production, which is important for climate modeling. The flight of the spacecraft will take place at an orbital altitude of around 60 thousand kilometers. At that time, gravitational, atmospheric and magnetic disturbances have little impact on orbiting satellites.

What is the solar corona and why is it important?

The solar corona is a region rarely seen from the Sun and is of interest to astronomers because it is extremely hot — its temperature reaches up to two million degrees Kelvin . Despite this, the crown does not produce or reflect much light. Therefore, it is only visible during a total solar eclipse.

To add, the corona influences space weather , generating solar wind. This wind sometimes accompanies coronal mass ejections, which can harm orbiting satellites and terrestrial power and communications networks.

Understand how a solar eclipse happens and how to follow it

A solar eclipse happens when the Moon is positioned between the Sun and the Earth, preventing light from reaching some points on our planet. Being in a place where it is total, it is possible to see the Moon blocking almost all the Sun's rays, making the day as dark as the night.

Total solar eclipses happen every 18 months and last a few minutes, while partial solar eclipses — in which the Moon does not completely cover the Sun — occur at least twice a year somewhere on Earth.

The eclipse that will take place next Monday (8) is a total solar eclipse , visible only in a small area of ​​the Earth, when the person is in the center of the Moon's shadow, when it hits the Earth. For a total eclipse to occur, the Sun, Moon and Earth must be completely aligned.

In Brazil, he cannot be seen. However, NASA (United States Space Agency) will make several broadcasts available for the whole world to follow the event. The phenomenon will begin at 4pm (Brasília time) off the coast of Mexico, and will end at 5pm (Brasília time) on the Atlantic coast of Canada. See which lives will be available .