A ‘space show’ was captured on video as Mercury, located in the innermost part of the solar system, crosses in front of the sun. On the 20th (local time), the European Space Agency (ESA) released a video of Mercury passing across the surface of the sun, captured by the Solar Orbiter.
The video, taken on January 3, clearly shows Mercury’s spherical black ball as it moves across the Sun’s plane. It is a realistic scene as if it were synthesized with computer graphics, and it is clearly distinguished from the sunspots (pictured below) located in various places at the top of the sun.
When a planet orbiting the sun passes in front of the sun, it is called a solar plane transit. Likewise, the moon passes in front of the sun, but is so close to the earth that it appears to us as a total solar eclipse.
This time, Mercury was clearly captured because the Solar Orbiter is equipped with 10 measuring instruments that can observe the sun in a wide range of wavelengths ranging from visible light, radio waves, extreme ultraviolet, and X-rays. A dual Extreme Ultraviolet Imager and Polarization and Solar Seismometer (PHI) each captured the same scene but different views of the Sun and Mercury.
According to experts, the so-called celestial plane transit (transit), in which a planet passes in front of the sun (star), has long been used by astronomers for various purposes. Centuries ago it was used to calculate the size of the solar system and is now the most successful way to discover exoplanets. In general, planets do not emit light by themselves, so when a planet passes in front of a star, a phenomenon in which light is briefly occluded is found, which confirms its existence. In the future, ESA believes that augmenting and correcting data obtained through Mercury’s solar transits will help discover more exoplanets.
Meanwhile, Solar Orbiter, which was launched in February 2020, is a joint project between ESA and NASA.
Reporter Park Jong-ik pji@seoul.co.kr
