The solar probe Solar Orbiter observed a small dark dot passing in front of the Sun on January 3. The identity of this black dot is Mercury.
Mercury’s diameter is 1,392,700 km in diameter, regarding one-third the diameter of Earth, and its smallness seems to stand out when lined up with the Sun. Solar Orbiter is a joint mission of the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA).
This time, Solar Orbiter detected the passage of Mercury through various observation instruments. The PHI device, designed to investigate the solar magnetic field, took pictures of Mercury, which looks like sunspots but crosses at high speed. Capturing intense solar coronal activity, extreme ultraviolet imaging captured the silhouette of Mercury passing through a layer of gas.
Another observational instrument, SPICE, aboard Solar Orbiter, also photographed Mercury. One expert revealed that Mercury might be seen not just passing in front of the Sun, but also passing in front of other layers of the atmosphere. Mercury is the innermost planet in the solar system and has an orbital period of 88 days, but its surface temperature is extremely high and extremely low. Because there is almost no atmosphere, the temperature can drop to close to minus 200 degrees. Solar Orbiter captured this Mercury orbiting at 47 km/sec. Related information this placecan be found in
