It's always wonderful when one of humanity’s cosmic explorers spots something unexpected. This time, is the turn of the European Space Agency’s Mars Express to get a glimpse of a rare event. The orbiting spacecraft has been studying the Red Planet for almost 20 years, and has now captured an astronomical occultation. Deimos, the smaller of the two moons of Mars, was seen passing in front of Jupiter and its four major satellites.
On February 14, 2022, Deimos passed perfectly in front of Europa, Ganymede, then Jupiter, Io, and Callisto – the largest planet and its four Galilean moons. The chance alignment between the 15-kilometer (less than 10-mile) Martian moon and the distant Jovian system provided scientists with great insights into the orbit of Deimos.
Understanding the dynamics of the martian moons is not an easy task, so this observation is important. Deimos is moving away from Mars, while its larger companion Phobos, it is getting closer. Phobos will eventually be destroyed by the Red Planet’s gravity and might give mars a ring.
The apparent bobbing up and down of Deimos is an artifact of the spacecraft, whose solar wings and radar antenna cause it to vibrate. Also, the Jovian moons were only visible due to image processing and enhancement. Without that, the light of Jupiter would have flooded the background. The king of the planets is a bright one (check it out in the sky tonight, towards the south in the Northern hemisphere.)