Our Solar System is just out there, beyond Earth’s soft blue sky, doing its job, every minute of every day, every year. If we’re at the right place at the right moment, we occasionally have the opportunity to view that situation from a different angle.
We are incredibly grateful that a little spacecraft located more than 100 million kilometres (62 million miles) from Earth was in the ideal location at the perfect time.
The Mars Express spacecraft, operated by the European Space Agency to monitor the red planet, recently captured an eclipse including Jupiter and its four Galilean moons, as well as the smaller Martian moon Deimos.
The distance between Mars and its enormous neighbour at the time was around 745 million kilometres, but for a fleeting while Deimos and the Jovian system appeared to be one contented family.
The alignment of these celestial bodies on February 14, 2022, was captured on camera and assembled into a movie from a collection of 80 photos.
According to the ESA, “such an alignment is highly exceptional” since it requires Deimos to be precisely in the orbital plane of Jupiter’s moons in order for it to happen.
Deimos, which is only 15 kilometres long, may be seen in the video travelling slowly across the screen from left to right. The ice moon Europa and the enormous moon Ganymede are obscured as it passes, appearing as tiny, star-like specks. Next, the disc of Jupiter, the volcanic moon Io, and then Callisto, the second-largest moon of Jupiter, are all visible.
Since the Martian moons are so small and faint, it is difficult to determine their positions and orbits from Earth. However, these observations helped Mars scientists achieve just that. To understand where they come from, it may be important to comprehend their orbits. Whether Deimos and Phobos, the bigger of the two moons, were previously pieces of a larger body that split apart or an asteroid that was passing by and caught in Mars’ gravity is unknown.
Scientists will be able to better predict what will happen to Mars’ moons in the future by better characterising the moons’ orbits. In the next 100 million years, Phobos will come so near to Mars that its gravity will shatter the moon, creating a temporary Phobos ring around the planet. Phobos is currently steadily heading towards Mars.
On the other side, Deimos is gradually relocating away from Mars. Scientists believe that if it keeps going in this direction, it will eventually break free of Mars’ gravitational pull and travel on its own through the vast Solar System.
Nothing lasts a lifetime. not even the bond a planet has with its moons.