On a rare occasion when the mother planet reaches opposition, with just a good pair of binoculars, you can observe Europa, the world that may be harboring life closest to us.
Europa is one of the four Galilean moons of Jupiter, alongside the volcanic moon Io, the larger-than-planet Ganymede, and the “purple moon” Callisto. Europa is known as a “moon of life”, not for extinct life like Mars, but for life that may still exist.
On the night of September 26, its mother planet – Jupiter – will come closest to Earth in 59 years, at a distance of over 590 million km according to NASA calculations, due to two overlapping phenomena.
- First, Jupiter is at opposition, meaning it and Earth are symmetrical about a line through Earth’s center.
- Second, the elliptical orbits of Jupiter and Earth inadvertently bring them closest together.
The four Galilean moons of Jupiter, from top to bottom: Ganymede, Callisto, Europa, and Io – (Photo: NASA/ASTRONOMY).
Typically, if the weather is good and the sky is not covered with clouds, you can always see Jupiter with the naked eye as it shines with a yellowish-white light, due to its massive size, which is 318 times that of Earth.
Even more spectacular, each time Jupiter reaches opposition, it showcases its four Galilean moons to Earth observers. However, due to the distance, you will need a good pair of binoculars to see them, preferably a type with a mount since you’ll need to keep it steady.
This is a rare opportunity, as these moons are usually only observable through telescopes. Jupiter being closest in 59 years also means these four moons will be most visible in 59 years.
The method for observing them is similar to observing celestial bodies in general: It’s best to choose an open area with a wide view of the sky, such as a rooftop. Allow your eyes to adjust to the darkness for a moment and locate Jupiter in the sky. Depending on the time of observation, it will be in different positions, but generally, it can be clearly seen with the naked eye.
Point your binoculars towards the giant planet, and you may see 3-4 Galilean moons.
Returning to Europa, clear signs of oxygen, water, and other necessary chemicals for life have been identified on this celestial body by two spacecraft exploring Jupiter: Galileo and Juno. Galileo (launched in 1989) was the fortunate first to be… sprayed with water vapor while flying past this moon of life.
The structure of Europa resembles an “upside-down Earth,” where a living world exists beneath the crust instead of above, but the conditions suitable for life are similar.
Many studies have provided evidence that this moon is habitable because it possesses a subsurface ocean beneath its icy crust, where warm water and hydrothermal systems similar to those in Hawaii or Antarctica, the “springs of life” on Earth, exist. The only difference is that it resembles an “upside-down Earth” because the living world is located beneath the crust instead of above it.
Most recently, research from the University of Texas at Austin suggests that life still exists in this environment.
With a similar belief, the two largest space agencies in the world, NASA and ESA (the space agencies of the United States and Europe), both plan to send exploratory missions to land directly on Europa, with the earliest being NASA’s Europa Clipper (scheduled for launch in 2024), equipped with ice-penetrating radar and a swarm of miniature robots aiming to drill through the icy crust and dive into the subsurface ocean in search of life.
