Europa, one of Jupiter’s moons, is being watched by astronomers this Sunday, June 19, 2022. The star must occult a star. This phenomenon is interesting, in the perspective of the future JUICE mission.
For one minute, a star will disappear behind one of Jupiter’s moons. It is Europe which is responsible for this occultation, indicates the European Space Agency (ESA). We are talking about concealmentwhen a celestial object blocks the light of another, more distant celestial object — an eclipse is a type of occultation.
The event is scheduled for this Sunday, June 19, 2022, at 5:05 a.m. (Paris time). By observing the passage of the moon in front of this star in the background, scientists will ” refine their understanding of Europa’s orbit “, explains the ESA.
We won’t be able to enjoy it from France – the occultation is visible from southern Africa, in Namibia, Botswana and Zimbabwe, through a telescope – but the phenomenon is no less fascinating. Thanks to this occultation, astronomers will be able to contribute to JUICE (JUpiter ICy moons Explorer), a future ESA space mission. Its takeoff is scheduled for August 2023, for insertion into orbit around Jupiter in 2030.
This is not the first time that astronomers have succeeded in anticipating an occultation by the moon Europa. This was already the case on March 31, 2017. Thanks to the Gaia satellite, launched in 2013 to measure the position of stars, scientists were able for the first time to observe Europa during a star occultation. These are again the data from Gaia which are used to anticipate the occultation of this June 19th.
A particular concealment: Europe itself will be invisible
The phenomenon that occurs in 2022 is a bit special, because “ this moon will be in the shadow of Jupiter [au moment de l’occultation] and […] it will be impossible to see Europa directly because it does not produce its own light “, explains the ESA. Like our Moon, Europa can only be seen when it reflects sunlight back to Earth. ” As Jupiter will block this light during the occultation, observers won’t know Europa is there until it temporarily causes the star to disappear. “, continues the ESA.
Estimating Europa’s orbit more precisely, thanks to this occultation, is important to help the future JUICE mission to evolve in the environment of Jupiter – the planet is sometimes compared to a mini solar system, with all its moons. During overflights of Europe by JUICE, we could thus obtain much more precise information on the composition of the star, if the distance of the probe to the moon is correctly determined.