The European Cheops planet-hunting space telescope was launched on Wednesday (December 18, 2019) to study the exoplanets outside our solar system. Cheops, an acronym for Characterizing Exoplanet Satellite, a joint endeavor of 11 member states of the European Space Agency (ESA), will observe the bright stars that are already known to be orbited by planets.

The telescope will measure the density, composition and size of the exoplanets. Didier Queloz, 2019 Nobel Physics Prize winner, told AFP in French Guiana, "Cheops is 710 kilometers (440 miles) away, exactly where we wanted it to be, it's absolutely perfect. This is really an exceptional moment in European space history and in the history of the exoplanets."

Representational picture of exoplanet
Representational picture of exoplanet NASA

The first exoplanet, dubbed 51 Pegasi b, was identified by Queloz and his colleague Michel Mayor about 24 years ago. Since then roughly a total of 4,000 such exoplanets have been discovered.

Existence of extraterrestrial life

The launch of the satellite took place a day after its lift-off was delayed due to a technical rocket glitch during the final countdown. However, on Wednesday it successfully took off at around 0854 GMT French Guiana. This year, it was the third launch for the Russian-built Soyuz rocket.

According to the scientists, there are at least as many galaxies as there are stars —approximately 100 billion and CHEOPS will help them to have a better understanding of what those planets are made of. "We want to go beyond statistics and study them in detail," mission chief David Ehrenreich had told AFP ahead of Wednesday's launch.

Scientists believe that this will be an important step to unravel the mystery of extraterrestrial life and get an idea of the origin of Earth.

Satellite to give a 'family photo of exoplanets'

Guenther Hasinger, ESA's director of science, told AFP on Tuesday that the aim of the satellite, which will orbit the Earth at a distance of 700 km (435 miles), is to compose "a family photo of exoplanets".

Queloz said the CHEOPS mission would help the scientists to measure the quantity of light that is reflected from the planets. It is believed that the measurement may provide valuable new insights about the planet's surface or atmosphere. "The launch is an important moment, an emotional step, but the real magic moment for us will be when the first results arrive," Queloz said. ESA suggests that the first results can be expected within months.

However, Queloz said CHEOPS may not completely solve the mystery about the existence of life on other planets. "In order to understand the origin of life, we need to understand the geophysics of these planets. It's as if we're taking the first step on a big staircase," he added.