A European-Japanese spacecraft set off on a treacherous seven-year journey to Mercury on Saturday, Oct. 20 to probe the solar system’s smallest and least-explored planet.
The BepiColombo mission, only the third ever to visit Mercury, blasted off from Europe’s spaceport in French Guiana aboard an Ariane 5 rocket at 10:45 p.m. local time on Oct. 19, according to the Japan Aerospace Exploration Agency (JAXA).
Few spacecraft have visited Mercury because of the planet’s proximity to the sun—less than 60 million kilometers (37.3 million miles) away compared with almost 150 million kilometers that the Earth is from the sun—which makes any trip there challenging. Surface temperatures on the planet can reach highs of over 400 Celsius (752 F) during the day and drop to minus 170 C (minus 338 F) at night.
BepiColombo, named after 20th century Italian mathematician and engineer Giuseppe (Bepi) Colombo, will slingshot off the Earth’s gravitational field 1.5 years after launch before picking up speed on its journey. It will fly past Venus twice and then fly by Mercury six times before slipping into its orbit around December 2025.