Mercury, the innermost planet in our solar system, has long intrigued scientists with its scorching temperatures, extreme solar exposure, and cratered surface. However, studying Mercury presents unique challenges. Its proximity to the Sun makes it difficult for spacecraft to enter orbit and survive the intense solar radiation.
Despite these challenges, missions to Mercury have provided valuable insights into the planet’s composition, geology, and magnetic field. Over the past few decades, only a few spacecraft have successfully reached Mercury, yet they’ve transformed our understanding of this mysterious, rocky world.
Key Missions to Mercury
Through these missions, Mercury has gone from an enigmatic, largely unexplored planet to one that is gradually giving up its secrets. While the challenges of Mercury exploration remain significant, each mission has provided data that brings us closer to a fuller understanding of this dynamic, Sun-scorched planet.
Mariner 10 (1974-1975)
Mariner 10, launched by NASA in 1973, was the first mission to explore Mercury and Venus. It was the first spacecraft to use a gravity-assist maneuver, which allowed it to approach Mercury by using Venus’s gravitational pull.
Mariner 10 completed three flybys of Mercury in 1974 and 1975, capturing the first close-up images of the planet’s surface. This mission revealed Mercury’s heavily cratered, Moon-like landscape and identified the presence of a weak magnetic field. Although Mariner 10 didn’t enter orbit around Mercury, its flybys provided groundbreaking data that served as the basis for future Mercury exploration.
- Status: Successful.
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) (2004-2015)
MESSENGER, a NASA mission launched in 2004, was the first spacecraft to orbit Mercury. It used a complex series of flybys—one of Earth, two of Venus, and three of Mercury itself—to gradually slow down enough to enter Mercury’s orbit in 2011.
During its four years in orbit, MESSENGER mapped nearly 100% of Mercury’s surface, studied its unique geology, and provided data on its thin atmosphere (exosphere) and magnetic field. One of MESSENGER’s most remarkable discoveries was the identification of water ice in permanently shadowed craters at Mercury’s poles. The mission ended in 2015 when MESSENGER ran out of fuel and deliberately crashed into Mercury’s surface.
- Status: Highly successful.
BepiColombo (2018-Present)
BepiColombo is a joint mission by the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), launched in 2018. It aims to build upon MESSENGER’s findings by providing even more detailed data on Mercury’s surface and magnetic field.
BepiColombo consists of two spacecraft: the Mercury Planetary Orbiter (MPO), provided by ESA, and the Mercury Magnetospheric Orbiter (MMO), provided by JAXA. Since entering its cruise phase, BepiColombo has conducted multiple flybys of Earth, Venus, and Mercury to gradually slow down for orbital insertion around Mercury, expected in 2025. Once in orbit, it will conduct comprehensive studies of Mercury’s composition, exosphere, and magnetosphere, adding to our understanding of this extreme environment.
- Status: Ongoing and progressing well.
