Planet Mercury

Planet Mercury Latest News

Mercury may have shrunk more than scientists previously estimated, with the planet’s diameter potentially reducing by as much as 23 km, a recent study has revealed.

About Planet Mercury

• It is the smallest planet in our solar system and the nearest to the Sun.  
• It is one of the four terrestrial (rocky) planets, along with Venus, Earth, and Mars. 
• As the closest planet to the Sun, it experiences extreme temperature variations at its surface, from about +450ºC (day) down to –180ºC (night). 
  • However, Mercury is not the hottest planet; Venus has the highest average surface temperature because of its thick atmosphere and strong greenhouse effect. 
• It has permanently shadowed regions at its poles that never see sunlight and thus enables ice to exist on its floor. 
• Mercury’s ancient, cratered surface shows signs of past volcanic and tectonic activity and is heavily weathered by the harsh space environment. 
• The planet has huge impact basins, including the Caloris Basin, one of the largest impact features in the solar system. 
• Mercury has a large iron-rich core, which occupies a substantial portion of the planet’s interior. 
• Its closeness to the Sun and its smallness make it the most elusive of the planets visible to the unaided eye. 
• NASA’s MESSENGER spacecraft became the first spacecraft to orbit Mercury, entering orbit in 2011 and studying the planet until 2015. 
• The BepiColombo mission, a joint mission of the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA), is studying Mercury and is expected to enter orbit in 2026. 

‹ ›

Planet Mercury Facts

• Diameter: 4879 km (0.38 Earths, or 1.40 Moons)
• Surface area: 74.8 million sq.km. (0.147 Earths)
• Gravity: 3.7 m/s2 (38% of Earth’s gravity)
• Mass: 3.3 × 1023 kg (0.055 Earths)
• Density: 5430 kg/m3 (Earth: 5515 kg/m3). It is the second-highest in the Solar System after earth.
• Distance from Sun: 46001200 – 69816900 km (Earth: 149 597 900 km)
• Solar irradiance: 6272 – 14448 W/m² (Earth: 1366 W/m²)
• Day: 58 Earth days to turn once on its axis (Mercury rotation period); 176 days for the Sun to return to the same spot in the sky, as seen from a fixed point on the surface (Mercury solar day)
• Year: 88 Earth days to orbit the Sun (Mercury orbital period). It has the shortest orbital period of any planet. 
• Obliquity to orbit (axial tilt): 0.01° (i.e., the equator of Mercury nearly coincides with the orbital plane of the planet)
• Atmosphere: Very thin (<10–14 bar), including oxygen (42%), sodium (29%), hydrogen (22%), helium (6%), and trace gases
• Moons: None

News: IT