行星

水星

The smallest planet and the closest to the Sun, with the most eccentric planetary orbit.

NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

The smallest planet, where one day from sunrise to sunrise lasts two whole Mercury years.

Mercury's grey, cratered horizon. — Mercury's cratered limb, seen by NASA's MESSENGER spacecraft. Credit: NASA

Mercury is a rocky world only slightly larger than our Moon. It has almost no atmosphere, so its surface swings between about 430 °C by day and −180 °C at night.

It spins exactly three times for every two orbits around the Sun, so one solar day (sunrise to sunrise) lasts two Mercury years. Its large iron core makes it the second densest planet after Earth.

探索它在orery

数据来源

关键事实
直径	4,879 km	[1]
质量	3.301 × 10²³ kg	[1]
密度	5.429 g/cm³	[1]
表面重力	3.7 m/s²	从数据集衍生
逃逸速度	4.25 km/s	从数据集衍生
自转(恒星)	58.6天	[1]
白天的长度	176天	[2]
軌道週期	88天	[3]
轴向倾角	0.034°	[2]
平均温度	167°C	[2]
已知衛星	0	[2]
距离太阳的平均距离(半长轴)	0.3871 au	[3]

工具和课程仅使用简化模型进行学习,不得用于导航、飞行任务规划或任何操作决策。证书是免费的且无认证。阅读教育内容免责声明