NASAのインスタグラム(nasa) - 5月16日 00時27分

In Case You Missed It: On May 9, 2016, Mercury passed directly between the sun and Earth. This event – which happens about 13 times each century – is called a transit. Our Solar Dynamics Observatory, or SDO, studies the sun 24/7 and captured the entire seven-and-a-half-hour event. This composite image of Mercury’s journey across the sun was created with visible-light images from the Helioseismic and Magnetic Imager on SDO.

Transits provide a great opportunity to study the way planets and stars move in space– information that has been used throughout the ages to better understand the solar system and which still helps scientists today calibrate their instruments.

Although Mercury whips around the sun every 88 days – over four times faster than Earth – the three bodies rarely align. Because Mercury orbits in a plane 7 degrees tilted from Earth’s orbit, it usually darts above or below our line of sight to the sun. As a result, a Mercury transit happens only about 13 times a century. The last one was in 2006, and the next one isn’t until 2019.

Image Credit: NASA/SDO

#nasa #space #astronomy #science #mercurytransit #solar #sun #mercury #solarsystem #planet #planets #orbit #shadow

[BIHAKUEN]UVシールド(UVShield) 更年期に悩んだら

>> 飲む日焼け止め！「UVシールド」を購入する