¡SkyCaramba! Weekly astronomy blog for the week ending April 18, 2015
Venus and Mercury both happen to be very close to the sun this coming weekend. Both inner planets will be at perihelion the weekend of April 18-19. Venus is first. Then Mercury.
For an object orbiting the sun, perihelion is the point when it’s closest to the sun. All the planets, asteroids, and comets orbiting the sun go through perihelion once per orbit. Also once per orbit, they go through aphelion which is a point that’s farthest from the sun.
Since our calendar is tied to our planet’s orbit around the sun, Earth goes through perihelion on or about January 3 every year and aphelion on or about July 3. The other planets’ perihelions and aphelions could occur on any date though. Jupiter last went through perihelion on March 18, 2011 and will do so again on January 20, 2023. Mercury goes through perihelion four times in 2015 and Venus does twice.
By coincidence Venus goes through perihelion on April 18 and Mercury the next day. Venus will be about 107,000,000 kilometers from the sun. Mercury will be 46,000,000 kilometers away. At their farthest from the sun, Venus is ...