The values of a, d and n are: 1  a = 1 (the first term) 2  d = 3 (the common difference between terms) 3  n = 10 (how many terms to add up)
Five planets will align in the predawn sky tomorrow, awakening Titans and office workers alike. Gulp. It must be time to unleash the Titans: five of the planets in our Solar System will align diagonally in the predawn night sky starting tomorrow morning. Mercury, Venus, Mars, Jupiter, and Saturn will all be visible with the naked eye starting January 20th and lasting until about February 20th. The last time a planetary party like this happened was in 2005. It's also slated to happen again later this year in August.
The Next Total Solar Eclipse in the U.S. Will Be August 2017. The next time the sun is completely eclipsed and viewable in the United States wonât be until August 2017. More specifically, according to NASA, it will take place on August 21, 2017. You should probably mark your calendars now! The total eclipse will only be viewable through a narrow corridor across the United States.