National Aeronautics and Space Administration

Goddard Space Flight Center

Sun-Earth Day 2010: Ancient Mysteries, Future Discoveries


Amateur Astronomers

Greetings, greetings fellow stargazers;

This year's Sun Earth Day pays homage to the astronomers of today and honors the contributions of astronomers of ages gone by. Our understanding of the universe is on a break neck pace today, powered by exponential advances in new and amazing technologies. But there was a time when the only instruments at astronomers' disposal were their eyes. Visual, naked eye astronomy still has much to offer and, if given a chance, can still inspire a sense of wonder, awe, and respect for the universe above.

For Sun Earth Day, 2011, your task is to hold a visual astronomy event for the public or a local school - no telescopes (I know that sounds harsh but bear with me...). The event should highlight at least one sun theme such as the analema, ancient solar alignment monuments, the timing and definition(s) of sunrise and sunset, eclipses, the equation of time, solar vs. lunar calendars, sun dials, and the reason for the seasons to name just a few possibilities. Of course, naked eye astronomy also includes stars and constellations, observation of lunar and planetary motions, and the Milky Way, so don't forget these after sunset!

Send us pictures of your event and we'll post them on the Sun Earth Day web site with proper attribution. Then download your NASA Sun Earth Day Certificate of Completion.

And remember to: Keep Looking Up!*

* With acknowledgement and thanks to Star Hustler / Star Gazer, Jack Horkheimer (1938 - 2010), who hosted the world's first and only weekly TV series on naked-eye astronomy for over 30 years and 1,708 episodes, since it first aired in 1976. Jack passed away August 20th at the age of 72. He would always begin his shows with "Greetings, greetings fellow star gazers" and would always end them with his now famous words of encouragement to "keep looking up!".


A total solar eclipse is not noticable until the Sun is more than 90 percent covered by the Moon. At 99 percent coverage, daytime lighting resembles local twilight.