A trajectory is the path followed by a moving object. An example of this is the path that Apollo 11 took from the Earth to the moon. Apollo 11 was the first ever spaceflight that landed humans on the moon. This was designed to be a free-return trajectory, meaning the gravity of the moon allowed the space shuttle to return to Earth without any propulsion. In the top image to the left, the larger circle represents the Earth and the small one represents the moon. These are both scaled accurately with the moon being 27% the size of the Earth, while the exact path is not to scale.
The Saturn V rocket launched from Kennedy Space Center on July 16, 1969. After liftoff, one and a half orbits were taken around the Earth. Then the orbit was broken and the space craft headed for the moon. On July 19 lunar orbit was entered. Astronaut Michael Collins remained aboard the Command Module Columbia, while astronauts Buzz Aldrin and Neil Armstrong took the lunar module to the surface.
The astronauts touched down on the moon on July 20. To hear the moment of the landing, click on the audio clip to the right. The astronauts spent just over 21.5 hours on the surface. Their entire roundtrip journey lasted just over eight days.
Want to learn more? Check out this official NASA Apollo 11 flight plan
The Apollo 11 Mission
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Moon Phases
The phases of the moon are caused by a different portion of the lit side of the moon facing the Earth. As the moon orbits the Earth, a different portion of the sunlit side faces our planet. At a new moon, none of this side of the moon is visible. This results in a completely black moon in the night sky. At the full moon, the entire sunlit side is visible.
As the moon transitions from new moon to full moon, it is refered to as waxing. The sunlit side is becoming more visible. As the moon transitions from full moon to new moon it is refered to as waning. The sunlit side is becoming less visible.
All of the phases of the moon are listed to the left. Each phase lasts about 7.4 days. The lengths vary slightly because of the moon's orbit's slightly elliptical shape.
Photo by Andonee
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The Voyager Golden Records
When it was launched in 1977, the Voyager 1 was simultaneously a scientific probe, time capsule, and message to any intelligent species in the the far reaches of the universe.
On the probe was a golden record containing important information about Earth and humanity including photos, recordings of world leaders and even instructions on how to build a machine in order to get the information off of the record. One of the leaders of the comitee that decided on the contents of the record was famous scientist and science educator Carl Sagan.
The necklace was specifically designed after the image you can see on the photo of the golden record to the right (Credit: NASA).
While you might not be going on an interstellar space mission anytime soon, the Voyage Beyond Necklace, modeled after Voyager 1's golden record, will give you the chance to serve as mankind's envoy where ever life takes you!
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Life as an Astronomer
Check out our feature on Ata Sarajedini, Astronomer, Professor and Associate Dean of Liberal Arts and Sciences at the University of Florida.
Hear about his experiences doing everything from groundbreaking observing to using the Hubble Space Telescope and even how he got into astronomy!