Since 1966, NASA has been landing the unmanned Surveyor probes onto the surface of the moon to collect data. In December 1968, NASA managed to get a manned spacecraft into lunar orbit with the Apollo 8 mission. The next goal to accomplish was to combine these feats in order to land a crewed spaceship onto the moon’s surface.
The Lunar Module seen from the Command Module. Credit: NASA
The first step was to find a suitable landing site. The Lunar Module would need to have a flat surface with no craters nearby. Additionally, the area would need to be well-lit enough at the time of landing. The approach would have to be clear so that the landing radar could work at its best. Finally, it would need to be at a location where landing and liftoff would use as little fuel as possible to make the return journey to orbit possible. Using images taken from the Lunar Orbiter satellites, the Apollo 8, and the Apollo 10 missions NASA narrowed down the number of possible landing sites to 5. After further investigation, the final landing site was chosen: The Sea of Tranquility.
Once Apollo 11 was in orbit around the moon, the Lunar Module detached from the Command Module and fired its engine to begin deorbiting. As it slowed its horizontal and vertical velocity, the Lunar Module used small thrusters to adjust its trajectory until it was hovering above the landing site. Then it slowly descended until it finally landed softly onto the lunar soil.
After the Apollo 11 mission, five other lunar landings occurred each more successful than the last. These missions helped build the foundation for NASA’s accomplishments over the past 50 years. Without the scientific and engineering breakthroughs of the Apollo program, our understanding of the universe would be vastly less.
During the 1960s, NASA had the daunting task of landing a person on the moon. When John F. Kennedy announced the goal to put a man on the moon by the end of the decade, they had only recently sent Alan Shepard into space for the first time. It would be another nine months before John Glenn would become the first American to orbit the Earth. NASA would need to perfect every step in just 8 short years. The first step is to reach the altitude of the moon. In order to get there efficiently, we must perform a maneuver known as a “Hohmann Transfer.” Designed to minimize fuel consumption, it allows us to build lighter, cheaper spacecrafts.
But once the spacecraft is headed to the moon, it will be going too fast to be fully captured by the moon’s gravity. At this speed, it will slingshot around it and head back to Earth. To insert itself into lunar orbit, the spaceship needs to slow down. The only way it can do this is by burning its rocket in the direction it’s flying. Once it’s burned for long enough, the speed of the rocket is low enough to establish a lunar orbit.
Both the US and the USSR had been trying to refine this technique since the late 1950s, with little success. Both nations had succeeded in getting impactors and landers onto the moon, but it wasn’t until November 1966 when NASA successfully put an unmanned craft into orbit. In December 1968, Apollo 8 would become the first manned spaceship to orbit the Earth.
Getting to lunar orbit was tricky, but once NASA engineers could consistently make the calculations correctly, they advanced to the next challenge – getting a manned lander onto the surface of the moon.
We can’t take our eyes off it, it helps control our tides, and wolves howl at it; can you name what “it” is? You probably guessed correctly, it’s Luna, also known as the moon! The moon is the largest satellite of Earth, and one of the only natural satellites. This means that there may be other satellites out there orbiting around Earth (thanks to space junk and our cell phone providers), but it is by far the largest and amongst the only that came from space to orbit our home planet. Our moon is also the brightest object in our night sky, so bright in fact that you can sometimes see it during the day. However, the moon seems to be constantly changing. How can that be possible?
To demonstrate what is happening, you can do an easy experiment at home. All you need is a single light source (representing the sun), your face (representing Earth), and a ball or your fist (modeling the moon).
Earth’s gravity has the moon tidally locked, meaning the same half of the moon is always facing Earth, and the other half is always facing away (the dark side of the moon). Since it is tidally locked, your model of the moon does not need to spin. All you have to do now is put your moon between your face and model of the sun and start to rotate counterclockwise (the same direction that Earth spins).
When the moon is between the sun and the Earth, light from the sun cannot reflect from the moon to Earth. This phase is called a “New Moon”. As you keep rotating you will first see a waxing crescent, then: the first quarter, waxing gibbous, full moon (Earth is between the moon and the sun), waning gibbous, third quarter, waning crescent, then back to New Moon. If you keep rotating the cycle will continue on and on. For our real moon this cycle will take about 29 days to be completed.
You can easily keep track of this cycle on your own as well. All you need to do is step outside each night and make some observations. Take note of what the day and time is, and what the moon looks like to you. Once you have done this for a couple of weeks you should be able to predict what you will see next! So go ahead, give it a try for yourself and have fun.
You may have heard about the solar eclipse that will be happening on August 21st. For just a few minutes, the moon will be in front of the sun, blocking its light and casting a shadow over parts of the earth. What do you need to know about the solar eclipse?
This is rare
Solar eclipses occur on the Earth about once every 18 months. That might actually sound pretty frequent, but there is also a lot of Earth. The shadow path from an eclipse is about 70 miles wide, so if you were to camp out in a lawn chair and wait from one eclipse to another, it would take (on average) about 360 years! This technique for observing this phenomenon is not recommended.
However, if you are captivated by the idea of seeing a solar eclipse, it doesn’t have to be a once in a lifetime event if you are willing to do some travelling. The motions of the earth and the moon are very predictable, so scientists have already figured out when (and where) eclipses will be for a very long time. The map below is an example of these predictions. As you can see, North America will see its next solar eclipse in 2024!
2. It’s not totally happening everywhere
This very much goes along with point number one. This particular eclipse will be sweeping the nation from Oregon to North Carolina. That path, known as the path of totality, is where the sun will appear to be completely covered but the moon. However, that doesn’t mean that if you are in another location like us, you’re totally out of luck.
Other areas will be experiencing a partial eclipse during this time. This awesome app will show you what you can expect from the eclipse in your location. At AstroCamp, we will definitely be checking out the eclipse even though we are almost 700 miles from the path. However, it’s important to have proper protections or techniques when viewing the eclipse, which brings us to point number 3.
The app linked above also has the time of the eclipse. At its longest, the eclipse will last 7 minutes, so don’t be late!
3. The dangers of staring at the sun
You have probably heard that it’s not a good idea to stare at the sun. As you have probably noticed, the sun is very bright. Having the moon block out half or more of the sun may seem like it makes it safe to look at, but it doesn’t!
Eclipse glasses are a piece of safety equipment used to view the sun. These glasses block out 99.997% of the light from the sun to make it comfortable and safe to view. Wearing these glasses around in a brightly lit room, the wearer literally can’t see anything. They are close to being complete blindfolds, until the sun comes into view. This cannot be emphasized enough: without these glasses, you should not be looking at the sun!
If you don’t have these glasses, you are not out of ways to view the eclipse. Through a very simple crafts project, you can view a projection of the eclipse on the ground or another screen. All it takes is getting a piece of paper (construction paper works well as its a bit sturdier) and poking a hole through the center. Then, by angling the paper towards the sun and looking at the small point of light in the center, you can view a projection of what is going on with the sun and the moon.
Here in Idyllwild, the sun will be 62% covered. However, due to the sun’s immense brightness, it won’t look dark outside. In fact, if you were to look at the sun (DON’T), it wouldn’t look any different. If you want to see what is happening with the sun, strangely, the best thing to do is look down. Try to find and look at the shadows from any small openings, like a hole made with your fingers, or those made from the leaves on a tree, you will notice something interesting: All of the shadows have little eclipses in them!
We would like to thank you for visiting our blog. AstroCamp is a hands-on physical science program with an emphasis on astronomy and space exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and astronomical happenings. This blog has been created by our staff who have at least a Bachelors Degree in Physics or Astronomy, however it is not uncommon for them to have a Masters Degree or PhD. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science, space and astronomy information. Feel free to leave comments, questions, or share our blog with others. Please visit www.astrocampschool.org for additional information. Happy Reading!