50 years on: Five moon mission facts that'll still wow you

50 years on: Five moon mission facts that'll still wow you

On the 50th anniversary of humanity’s first walk on the moon, we asked a physicist, former astronaut trainer and all-round space nerd to shares her favourite lunar factoids.

Dr Gail Iles from RMIT University's School of Science was once an astronaut instructor at the European Astronaut Centre in Germany.

She holds awards for her time spent experimenting in zero gravity, and awards for inspiring children, particularly girls, to study STEM subjects.

Iles is mad about space, and her enthusiasm is contagious.

“Space is so fascinating that I find it surprising how little people actually know about what we’ve done up there, the things we’ve learnt and how we managed to achieve the seemingly impossible,” she says. 

Now a lecturer in Physics at RMIT University, Iles is leading the new Bachelor of Space Science degree, starting 2020.

These are her five favourite facts about the Apollo moon missions.

credit: A Le Floch Dr Gail Iles completing experiments on a zero-gravity scientific flight for the European Space Agency. Credit: A Le Floch.

1. Apollo 11 astronauts knocked their own flag over

The famous US flag planted by Neil Armstrong and Buzz Aldrin in 1969 was knocked over by their rocket blast as they left the moon to return to earth. Buzz Aldrin says he saw it happen. 

One of the most iconic flags of the 20th century, left lying there in the lunar dust. Many believe it may have been completely obliterated. Whoops!

The Americans later left another five flags behind on the moon. 

Whatever's left of the six flags - if they're not completely disintegrated - many believe the cloth would now be bleached white after 50 years of pure unfiltered sunlight.

Buzz Aldrin salutes the first American flag erected on the Moon, July 21, 1969. Credit: NASA.

2. Mirrors on the moon are how we measure its distance

Retroreflectors left on the moon in 1969, and more on subsequent moon missions, are still used today to measure the exact distance between the earth and the moon.

Scientists shoot powerful laser beams at them from earth, while a high-speed clock measures the time it takes the beam to travel there and bounce back, thus calculating the exact distance.

At the time of writing this, the moon was exactly 369,656.661 km away from earth! 

Oh, and there’s an app for that. It's called Phases of the Moon, and it’s free.

Lunar retroreflector left on the moon during the Apollo 11 mission. Credit: NASA.

3. A hammer and feather dropped in space fell together.

At the end of the last Apollo 15 moon walk, in 1971, astronuat David Scott performed a live demonstration for the TV camera.

It came to be known as the 'the Apollo 15 Hammer-Feather Drop'.

Scott held out an aluminium geologic hammer and a falcon's feather, then dropped them both at the same time.

Because they were essentially in a vacuum, there was no air resistance and the feather fell at the same rate as the hammer.

It demonstrated what Italian astronomer Galileo Galilei had concluded well over 300 years earlier: that all objects released together fall at the same rate regardless of mass. 

4. Moonquakes are real 

Astronauts in the Apollo 11 mission detected lunar "moonquakes" after installing the Passive Seismic Experiment on the moon in 1969. 

This experiment studied the movement of seismic waves through the moon and provided our most detailed look at the moon's internal structure. 

The Apollo 11 seismometer returned data for just three weeks but provided a useful first look at lunar seismology.

More advanced seismometers were deployed at the Apollo 12, 14, 15, and 16 landing sites and transmitted data back to earth until September 1977. 

Buzz Aldrin with the seismic experiment during the Apollo 11 mission in 1969. Credit: NASA.

5. Moondust makes you sneeze 

The Apollo astronauts ran into many problems due to the very fine dust on the moon. 

The full-colour photo here shows how everything, including the astronauts, got covered in the fine grey dust.

The dust is composed mainly of silicates (glass) and alumina (ceramic) – both abrasive and very damaging to the spacesuits, spaceboots and spacecraft. 

Harrison Schmitt – the only civilian and scientist of the 12 Apollo astronauts - had a severe allergic reaction to the dust when he took off his helmet once back in the lunar module. 

Solving problems related to this dust is one of the main challenges delaying our return to the moon

Geologist-astronaut Harrison “Jack” Schmitt collects lunar rake samples during an Apollo 17 moonwalk. Credit: NASA.
Interested in learning more about space? RMIT's new Bachelor of Space Science covers physics, geospatial science and engineering. It includes special courses on space exploration, satellites and space debris, microgravity and rocket science.

Story: Michael Quin


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