Page 114 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

Is there sound in space?

ound exists as waves that travel through proof that Voyager 1 had left the heliosphere.
S air, but in space there’s no air through It picked up audible tones that were very low
which these waves can travel. However, in at around 300 hertz as it travelled inside,
2013 a NASA physicist announced that he thanks to bursts of plasma called solar
had recorded sounds in interstellar space. storms. Once the ship left the heliosphere
Don Gurnett used an instrument that and began travelling through interstellar
detects the electromagnetic vibrations that medium, the frequency changed to between
electrons make as they travel through two and three kilohertz because the gas
What would plasma. They aren’t sound waves, but they there is denser. So there is not true ‘sound’
do pulse at similar frequencies. Once the in space, but you can hear something if you
happen if the data was recorded and processed, it could have the right knowledge and
be heard as sound. Gurnett was seeking instrumentation.
ISS had to be

evacuated? How do we measure the distance

n case of emergency, astronauts on to galaxies?
I the International Space Station can
take refuge or return to Earth on board
the Soyuz escape capsules. One or two stronomers estimate the distances to
Soyuz spacecraft remain docked with A far-away galaxies by measuring the
the station at all times, with each brightness of their stars. The easiest way of
accommodating up to three people. doing this is to find a special type of star
Since the ISS’ launch in 1998, its crew called a Cepheid variable, whose brightness
have never had to make an emergency varies over time. US astronomer Henrietta
return to Earth. In January 2015, a Leavitt discovered over 100 years ago that
suspected ammonia leak forced the period of these fluctuations relates to
American astronauts to shelter Cepheid variable stars’ true brightness. By
temporarily in the Russian section of comparing the star’s true brightness to how
the ISS. Close encounters with space bright it appears from Earth, its distance
debris have also forced crew to move to can then be calculated. Edwin Hubble used
Soyuz as a precautionary measure three this method in 1923 to make the first
times, but no collisions occurred. accurate measurements of how far away
the Andromeda galaxy is.

114 How It Works