Today’s questions about space are a little bit less about standing on the ground looking up, and a bit more about getting into space ourselves. The answers are brought to you by AC, who is not an astronaut, despite wanting to be one until about year 10, when she realised she was going to be too short. (Who knew there were height limits on rockets?). Also, Australia STILL doesn’t have a space program, which she finds really annoying…
What do you do when a spacecraft or something in space is broken or slightly damaged? – Anna, 11
Fix it! Depending on what it is that can be relatively straightforward (if it’s inside) or involve a very carefully planned series of steps if a spacewalk is required. All external repairs are planned in a meeting with people on earth before anyone leaves the space station.
Astronauts (and cosmonauts) do a lot of training. Many – though not all – have engineering degrees. practice fixing things before they go into space – they do “spacewalks” in the suits in a giant pool to get used to working in them, and practice changing and mending things that are part of the space station systems so they know what to do. The aim of this is of course so that if something does go wrong in space they don’t panic but can rely on their training and practice to come up with solutions.
Depending on what the thing that is broken/damaged is they may try fixing it by welding or replacing it. I suspect they occasionally try thumping it, but never having been in space I can’t be certain about that. Some things are obviously a lot easier to fix than others – something that is shielding the space station from solar radiation obviously can’t just come off so you can replace it – you have to go outside and do it, which involves a lot of safety measures.
Because the International Space Station stays in space the astronauts living there do also maintenance on the inside of the station to make sure that nothing breaks, as well as doing house cleaning to keep the systems in good working order. While they try to have tools available to fix things on the space station the astronauts have made required tools out of things that are available – such as duct tape!
How can there not be any gravity in space, but more on earth? – Vihaan, 8
Strangely enough there is actually gravity in space – it’s just much weaker than the gravity we feel on earth. When you are very close to a large body such as earth, the moon, the sun or other planets, then you can feel the effects of gravity quite easily. On earth, we’re all used to falling if we jump off the edge of the pool into the water for example. It’s easy to tell that we’re falling – air whooshes past you, the water seems to come towards you and then you splash into it.
In space you firstly don’t have those kind of cues, and secondly the further you are away from large bodies the less you notice the effects. You are still “falling” towards the local source of the gravity (for astronauts that is mostly either earth or the moon) but much more slowly than you would be on the surface or even in the planet’s atmosphere. Satellites and the space station which are orbiting the planet are actually “falling in circles” – but missing hitting the earth because planets are very small (galactically speaking). So instead of coming inwards they loop around.
Occasionally a satellite does actually fall to earth – at this point the loop has actually come close enough that the gravity is stronger and the pull towards earth much stronger, and so it stops falling in large orbital circles and instead starts falling in much smaller circles until it hits earth (or burns up due to the atmosphere, sometimes both).
Have many other planets been discovered? – Tom, 8
Is there a higher or lower chance of having life on other planets? -Douglas, 8
Yes! As well as the ones in our solar system (and Pluto depending on who you ask), planets have also been discovered orbiting other stars. Currently there are over 4,000 known planets that have been found, of which about 60 so far may be habitable in the terms that we understand, which is basically close enough to their sun to have liquid water and heat but not so close that the water evaporates or so far away that it freezes. (In our solar system the planets fitting that description are Earth and Mars).
The closest habitable planet is about 12 light years away – or 113,500,000,000,000,000 km! As to whether there is a higher or lower chance of finding life on other planets – no one is really sure, but certainly if the conditions that allowed life to develop on Earth are similar to other planets then there is a good chance that it could happen again.
My question has a scientist ever seen a UFO? – Sienna, 8
Are aliens real? – Ethan, 8
Many scientists have seen UFOs – however generally speaking they stop being “unidentified” and become “identified” flying objects as someone works out what they are. Things like ball lightning (which looks like glowing spheres), strange blips on the radar screen (could be kites or drones, once turned out to be a person sitting in a deckchair attached to helium balloons), and unexpected lights in the sky are all investigated and have in the main been identified.
Are aliens real… well, there are still unidentified objects (officially so at least – the Cold War in particular had a lot of UFOs that were secret tests of new aeroplanes etc), and we know of 60 planets so far that could have life. So it’s not impossible – but they are still a very long way from us, and with our current technology we won’t be able to find out for sure very easily.
AC has been a member of Team WEHI since 2018. She has previously worked as a research assistant in cancer biology, bio production of vaccines in plant systems, on clinical trials investigating earlier detection of infection in cancer patients, and in trying to encourage scientists and medical staff to work together in medical research (which is tricky when they speak different work-related languages). She has now moved out of the laboratory to a science-adjacent field, helping scientists apply for research funding. She honestly thought there would be space tourism by now, but here we are in 2021 instead.
Team WEHI Relay for Life 