I’m going to try to rush over to the Dollar Store tonight at the Hideout. If you’re in Chicago, be there.

Parents loved this feature so much last time that I decided to bring it back.

Q: Dear Real-Life Scientist, my name is Kaitlyn and I am in the second grade at Harrison Elementary School. My teacher says that on the moon, we would only weigh half as much, so we could jump really high. That sounds like fun! Is it true?
-Kaitlyn S., Toledo, OH

Dr. Robert Pohler, Assistant Director of Aeronautics at NASA: Kaitlyn, your teacher is only half right. Gravity is a pull of force between two different objects. When you’re on Earth, the pull is big because Earth is very, very big. But the moon is smaller, so there is less pull between you and the moon– less gravity, and that means that you weigh less. In fact, you only weigh 1/6 as much as you do on Earth! You’re right, this would make for some pretty big jumps!
At least it would, if the astronauts had time to jump around. Instead, their time is used up doing all sorts of boring experiments on moon rocks. The rest of their time is taken up by fearfully reflecting on the horrible trip they have to make back to Earth, through fire and friction in the Earth’s atmosphere. Faced with a terrible ordeal which could very likely result a painful death and complete vaporization, they really don’t have much time to go bounding around, 1/6 weight or not.

Q: Dear Real-Life Scientist: I saw on TV that the nearest star to the Sun is 4 light years away. That seems like a long way! Do you think we’ll ever get there?
-Tommy P., Minneapolis, MN

Dr. Pohler: Yes, Tommy, four light years is a very, very long ways away. It means that it would take light (which is very, very fast) four years to get from here to there. We can’t move anywhere near the speed of light, and probably won’t be able to for the foreseeable future, so it would take us a very, very long time to travel from Earth to Proxima Centauri, the nearest star to our Sun.
There are theories being put forth about how we could make such a trip, however. Most of the plans involve huge living spaces, so that it would take one or more generations for a group to travel great distances. Because it takes so long, some scientists are thinking that we could send a Daddy and Mommy on a trip, and then their grandchildren or greatgrandchildren would arrive at the destination. Imagine, living your life trapped inside a spaceship in the inky blackness of space, never knowing anything besides metal and plastic in front of dark windows from birth until death! Horrifying prospect, indeed! Want to go to Proxima Centauri? Maybe we should send you, Tommy!

Q: Dear Real-Life Scientist: Last week I saw this scary movie that had a bunch of aliens in it. They shot a bunch of laser guns and killed lots and lots of people. I didn’t like it at all. Are there really aliens in space?
-Sarah R., San Diego, CA

Dr. Pohler: Sarah, you can rest easy. We at NASA have never found any evidence whatsoever of any extraterrestrial intelligence– aliens, in non-scientist speak. We’ve been to the moon plenty of times, we’ve been to Mars now twice, and we’ve sent probes into the farthest reaches of space, and we’ve never see any signs of any other beings anywhere. There are no aliens in the space that we’ve explored.
On the other hand, space is an infinite place, so it’s very likely that there could be millions and millions of civilizations and galaxies out there that we haven’t yet discovered. It’s very unlikely that humanity would be the only intelligent being in the entire universe, a place of such infinite possibility. And, considering humanity’s actions so far, and the seemingly inherent violence of the universe, any existing extraterrestrial intelligence would probably not be very benevolent at all. And of course, if their technology has advanced as much as we might suspect, it would be very hard for us to detect their advance, much less come up with any method of repelling it. In short, Sarah, if there are aliens out there (and, in all likelihood, there are), they probably hate you, and you won’t see them coming until it’s too late.

That’s all for today’s edition of A Real-Life Scientist Answers Your Questions! Have a good weekend, kids! Sleep tight!