Alien Life The SETI Institute is after alien signals. Assuming another world is beaming a 1-million-watt radio signal in our direction, how far away can that source be before the signal is lost in intergalactic noise?
Exoplanets, Planets, Solar System Is Jupiter’s Moon Amalthea ever visible in amateur instruments? If so, what aperture and magnification are needed, and when is a good time to try?
Stars I read that once every second, somewhere in the universe a massive star ends its life as a supernova. How does that compare to the rate of new star formation?
Exoplanets, Human Spaceflight, Planets, Robotic Spaceflight, Solar System Why won’t the new Horizons spacecraft stop or slow down when it gets to Pluto?
Human Spaceflight Why doesn’t the International Space Station rotate to create artificial gravity like stations in the movies?
Exotic Objects, Stars If a supernova’s original star is massive enough to form a black hole, why is there any explosion? Why doesn’t the entire mass of the original star simply fall onto the newly formed black hole and instantly vanish?
Exoplanets, Planets, Robotic Spaceflight, Solar System How does NASA navigate a Mars rover’s direction and determine its location with the planet having no global magnetic field?
Exotic Objects, Stars I’ve read that the gas ejected during supernova explosions glows at millions of degrees; I also have read that gas is tenuous. How would a million-degree gas feel physically? Would I vaporize while flying through such a cloud?
