Our Solar System

Planets of Our Solar System

The Limits of Our Solar System

The heliosphere is the bubble the Sun carves out of the interstellar medium. The solar wind moves outward at supersonic speeds and carries with it the Sun’s magnetic field. The interstellar medium is also moving at supersonic speeds and carries with it the interstellar magnetic field. The boundary between the solar wind and the interstellar medium is called the heliopause. Before these plasmas ...

What can exoplanets tell us about our Solar System ?

We update our analysis of recent exoplanet data that gives us a partial answer to the question: How does our Solar System compare to the other planetary systems in the Universe? Exoplanets detected between January and August 2002 strengthen the conclusion that Jupiter is a typical massive planet rather than an outlier. The trends in detected exoplanets do not rule out the hypothesis that our So...

Less Likely Places to Find Life in Our Solar System

The Moon is the closest astronomical object to the Earth, and the only one on which we can see significant surface features with our naked eyes (the Sun is too bright, and everything else is pointlike or, like the Andromeda galaxy, too dim). As a result, it has from time immemorial inspired many fanciful notions, including that the Moon is inhabited. In fact, life on the Moon was the subject of...

Searching for Extraterrestrial Technologies Within Our Solar System

We speculate about possible cosmic exploration by extraterrestrial civilizations using interstellar smart probes. We call attention to some emerging technologies that may be used for interstellar exploration. We estimate that advanced civilizations may already have these technologies and may be using them to contact their galactic neighbors. We explore some observational consequences of these c...