To put things into a perspective, here are the moons of our solar system (including our moon) and their sizes compared to Earth.
Continue reading The Moons of the Solar System in Perspective
Are we alone in the universe? Or are there any other “living planets” other than Earth? Until 1992, we even don’t know if there are any other planets around the other stars or not. In 1992, two Swiss astrophysicists, Michel Mayor and Didier Queloz the first “exoplanet” (a planet orbiting another star than the Sun). Then discoveries continued. Especially after the launch of Kepler space telescope on March 7, 2009, which is a space observatory launched by NASA to discover Earth-size planets orbiting other stars, we quickly learned that our Solar System is not a rare phenomenon at all. As of November 2017, scientists have confirmed more than 3,500 exoplanets in more than 2,700 star systems. Now, the question is: are any of these planets (or the planets waiting to be discovered in the future) harbor life? If so, how we can find out? How to tell if a planet harbors life?
Currently, we have only one example: the Earth itself. Studying Earth and trying to figure out how we’d conclude the Earth harbors life from a distance (from space) can show us how to find out if a planet harbors life or not. Since 1997, NASA satellites have continuously observed all plant life at the surface of the land and ocean.
Continue reading Watch: How to tell if a planet harbors life?