Here I show the Earth in the deep future, when our technology has advanced to the point that we can clearly see it from orbit. Or perhaps it's a different planet elsewhere in the universe, somewhat like the Earth but having a greater technology than ...

We're going back several billion years here. The planet Earth had already started to form, when it was hit by a gigantic protoplanet roughly three times the mass of present-day Mars. As a result, debris was blown into Earth orbit. Some of the debris ...

This is a purely imaginary gas giant planet (green) shown with an Earth-like moon orbiting in close attendance. It is not yet known if habitable moons such as this can actually exist, though....

The near-Earth asteroids (NEAs) are those whose orbits cross that of our planet. It is these worldlets that pose the greatest threat to the Earth and its fragile biosphere. They have hit us in the past, and certainly will do so again....

We're going back several billion years here. The planet Earth had already started to form, when it was hit by a gigantic protoplanet roughly three times the mass of present-day Mars. As a result, debris was blown into Earth orbit. Some of the debris ...

An animation of the primitive Earth in the process of formation. We view the newborn world from its troubled surface – a sea of lava dotted with volcanoes spewing more lava, ash and smoke into the atmosphere. Meteorites fall frequently, illuminatin...

This is an alternative impression of the extrasolar planet Gliese 581c, which resembles the Earth but which is five times its mass. I show the planet as seen from one of two hypothetical satellites....

Another impression of the extrasolar planet Gliese 581c, which resembles the Earth but which is five times its mass. I show the planet with two hypothetical satellites and a system of rings....

This is Gliese 581 c, one of three planets orbiting the star Gliese 581. Gliese 581 c has garnered much attention because it is very small compared to virtually all other known exoplanets to date, at only 1.5 times the radius of the Earth and five ...

A diagram showing how the interaction of our atmosphere with the Sun's 'wind' produces the so-called magnetosphere....