Dawn of the asteroids

Dawn of the asteroids

ABOVE: The Dawn spacecraft’s ion engine allowed for slow but steady acceleration in order to reach the asteroid belt. Image credit: NASA/JPL. By David Ellyard WE’VE KNOWN OF THE EXISTENCE of ‘minor planets’ or asteroids in the Solar System since the start of the 19th...
The search for Planet X

The search for Planet X

Above: Now classed as a dwarf planet, Pluto was discovered in February 1930 by Clyde Tombaugh. Image credit: NASA/JHU APL/SwRI/A. Parker. By David Ellyard AT A TIME WHEN WE ARE FINDING PLANETS by the hundred orbiting stars other than our own, it is worth recalling the...