Nothing like it has ever been seen before. The unusual space rock 'Oumuamua is so intriguing mainly because it is the first asteroid ever detected from outside our Solar System -- although likely many more are to follow given modern computer-driven sky monitoring.

Why do many galaxies appear as spirals? A striking example is M101, shown above, whose relatively close distance of about 22 million light years allow it to be studied in some detail. Recent evidence...

Did you enjoy the moonlight last night? The Full Moon closest to autumnal equinox and the beginning of Fall is traditionally known as the Harvest Moon, rising opposite the Sun and illuminating fields at harvest time after sunset. This year's northern hemisphere autumnal equinox occurred yesterday, September 23rd, at 03:09 Universal Time.