Astronomers have discovered possible evidence for water on the surface of 16 Psyche, the largest metallic asteroid in the solar system. Measuring 186 miles across and consisting of almost pure nickel-iron metal, Psyche is thought to be the remnant core of a planetary embryo that was mostly destroyed by impacts billions of years ago.
Astronomers were watching when comet P/2016 BA14 flew close by Earth on 22 March at a distance of slightly more than nine times the distance of the Moon. Radar images from the flyby indicate that the body is about a kilometre in diameter, while infrared spectra indicate that the comet’s nucleus is as dark as fresh asphalt.
Somewhat appropriately spooky for Halloween in recent radar images, 600 metre-wide near-Earth object 2015 TB145 dashes by our planet today. Now believed to be a dead comet that has shed its volatiles after numerous passes around the Sun, the object makes its closest approach to Earth at 5pm GMT. UK observers with clear skies may see it with modest telescopes in the early evening.