On Sunday, 26 May at 21:17 UT, 1 Ceres, the nearest and brightest of the dwarf planets and the largest minor planet inside the orbit of Neptune, passed closest to Earth for this year. At this instant, Ceres was 1.7513 astronomical units, or 262 million kilometres (162.8 million miles) from our planet.
Ceres presently lies in the constellation of Ophiuchus, the Serpent Bearer, but the dwarf planet’s westerly motion relative to the stars carries it into Scorpius on 29 May where it resides until 22 June.Ceres reaches opposition close to 12am BST on 29 May and shines at its peak magnitude of +7.0 for 2019, fading to +7.8 by the end of June, hence it’s a comfortable binocular or small telescope target — if you know exactly where to look. Click here for a printable PDF version of the finder chart at the top of the page.
As viewed from the UK, Ceres is currently highest in the sky close to 1am BST, or by 10:30pm BST at the end of June, when the dwarf planet is just 18 degrees high in the south as seen from the centre of the British Isles.
Ceres is also occulted (hidden) by the Moon on 15 June as seen from Russia (central and east), Kazakhstan (northeast), China (north and east) and Japan.
Within Pluto’s informally named Vega Terra region is a field of eye-catching craters that looks like a cluster of bright haloes scattered across a dark landscape. NASA’s New Horizons spacecraft has revealed that the floors and terrain between the craters show signs of water ice, but exactly why bright methane ice settles on these crater rims and walls is a mystery.
Look low to the south-southeast at 11:35pm BST tonight and, if the current British “monsoon” clears, you will see the full Moon rising at dusk at the instant the 2016 summer solstice occurs in the Northern Hemisphere. The last time that this happened on the same UK day was 22 June 1967.
Observers in Western Europe with a clear view to the south-southeast at nautical dawn can watch the changing configuration two prominent naked-eye planets over the next few mornings, culminating in a beautiful close conjunction of Venus and Jupiter on 22 January 2019.