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.
Pluto’s day is 6.4 Earth days long. The dwarf planet’s largest moon, Charon, also rotates once every 6.4 days as the two worlds are tidally locked to each another. This sequence of images from the Long Range Reconnaissance Imager (LORRI) and the Ralph/Multispectral Visible Imaging Camera on NASA’s New Horizons spacecraft shows us full rotations of the two bodies.
Scientists with NASA’s New Horizons mission have assembled this highest-resolution colour view of Wright Mons, one of two potential cryovolcanoes spotted on the surface of Pluto by the New Horizons spacecraft in July 2015. The feature is 90 miles across and 2.5 miles high, which would make the largest volcano in the outer solar system.
The science team of NASA’s New Horizons mission has produced an updated global map of dwarf planet Pluto that includes all resolved images of the surface acquired 7-14 July 2015, up to 400 metres/pixel resolution. Many additional images are expected in autumn 2015 and these will be used to complete the global map.