Now that the Moon is a waning crescent rising after midnight, observers in the British Isles can take advantage of at least three hours of darkness from 9pm BST to track down Comet Africano (C/2018 W2) at its closest and brightest as it speeds through the constellations of Pegasus, Pisces and Aquarius.
At 10:56 UT on 27 September, C/2018 W2 (Africano) passes just 0.494 astronomical units, or 74 million kilometres (46 million miles) from Earth. At this time the comet is moving against the stars of Pegasus at a rate of 3⅔ degrees per day, equivalent to the width of the full Moon every 3¼ hours.
Discovered almost simultaneously on 27 November 2018 by B. M. Africano with the Mount Lemmon 1.5-metre reflector and H. Groeller with the Catalina Sky Survey’s 0.68-metre Schmidt telescope (Africano’s report was submitted just 21 minutes earlier), C/2018 W2’s integrated magnitude is currently about +9 and may peak at about +8.5 over the coming week. Note that Comet Africano lies within a binocular field of view of outermost planet Neptune on the night of 3–4 October.
Having passed perihelion (closest point to the Sun) on 5 September, don’t miss any opportunities to view C/2018 W2 because it’s visiting the inner planets on a hyperbolic trajectory, meaning that it will never return to the Sun – unless its orbit is perturbed by the gravitational influence of a body in the outer Solar System in the distant future.
Have you ever seen planet Uranus? If UK skies are clear on the evening of Sunday, 22 November, the icy gas giant lies just 1.5 degrees (or three lunar diameters) from the 11-day-old waxing gibbous Moon, making it very easy to locate in binoculars and small telescopes. Here’s our online guide to locating this fascinating distant world.
Currently setting over four hours after the Sun as seen from the heart of the UK and visible in the west-southwest at dusk, dazzling Venus is about to hit peak brightness in the constellation of Pisces. The planet attains magnitude -4.8 on Friday 17 February — some 21 times the luminosity of brightest star Sirius gracing the southeast horizon as darkness falls.
Astronomers using the NASA/ESA Hubble Space Telescope have conducted the first search for atmospheres around temperate, Earth-sized planets beyond our solar system. They found indications that increase the chances of habitability on two exoplanets known as TRAPPIST-1b and TRAPPIST-1c orbiting a red dwarf star approximately 40 light-years away.