Brilliant planet Venus attains its greatest elongation almost 47° west of the Sun at dawn in the UK on Sunday, 6 January. Find a location that offers you a view down to the southeast horizon around 7am GMT and you may catch a glimpse of Jupiter too. The planetary duo is currently 14 degrees apart – about one-and-a-half spans of a fist at arm’s length – but drawing nearer for a close conjunction on 22 January. AN graphic by Ade Ashford.It currently pays to be an early riser if you wish to see some spectacular planetary activity. Even casual skywatchers cannot fail to notice dazzling Venus hanging like a lantern, brighter than any other natural nighttime object except the Moon, low in the south-southeast at the start of nautical twilight around 90 minutes before sunrise in the UK (see our interactive Almanac for local times).
Magnitude -4.4 Venus presently lies in the constellation of Libra, moving into Scorpius on 9 January. The planet has a disc almost 25 arcseconds across and currently appears exactly half illuminated — just like a miniature first or last quarter Moon (depending on your telescope view). At this time, a telescope magnification of just 75× enlarges Venus to the same size as the Moon appears to the unaided eye.
Venus attains its greatest elongation of 46° 57′ 22″ west of the Sun at 04:54 UTC (4:54am GMT) on 6 January. As seen from the heart of the British Isles, the brightest planet presently rises in the east-southeast close to 4:30am GMT some four hours before the Sun. At 7am GMT on 6 January, Venus lies 0.675 astronomical units, or 100.9 million kilometres from Earth, which is about 260 times farther than the Moon.
Some of the final results sent back by ESA’s Venus Express before it plummeted down through the planet’s atmosphere have revealed it to be rippling with atmospheric waves and, at an average temperature of -157 °C, colder than anywhere on Earth. The aerobraking experiment has improved our knowledge of our planetary neighbour and holds great promise for ESA’s forthcoming ExoMars mission.
NASA’s Cassini spacecraft has observed geysers erupting on Saturn’s icy moon Enceladus since 2005, but the process that drives and sustains these eruptions has remained a mystery. Now, scientists have pinpointed a mechanism by which cyclical tidal stresses exerted by Saturn can drive Enceladus’s long-lived eruptions.
On the evening of Monday, 30 May, Mars is closer to Earth than at any time since 30 October 2005. This begs the question: just how close can Mars get? Ade Ashford gives you an overview of close Martian oppositions past, present and future. Also, Friday, 3 June sees the opposition of Saturn, the other planet visible low in the south around midnight.
