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.
A team of scientists has documented atmospheric changes on Io, Jupiter’s volcanically active satellite, as the giant planet casts its shadow over the moon during daily eclipses. Io’s thin atmosphere collapses as the sulfur dioxide gas emitted from volcanoes freezes when shaded by Jupiter. The atmosphere reforms when Io moves out of eclipse and the ice sublimates.
Dazzling Venus and much fainter Mars have a close encounter with a young Moon in the constellation of Pisces at UK dusk on Tuesday 31 January. The trio form an equilateral triangle small enough to be encompassed by the field of view of a 7x binocular low in the west-southwest for a couple of hours from 7pm GMT.
Setting up post at the king of planets, NASA’s Juno spacecraft fired its main engine for 35 minutes Monday, steering into orbit around Jupiter to peer inside the gas giant and give scientists a better idea of how the solar system took shape 4.6 billion years ago.
