Skywatchers in the UK and Western Europe should look low in the southern sky at 12am local time on 17, 18 and 19 June to see the waxing gibbous Moon in the vicinity of planets Mars and Saturn, plus first-magnitude star Antares in the constellation of Scorpius. This looping animation shows the passage of the Moon through this region of sky at the stated times for an observer in the centre of the British Isles. For scale, the view is 40 degrees wide, or twice the span of an outstretched hand at arm’s length. Note that the Moon’s size has been slightly enlarged for clarity. Click the graphic for a full-size version. AN animation by Ade Ashford.In an earlier post, I drew your attention to the Moon‘s close approach to Jupiter at dusk on 11 June, essentially the planet’s swan song of this apparition. Six nights later, the Moon’s orbital motion brings it between two prime-time planets: Mars and Saturn.
The Red Planet was closest to Earth at the end of May (see this story for the details), so it is still at its best during 2016, despite the very low altitude as seen from the UK. Currently highest in the sky due south at dusk, ochre-colour Mars is shining at magnitude -1.8 — brighter than any star.
This labelled computer-generated map of the Red Planet obtained through our interactive Mars Mapper app shows the Martian hemisphere facing Earth mid-June at around 11:30pm BST. The map has south up and east to the right. Click the graphic to launch Mars Mapper in a new window. AN graphic by Ade Ashford.Late into the night of Friday, 17 June, when the gibbous lunar disc is close to Mars, the planet has an angular diameter slightly less than 18 arcseconds. This means that the Red Planet requires a telescope magnifying 100x to enlarge it to the same size as the Moon appears to the unaided eye. You can use our interactive Mars Mapper to help identify Martian surface features. Note that the planet’s prominent v-shaped Syrtis Major is well placed mid-month for observers in the British Isles.
Ringed planet Saturn was at opposition on 3 June, so it is still at its closest to Earth for the year. Like Mars, the planet’s low altitude as seen from the UK will mean that poor seeing will make observations challenging, but on slightly misty nights when a high pressure weather system sits overhead, the jewel of the planets is still an arresting sight. At 18 arcseconds in diameter, Saturn’s disc is currently fractionally larger than Mars, while the northern aspect of its 42-arcsecond-wide ring system is prominently displayed.
Inside the magazine
Find out all you need to know about what is currently happening in the night sky and how to observe it in the June 2016 edition of Astronomy Now.
Phenomenally durable crystals called zircons are used to date some of the earliest and most dramatic cataclysms of the solar system, such as the late heavy bombardment that created hellish surface conditions on the young Earth and Moon about 4 billion years ago. Now a study of zircons from a gigantic meteorite impact in South Africa casts doubt on the methods used to date lunar impacts.
A thrilling ride is about to begin for NASA’s Cassini spacecraft. Engineers have been pumping up the probe’s orbit around Saturn this year to increase its tilt with respect to the planet’s equator and rings. And on 30 November, following a gravitational nudge from Saturn’s moon Titan, Cassini will enter the first phase of the mission’s dramatic endgame.
High Resolution Imaging Science Experiment – HiRISE – camera aboard NASA’s Mars Reconnaissance Orbiter captured this intriguing view of “corduroy” dunes on Mars permanent polar cap, an image seemingly as much art as science.
