Jupiter comes to opposition in April and now rules our night sky. Also at its best is Mercury, while comet 41P/Tuttle–Giacobini–Kresák appears as an inflated greenish hazy blob as it sweeps between the Plough and Polaris – our previous Starwatch carried details and a chart.
This time our maps show the Plough in the zenith as Leo crosses the meridian and Vega in Lyra begins its climb in the NE. Meteors of the Lyrids shower radiate from a point to the right of Vega between the 18th and 25th. Up to 18 meteors per hour might be glimpsed near maximum on the 22th, all of them swift and some leaving glowing trains.
Jupiter moves from low in the E at nightfall to its highest in the S in the middle of the night and onwards to sink in the W before dawn. When it stands opposite the Sun on the 7th, it is at its closest (666 million km) and brightest (mag –2.5). Lying above and to the right of Spica in Virgo, the giant planet is edging westwards close to the 4th mag star Theta Virginis. Telescopes show it to be 44 arcsec wide when it stands close to the Moon on the 10th.
Venus, brighter at mag –4.2 and a large crescent through binoculars, rises only one hour before the Sun to blaze very low down in our E morning twilight. The other inner planet, Mercury, is an evening star which shines at mag 0.0 and stands 12° high in the W 30 mins after sunset on the 1st. By the 8th, though, it is one quarter as bright at mag 1.6 and stands 2° lower as it begins to dive towards the Sun’s near side, so catch it while you can.
Mars is also sinking into our evening twilight, in its case towards the Sun’s far side. At mag 1.5, it stands some 15° above-left of Mercury and tracks from Aries to pass 4° S of the Pleiades on the 20th and between the cluster and Aldebaran late in April when our chart plots it on our NW horizon. The young earthlit Moon lies close to Aldebaran and 9° left of Mars on the 28th.
Saturn, mag 0.4 to 0.3 in Sagittarius, rises in the SE in the early hours to become the brightest object low in Britain’s S sky before dawn.
1st 11h Mercury furthest E of Sun (19°)
3rd 20h First quarter
6th 06h Saturn stationary
7th 06h Moon 0.7° S of Regulus; 23h Jupiter at opposition
10th 22h Moon 2.2° N of Jupiter
11th 07h Full moon
16th 19h Moon 3° N of Saturn
19th 11h Last quarter
20th 07h Mercury in inferior conjunction; 13h Mars 4° S of Pleiades
22nd 13h Peak of Lyrids meteor shower
23rd 19h Moon 5° S of Venus
26th 13h New moon
28th 08h Moon 6° S of Mars
28th 19h Moon 0.5° N of Aldebaran
* Times are BST