2019 Planetary Positions
Venus (magnitude –3.9) shines brightly in the west-northwest during evening twilight and just after. It's nearly as high
as it will get all this spring and summer. In a telescope (look early!) Venus is a little disk 12 arc seconds wide and slightly
gibbous: 87% sunlit. Venus is currently traveling through Sagittarius.
Jupiter (magnitude –2.2, between the feet of Ophiuchus) is the white dot hanging in the south-southwest as twilight fades
away. Get your scope on it early before it sinks lower into poorer seeing. Orange Antares, much fainter at magnitude +1.0,
twinkles 7° to Jupiter's lower right. In a telescope, Jupiter is only 39 arcseconds wide and shrinking.
Saturn (magnitude +0.3, in Sagittarius) is the steady, pale yellowish "star" in the south-southeast during and after dusk, 30° left or upper left of
Jupiter. Below Saturn is the handle of the Sagittarius Teapot and currently moving retrograde through Capricorn.
Uranus (magnitude 5.7, in Taurus) is well up in the east by midnight and highest in the south before the beginning of dawn.
Neptune (magnitude 7.8, very close of 4th-magnitude Phi Aquarii this week) is well up in the southeast by 10 or 11 p.m. and highest in the south by 1 or 2 a.m.
Neptune is almost at opposition with the Sun, as it moves retrograde through Pisces.
Denser than the other gas giants, Neptune probably has ice and molten rock in its interior, although rotational data imply that these heavy materials are spread out rather
than concentrated in a small core. The atmosphere is swept by winds moving at up to 2,300 feet per second, the fastest found on any planet. At the equator, the winds blow
westwards (retrograde) and beyond latitude 50 degrees they become eastwards. Temperature measurements show that there are cold mid-latitude regions with a warmer
equator and pole.
Neptune's thirteen known moons include Nereid, with the most eccentric orbit of any planetary satellite, seven times as distant from the planet at its farthest compared with its closest approach; and
Triton, the only large moon in the solar system with a retrograde orbit, which is an orbit in the opposite direction to that of Neptune's.
The dwarf planet Pluto lies in northern Capricorn and is highest above the southern horizon just before dawn. Search for it under a dark,
moonless sky. Pluto glows atmagnitude+14, and as a result, it is a challenge to spot. An 8-inch telescope on a perfect night brings Pluto to
the edge of visibility. For a direct view, however, you will want touse at least a 10- inch scope.
Mercury is hidden in the glare of the Sun. Mercury is currently moving through Capricorn!
Mars and Saturn rise late at night, around 1:30 a.m. and midnight, respectively (daylight-saving time). They're on opposite
sides of Sagittarius, shining at magnitudes –0.5 and +0.3, respectively, with Mars on the lower left. Saturn is above the
Teapot. By early dawn they're higher in the south.