The Moon waxes through first quarter to gibbous this week, passing Jupiter and Saturn along the way. And by the end of twilight, Jupiter-bright Mars glares low in the east. It's big, bold, and almost at opposition!
Jupiter and Saturn continue shining nearly level in the south at dusk. Meanwhile, the stars show the changing of the seasons: Just after nightfall, Cassiopeia has climbed higher in the northeast than the Big Dipper has sunk in the northwest.
Vega passes the zenith in late twilight. Vega is bigger, hotter, and 50 times brighter than our Sun. But at a distance of 25 light-years, it's 1.6 million times farther away. Jupiter and Saturn still dominate the south at dusk. And fiery Mars, close and almost Jupiter-bright, rises in the east around the end of twilight. It's at its highest and telescopic best in the south around 3 a.m. daylight-saving time.
Betelgeuse is dimming again. . . somewhat. After its historic fade last winter to magnitude +1.6, Orion's red supergiant Betelgeuse fully recovered, to +0.4, before it disappeared into the sunset for the season. But now as it emerges low in the east before dawn, it seems to have faded back…
Jupiter and Saturn line up level in the south earlier in the evening now, as summer proceeds. How early in twilight can you see them both? High upper left of them shines Altair. As night comes on, look for the Sagittarius Teapot to Jupiter's lower right.
It's Perseid meteor week! The shower peaks on the night of August 11th, but you may see the occasional Perseid any night and perhaps already have. Jupiter and Saturn shine in the southeast after dark. Bright Vega passes closest to overhead around 10 or 11 p.m.
Jupiter and Saturn rise in twilight this week. Mars is a fire-beacon high in the southeast by the beginning of dawn. Venus, low as dawn begins to brighten, passes just 1° from Aldebaran on Saturday and Sunday mornings July 11th and 12th.
Leo the Lion is mostly a constellation of late winter and spring. But he's not gone yet. As twilight ends look due west, somewhat low, for Regulus, his brightest and now lowest star: the forefoot of the Lion stick figure. The Sickle of Leo extends upper right from Regulus. The rest of the Lion's constellation figure extends for almost three fists to the upper left, to his tail star Denebola, the highest. He'll soon be treading away into the sunset.
As we count down the days to official summer (the solstice is June 20th), the big Summer Triangle shines high and proud in the east after dark. Its top star is bright Vega. Deneb is the brightest star to Vega's lower left. Look for Altair farther to Vega's lower right.
FRIDAY, JUNE 5 ■ Catch Mercury in twilight! It's under Pollux and Castor this week, as shown below. Mercury is ending its last good evening showing until winter 2021. Mercury is still visible in the western twilight, under the heads of Gemini, but it's fading. This scene is drawn for…
Bright Capella is still up in the northwest in twilight, but it sets in the northwest fairly soon after dark. That leaves Vega and Arcturus as the brightest two stars in the evening sky. Both are magnitude 0. Vega shines in the east-northeast. Arcturus is very high toward the south.
Venus is a super-thin crescent as it plunges down to the sunset horizon this week. Bring out the telescope and/or binoculars. Mercury, also in the western evening twilight, is a tiny "half Moon" with a much less intense surface brightness.