Your daily digest of celestial events coming soon to a sky near you.
Everyone’s favorite dwarf planet glows at 14th magnitude in Sagittarius, close to magnitude 3.5 Xi2 (ξ2) Sagittarii.
Astronomy: Rick Johnson
Friday, August 28
Although NASA’s New Horizons spacecraft is now tens of millions of miles beyond Pluto, the distant world remains at the top of many amateur astronomers’ observing lists. Fortunately, Pluto reached opposition and peak visibility in July, so it is still a tempting target during the evening hours. It glows dimly at magnitude 14.1, however, so you’ll need an 8-inch or larger telescope with good optics to spot it visually. Pluto currently lies in northern Sagittarius, some 0.6° west-northwest of magnitude 3.5 Xi2 (ξ2) Sagittarii.
Saturday, August 29
Full Moon arrives at 2:35 p.m. EDT. It rises in the eastern sky minutes before the Sun sets and reaches its peak in the south around 1 a.m. local daylight time. The Moon lies among the background stars of Aquarius the Water-bearer, due south of the Great Square of Pegasus.
Although NASA’s New Horizons spacecraft is now tens of millions of miles beyond Pluto, the distant world remains at the top of many amateur astronomers’ observing lists. Fortunately, Pluto reached opposition and peak visibility in July, so it is still a tempting target during the evening hours. It glows dimly at magnitude 14.1, however, so you’ll need an 8-inch or larger telescope with good optics to spot it visually. Pluto currently lies in northern Sagittarius, some 0.6° west-northwest of magnitude 3.5 Xi2 (ξ2) Sagittarii.
Saturday, August 29
Full Moon arrives at 2:35 p.m. EDT. It rises in the eastern sky minutes before the Sun sets and reaches its peak in the south around 1 a.m. local daylight time. The Moon lies among the background stars of Aquarius the Water-bearer, due south of the Great Square of Pegasus.
Neptune
comes to opposition August 31, when viewers can spot the distant
world’s 8th-magnitude glow among the background stars of Aquarius.
Astronomy: Rick Johnson
Sunday, August 30
The Moon reaches perigee, the closest point in its orbit around Earth, at 11:21 a.m. EDT. It then lies 222,631 miles (358,290 kilometers) away from us.
Monday, August 31
Neptune reaches opposition and peak visibility today. Because it lies opposite the Sun in our sky, it rises at sunset and appears highest in the south around 1 a.m. local daylight time. But you can start searching for it by 10 p.m., when it lies one-quarter of the way from the southeastern horizon to the zenith. Neptune glows at magnitude 7.8, bright enough to spot through binoculars if you know where to look. The trick is to find the 4th-magnitude star Lambda (λ) Aquarii, which lies about 10° southeast of Aquarius’ distinctive Water Jar asterism. At opposition, Neptune appears 3.4° southwest of this star. When viewed through a telescope, Neptune shows a blue-gray disk measuring 2.4" across.
The Moon reaches perigee, the closest point in its orbit around Earth, at 11:21 a.m. EDT. It then lies 222,631 miles (358,290 kilometers) away from us.
Monday, August 31
Neptune reaches opposition and peak visibility today. Because it lies opposite the Sun in our sky, it rises at sunset and appears highest in the south around 1 a.m. local daylight time. But you can start searching for it by 10 p.m., when it lies one-quarter of the way from the southeastern horizon to the zenith. Neptune glows at magnitude 7.8, bright enough to spot through binoculars if you know where to look. The trick is to find the 4th-magnitude star Lambda (λ) Aquarii, which lies about 10° southeast of Aquarius’ distinctive Water Jar asterism. At opposition, Neptune appears 3.4° southwest of this star. When viewed through a telescope, Neptune shows a blue-gray disk measuring 2.4" across.
The
predawn sky comes alive with planets in late summer. Both Venus and
Mars emerge from the Sun’s glare to start long morning apparitions.
Astronomy: Rick Johnson
Tuesday, September 1
Although Venus passed between the Sun and Earth in mid-August, its rapid orbital motion brings it back into view quickly. This morning, the planet rises nearly two hours before the Sun and climbs 10° high in the east 45 minutes before sunrise. Shining at magnitude –4.5, the brilliant world appears conspicuous against the twilight glow. Harder to see is magnitude 1.8 Mars, which stands some 9° north (to the upper left) of Venus. Binoculars will help you spot the Red Planet. When viewed through a telescope, Venus displays a 52"-diameter disk that is just 9 percent lit.
Wednesday, September 2
The constellations Ursa Major the Great Bear and Cassiopeia the Queen lie on opposite sides of the North Celestial Pole, so they appear to pivot around the North Star (Polaris) throughout the course of the night and the year. In late August and early September, these two constellations appear equally high as darkness falls. You can find Ursa Major and its prominent asterism, the Big Dipper, about 30° above the northwestern horizon. Cassiopeia’s familiar W shape, which currently lies on its side, appears the same height above the northeastern horizon. As the night progresses, Cassiopeia climbs above Polaris while the Big Dipper swings below.
Although Venus passed between the Sun and Earth in mid-August, its rapid orbital motion brings it back into view quickly. This morning, the planet rises nearly two hours before the Sun and climbs 10° high in the east 45 minutes before sunrise. Shining at magnitude –4.5, the brilliant world appears conspicuous against the twilight glow. Harder to see is magnitude 1.8 Mars, which stands some 9° north (to the upper left) of Venus. Binoculars will help you spot the Red Planet. When viewed through a telescope, Venus displays a 52"-diameter disk that is just 9 percent lit.
Wednesday, September 2
The constellations Ursa Major the Great Bear and Cassiopeia the Queen lie on opposite sides of the North Celestial Pole, so they appear to pivot around the North Star (Polaris) throughout the course of the night and the year. In late August and early September, these two constellations appear equally high as darkness falls. You can find Ursa Major and its prominent asterism, the Big Dipper, about 30° above the northwestern horizon. Cassiopeia’s familiar W shape, which currently lies on its side, appears the same height above the northeastern horizon. As the night progresses, Cassiopeia climbs above Polaris while the Big Dipper swings below.
Any
telescope pointed at Saturn this September will show the planet's
16"-diameter globe surrounded by a ring system that spans 37".
Christopher Go
Thursday, September 3
Saturn remains a gorgeous sight in the evening sky all week. It lies some 20° high in the southwest as darkness falls and doesn’t set until 11 p.m. local daylight time. The ringed world resides among the background stars of eastern Libra, some 13° northwest of Antares, the brightest star in neighboring Scorpius. The planet shines at magnitude 0.5 and appears significantly brighter than the ruddy star. When viewed through a telescope, Saturn shows a 16"-diameter disk surrounded by a dramatic ring system that spans 37" and tilts 24° to our line of sight.
Friday, September 4
Mercury reaches greatest elongation today, when it stands 27° east of the Sun. For observers at mid-northern latitudes, however, the innermost planet barely scrapes the western horizon just after sunset. From 40° north latitude, it stands only 3° high 30 minutes after the Sun goes down. You’ll need a flat, unobstructed horizon and a pristine sky to see Mercury. Fortunately, it shines brightly at magnitude 0.1, so you should be able to spot it through binoculars.
Saturn remains a gorgeous sight in the evening sky all week. It lies some 20° high in the southwest as darkness falls and doesn’t set until 11 p.m. local daylight time. The ringed world resides among the background stars of eastern Libra, some 13° northwest of Antares, the brightest star in neighboring Scorpius. The planet shines at magnitude 0.5 and appears significantly brighter than the ruddy star. When viewed through a telescope, Saturn shows a 16"-diameter disk surrounded by a dramatic ring system that spans 37" and tilts 24° to our line of sight.
Friday, September 4
Mercury reaches greatest elongation today, when it stands 27° east of the Sun. For observers at mid-northern latitudes, however, the innermost planet barely scrapes the western horizon just after sunset. From 40° north latitude, it stands only 3° high 30 minutes after the Sun goes down. You’ll need a flat, unobstructed horizon and a pristine sky to see Mercury. Fortunately, it shines brightly at magnitude 0.1, so you should be able to spot it through binoculars.
Last Quarter Moon is the perfect time to explore features in the southern highlands of the lunar surface.
Jamie Cooper
Saturday, September 5
Last Quarter Moon occurs at 5:54 a.m. EDT. It rises shortly before midnight local daylight time on the 4th and climbs high in the southeast by the time morning twilight starts to paint the sky. But the Moon’s main claim to fame this morning is that many people will be able to watch it pass in front of the 1st-magnitude star Aldebaran in the constellation Taurus the Bull. Observers along a line that runs from the western shore of Lake Superior to Florida’s east coast will see the star emerge from behind the Moon’s dark limb as the pair rises. The farther north and east of this line you live, the higher the two objects appear. From New York City, for example, they stand 11° above the eastern horizon when Aldebaran returns to view at 12:40 a.m. EDT.
Sunday, September 6
If you look overhead as darkness falls anytime this week, your eyes will fall on the brilliant star Vega in the constellation Lyra the Harp. At magnitude 0.0, Vega is the brightest member of the prominent Summer Triangle asterism. The Triangle’s second-brightest star, magnitude 0.8 Altair in Aquila the Eagle, lies some 35° southeast of Vega. The asterism’s dimmest member, magnitude 1.3 Deneb in Cygnus the Swan, stands about 25° east-northeast of Vega. Deneb trails Vega by about two hours and passes through the zenith at approximately 10:30 p.m. local daylight time.
Last Quarter Moon occurs at 5:54 a.m. EDT. It rises shortly before midnight local daylight time on the 4th and climbs high in the southeast by the time morning twilight starts to paint the sky. But the Moon’s main claim to fame this morning is that many people will be able to watch it pass in front of the 1st-magnitude star Aldebaran in the constellation Taurus the Bull. Observers along a line that runs from the western shore of Lake Superior to Florida’s east coast will see the star emerge from behind the Moon’s dark limb as the pair rises. The farther north and east of this line you live, the higher the two objects appear. From New York City, for example, they stand 11° above the eastern horizon when Aldebaran returns to view at 12:40 a.m. EDT.
Sunday, September 6
If you look overhead as darkness falls anytime this week, your eyes will fall on the brilliant star Vega in the constellation Lyra the Harp. At magnitude 0.0, Vega is the brightest member of the prominent Summer Triangle asterism. The Triangle’s second-brightest star, magnitude 0.8 Altair in Aquila the Eagle, lies some 35° southeast of Vega. The asterism’s dimmest member, magnitude 1.3 Deneb in Cygnus the Swan, stands about 25° east-northeast of Vega. Deneb trails Vega by about two hours and passes through the zenith at approximately 10:30 p.m. local daylight time.
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