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We had a beautiful dusk gathering of the planets Venus and Jupiter early this summer. You probably noticed these two blazing dots in the west on June and July evenings. However, all things come to an end, and we lose Jupiter and Venus into the sun early in August.
Let’s look at finding these two planets in late July and in the first days of August.
This evening, look west as it gets dark around 7:30 p.m. Venus will be to the left of Jupiter. Later in the night, the two planets will be almost exactly side by side. Venus is the brighter one, shining at minus 4.4 magnitude; Jupiter shines at minus 1.7 magnitude, still brighter than any star in the sky. As they emerge at twilight, the two planets will be only about 10 degrees above the western horizon, which is about the width of your palm held at arm’s length. You will have less than an hour to catch the planets, since they set at 8:30 p.m.
Every night from this evening on, the two planets will be a little lower in the west as it gets dark. Venus will appear a little bit lower than Jupiter night by night. By Friday, as it gets dark at 7:30 p.m., Venus will be a mere 7 degrees (roughly the width of three fingers at arm’s length) above the western horizon, and Jupiter will be about nine degrees above the horizon, slightly less than a palm’s width. Your viewing window on the last day of July is really narrow: The planets appear at darkness around 7:30 p.m., Venus sets by 8 p.m. and Jupiter by 8:10 p.m.
By Aug. 5, which is just about your last chance to see both planets, Venus will be so low in the west that it will barely emerge above the western horizon at dusk before it sets at 7:30 p.m. Jupiter will hang on for a few more days, but by Aug. 10 it will be in the same situation as Venus five days earlier, barely emerging at twilight before it sets.
This will draw the curtain on the beautiful spring-summer evening appearance of the sky’s two brightest dots.
While we lose Venus from the night sky in early August, it’s not gone for long; by Aug. 23 it reappears as a morning “star.” On that day, look for the planet rising in the east, before the sun, around 5:30 a.m. By Aug. 31, Venus rises by 4:45 a.m. and is 15 degrees up in the east at daybreak. Venus as always is the sky’s brightest dot.
Jupiter, slower-moving, passes on the far side of the sun on Aug. 26.
Other planets
In early August, Saturn is due south at dusk and spends the night working its way down the western sky, setting in the west at 1:15 a.m. By the end of August, Saturn is halfway up in the southwest at dusk, and sets in the west by 11:15 p.m. The planet shines nicely at 0.05 magnitude; it appears white, tinged ever so slightly with yellow. Saturn is currently to the right of the claw of Scorpius the Scorpion.
Mercury hangs out low in the western sky at dusk throughout August; a good chance to spot it occurs on Aug. 6. On that night, looking west, Mercury is one degree to the right of Jupiter. Jupiter shines at minus 1.7, and Mercury is a little dimmer at minus 0.6. This is a “look fast or miss it” situation, since the two planets are only about 3 degrees above the horizon as they emerge at dusk on Aug. 6 around 7:30 p.m., and set by 8 p.m.
Mars finally returns to our sky in mid-August. The Red Planet rises at 5 a.m. in the east-northeast around Aug. 15, and is about 10 degrees above the eastern horizon at day’s break. By the end of the month Mars is up by 4:45 a.m. and has a brilliant companion: The blazing Venus will be to the right of Mars for the last week of the month. Mars is quite faint, only about 1.7 magnitude.
Other August sky events
>> The full moon on Aug. 29 is considered a “supermoon,” since it occurs at a time when the moon is a little closer than normal in its orbit around the Earth. This full moon will be a little bigger and brighter than usual. Bishop Museum is planning a supermoon concert, astronomy experience and celebration of the new Duke Kahanamoku exhibit on the evening of Aug. 29; visit bishopmuseum.org in August for details.
>> The Perseids, the most famous annual meteor shower, returns in mid-August, as it does every year. Annual meteor showers such as the Perseids are caused as the Earth enters into debris left over from a specific comet.
The Perseids shower is generated by debris from Comet 109 P Swift Tuttle. As the Earth goes around the sun, our planet runs into the same debris at the same time each year. This is why these showers occur at the same time each year.
After midnight, the part of the Earth that you are on is facing toward the debris that causes the meteor shower; this is why the Perseids shower, like all meteor showers, is always better after midnight, till dawn.
The Perseids are a consistent, reliable shower, with up to 80 shooting stars an hour. Since the moon is new on Aug. 14, it will not be visible during the meteor peak, giving us nice dark skies for viewing.
Go out from midnight to dawn, early on Aug. 12 or 13; find a good, dark location and get comfortable (a lawn chair is a good idea). Scan the skies for streaks of light. Meteor showers are good naked-eye, do-it-yourself events; a telescope is neither needed nor useful.
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