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Venus in August 2018 August 1, 2018

Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
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Everyone else may be talking about Mars, but don’t miss your chance to check out Venus this month!

 

The orbits of Earth, Venus, and Mercury about the Sun, with 16º elongation and maximum eastern and western elongation shown.
The maximum elongations for Venus are shown with the dashed lines, and those for Mercury are shown with the dotted lines.

Venus orbits closer to the Sun than we do. That means from our point of view, it never gets very far from the Sun. When it is farthest in the sky from the Sun, we call it greatest elongation. On August 18, Venus will be at greatest eastern elongation, and it’ll be a little over 45º east of the Sun. That means it’ll be easy to see in the western sky for at least an hour after sunset.

 

 

Additionally, Venus will be headed for a crescent phase, which brings it closer to us, so it’ll be getting bigger and brighter. It’ll actually be at it’s brightest near the end of September.

 

 

Because of the angle of the ecliptic, it sets a lot sooner in September. Here are a couple maps showing the ecliptic from SE Michigan (or anywhere between 40 – 50º N latitude) on August 1st and 30th, both 1 hour after sunset. You can see the ecliptic moves southward, which means anything on the ecliptic will set earlier in the northern hemisphere.

W (west) is at the center bottom and NW near the bottom right corner. The ecliptic runs from the top left corner to the bottom about 1/4 of the way between W and NW.

Venus and the ecliptic on August 1st 2018, 1 hour after sunset.

W (west) is at the center bottom and NW near the bottom right corner. The ecliptic runs from the top left corner to the bottom just to the left of W.

Venus and the ecliptic on August 30th 2018, 1 hour after sunset.

So now’s the time for the easiest and latest observations of Venus, and September will be the time for the brightest and most interesting telescopic view of Venus!

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Observing tips for July 4th, 2018 July 2, 2018

Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
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The forth of July brings a lot of people outside after dark. While you’re waiting for those fireworks to begin, here are a few things to look for.

I recommend taking along a pair of binoculars.

03July2130W_VeMe

Venus and Mercury in the West July 3, 2018, 9:30 PM.

Start about half an hour after sunset (or about 9:30 in SE Michigan) and look west. About 20º ( 2 sideways fists) above due west is Venus. As the skies darken, it stands out like a beacon! look 16º (index finger to pinky) down and to the right for Mercury. Mercury can be a tough object to spot because it’s never far from the Sun, so it’s never visible in really dark skies. The first map is for July 3, 9:30 PM in Ann Arbor, but should be good for the 4th as well.

04July2200S_JuSa

Jupiter and Saturn in the south at 10 PM July 4

Fireworks usually begin around 10 PM (especially if you’re farther north.) Get a seat facing south for some of the summer’s best celestial show. Jupiter is about 30º above the southern horizon, and Saturn about 10º up in the SE. While you’re looking that way, be sure to check out Scorpio and Sagittarius too. Bright Antares, the heart of the scorpion, falls between Jupiter and Saturn right now.

With binoculars or a small telescope, you can pull in the 4 brightest moons of Jupiter. They’ll be lined up in a tight row on the 4th, which helps make it easier to pick them out at low magnification.

From left to right, Io, Europa, Jupiter, Ganymede, and Callisto

The Galilean Moons of Jupiter at 10 PM July 4, 2018.

If you actually have a small telescope and can pull your eye away from Jupiter, check out nearby Zubenelgenubi, a nice double star whose name means “southern claw” because it was once considered part of Scorpius.

Saturn is sitting on the top of the teapot. If your skies are dark enough later in the evening, you’ll be able to see the Milky Way trailing up the sky next to it. With binoculars or a small scope, the rings should be visible, if only as a strangely oblong shape. Some of the brighter moons may also be visible, though they aren’t nearly as easy as Jupiter’s moons.

From left to right, Iapetus, Rhea, Saturn, Tethys, and Titan, which is actually much lower that the other moons.

Saturn and its moons, July 4, 2018 at 10 pm

It’s early days yet for Mars, but if you’re out past midnight, look back to the same are Saturn was at 10 PM. Mars rises ESE around 11 PM, so it’s up nearly 10º in the SE at midnight. It’s the brightest thing in that area right now, and only getting brighter, so if your skies are clear, it’ll be hard to miss. Keep an eye on it the rest of the month as it moves toward closest approach on July 31!

Elusive Mercury in the Evening December 1, 2017

Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
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This weekend promises amazing weather for December in SE Michigan. Take advantage of it by looking for the elusive planet Mercury!

Sunset on December 1 in A2 is at about 5:03 PM, and Mercury sets at about 6, so grab a pair of binoculars and go out between roughly 5:15 – 5:45 and look low in the SW. Be sure to check out Saturn too: it’ll disappear behind the Sun soon! The image below is for 5:30 on Friday December 1, 2017

As the days progress, Mercury gets closer to the Sun in the sky (yes, it’s in retrograde), so by the 5th or 6th it’ll be all but impossible to catch! Conjunction is on the 12th. Saturn conjunction is December 21. 01Dec1730SW_Mercury.png

Venus and the Beehive August 30, 2017

Posted by aquillam in Astronomy, MichiganAstro, Urban Observing.
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If you happen to be up around 6 AM local time the next few mornings (August 31 – September 2, 2017) grab a pair of binoculars. Venus skims past one of my favorite open clusters in the pre-dawn hours.

Look east, between the Big Dipper and Orion, just below Gemini. You won’t be able to miss Venus. It’ll even shine through light cloud cover! If it’s clear, point your binoculars that way and you’ll see the Beehive cluster, so called because it sort of looks like a bee skep tipped on its side with the bees buzzing around it (a skep is the round, woven grass type of beehive.) It’s a fairly bright cluster, so even a small pair of binoculars will do. You probably won’t want to haul out the telescope for this because you need a 2º field of view, which most telescopes won’t do.

If you live in really dark skies, plop a camera down on a tripod and try taking a 1 – 2 second exposure. Longer will capture more stars, but overexpose Venus.

Here’s a chart looking east at 6 AM on August 31 from Ann Arbor:

31Aug0600E