Science
Like fireworks, July is mostly quiet and dull, but the noisy and bright events really make it worthwhile. We have two pairs of planets, visible during opposite times in opposite places, and surreptitious visits from the Moon. Welcome to Observing With Webb, where a high school astronomy teacher tells you what you’re looking at, why it’s so cool, and what you should check out later this month…at night. Naked-eye PLANETS Sunset – Mars, Venus Mars (W) – This is your last month to see Mars for a couple more months, as Earth flies around the Sun opposite of Mars in August. Just look West after sunset but before 9:30pm. You might have some help from Venus and the Moon midmonth. Venus (W) – Staying about 15˚ above the horizon all month, Venus is a glorious sight for those looking West around the time fireworks start. Throughout the night – Saturn, Jupiter Saturn, Jupiter – I might be jumping the gun here a little bit, but sometimes we stay up late in the Summer. Saturn rises around 10:30pm, with Jupiter rising about an hour later. Look low in the ESE around this time and you’ll see bright Jupiter down and to the left of bright, but less so, Saturn. Now that’s in the beginning of the month, and they rise earlier and earlier each day. By the end of July, Saturn and Jupiter rise around 8:15pm and 9:15pm, respectively, during dusk. Of course, this means it’s a great time for checking out Saturn’s rings and Jupiter’s moons through your telescopes, but you’ll probably want to stay up until, or get up early in, the morning, when they are higher in the sky, and thus clearer in the telescope. Morning – Saturn, Jupiter Saturn, Jupiter – Speaking of staying up to observe Saturn and Jupiter, where are they around Sunrise? In the beginning of July, before 5am, look S or SE almost half-way up the sky, and Saturn will be to the right and little down from the very bright Jupiter. But at the end of July, both will be close to setting in the SW during the 5:30am dawn, with Jupiter about 15˚ higher than Saturn. EVENTS Last Quarter Moon – 1st (Visible from midnight into the morning) Morning Crescents (look East in the AM) New Moon – 9th (darkest skies) Evening Crescents (look West after Sunset) First Quarter Moon – 17th (Visible until midnight) Evening Gibbous (Mostly lit, after Sunset) Full Moon – 23rd (Visible all night) Waning Gibbous (Mostly lit, rises later at night) Last Quarter Moon – 30th (Visible from midnight into the morning) July 11th – 14th – Close Encounter – Moon, Venus, Mars – Not only are Mars and Venus getting less than a degree from each other on the 12th, the Moon is joining the party! Get out there after sunset, but before 9:30 and look West. The easiest to find will likely be the bright beacon known as Venus. On the 11th, Mars will be only a pinky-width to the left, but very dim, while a 2 day old crescent Moon hangs out about 3 finger-widths to the right at about the same height. The best night is likely the 12th, when Mars and Venus are half as far apart as the previous night, and the Moon is thicker and easier to find just 6˚ up and to the left, with Leo the lion right above the Moon. Over the next two nights, the Moon leaves the party, through Leo, and Mars and Venus separate, but are still in the same area. Get out those binoculars and telescopes! Find a good horizon! You’ll be looking at the three closest worlds to earth all in one view! 22nd – 26th – Close Encounter – Moon, Saturn, Jupiter – After 10:30pm look SE, or before dawn look SW to find the Moon, with bright Jupiter and Saturn nearby. The Moon is far to the right of Saturn on the nights of the 22nd and 23rd. On the 24th the Moon moves in between the planets, and closes in below Jupiter on the 25th, and leaves this party on the 26th. CONSTELLATIONS... Use a sky map from www.skymaps.com to help you out. After Dinner, Before Bed: Spring Constellations: Big Dipper, Bootes, Virgo, Corona Borealis, Hercules – Gaze almost vertically as you face the NW, and you’ll easily find the Big Dipper: seven very bright stars that form a spoon shape. Now if you take the handle of the Dipper, follow its curve to the next bright star you see, about 20˚ away, which is Arcturus. “Follow the arc to Arcturus.” That’s the brightest star in Bootes, which looks like a kite. Take that same curve, and follow it about another 20˚ to “speed on to Spica”, the brightest star in Virgo, one of my favorite constellations, since it reminds me of the Dickinson Mermaid. Now go back to Bootes, and just to the left of Bootes are seven stars that form the northern crown Corona Borealis, which looks more like a small bowl or a “C” in the sky. Continue a little further to the left and you’ll find the keystone asterism which is part of the constellation Hercules. Extra Challenge! Look for M13, the Hercules Cluster in between two of Hercules’ “keystone” stars. It known as the best globular cluster in the northern skies. It will be a fuzzy spot in binoculars and will be even cooler through a telescope Summer Constellations: Lyra, Cygnus, Aquila – Look pretty much straight above you, and find the brightest star up there. You’ll notice a parallelogram attached to it. This is the brightest star Vega, part of the constellation Lyra, the harp. Directly above you will be Cygnus the Swan, with its brightest star Deneb. It will look like a large cross, or if you look out a little further, a swan flying above you. Below Cygnus and Lyra is the third constellation of the Summer Triangle, Aquila the Eagle, with its brightest star Altair. The three bright stars in this one can be easily confused for Orion’s belt, given their similar size, however they are not in line as straight, and are part of a bigger diamond shape. Use a star chart to find small Delphinus and Sagitta in the area as well. Before Work: Pegasus, Andromeda – Look directly south and most of the way up the sky and you’ll find the very big and almost perfect square of Pegasus, the winged horse. Now if you look to the top left of the square, you’ll see three pairs of stars creating a neat double curve to the left and up from that corner star. That is Andromeda. If you have a little extra time, find the middle pair of stars, connect them with a line, and move toward the inside of the curve about the same distance as those stars are apart. There you’ll find the Andromeda Galaxy, which will be just a small faint fuzzy with your naked eye. The cool part is that you are looking at billions of stars that are 2.9 million light years away, that spread out about 150,000 light years across. Don’t forget this podcast is found on my Podbean page, Stitcher, and iTunes. There’s also a video version on my YouTube Channel and I can be found on Twitter and Instagram as @mrwebbpv. The Pequea Valley Planetarium and its events and updates are on Facebook, Twitter, and Instagram as @pvplanetarium.