Posts Tagged ‘Astronomy’


Hunter’s Moon

by Maeve Clark on October 22nd, 2018

 

Image via EarthSky.com

Have you noticed moon recently? It will be full this Wednesday. It’s a Hunter’s Moon, (though with harvest delay it might be called a Harvest and Hunter’s Moon).

According to the website EarthSky “every full moon has many names, and most are tied to months of the year. But some moon names are tied to seasons, such as the Harvest and Hunter’s Moons. The Harvest Moon is the full moon closest to the autumnal equinox. The Hunter’s Moon is the full moon after the Harvest Moon. The 2018 autumnal equinox was on September 22-23 and the Harvest Moon was around September 24-25. So the upcoming full moon – on the night of October 24, 2018 – is the Hunter’s Moon.

What makes a Hunter’s Moon unique?

Nature is particularly cooperative around the time of the autumn equinox to make the fall full moonrises special. On average, the moon rises about 50 minutes later each day. But when a full moon happens close to the autumnal equinox – either a Harvest or a Hunter’s Moon – the moon rises only about 30 to 35 minutes later daily for several days before and after the full moon. The reason is that the ecliptic – or the moon’s orbital path – makes a narrow angle with the evening horizon around the time of the autumn equinox. The result is that there’s a shorter-than-usual lag time between successive moonrises around the full Hunter’s Moon.

These early evening moonrises are what make every Hunter’s Moon special. Every full moon rises around sunset. After the full Hunter’s Moon, you’ll see the moon ascending in the east relatively soon after sunset for several days. The moon will be bright and full-looking for several nights beginning around October 23 or 24.

The narrow angle of the ecliptic means the moon rises noticeably farther north on the horizon from one night to the next. So there is no long period of darkness between sunset and moonrise, and, around the time of full moon, many people see the moon in a twilight sky.

How did the Hunter’s Moon get its name? There are many different explanations for the name Hunter’s Moon. In the autumn there is not long period of darkness between sunset and moonrise for several days in a row, around the time of full moon. Before there were tractors or tractors with lights, the glow of the Harvest Moon helped farmers to gather their crops. As the sun’s light faded in the west, the moon would soon rise in the east to illuminate the fields throughout the night. A month later, after the harvest was done, the full Hunter’s Moon was said to illuminate the prey of hunters, scooting along in the stubble left behind in the fields.”

I love to watch the night sky, do you?

The Lunar Trifecta – A Super Blood Blue Moon Lunar Eclipse – where and when to watch

by Maeve Clark on January 30th, 2018

If you are an early morning skywatcher, you are in for a treat tomorrow.   Monday’s Trilobites column by  Nicolas St. Fleur in the New York Times details what will happen during this celestial event – “Lunar eclipses are not uncommon, but the coincidence of Wednesday’s blood moon with other astronomical events is what makes this event special. First, because it is a “blue moon” — that means it is the second full moon to occur in a month. Also, it is a supermoon, meaning it will be closer to the Earth than usual, ” According to Mr. Johnston.  a program executive at NASA””Midwesterners are a tad luckier as they will be able to see more of the event. For them, the moon enters the penumbra at 4:51 a.m. Central Time and starts to turn reddish around 6:15 a.m. Central Time. Between 6:15 a.m. and 6:30 a.m. local time will be the best chance for anyone living in the Midwest to see the spectacle before the sun rises.”   Johnston has been blogging about the moon for NASA since 2004

The best tip for anyone trying to see the eclipse is to get a clear view of the horizon and look in the west-northwest direction. “The farther west you are, the higher in the west-northwest the moon will appear, the darker the sky will be,” said Mr. Johnston, “and the longer you will be able to view the eclipse before sunrise and moonset.”  NASA will be streaming the lunar event at NASA.gov/live and has a lot of great information at it including a graphic that shows the cycle of the eclipse. If this post and the upcoming lunar trifecta has piqued your interest in the skywatching, the library has a wealth of books for all ages of readers.  We also have spectacular dvds to aid you in your understanding of the universe.

Orionid Meteor Shower reaches it’s peak this weekend!

by Beth Fisher on October 20th, 2017

 

orionidsIf you’re not often outside late at night, you might not be aware that something pretty special has been going on this week.  The 2017 Orionid Meteor Shower began on October 15 and ends October 29th.  Peak nights for viewing the meteor shower are tonight and tomorrow night  – with prime viewing time around around 2:00a.m Saturday and Sunday.

 

 

 

haleysThe Orionids happen every year in late October when the earth passes through the stream of ice particles and rocks trailing Haley’s Comet. Haley’s Comet has a highly elliptical 75.5 year orbit around the Sun. It last passed through the inner part of the solar system in 1986.  Each time it passes the Sun a bit of the ice on the comet melts and rocks and larger chunks of ice break off and join the stream of debris following the comet.

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The Great Solar Eclipse of 2017!

by Maeve Clark on August 9th, 2017

Something very exciting will happen on Monday, August 21.  We will get to witness a solar eclipse.  While we aren’t in the path for the total eclipse, at 1:12:42 thnasa_eclipse_mape moon will obscure 92.3% of the sun.   I witnessed a total solar eclipse in 1980 while I was a Peace Corps volunteer in Zaire, (Democratic Republic of Congo) and it was truly awe inspiring.  The day went black, the temperature dropped, the roosters crowed, the peafowl and other birds took to the trees.

There are hundreds of websites to find out information about this phenomenal astronomical event.   One of my favorite is from eclipseVOX.  It has a eclipse location function where you can type in your zip code and find out how much of the sun will be obscured.  NASA, of course, has excellent resources. NPR has run a couple of stories about the excitement around the eclipse including one on the first photograph taken of a solar eclipse.

The Children’s Department has programs on Sundays about the eclipse. On Monday, August 14 at 7 pm in Meeting Room A, Brent Studer, Adjunct Professor of Astronomy at Kirkwood Community College, will explain the circumstances under which eclipses occur and what you can do to be ready for the upcoming solar eclipse, the first total solar eclipse visible in the continental United States since 1979.   Join us on Monday, August 21 while we step outside the library to safely view the eclipse.  Another eclipse watching event will be hosted by the University of Iowa Sciences Library, the UI Museum of Natural History (Pentacrest Museums) and the UI Astronomy Club, on the Pentacrest lawns.

The library has books and videos galore for all ages on astronomy and the natural wonders of the sky.  Come learn more about the Great Solar Eclipse of 2017. We might just make an umbraphile out of you!

The 2015 Perseid Meteor shower has begun.

by Beth Fisher on July 30th, 2015

perseid showerThis annual celestial event occurs each year in late Summer, with peak viewing near the 2nd week of August.  In 2015, the peak will be August 9-13 when up to 60 meteors an hour should be visible in the night sky, especially in the hours between midnight and dawn.

The Perseid Meteor shower is what we see when the Earth passes through the orbital path of the Swift-Tuttle comet.   Swift Tuttle orbits the Sun every 133 years, and each time it gets close to the Sun, small pieces break off and join the cloud of debris in the comet’s orbit.  Each year when the Earth passes through the Swift-Tuttle’s debris field,  the debris bounces off the Earth’s atmosphere creating the Perseid Meteor Shower.

Perseid_Vic_radiantsThe Perseids appear to originate from the top of the constellation Perseus. During August, Perseus will be found in the Northeastern part of the sky, left of the Big Dipper.   The point in space where the shower seems to originate is called a “Radiant”.   The map to the left, from Sky & Telescope, the radiant is shown in yellow text.   All the Perseid meteors will appear fly outwards from that point in the sky.

There are many great Astronomy websites with information about the Perseids.

stardateUniversity of Texas at Austin McDonald Observatory’s web site “StarDate” has a lot of information for people new to star gazing and astronomy.  Clicking on the “Stargazing” tab on their homepage will give you a list of the things visible in the night sky this week.  This is also where you’ll find a link to their Meteor Shower page.

earth sky The Earth Sky website managed by Deborah Byrd, the host of the long running public radio series EarthSky: A Clear Voice for Science, is a great science web site for non-scientists.  The information about the Perseids   section of their website is easy to read and has lots of information about the origins of the Perseids as well as how and when to find them and general tips on viewing.

NASATo learn more about Comets, Meteors and meteor showers, the NASA website is a great place to start.   Plantes, asteroids, meteors, and comets – there are all sorts of neat things at NASA.

 

 

2015 meteor showers

There are many other regular meteor showers throughout the year if you can’t make the Perseids.   Some of the most common can be found on this table, from the University of Texas at Austin McDonald Observatory’s  StarDate website mentioned above.

Of course, the Iowa City Public Library has lots of material about Astronomy and Stargazing and the staff at any of the public service desks in the Library can help you find more information.