Archive

Archive for the ‘Observing’ Category

08/06/2019 – Ephemeris – More about viewing the Perseid meteor shower: Meteor trains

August 6, 2019 Comments off

Ephemeris for Tuesday, August 6th. Today the Sun will be up for 14 hours and 27 minutes, setting at 9:02, and it will rise tomorrow at 6:35. The Moon, 1 day before first quarter, will set at 12:29 tomorrow morning.

The Perseid meteor shower has to compete this years with the bright waxing Moon, so only the brightest meteors will be visible, However even though this cuts down on the meteors visible, it happens that some of the brightest of meteors leave smokey trains, which can be seen in binoculars. Unlike aircraft contrails which are created the same altitude, meteor trains descend through the atmosphere where the winds at the different altitudes slowly bend and twist the train, tearing it up. The same occurs with any really bright meteor, Perseid or not. So remember to add binoculars to your meteor viewing kit along with a blanket, warm coat, mosquito spray and hot coffee or other beverage.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

These are screen caps from a time lapse video by Australian Phil Hart of a meteor train being torn apart by upper level winds. Credit Phil Plait’s Bad Astronomy/Phil Hart.  This was not a Perseid meteor.

The actual video and much more about meteor trains are located here:  https://www.syfy.com/syfywire/catching-meteor-train.

08/05/2019 – Ephemeris – Previewing the Perseid meteor shower

August 5, 2019 Comments off

Ephemeris for Monday, August 5th. Today the Sun will be up for 14 hours and 30 minutes, setting at 9:03, and it will rise tomorrow at 6:34. The Moon, 2 days before first quarter, will set at 12:01 tomorrow morning.

After the Moon sets in the morning hours for the next week and a half the numbers of meteors visible will increase each night. These are members of the Perseid meteor shower of August. The peak this year is expected to be during the morning of the 13th. However by then the Moon will be nearly full. These meteors are the result of debris left along the orbit of Comet 109P/Swift-Tuttle shed by innumerable visits to the inner solar system. Every year at this time the Earth passes through this trail of debris which intersects its orbit giving rise to the meteor shower. We call them the Perseids, because they appear to come from the direction of the constellation Perseus the hero, which is first seen in the early evening low in the northeast.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Perseid Radiant

The Perseid radiant is located off the highest star in Perseus as it ascends the sky at about 10:30 p.m. The Perseid radiant is circumpolar for observers in northern Michigan. Click on the image to enlarge. Created using Stellarium.

Swift-Tuttle 1992 plot

The passage of Comet 109P/Swift-Tuttle through the inner solar system November 1, 1992 to January 30, 1993. The meteoroids shed by the comet on its numerous trips close to the Sun lie close to that orbit. Note that its orbit intersects with the Earth’s orbit. That’s where the Earth will be around August 12-13 every year. Created using my LookingUp program.

 

08/02/2019 – Ephemeris – The Milky Way

August 2, 2019 Comments off

Ephemeris for Friday, August 2nd. Today the Sun will be up for 14 hours and 37 minutes, setting at 9:07, and it will rise tomorrow at 6:31. The Moon, 2 days past new, will set at 10:31 this evening.

We’ll get darkness tonight, but that will erode night by night as the Moon waxes in our evening sky. At mid month this month and September will be the start of about two weeks of the best evening sky viewing of the year. This is the period the summer Milky Way is displayed to its fullest to the southern horizon. City folk come to our area and are sometimes fooled by the brightness and expanse of the Milky Way and think it’s clouding up. Yes those are indeed clouds, but they are star clouds. Binoculars will begin to show them to be millions of stars, each too faint to be seen by themselves to the naked eye, but whose combined glow give the impression of a luminous cloud. Binoculars are the ideal tool to begin to explore the Milky Way. Objects still too fuzzy can be checked out with a telescope to reveal their true nature.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Great Rift in the Summer Triangle

The Milky Way in the Summer Triangle, also showing the constellations of Cygnus the swan and the the northern part of Aquila the Eagle. This image a stack of 5 30 second exposures taken the morning of the Perseid meteor shower the is year in a vain attempt to capture some meteors.  I was hampered by a smoky haze blown in all the way from the West Coast from forest files out there.

 

06/25/2019 – Ephemeris – Weird clouds of the twilight zone

June 25, 2019 Comments off

Ephemeris for Tuesday, June 25th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:32, and it will rise tomorrow at 5:58. The Moon, at last quarter today, will rise at 2:23 tomorrow morning.

This time of year one can see, on rare occasions, some ghostly clouds called noctilucent clouds. Noctilucent means night shining. These are silvery clouds that can be seen near the end of twilight. We’re a bit south of the prime latitudes to see them from 50 to 70 degrees both north and south of the equator. I’ve seen them a few times. They move rather rapidly, even though they’re at an altitude of around 50 miles. The clouds appear to be made of ice crystals that possibly form around meteoric dust. Their appearance cannot be predicted, but show up near the end of twilight and they are white, and are not the usual reddish clouds of twilight. These clouds mostly appear in July and August. But I’ve seen many recent reports of them from Europe.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Noctilucent Clouds

Noctilucent clouds, Kuresoo bog, Soomaa National Park, Estonia. July 26, 2009 by Martin Koitmäe. From Wikimedia Commons.

Spaceweather.com is a great place to learn more and hosts a gallery of recent noctilucent cloud photos.

 

06/14/2019 – Ephemeris – I’m giving the talk Apollo and the Race to the Moon tonight at the Library in Thompsonville

June 14, 2019 Comments off

Ephemeris for Flag Day, Friday, June 14th. Today the Sun will be up for 15 hours and 33 minutes, setting at 9:29, and it will rise tomorrow at 5:56. The Moon, 3 days before full, will set at 4:55 tomorrow morning.

Tonight the Grand Traverse Astronomical Society will host a star party… well a Moon party at the Betsie Valley District Library in Thompsonville, MI. It starts at 8:30 p.m. With what I like to call a twilight talk by yours truly, the title of which is Apollo and the Race to the Moon. I’ll explore the Apollo 11 mission and the events leading up to it both in the United States and the USSR. The bright Moon tonight will uncover all the Apollo landing areas, even though there too small to be seen from the Earth, though they will be shown in the presentation. Twilight talks at the library also involves a slide or planetarium-like presentation, so if it’s cloudy we’ll also explore the starry nights of summer inside. So come out clear or cloudy.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Saturn V vs. N1

Comparison between The United States Saturn V and the Soviet N-1. Click on the Image to enlarge. Credit Karl Tate, Space.com.

06/04/2019 – Ephemeris – The night sky previews summer

June 4, 2019 Comments off

Ephemeris for Tuesday, June 4th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, 1 day past new, will set at 10:51 this evening.

The Moon will be visible early this evening. By early I mean by 10 p.m. since the Sun sets so late now. By the time you see it it will be a day and a half old and a thin sliver. Closer inspection will reveal the the whole Moon will be visible due to Earth shine. That’s due to the nearly full Earth shining on the night side of the Moon.

Even though Summer is 17 days away the three bright stars of the Summer Triangle are visible in the eastern sky at 11 p.m. The three stars are Vega highest in the east. Deneb is lower in the northeast. Altair is lower close to the horizon in east. They will rise higher throughout the summer season. Looking close to the horizon in the southeast that bright star at that hour is the planet Jupiter.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The eastern skies at 11 p.m.

The eastern skies at 11 p.m. June 4, 2019. Click on the image to enlarge. Created using Stellarium and GIMP.

05/27/2019 – Ephemeris – The bright star Spica

May 27, 2019 Comments off

Ephemeris for Memorial Day, Monday, May 27th. Today the Sun will be up for 15 hours and 13 minutes, setting at 9:16, and it will rise tomorrow at 6:03. The Moon, 1 day past last quarter, will rise at 3:34 tomorrow morning.

Just about due south at 10:30 p.m. is the bright star Spica which can be found from all the way back overhead to the Big Dipper. Follow the arc of the handle of the Big Dipper to the bright star Arcturus high in the south-southeast. Then straighten the curve of the arc to a straight spike which points to Spica the brightest star in the zodiacal constellation of Virgo the virgin. Arcturus is much brighter than Spica and has an orange tint to Spica’s bluish hue. In fact Spica is the bluest of the 21 first magnitude stars. That means that it is hot. Actually Spica is really two blue stars orbiting each other every 4 days. Spica is 250 light years away, which is reasonably close. Spica was an important star to the ancient Greeks. One temple was built, and aligned to its setting point.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Finding Spica

Spica finder animation for 10:30 p.m., May 27th. Click on the image to enlarge. Created using Stellarium and GIMP.