Archive

Archive for September, 2017

09/29/2017 – Ephemeris – Last festival of the year for the GTAS – Acme Fall Fest tomorrow

September 29, 2017 1 comment

Ephemeris for Friday, September 29th. The Sun will rise at 7:38. It’ll be up for 11 hours and 47 minutes, setting at 7:26. The Moon, 2 days past first quarter, will set at 1:59 tomorrow morning.

The Grand Traverse Astronomical Society will be at the Acme Fall Festival tomorrow, that’s Saturday September 30th from 10 to 4 p.m. It will be held at Flintfields Horse Park on Bates Road, north of M 72. The society members will bring their telescopes which will be used to view the sun if it’s clear. There will also be exhibits of astronomical photos from NASA, professional and our own amateur astronomers. As the festival and star party year winds down and the school year begins members of the society can bring astronomy and space to the classroom. Plus the society is beginning to plan for next year. Contact the Grand Traverse Astronomical Society via email at info@gtastro.org for information or to set up a date and topic.

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

Advertisements

09/28/2017 – Ephemeris – View the Moon and Saturn tonight at the library

September 28, 2017 Comments off

Ephemeris for Thursday, September 28th. The Sun will rise at 7:37. It’ll be up for 11 hours and 51 minutes, setting at 7:28. The Moon, 1 day past first quarter, will set at 1:05 tomorrow morning.

Tonight the Grand Traverse Astronomical Society will set up their telescopes at the Traverse Area District Library Central Library on Woodmere Avenue in Traverse City from 7 to 9 p.m. weather permitting for a star party, though it won’t actually feature stars. It will feature the Moon in its gibbous phase and the planet Saturn probably after 8 p.m. We might also catch a glimpse of the Sun, since the event starts before sunset. The Sun’s sunspot activity has picked up a bit in the last month or so, since just before August’s solar eclipse. We’ve had a pretty sunspot-less early summer.

There will be a visible pass of the International Space Station, which will be high in the south at 8:30 p.m.  It will rise above the southwestern horizon at 8:25, and disappear into earth’s shadow at 8:33 p.m. in the south-southeast.  It will be visible from anywhere in Michigan, though the times may vary by a minute or so.  It’s traveling at 5 miles per second (8 km/s).

The library has a telescope, donated by the society and Enerdyne that they lend out, which has been in heavy demand. See the library for details.

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

 

09/27/2017 – Ephemeris – Where are the naked eye planets tonight

September 27, 2017 1 comment

Ephemeris for Wednesday, September 27th. The Sun will rise at 7:35. It’ll be up for 11 hours and 54 minutes, setting at 7:29. The Moon, at first quarter today, will set at 12:16 tomorrow morning.

Let’s take our weekly look at the bright planets. Jupiter is really low in the west-southwest after sunset setting in bright twilight at 8:22 p.m. Saturn can be seen low in the southwest tonight. The reddish star Antares is below and right of Saturn before it sets at 9:50 p.m. Saturn’s rings are spectacular in telescopes. With the demise of the Cassini spacecraft orbiting Saturn for the last 13 years, there is no telescope closer to Saturn than yours. The planet will set at 11:09 p.m. In the morning sky, brilliant Venus will rise at 5:23 a.m. in the east-northeast. Much dimmer Mars will rise in the east-northeast at 5:46 a.m. Mars will brighten greatly as it approaches us in the next 10 months. Mercury is too close to the glare of the Sun to be spotted.

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

Addendum

Saturn and the Moon

Saturn and the Moon tonight at 9 p.m., September 27, 2017. Created using Stellarium.

Saturn and its brightest moons

Saturn and its brightest moons overnight September 27/28, 2017. Created using Cartes du Ciel (Sky Charts).

Binocular Moon

The Moon as it might be seen in binoculars, 9 p.m. September 27, 2017. Created using Stellarium.

Venus and Mars

Venus and Mars close up at 6:30 a.m. September 27, 2017. Created using Stellarium.

Planets and the Moon on a single night

Planets at sunset and sunrise of a single night starting with sunset on the right on September 27, 2017. The night ends on the left with sunrise on the 28th. I’ve rotated the sunrise plot so the planet labels wouldn’t overlap. Click on the image to enlarge. Created using my LookingUp program.

09/26/2017 – Ephemeris – Saturn appears near the Moon tonight

September 26, 2017 1 comment

Ephemeris for Tuesday, September 26th. The Sun will rise at 7:34. It’ll be up for 11 hours and 57 minutes, setting at 7:31. The Moon, 1 day before first quarter, will set at 11:32 this evening.

Tonight the Moon will to be near the planet Saturn. At 9 p.m. the ringed planet will be seen below the crescent Moon. It’s a good way to spot Saturn if you’ve never be able to figure out which of those “stars” in the sky is Saturn. It’s easy to confirm with a small telescope. Even in binoculars Saturn is not quite a star-like point. Saturn’s rings begin to show distinctly with 20 power magnification. The Moon too is great to view at low power, even binoculars. A new sea has appeared since last night. It is the Sea of Serenity above the center of the Moon. The lunar seas are really large nearly circular lava filled craters that appear to have been the result of asteroid impacts about 3.8 or so billion years ago.

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

Addendum

Saturn and the Moon

Saturn and the Moon tonight, 9 p.m. September 26, 2017. Created using Stellarium.

Binocular Moon

The Moon as it might be seen in binoculars, 9 p.m. September 26, 2017. Created using Stellarium.

Compare with last night’s Moon.

The Moon tonight

The annotated crescent moon tonight, September 25, 2017. Created using Virtual Moon Atlas.

09/25/2017 – Ephemeris – Lets look at the Moon tonight

September 25, 2017 1 comment

Ephemeris for Monday, September 25th. The Sun will rise at 7:33 a.m. It’ll be up for 12 hours exactly, setting at 7:33 p.m. The Moon, 2 days before first quarter, will set at 10:52 this evening.

Let’s take a look at the crescent Moon tonight. It will be fairly low in the southwestern sky this evening. Four of the gray lava plains called seas are now visible in binoculars or small telescopes. Nearest the right limb of the Moon is the Sea of Crises, next nearest if the Sea of Fertility. A small sea next to that is the Sea of Nectar. Above that, mostly exposed to sunlight is the Sea of Tranquility. The Sun is just rising at Tranquility Base, where Apollo 11 landed, where the Lunar Module’s descent stage still lies, forlorn and empty. Below that is the beautiful crater Theophilus with its central peak. It is 61 miles (101 km) in diameter, and its crater walls rise over 13,000 feet (4,400 meters) above the crater floor.

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

Addendum

The Moon tonight

The annotated crescent moon tonight, September 25, 2017. Created using Virtual Moon Atlas.  Click on the image to enlarge.

Apollo 11 landing site

The Apollo 11 landing site in one photograph by the Lunar Reconnaissance Orbiter. There are many with varying Sun angles in the Internet. Search for: Apollo 11 LRO images. Credit NASA.

09/22/2017 – Ephemeris – September star party at Sleeping Bear Dunes National Lakeshore tomorrow night

September 22, 2017 1 comment

Ephemeris for Friday, September 22nd. The Sun will rise at 7:29. It’ll be up for 12 hours and 9 minutes, setting at 7:39. The Moon, 2 days past new, will set at 9:14 this evening.

Autumn starts at 4:02 this afternoon.

The first star party of autumn will be held at the Sleeping Bear Dunes National Lakeshore tomorrow evening starting at 9 p.m. at the Dune Climb if it’s clear. It will be hosted by the Park Rangers and the Grand Traverse Astronomical Society. The society invites all to come, especially those with telescopes willing to share the wonders of the Milky Way, which will span the skies from horizon to horizon, and the planet Saturn. The park has one of the darkest skies in the Lower Peninsula, and the Milky Way is especially impressive in late summer and early autumn.

Please call 231-326-4700, ext. 5005 if in doubt about weather conditions. A decision will be made by 2 hours before the event.

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

09/21/2017 – Ephemeris – Summer ends and autumn begins tomottow

September 21, 2017 1 comment

Ephemeris for Thursday, September 21st. The Sun will rise at 7:28. It’ll be up for 12 hours and 12 minutes, setting at 7:41. The Moon, 1 day past new, will set at 8:45 this evening.

Enjoy the last full day of summer. Summer will last until 4:02 p.m. (20:02 UTC) tomorrow when the center of the Sun will cross the celestial equator, an imaginary line above the Earth’s equator, heading southward. At that instant autumn will begin. Shortly the Sun will be up less than half the day. The day and the point in the sky that the Sun crosses is called the autumnal equinox. The word equinox means equal night, implying that day and light are of equal length. Geometrically that’s true, but the Earth’s atmosphere and the definition of sunrise and sunset, prolong daylight by a few minutes. The amount of heat we are getting and will get from the Sun cannot sustain our current temperatures, and it will get a lot colder before it gets warmer again.

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

Addendum

Autumnal equinox from space

Image from the Earth Polychromatic Imaging Camera (EPIC) on NOAA’s DSCOVR satellite in halo orbit around the Earth-Sun L-1 point 1 million miles sunward from the Earth last autumnal equinox (2016) at about the same time the autumnal equinox will occur this year.

Sunrise on the autumnal equinox

That is not a pumpkin on the head of the motorcyclist. That’s the Sun rising as I’m traveling east on South Airport Road south of Traverse City Mi. on the autumnal equinox. This is the east-west section of the road. The Sun is rising over the hills some 6 miles to the east. Credit: Bob Moler.