05/25/2018 – Ephemeris – Star party scheduled for Sleeping Bear Dunes National Lakeshore May 26, 2018

May 25, 2018 Leave a comment

Ephemeris for Friday, May 25th. Today the Sun will be up for 15 hours and 9 minutes, setting at 9:15, and it will rise tomorrow at 6:04. The Moon, half way from first quarter to full, will set at 4:52 tomorrow morning.

Tomorrow night May 26th there will be, weather permitting a star party at Sleeping Bear Dunes National Lakeshore, this will take place at the Dune Climb. Telescopes will take over the parking lot closest to the Dunes The event starts at 9 p.m., while it’s still light out and the location can be found. The nearly full Moon will be first to be spotted, followed by Venus and Jupiter. The planet Jupiter’s four brightest moon will be seen along with its cloud bands. Starting at 9 p.m. there will be a short ranger talk, followed by an astronomer to explain what will be seen that night. The star party is made possible by the rangers of the park and the Grand Traverse Astronomical Society.

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

Addendum

Dune Climb Setup

This is the beginning of setup for the October 21, 2017 star party at the dune climb. Taken early while there was enough light. The dune blocks up to 12 degrees from the southwest to northwest, but the rest of the horizon is quite low. Venus will be high enough to clear the dune for most of the evening.  The ladder is up to assemble the society’s 25 inch “Emmettron” Obsession Dobsonian telescope.  The telescope was overhauled including having the mirror aluminized and new encoders over the winter, thanks to Don Flegel our telescope wrangler.  Click to enlarge.  Photo by Bob Moler.

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05/24/2018 – Ephemeris – Jupiter is really BIG

May 24, 2018 Leave a comment

Ephemeris for Thursday, May 24th. Today the Sun will be up for 15 hours and 8 minutes, setting at 9:14, and it will rise tomorrow at 6:05. The Moon, 3 days past first quarter, will set at 4:24 tomorrow morning.

Jupiter is a big planet. How big is it? One could fit thirteen hundred Earths inside it. Even so Jupiter has the mass of only 318 Earths, so Jupiter is made of lighter stuff than the Earth, including a lot of hydrogen and helium. NASA’s Juno spacecraft is currently orbiting Jupiter, working that out. Still, Jupiter is massive. The late science and science fiction writer Isaac Asimov wrote that the solar system consists of the Sun, Jupiter and debris. Jupiter contains more than twice the mass of all the other planets and asteroids combined. Jupiter is also surrounded by a huge set of radiation belts, lethal to all but the most radiation hardened spacecraft. And that goes for would be astronauts too.

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

Addendum

Planet size comparison

Planet size comparison. Note that even though Saturn looks almost as large as Jupiter it is less than 30% of Jupiter’s mass. From connormorency.wordpress.com

05/23/2018 – Ephemeris – Wednesday is bright planet day on Ephemeris

May 23, 2018 Leave a comment

Ephemeris for Wednesday, May 23rd. Today the Sun will be up for 15 hours and 6 minutes, setting at 9:13, and it will rise tomorrow at 6:05. The Moon, 2 days past first quarter, will set at 3:56 tomorrow morning.

It’s Wednesday again and time to look for the bright planets. Two of them are in the evening sky. The brilliant beacon of Venus will be visible in the western twilight from about 9:35 p.m. until it sets at 11:54. Jupiter will be in the southeast as it gets dark. Jupiter is only out shown by Venus and the Moon. And after Venus sets will have the night to itself as the brightest star-like object until it sets at 5:31 a.m. Binoculars will show it to be not quite star-like in size, that is it will appear as a tiny orb flanked by little star-like moons. Saturn will rise at 11:43 p.m. in the east-southeast. Mars will rise at 1:28 a.m. and is now outshining Saturn, and will, this summer even outshine Jupiter.

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

Addendum

Panorama of the Moon and planets

Panorama of the Moon and planets Venus and Jupiter at 10 p.m. May 23, 2018. Click on image to enlarge. Created using Stellarium.

Binocular Moon

The Moon as it might appear in a small telescope or binoculars tonight May 23, 2018 at 10 p.m. Created using Stellarium.

Jupiter and moons

Jupiter and its 4 Galilean moons at 10 p.m. EDT May 23, 2018 (2:00 UT, May 24, 2018) Io is transiting the face of Jupiter at that time. Io transit begins at 8:52 p.m. EDT ():52 UT, Shadow start 9:13 p.m. EDT 1:13 UT, Transit ends 11:00 p.m. EDT, 3:00 UT, Shadow ends at 11:22 p.m. EDT, 3:22 UT.  Io actually will be practically invisible during its transit, but its shadow may be spotted in small telescopes. Created using Stellarium. 

Morning planets

The morning planets Mars and Saturn at 5 a.m. May 24, 2018. Created using Stellarium.

Telescopic morning planets

Saturn and Mars with the same magnification with an inset of Mars at higher magnification at 5 a.m. May 24, 20`8. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on May 23, 2018. The night ends on the left with sunrise on the 24th. Click on the image to enlarge. Created using my LookingUp program.

05/22/2018 – Ephemeris – Seeing detail on the face of Jupiter with a small telescope

May 22, 2018 Leave a comment

Ephemeris for Tuesday, May 22nd. Today the Sun will be up for 15 hours and 4 minutes, setting at 9:12, and it will rise tomorrow at 6:06. The Moon, 1 day past first quarter, will set at 3:27 tomorrow morning.

Even in small telescopes Jupiter shows some detail. The larger the telescope in diameter the more detail can be seen. It also depends on what astronomers call seeing, or the steadiness of the atmosphere. The easiest detail to spot are the parallel brown and cream-colored cloud bands. These run in the direction that Jupiter’s moons move, since the four Galilean moons orbit over Jupiter’s equator. Jupiter, 11 time’s the Earth’s diameter, rotates on its axis in a bit less than 10 hours, though the clouds at the equator rotate faster than those at higher latitudes. It also gives Jupiter a slightly squashed appearance., enhanced by the horizontal stripes. Embedded in one of the dark stripes is the famous Great Red Spot.

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

Addendum

Jupiter with red spot

Scott Anttila image of Jupiter from November 14, 2011.

 

05/21/2018 – Ephemeris – 408 years ago Galileo discovered that Jupiter had moons

May 21, 2018 Comments off

Ephemeris for Monday, May 21st. Today the Sun will be up for 15 hours and 2 minutes, setting at 9:10, and it will rise tomorrow at 6:07. The Moon, at first quarter today, will set at 2:55 tomorrow morning.

Jupiter is the bright star-like object in the southeast in the evening. In telescopes and even in binoculars the observer can spot up to four stars nearby. These aren’t stars, but moons or satellites of Jupiter. Galileo discovered them 408 years ago with his small telescope. Jupiter has 69 satellites in all at last count, but the rest are tiny objects. Of the four ‘Galilean’ satellites all but one is larger than the Moon. They are, in order from Jupiter Io, a volcano riddled world which is constantly resurfacing itself. Next is Europa an icy moon with a good probability of a salty ocean beneath. Giant Ganymede is next, larger than Mercury, it is also icy with the possibility of an ocean. Last is Callisto a dark moon with bright craters.

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

Addendum

Galileo's moons

Multiple night sightings of Jupiter’s moons by Galileo.

Jupiter and its moons tonight

Jupiter and its moons tonight, May 21, 2018. Created using Cartes du Ciel (Sky Charts).

05/18/2018 – Ephemeris – Two GTAS outreach events this weekend

May 18, 2018 Comments off

Ephemeris for Friday, May 18th. Today the Sun will be up for 14 hours and 56 minutes, setting at 9:07, and it will rise tomorrow at 6:10. The Moon, half way from new to first quarter, will set at 12:41 tomorrow morning.

The Grand Traverse Astronomical Society will be part of two events this weekend. Saturday evening, that’s tomorrow night, society members will be at Northwestern Michigan College’s Rogers Observatory, south of Traverse City, on Birmley Road, for a star party starting at 9 p.m. viewing the Moon and planets Venus and Jupiter with its four largest moons. There will be some actual star observing too as the sky gets darker.

On Sunday the society will be part of the Northwestern Michigan College’s Barbecue, with telescopes to observe the Sun safely. There will be videos and exhibits of photographs and actual meteorites, and videos in the Health and Science Building.

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

05/17/2018 – Ephemeris – Venus and the Moon tonight and viewing Venus in the daytime

May 17, 2018 Comments off

Ephemeris for Thursday, May 17th. Today the Sun will be up for 14 hours and 54 minutes, setting at 9:06, and it will rise tomorrow at 6:11. The Moon, 2 days past new, will set at 11:40 this evening.

This afternoon at 2:11 the Moon will appear to pass Venus. This will be impossible to see since the Moon is going to be much dimmer than Venus. Venus can indeed be seen in the daylight. I’ve seen it many times with binoculars or a telescope, but only once with the naked eye. The latter time was not long before sunset. It is essential that to spot Venus in the daytime by any of these means that one is in the shade, by putting the Sun behind a building, and knowing where Venus is supposed to be using a program on a smart phone. By tonight the Moon will have moved eastward past Venus by up to 13 of its diameters and will also be displaying earthshine, the reflection of the Earth off its night side.

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

Addendum

Venus and the Moon

Venus and the Moon at 10 p.m. May 17, 2018. Created using Stellarium.