Archive
11/22/10 – Ephemeris – Some Comet Hartley 2 results
Monday, November 22nd. The sun will rise at 7:48. It’ll be up for 9 hours and 20 minutes, setting at 5:08. The moon, 1 day past full, will rise at 5:46 this evening.
NASA held a news conference last Thursday, two weeks after the Deep Impact spacecraft’s encounter with Comet Hartley 2 on November 4th. The comet didn’t disappoint. It was the most active nucleus found by any spacecraft, and its most active jets were powered by dry ice, something not seen before. The jets also disgorged bits of ice that looked like a snow storm in the spacecraft’s high resolution imagers. This was another first. The chicken drumstick shape of the nucleus was expected by beforehand. But the difference in the surface between the lobes which was smooth and the lobes themselves which were rough and actively spewing jets of CO2 and snow was a surprise. Looks like astronomers will be chewing on this drumstick for years to come.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
11/12/10 – Ephemeris – Viewing Night tomorrow
Friday, November 12th.* The sun will rise at 7:35. It’ll be up for 9 hours and 42 minutes, setting at 5:17. The moon, 1 day before first quarter, will set at 11:26 this evening.
Tomorrow night the Grand Traverse Astronomical Society and NMC Astronomy Club will host a public viewing night at Northwestern Michigan College’s Rogers Observatory starting at 9 p.m. On tap, if it’s clear, will be the moon, and the planets Jupiter and possibly Uranus which will appear near Jupiter. There are also some interesting binary stars and star clusters visible including the famous Double Cluster, and using binoculars or telescope finder scopes, the even more famous Pleiades or Seven Sisters may be seen. The NMC Astronomy Club has hand on activities for visitors, especially the kids, in case of cloudy skies. The observatory is located south of Traverse City, on Birmley Road between Garfield and Keystone roads.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
11/11/10 – Ephemeris – The Greeks measured the moon and the earth
Veteran’s Day, Thursday, November 11th. The sun will rise at 7:33. It’ll be up for 9 hours and 45 minutes, setting at 5:18. The moon, 2 days before first quarter, will set at 10:22 this evening.
Check out the moon tonight. The Greeks were able to use it to make two great discoveries. First they knew that lunar eclipses were caused by the moon entering the earth’s shadow. That wasn’t the discovery, the discovery was that the edge of the earth’s shadow was always circular. The only object that casts a circular shadow no matter what its orientation is a sphere. So the Greeks knew the earth was round long before the birth of Christ. They were also able to determine the distance of the moon via eclipses as 60 earth radii, which is within the moon’s actual distance range. It was in the 3rd century B.C. that Eratosthenes determined the circumference of the earth to provide an actual distance scale to the moon.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
11/10/10 – Ephemeris – The bright planets this week
Wednesday, November 10th.* The sun will rise at 7:32. It’ll be up for 9 hours and 47 minutes, setting at 5:19. The moon, 3 days before first quarter, will set at 9:18 this evening.
Lets take a look at the bright planets for this week. Mars is very low and lost in the evening twilight. The planet Jupiter is up at sunset appearing in the southeastern sky in the early evening. It will move due south at 9:01 p.m.. It is the brightest starlight object in the sky. It’s located in Pisces this year and will set at 2:47 a.m. The ringed planet Saturn will rise at 4:20 a.m. in the east southeast. It’s located in the constellation Virgo this year. It’s rings are opening nicely for telescopic observers. Venus is in the morning sky and will rise at 5:56 a.m. in the east southeast but may be hard to spot in the twilight. Mercury is also too close to the sun to be seen. It’s near where Mars is this year, in the evening sky.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
11/09/10 – Ephemeris – The constellations Triangulum and Aries
Ephemeris for Tuesday, November 9th.* The sun will rise at 7:31. It’ll be up for 9 hours and 50 minutes, setting at 5:21. The moon, half way from new to first quarter, will set at 8:13 this evening.
High in the south at 9 p.m. can be seen the Great Square of Pegasus. From the top left star of the square diverge two curved lines of stars that is Andromeda the chained princess. Just below and left of Andromeda is a slender triangle of stars, none particularly bright. It has a name you can easily see in the stars, Triangulum, the triangle. Early Christians saw it as the Mitre of Saint Peter or the Trinity. Another small constellation seen below Triangulum is the much better known constellation Aries the ram, a small hockey stick constellation, not that hard to spot. It is the first constellation of the Zodiac, where the sun is supposed to enter on the first day of spring. Due to the wobble of the earth’s axis, that honor is now given to Pisces.
* Times, as always are for the Traverse City/Interlochen area of Michigan.
