03/26/2014 – Ephemeris – It’s Wednesday, do you know where the bright planets are?
Ephemeris for Wednesday, March 26th. The sun will rise at 7:34. It’ll be up for 12 hours and 28 minutes, setting at 8:02. The moon, 3 days past last quarter, will rise at 5:31 tomorrow morning.
Wednesday is Bright Planets Day here on Ephemeris. Jupiter will be in the southern sky as darkness falls tonight. It’s cruising against the stars of Gemini now, and moving east after spending a couple of months backtracking to the west. It will set at 3:56 a.m. in the west-northwest. Reddish Mars is in Virgo now and left and a bit above bright star Spica in the late evening, which it now outshines. Mars will rise at 9:19 p.m. It will pass due south at 2:54 a.m. It’s 61 million miles away now. Saturn will rise at 11:53 p.m. in the east-southeast. It’s seen against the stars of Libra the scales this year. Venus will rise at 5:43 tomorrow morning. The crescent moon will appear above left of Venus then.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter and the winter constellations at 10 p.m. on March 26, 2014. Created using Stellarium.
Mars and the spring constellations at 10 p.m. on March 26, 2014. Created using Stellarium.
Saturn, Venus and the Moon with the constellations of summer at 6:30 a.m. on March 27, 2014. I’ve added Venus’ orbit and the ecliptic. Created using Stellarium.
Venus and the crescent Moon at 6:30 a.m. March 27, 2014. Created using Stellarium.
Relative sizes of the planets as seen in a telescope using the same magnification. Created using Stellarium.
03/25/2014 – Ephemeris – The new Cosmos series
Ephemeris for Tuesday, March 25th. The sun will rise at 7:36. It’ll be up for 12 hours and 24 minutes, setting at 8:01. The moon, 2 days past last quarter, will rise at 4:52 tomorrow morning.
Unless you’ve been living under a rock for the past few months, you are aware of the new Cosmos series that’s been broadcast on Fox and National Geographic Channels. The title is Cosmos, a Spacetime Odyssey, and it’s hosted by New York’s Hayden Planetarium director Neil deGrasse Tyson. If the TV is not your thing there are free apps for the iPhone, iPad and Android devices to view the programs. Also there’s a website cosmosontv.com, where the episodes can be replayed. However it looks like each episode will be only be available for something like 8 weeks from the air date. It’s on Fox TV at 9 p.m. on Sundays, National Geographic Channel at 10 p.m. on Mondays. Cosmos: A Spacetime Odyssey is a really great series, a worthy successor to Carl Sagan’s original Cosmos series 34 years ago.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
03/24/2014 – Ephemeris – The spring constellation of Leo the lion
Ephemeris for Monday, March 24th. The sun will rise at 7:38. It’ll be up for 12 hours and 21 minutes, setting at 7:59. The moon, 1 day past last quarter, will rise at 4:09 tomorrow morning.
Tonight about 10:00 the constellation of Leo the lion can be seen half way up the sky in the east-southeast. The head and mane of a male lion is seen as a backward question mark. This pattern of stars is also called the sickle. The bright star that is the dot at the bottom is Regulus, the “Little King Star”. To the lower left is a triangle of stars that is the lion’s hind end with the star Denebola at the far end. It is said that the reason the figure of a lion came to be seen in the stars here is because lions came from the desert, driven by the heat, to drink from the river Nile the time of the year that the sun was in this part of the sky. Leo is one of the constellations of the Zodiac. Leo can also be found by first locating the Big Dipper high in the northeast. Imagine a hole drilled in the bowl of the dipper and the water will fall on Leo’s back.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Leo and the Big Dipper (Ursa Major) using the angle measuring tool as an arrow. Date: March 24, 10 p.m. Created using Stellarium.
03/21/2014 – Ephemeris – Star party and Venus this weekend
Ephemeris for Friday, March 21st. The sun will rise at 7:43. It’ll be up for 12 hours and 12 minutes, setting at 7:56. The moon, 2 days before last quarter, will rise at 1:27 tomorrow morning.
Tomorrow evening the Grand Traverse Astronomical Society will host a star party at Northwestern Michigan College’s Rogers Observatory starting at 9 p.m. On tap if it’s clear will be the planets Jupiter and Mars. As it gets darker, the wonders of the winter sky will still be visible, along with those of the spring skies. The observatory is located south of Traverse City, on Brimley Road between Garfield and Keystone roads. There is a small admission charge for the college. For early morning risers the planet Venus will reach its greatest elongation west of the sun tomorrow at an angle of 47 degrees. From there on late October Venus will appear to be approaching the sun, before emerging into the evening sky.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus at greatest western elongation and its orbit as seen from the earth on March 22, 2014. Created using Stellarium.
The sun looks off-center because we are looking at the orbit from the Earth, and Venus’ orbit is inclined by about 3º from our orbit. The near side of the orbit is only 25 million miles (40 million km) from Earth and is thus foreshortened. The part of the orbit right below the Sun is beyond the Sun and about 93 million miles (150 million km) away from us. Mercury is shown, but not its orbit.
03/20/2014 – Ephemeris – Spring is a few hours away
Ephemeris for Thursday, March 20th. The sun will rise at 7:45. It’ll be up for 12 hours and 9 minutes, setting at 7:54. The moon, 3 days before last quarter, will rise at 12:24 tomorrow morning.
Just hang on for a few more hours and winter will be over. At 12:57 p.m. this afternoon (16:57 UT, March 20, 2014) the sun will appear to cross the earth’s celestial equator heading northward signaling the start of spring in the northern hemisphere. Unfortunately our weather won’t change that instantaneously. The word equinox means equal night, meaning at day and night are of equal length. However due to how astronomers actually define the instant of sunrise and sunset we are already above 12 hours daylight, and increasing by 3 minutes a day. The southern hemisphere of the earth will see the start of autumn as we see spring. The sun will rise due east today and set due west, which may mean hazardous visibility on east west roads with the low sun for a few days.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The sun at the vernal equinox point in the sky. The horizontal line the sun is crossing is the celestial equator. The red line is the sun’s path, the ecliptic. The sun is heading to the upper left. Created using Stellarium.
03/19/2014 – Ephemeris – Wednesday is bright planet day
Ephemeris for Wednesday, March 19th. The sun will rise at 7:47. It’ll be up for 12 hours and 6 minutes, setting at 7:53. The moon, 3 days past full, will rise at 11:19 this evening.
Wednesday is bright planet day on Ephemeris. Jupiter will be in the southern sky as darkness falls tonight. It’s cruising against the stars of Gemini now, and moving east after spending a couple of months backtracking to the west. It will pass due south at 8:39 p.m., and will set at 4:22 a.m. in the west-northwest. Reddish Mars is in Virgo now and left and a bit above bright star Spica in the late evening, which it now outshines. Mars will rise at 9:56 p.m. It will pass due south at 3:29 a.m. Saturn will rise at 12:21 a.m. in the east-southeast. It’s seen against the stars of Libra the scales this year. Venus will rise at 5:48 tomorrow morning and shines brightly in the southeast before sunrise. It will reach its greatest angle from the sun on Saturday.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter and the winter constellations at 10 p.m. on March 19, 2014. Created using Stellarium.
- Jupiter and moons at 10 p.m. on March 19, 2014. Created using Cartes du Ciel.
Note the Great Red Spot. It will transit the disk ( be centered) at 10:48 p.m. Since the 1960’s the Great Red Spot has not been that red. It’s faded quite a bit since then. I tend to think of it a a pastel pink. This is a north is up view, but most telescopes invert the image and/or show a mirror image, so don’t give up too soon.
Mars low in the east at 11 p.m. on March 19, 2014. Created using Stellarium.
- Mars, Saturn, and Venus with the constellations of summer at 6:30 a.m. on March 20, 2014. I’ve added Venus’ orbit and the ecliptic. Created using Stellarium.
Saturday Venus will be at its greatest western elongation from the sun of 47º. As can be seen it’s about there now. The ecliptic is the plane of the earth’s orbit, and the other planets stick reasonably close to it because the solar system is essentially flat. I’m sure the new Cosmos will cover how the solar system formed and the reason the solar system is flat and also one way.
Saturn and its moons at 6:30 a.m., March 20, 2014. Only the moon Titan can be easily seen in small telescopes. Created using Stellarium.
Venus at 6:30 a.m., March 20, 2014. I burned in the image of Venus because that’s what it looks like. Stellarium shows the Venusian clouds as seen in ultraviolet light. In white light Venus is a cue ball. Created using Stellarium.
Spring starts tomorrow!
03/18/2014 – Ephemeris – Thursday a.m. many folks including New Yorkers will see a bright star wink out
Ephemeris for Tuesday, March 18th. The sun will rise at 7:49. It’ll be up for 12 hours and 3 minutes, setting at 7:52. The moon, 2 days past full, will rise at 10:15 this evening.
On Thursday morning the 20th around 2 a.m. the star Regulus, the brightest star in the constellation Leo the lion will wink out for up to 14 seconds for observers in New York City. That will be exceptionally cool, because Regulus is one of the few stars actually bright enough to be visible from that metropolis. Regulus will not be at fault, but for a narrow band of the earth running northwest of there the asteroid 163 Erigone will pass in front of Regulus in an extremely rare occultation of a bright star. This will allow observers on the ground to time the duration of the event and put together the silhouette of the asteroid, which is thought to be 45 miles wide. Observers have in the past spotted secondary occultations of another asteroid and discovered an asteroid satellite.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Part of the occultation path of Regulus. See link below. Credit: Geoff Hitchcox / IOTA and Sky & Telescope magazine
Here’s a link to the Sky and Telescope site with lots more information. Clicking on their map will bring up an interactive Google earth map.
03/17/2014 – Ephemeris – When Ireland had the world’s largest telescope
Ephemeris for St. Patrick’s Day, Monday, March 17th. The sun will rise at 7:51. It’ll be up for 11 hours and 59 minutes, setting at 7:51. The moon, 1 day past full, will rise at 9:11 this evening.
In the 19th century Ireland laid claim to having the largest telescope. It was a reflecting telescope with a mirror diameter of 72 inches. It was built by William Parsons the Third Earl of Rosse. The base of the telescope tube rested in a pit between two massive walls and could only look in a north-south direction. It saw first usage in 1847. The telescope was called the Leviathan of Parsonstown, and was in use until 1890. Mirrors in those days was made of a silvery alloy called speculum. Two mirrors were used alternately because speculum tarnished. The mirror not in use would have to be re-polished and swapped in from time to time. It was the largest telescope until the 100 inch at Mt. Wilson was put in service in 1917.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The 72 inch Leviathan of Parsonstown. source: http://www.klima-luft.de/steinicke/ngcic/persons/rosse3.htm
03/14/2014 – Ephemeris – Oldest (so far) earthly rock found
Ephemeris for Pi Day 3/14, Friday, March 14th. The sun will rise at 7:56. It’ll be up for 11 hours and 50 minutes, setting at 7:47. The moon, 2 days before full, will set at 7:08 tomorrow morning.
Scientists have found the oldest earth rock, actually a tiny zircon from Jack Hills in western Australia. The earth, with plate tectonics, and weathering is pretty hard on rocks, so it’s impossible to date the age of the Earth from them. The age of the solar system, and presumably the Earth is measured from meteorites which have been pretty much unaltered since the beginning. Dating meteorites gives us a pretty consistent 4.567 billion years as the oldest age. One spot in the zircon measures to date of 4.374 billion years ago. If the date holds up, it means the molten earth formed a solid surface very early, maybe 160 million years after its formation and 100 million years after a Mars sized object slammed into the Earth creating the Moon.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Link to LiveScience Article for more information.
03/13/2014 – Ephemeris – An asteroid self destructs
Ephemeris for Thursday, March 13th. The sun will rise at 7:58. It’ll be up for 11 hours and 47 minutes, setting at 7:46. The moon, 3 days before full, will set at 6:40 tomorrow morning.
The solar system is getting weirder and weirder. Last week came the announcement from the Hubble Space Telescope folks, that they have been watching an asteroid in the main asteroid belt falling apart. The object was picked up last year by two sky survey groups and communicated to the Keck Telescope and Hubble telescope folks for further study. Both found that it was an asteroid slowly breaking up into smaller pieces, and watched it over several months breaking into smaller and smaller pieces. It’s thought that this asteroid is or was a rubble pile and the pressure of sunlight caused it to rotate fast enough to break it apart. The speeds of the dispersing particles is a mere earthly walking speed, ruling out a collision.
Addendum
Four images of an asteroid breaking up over 3 months. The largest piece is perhaps the size of 4 football fields. Image Credit: NASA, ESA, D. Jewitt (UCLA).
Click here for the NASA page with more information.
