Archive
07/30/2013 – Ephemeris – Mercury appears in the morning
Ephemeris for Tuesday, July 30th. The sun rises at 6:27. It’ll be up for 14 hours and 43 minutes, setting at 9:10. The moon, 1 day past last quarter, will rise at 1:23 tomorrow morning.
Mercury is joining the morning planets Jupiter and Mars now. This morning is the time of its greatest elongation or separation from the sun of 20 degrees, but this planet will actually brighten as it starts its journey back around the sun. Mercury’s phase at greatest elongation is half illuminated. As it moves back around the sun the phase becomes fuller. To find Mercury it’s best to use binoculars. At around 5:30 look to the east northeast on a very low horizon. First locate Jupiter, the brightest and highest of the three. Then look below for reddish Mars. Once found, Mercury can be located by extending a line one and a half times further than Mars. These planets can be seen until 6 a.m. or a bit later.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Animation of Mercury, Mars and Jupiter at one day intervals from July 31 to August 7, 2013 at 5:45 a.m. Created using Stellarium and the GIMP. Click to enlarge and animate.
03/29/2013 – Ephemeris –
Ephemeris for Thursday, March 28th. The sun will rise at 7:30. It’ll be up for 12 hours and 34 minutes, setting at 8:05. The moon, 1 day past full, will rise at 10:01 this evening.
Venus is passing superior conjunction with the sun today. Superior means Venus is passing behind, thought not directly behind the Sun. You can see it only in the images of the SOHO spacecraft. On the Internet google soho nasa to find the site. Our last inferior conjunction of Venus was the transit of Venus last June, when Venus crossed the face of the sun. Mars is about to pass in conjunction with the sun. All its conjunctions are superior. For about a month, starting April 4th. the satellites and rovers cannot receive transmissions from the earth due to the sun’s radio noise, so they are put into a passive state. The Deep Space Network on the earth can pick up their transmissions, though not well during this period due to its greater sensitivity.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Annotated SOHO LASCO C3 image of the sun, behind the occulting disk with Venus and Mars. Image: ESA, NASA
11/27/2012 – Ephemeris – What’s Curiosity’s big secret?
Ephemeris for Tuesday, November 27th. The sun will rise at 7:55. It’ll be up for 9 hours and 10 minutes, setting at 5:05. The moon, 1 day before full, will set at 7:53 tomorrow morning.
Last Tuesday NPR’s Joe Palca revealed that John Grotzinger the Principal Investigator for the Curiosity Rover mission on Mars had let slip that they may soon announce an earth shaking discovery. The Jet Propulsion Laboratory and NASA have been backpedaling ever since. The announcement may come next week Monday. The discovery may have been made with the SAM instrument, the most complex chemical lab sent into space. SAM is an acronym for Sample Analysis at Mars. It is hoped that SAM might detect organic compounds. Maybe it has. The Viking missions in 1976 failed to detect organics. It’s thought for organics to survive they would have to be below the surface shielded from the sun’s x-rays that get in through Mars’ thin atmosphere.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Scoop marks at RockNest. Image credit: NASA/JPL-Caltech/Malin Space Science Systems. Did the sample in question come from there?
When the Bad Astronomer Phil Plait posted his take on this last week. I responded that I thought it was a discarded Earth Bar wrapper. Think about it.
08/23/2012 – Ephemeris – A belated salute to Curiosity
Ephemeris for Thursday, August 23rd. The sun rises at 6:55. It’ll be up for 13 hours and 38 minutes, setting at 8:34. The moon, 1 day before first quarter, will set at 11:41 this evening.
It’s been two and a half weeks since the Curiosity Rover landed on Mars. I finished the prior two weeks programs less than an hour before Curiosity landed and before heading off for vacation, so this is my first opportunity to talk about the landing. The so-called “Seven Minutes of Terror” went without a hitch. Either receiving transmissions directly from the spacecraft or through the Odyssey Mars orbiter, tones from the spacecraft ticked off the landing milestones right on time. As I’m recording this Curiosity hasn’t moved, however it’s already zapped a rock with its laser, its delivered a panorama of its surroundings, and is still sending frames of the descent movie it took when the heat shield was dropped, until it touched down.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Here’s a mix from the Seven Minutes of Terror video created before landing cut with actual Jet Propulsion Laboratory (JPL) Mission Control footage as Curiosity actually landed.
Here’s another video of the landing cut with scenes of gatherings around the country including Times Square, and video from the landing imager and Curiosity descending on the parachute from the Mars Reconnaissance Orbiter.
Here is a hi-res descent and landing from the MARDI landing imager. Hat tip to the Bad Astronomer. Play at full screen for best effect.
Curiosity has Landed!
Congratulations to JPL and NASA!
08/03/2012 – Ephemeris – Weekend events here and on Mars.
Ephemeris for Friday, August 3rd. The sun rises at 6:31. It’ll be up for 14 hours and 32 minutes, setting at 9:04. The moon, 2 days past full, will rise at 9:34 this evening.
The Northwestern Michigan College’s Rogers observatory will be open this evening starting at 9 p.m. For views of the heavens including the planet Saturn and the moon. There’s some bright deep sky objects also visible. Mars though up is a very tiny planet and is quite distant. What can’t be seen in a telescope will be visible shortly. Monday at 1:31 a.m. The Curiosity Mars Science Laboratory will land in Gale Crater. If the landing is successful the new rover will be bringing a new arsenal of scientific instruments to probe the martian past. From our vantage point on the earth Mars looks like a tiny yellowish orange disk. We will be back to two operational rovers joining the three operational satellites now orbiting Mars.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Here’s a movie from the Jet Propulsion Laboratory (JPL) of Curiosity’s entry descent and landing called Seven Minutes of Terror: http://youtu.be/ISmWAyQxqqs
03/14/2012 – Ephemeris – Where are the bright planets this week?
Wednesday, March 14th. The sun will rise at 7:55. It’ll be up for 11 hours and 52 minutes, setting at 7:47. The moon, at last quarter today, will rise at 3:35 tomorrow morning.
Let’s see what’s happening with the bright planets for this week. Mercury will make a brief appearance in the west after sunset. It will set at 8:54. Venus and Jupiter are brilliant in the western sky after sunset. Jupiter will be just below left of Venus, the brighter planet. Jupiter will set first at 11:40 p.m. followed by Venus at 11:53. Mars is up in the east in the evening with its unmistakable bright reddish color. It’s in the constellation Leo the lion now. It is 63.5 million miles and moving away. Mars will pass due south at 1:04 a.m. and will be setting in the west near sunrise. Saturn will rise at 10:31 p.m. just to the left of the bright star Spica in the east southeast.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The planets at 11 p.m. March 14, 2012. Created using Stellarium.
03/05/2012 – Ephemeris – Mars closest and Mercury at greatest elongation from the sun
Ephemeris for Monday, March 5th. The sun will rise at 7:12. It’ll be up for 11 hours and 24 minutes, setting at 6:36. The moon, 3 days before full, will set at 5:48 tomorrow morning.
The planet Mars is at its closest to the earth of this time around today. The distance is 62.6 million miles. All planets have elliptical orbits. The Earth varies its distance from the sun by 3 million miles. Mars has a remarkably elliptical orbit which varies its distance from the sun by nearly 30 million miles. It is now at its farthest from the sun. Another small planet is making its appearance in the evening sky now. That’s Mercury seen low in the west after sunset, much closer to the horizon than bright Venus and Jupiter. Mercury is at its greatest apparent distance or elongation from the sun. Mercury will set at 8:14 p.m. It is hard to spot in twilight, so binoculars will help. Like Mars Mercury’s orbit is also very elliptical.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The southern sky with the planets at 7:15 p.m. Created using Stellarium.
The sky after sunset showing all the evening planets. Created using Stellarium.
Click on the image to enlarge.
03/01/2012 – Ephemeris – Preview of March skies
Ephemeris for Thursday, March 1st. The sun will rise at 7:19. It’ll be up for 11 hours and 11 minutes, setting at 6:30. The moon, 1 day past first quarter, will set at 3:18 tomorrow morning.
Let’s look at the skies for the month of March. The sun will pass the celestial equator as the promising season of spring will begin. Daylight hours in the Interlochen/Traverse City area and will increase from 11 hours and 11 minutes today to 12 hours 44 minutes on the 31st. The altitude, or angle, of the sun above the southern horizon at local noon will be 38 degrees today and will ascend to nearly 50 degrees on the 31st. The altitude of the sun in the Straits area will be a degree lower. Local apparent noon this month, when the sun passes due south, will be about 12:49 p.m. Spring will begin on the 20th at 1:14 a.m. Mars will be in opposition with the sun Saturday and closest to us on Monday.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/08/2011 – Ephemeris – Where are the bright planets?
Ephemeris for Wednesday, February 8th. The sun will rise at 7:53. It’ll be up for 10 hours and 7 minutes, setting at 6:00. The moon, 1 day past full, will rise at 7:24 this evening.
Let’s see what’s happening with the bright planets for this week. Venus is brilliant in the southwestern sky after sunset and will set at 9:35 in the west. Jupiter the second brightest planet after Venus. It’s located high in the southwest as it gets dark and is seen against the stars of the constellation Aries. It will set at 12:25 a.m.. Mars is the up and coming planet. It will rise at 8:31 p.m in the east and is below the hind end of the constellation Leo the lion. It is 69.2 million miles away and closing and is getting brighter. It’s now as bright as most first magnitude stars. Mars will pass due south at 3:01 a.m. Saturn will rise at 11:54 p.m. just to the left of the bright star Spica in the east southeast.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Venus by Scott Anttila. Taken Monday evening February 6, 2012
Jupiter by Scott Anttila. Taken Monday evening February 6, 2012
Bob Moler's Ephemeris Blog 