Archive
03/03/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, March 3rd. Today the Sun will be up for 11 hours and 17 minutes, setting at 6:33, and it will rise tomorrow at 7:14. The Moon, 2 days before last quarter, will rise at 12:09 tomorrow morning.
Let’s search for the naked-eye planets for this week. Unfortunately the only one you’ll find is Mars. The other four are hanging out in the direction of the Sun and won’t be seen for a week or so. Mars can be found high in the west-southwest and below left of the Pleiades at 8 pm tonight. Mars will be due south of the Pleiades tonight, which from our cockeyed view of the heavens, from north of the equator, places Mars below and left of the Pleiades. The Red Planet will set at 1:20 am. Of the outer planets Mars is the fastest, being the nearest to the Sun, and to the Earth. So unlike Jupiter, Saturn, and the stars which rise and set about four minutes earlier each night, Mars sets about a minute earlier each night now.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Here’s an animation showing why Mars being south of the Pleiades doesn’t look like it in the sky. This is all about directions on the celestial sphere. This will be the position of Mars at 8 pm on March 3rd, 2021, seen in the west-southwest. It is a three frame animation. The first is without coordinate grids as one would see it from about 45 degrees north latitude. The second frame contains the equatorial grid. The lines to the upper right point to the North Pole of the sky near Polaris, so that’s north. The third frame has an alt-azimuth grid. Its lines run vertically and horizontally. Created using Stellarium and GIMP.
The moon as it might appear in binoculars at 6 am tomorrow morning March 4, 2021. Created using Stellarium.
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on March 3, 2021. The night ends on the left with sunrise on the 4th. There is a planet traffic jam in the morning and the symbols and labels for Jupiter and Mercury overlap. Unfortunately these planets rise too soon before the Sun to be seen for us up north. It is a great sight for Southern Hemisphere observers. Click on the image to enlarge. Created using my LookingUp program.
03/02/2021 – Ephemeris – Sirius and the Pup
This is Ephemeris for Tuesday, March 2nd. Today the Sun will be up for 11 hours and 14 minutes, setting at 6:32, and it will rise tomorrow at 7:16. The Moon, halfway from full to last quarter, will rise at 10:51 this evening.
Sirius is the brightest night-time star and is located in the south at 9 p.m. below and a bit left of Orion the Hunter. We’ve visited Sirius a month ago. But there is another star in the Sirius system that is practically invisible due to Sirius’ dazzling glare. Its name is Sirius B, nicknamed the Pup, alluding to Sirius’ Dog Star title. The tiny star was suspected as far back as 1834 due to Sirius’ wavy path against the more distant stars in the sky. Sirius and the Pup have 50-year orbits of each other. The Pup was first seen in 1862. It was the first of a new class of stars to be discovered, white dwarfs. The Pup is a dying star with the mass of the Sun, collapsed down to the size of the Earth after running out of hydrogen fuel in its core.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A Sirius finder animation for late January/early February at around 8 pm. Even in bright moonlight the seven bright stars of Orion can be seen. The three stars of Orion’s belt make a great pointer to Sirius. Created using Stellarium, GIMP and Libreoffice (for the arrow).
Sirius A & B’s path in the sky showing the wobble that betrayed the Pup’s presence. Credit Mike Guidry, University of Tennessee.
Sirius A and B imaged by two different space telescopes, revealing dramatically different views! Hubble’s image (left) shows Sirius A shining brightly in visible light, with diminutive Sirius B a tiny dot. However, in Chandra’s image (right) tiny Sirius B is dramatically brighter in X-rays! The “Universe in a Different Light” activity highlights more surprising views of some familiar objects: http://bit.ly/different-light-nsn NASA, ESA, H. Bond (STScI), and M. Barstow (University of Leicester) (left); NASA/SAO/CXC (right).
03/01/2021 – Ephemeris – Previewing March skies
This is Ephemeris for Monday, March 1st. Today the Sun will be up for 11 hours and 11 minutes, setting at 6:30, and it will rise tomorrow at 7:18. The Moon, 2 days past full, will rise at 9:33 this evening.
Let’s preview the month of March. In March the increase in daylight hours is at its greatest, with Spring 3 weeks away. Daylight hours will increase from 11 hours and 11 minutes today to 12 hours and 44 minutes on the 31st. Along with that the altitude of the Sun at local noon will increase from 38 degrees today to 49 ½ degrees at month’s end. Local noon today, by the way, for Interlochen and Traverse City is 12:54 pm, which is mainly due to the fact that our standard time meridian happens to run through Philadelphia. That’s before daylight time starts on the 14th. On that date local noon will be 1:50 pm. Spring will begin later this month on the 20th when the Sun will pass overhead for someone on the equator heading northward.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
March Evening Star Chart
Star Chart for March 2021 (10 p.m. EDT March 15, 2021). Click on image to enlarge. Created using my LookingUp program. Click on image to enlarge. Created using my LookingUp program.
The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian. (An hour and 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere (rotating star finder) you may have to set it to 45 minutes or 1 hour 45 minutes earlier than your current time.
Note the chart times of 10 p.m. and 6 a.m. are for the 15th. For each week before the 15th add ½ hour (28 minutes if you’re picky). For each week after the 15th subtract ½ hour. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog.
March Morning Star Chart
Star Chart for March mornings 2021 (6 a.m. EST March 15, 2021). Click on image to enlarge. Created using my LookingUp program.
The morning planets have yet to rise at chart time.
For a list of constellation names to go with the abbreviations click here.
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
- The leaky bowl of the Big Dipper drips on Leo.
- Follow the arc of the handle of the Big Dipper to the star Arcturus, and
- Extend it as a spike to Spica.
- The Summer Triangle appears in red.
Twilight Limits, Nautical and Astronomical
| EST/EDT | |||||||
| Morning twilight | Evening twilight | Dark night | Moon | ||||
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2021-03-01 | 5h43m | 6h17m | 19h32m | 20h06m | 20h06m | 21h34m | 0.89 |
| 2021-03-02 | 5h41m | 6h15m | 19h33m | 20h07m | 20h07m | 22h51m | 0.81 |
| 2021-03-03 | 5h40m | 6h14m | 19h35m | 20h09m | 20h09m | – | 0.71 |
| 2021-03-04 | 5h38m | 6h12m | 19h36m | 20h10m | 20h10m | 0h09m | 0.6 |
| 2021-03-05 | 5h36m | 6h10m | 19h37m | 20h11m | 20h11m | 1h27m | 0.49 |
| 2021-03-06 | 5h34m | 6h08m | 19h39m | 20h13m | 20h13m | 2h41m | 0.37 |
| 2021-03-07 | 5h32m | 6h07m | 19h40m | 20h14m | 20h14m | 3h48m | 0.27 |
| 2021-03-08 | 5h31m | 6h05m | 19h41m | 20h15m | 20h15m | 4h47m | 0.18 |
| 2021-03-09 | 5h29m | 6h03m | 19h43m | 20h17m | 20h17m | 5h29m | 0.11 |
| 2021-03-10 | 5h27m | 6h01m | 19h44m | 20h18m | 20h18m | 5h27m | 0.05 |
| 2021-03-11 | 5h25m | 5h59m | 19h45m | 20h20m | 20h20m | 5h25m | 0.02 |
| 2021-03-12 | 5h23m | 5h57m | 19h47m | 20h21m | 20h21m | 5h23m | 0 |
| 2021-03-13 | 5h21m | 5h56m | 19h48m | 20h22m | 20h22m | 5h21m | 0.01 |
| 2021-03-14 | 6h19m | 6h54m | 20h49m | 21h24m | 21h24m | 6h19m | 0.03 |
| 2021-03-15 | 6h17m | 6h52m | 20h51m | 21h25m | 22h13m | 6h17m | 0.07 |
| 2021-03-16 | 6h15m | 6h50m | 20h52m | 21h26m | 23h15m | 6h15m | 0.13 |
| 2021-03-17 | 6h13m | 6h48m | 20h53m | 21h28m | – | 6h13m | 0.2 |
| 2021-03-18 | 6h11m | 6h46m | 20h54m | 21h29m | 0h18m | 6h11m | 0.28 |
| 2021-03-19 | 6h09m | 6h44m | 20h56m | 21h31m | 1h21m | 6h09m | 0.37 |
| 2021-03-20 | 6h11m | 6h46m | 21h01m | 21h36m | 2h23m | 6h11m | 0.46 |
| 2021-03-21 | 6h09m | 6h44m | 21h02m | 21h38m | 3h23m | 6h09m | 0.56 |
| 2021-03-22 | 6h07m | 6h42m | 21h04m | 21h39m | 4h19m | 6h07m | 0.66 |
| 2021-03-23 | 6h05m | 6h40m | 21h05m | 21h41m | 5h08m | 6h05m | 0.75 |
| 2021-03-24 | 6h03m | 6h38m | 21h07m | 21h42m | 5h51m | 6h03m | 0.84 |
| 2021-03-25 | 6h01m | 6h36m | 21h08m | 21h43m | – | – | 0.91 |
| 2021-03-26 | 5h59m | 6h34m | 21h09m | 21h45m | – | – | 0.97 |
| 2021-03-27 | 5h57m | 6h32m | 21h11m | 21h46m | – | – | 1 |
| 2021-03-28 | 5h55m | 6h31m | 21h12m | 21h48m | – | – | 1 |
| 2021-03-29 | 5h52m | 6h29m | 21h13m | 21h50m | – | – | 0.97 |
| 2021-03-30 | 5h50m | 6h27m | 21h15m | 21h51m | 21h51m | 22h50m | 0.92 |
| 2021-03-31 | 5h48m | 6h25m | 21h16m | 21h53m | 21h53m | – | 0.84 |
Twilight calendar was generated using Cartes du Ciel (Sky Charts).
See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2019/09/27/
NASA Calendar of Planetary Events
Date Time Event
Mar 1 Mo Venus: 6.3° W
2 Tu 12:19 am Moon Perigee: 365400 km
3 We 6:32 pm Mars-Pleiades: 2.6° S
5 Fr 12:11 am Mercury-Jupiter: 0.3° N
5 Fr 7:56 pm Moon Descending Node
5 Fr 8:30 pm Last Quarter
6 Sa 5:59 am Mercury Greatest Elongation: 27.3° W
In morning. Not the best for our latitude.
7 Su 3:45 pm Moon South Dec.: 25.2° S
9 Tu 6:02 pm Moon-Saturn: 3.9° N
10 We 10:35 am Moon-Jupiter: 4.3° N
10 We 6:36 pm Neptune Conjunction
10 We 8:02 pm Moon-Mercury: 3.9° N
13 Sa 5:21 am New Moon
18 Th 1:04 am Moon Apogee: 405300 km
19 Fr 1:48 pm Moon-Mars: 2.1° N
19 Fr 11:31 pm Moon Ascending Node
20 Sa 5:37 am Vernal Equinox Yea Spring!
20 Sa 3:15 pm Mars-Aldebaran: 6.9° N
21 Su 10:40 am First Quarter
22 Mo 4:35 am Moon North Dec.: 25.3° N
24 We 5:58 am Moon-Beehive: 2.7° S
26 Fr 2:17 am Venus Superior Conjunction
Enters the evening sky
28 Su 2:48 pm Full Moon (supermoon)
30 Tu 2:12 am Moon Perigee: 360300 km
Apr 1 Th Venus: 2° E
All event times are given for UTC-5:00: Eastern Standard Time before the 14th or UTC-4:00 Daylight Saving Time thereafter.
Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html
If you go to the above site you can print out a list like the above for the entire year or calendar pages for your time zone.
Note that the site is now kept up for archival purposes. Fred Espenak retired from NASA several years ago and has his own site, AstroPixels, which contain the same information: http://astropixels.com/almanac/almanac.html.
Sun and Moon Rising and Setting Events
Ephemeris of Sky Events for Interlochen/TC March, 2021 Local time zone: EST +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Mon 1| 07:19a 06:30p 11:11 | 07:34p 06:16a | Rise 09:33p 90%| |Tue 2| 07:18a 06:32p 11:14 | 07:35p 06:15a | Rise 10:51p 82%| |Wed 3| 07:16a 06:33p 11:17 | 07:36p 06:13a | Rise 12:09a 73%| |Thu 4| 07:14a 06:34p 11:20 | 07:38p 06:11a | Rise 01:26a 62%| |Fri 5| 07:12a 06:36p 11:23 | 07:39p 06:09a |L Qtr Rise 02:41a 51%| |Sat 6| 07:11a 06:37p 11:26 | 07:40p 06:08a | Rise 03:48a 40%| +------+-----------------------+----------------+-----------------------+ |Sun 7| 07:09a 06:38p 11:29 | 07:41p 06:06a | Rise 04:46a 29%| |Mon 8| 07:07a 06:40p 11:32 | 07:43p 06:04a | Rise 05:34a 20%| |Tue 9| 07:05a 06:41p 11:35 | 07:44p 06:02a | Rise 06:12a 12%| |Wed 10| 07:03a 06:42p 11:39 | 07:45p 06:00a | Rise 06:43a 6%| |Thu 11| 07:01a 06:44p 11:42 | 07:47p 05:59a | Rise 07:09a 2%| |Fri 12| 07:00a 06:45p 11:45 | 07:48p 05:57a | Rise 07:31a 0%| |Sat 13| 06:58a 06:46p 11:48 | 07:49p 05:55a |New Set 07:06p 0%| +------+-----------------------+----------------+-----------------------+ | EDT | Time Change | | | |Sun 14| 07:56a 07:48p 11:51 | 08:51p 06:53a | Set 09:09p 3%| |Mon 15| 07:54a 07:49p 11:54 | 08:52p 06:51a | Set 10:12p 6%| |Tue 16| 07:52a 07:50p 11:57 | 08:53p 06:49a | Set 11:15p 12%| |Wed 17| 07:50a 07:51p 12:00 | 08:55p 06:47a | Set 12:18a 18%| |Thu 18| 07:49a 07:53p 12:04 | 08:56p 06:45a | Set 01:21a 26%| |Fri 19| 07:47a 07:54p 12:07 | 08:57p 06:44a | Set 02:23a 35%| |Sat 20| 07:45a 07:55p 12:10 | 08:59p 06:42a | Set 03:23a 44%| +------+-----------------------+----------------+-----------------------+ |Sun 21| 07:43a 07:56p 12:13 | 09:00p 06:40a |F Qtr Set 04:18a 54%| |Mon 22| 07:41a 07:58p 12:16 | 09:01p 06:38a | Set 05:08a 64%| |Tue 23| 07:39a 07:59p 12:19 | 09:03p 06:36a | Set 05:50a 73%| |Wed 24| 07:37a 08:00p 12:22 | 09:04p 06:34a | Set 06:26a 82%| |Thu 25| 07:36a 08:02p 12:25 | 09:05p 06:32a | Set 06:57a 89%| |Fri 26| 07:34a 08:03p 12:29 | 09:07p 06:30a | Set 07:24a 95%| |Sat 27| 07:32a 08:04p 12:32 | 09:08p 06:28a | Set 07:50a 99%| +------+-----------------------+----------------+-----------------------+ |Sun 28| 07:30a 08:05p 12:35 | 09:10p 06:26a |Full Rise 08:08p 100%| |Mon 29| 07:28a 08:07p 12:38 | 09:11p 06:24a | Rise 09:28p 98%| |Tue 30| 07:26a 08:08p 12:41 | 09:12p 06:22a | Rise 10:50p 93%| |Wed 31| 07:24a 08:09p 12:44 | 09:14p 06:20a | Rise 12:11a 85%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunrise and sunset
Created using my LookingUp for DOS output as text.
02/26/2021 – Ephemeris – Origin of the Moon
This is Ephemeris for Friday, February 26th. Today the Sun will be up for 11 hours and 1 minute, setting at 6:26, and it will rise tomorrow at 7:23. The Moon, 1 day before full, will set at 7:59 tomorrow morning.
The origin of the Moon is a question that has vexed astronomers for years. Did it break off the molten Earth like a cell dividing? Was it captured by passing too close to the Earth? Neither is satisfactory. Chemical elements have different isotopes depending on the number of neutrons in their nucleus. The rocks brought back by the Apollo astronauts show that the isotopes of the elements in the rocks are the same as for the Earth. We know that Mars and the asteroids have different isotope ratios. The hypothesis that seems most likely is that another planet, the size of Mars collided with the 100 million-year-old Earth in a glancing blow that gave rise to a disk of material that eventually coalesced to form the Moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A progression of how the Moon may have formed by a small protoplanet crashed into the Earth. Credit: Brian Koberlein.
02/25/2021 – Ephemeris – Moon Dust, bad stuff
This is Ephemeris for Thursday, February 25th. Today the Sun will be up for 10 hours and 58 minutes, setting at 6:25, and it will rise tomorrow at 7:24. The Moon, 2 days before full, will set at 7:30 tomorrow morning.
One of the big problems that will have to be solved before the Artemis program sets up a permanent base on the Moon is what to do about lunar soil or Moon dust. That stuff gets into everything. The Apollo astronauts said it smelled like gunpowder. Unlike beach sand the particles aren’t rounded, but angular, being produced by rocks being hit by meteoroids large and micro over the eons by space weathering. With no atmosphere small particles can even weld themselves together. Though no studies have been done, any brought into the habitat would do damage to the lungs, like that to miners on Earth. Moon dust has compromised the seals on the containers of soil the Apollo crews brought back from the Moon.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Lunar soil sample. Credit Larry Taylor U of TN Knoxville from https://ntrs.nasa.gov/api/citations/20090026015/downloads/20090026015.pdf
02/24/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, February 24th. Today the Sun will be up for 10 hours and 55 minutes, setting at 6:24, and it will rise tomorrow at 7:26. The Moon, 3 days before full, will set at 6:56 tomorrow morning.
Let’s search for the naked-eye planets for this week. Unfortunately the only one you’ll find is Mars. The other four are hanging out in the direction of the Sun and won’t be seen for a week or two. They’ll be first seen low in the morning sky. Mars can be found high in the west-southwest and below the Pleiades at 8 pm tonight. Mars is moving rapidly eastward. It just entered the constellation of Taurus the bull, which is a lot wider than Aries, astronomically*, and will set at 1:26 am. Of the outer planets Mars is the fastest, being the nearest to the Sun, and to the Earth, so unlike Jupiter, Saturn and the stars which rise and set about four minutes earlier each night, Mars sets about a minute earlier each night now.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
* Astrologically the all the constellations or signs of the zodiac are 30 degrees wide. According to the International Astronomical Union (IAU) Aries is 25 degrees wide along the ecliptic, while Taurus is 37 degrees wide as measured using the Stellarium planetarium program. I do astronomy on Ephemeris, and consider astrology astronomy’s illegitimate parent.
Addendum
Mars finder animation with 3 layers: Unannotated chart, Labels and constellation lines added, and boundaries added. Created using Stellarium and GIMP.
The gibbous Moon as it might be seen in binoculars this evening at 8 pm tonight, February 24, 2021. Created using Stellarium.
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on February 24, 2021. The night ends on the left with sunrise on the 25th. There is a planet traffic jam in the morning and the labels for Jupiter and Mercury overlap. Unfortunately these planets rise too soon before the Sun to be seen for us up north. It is a great sight for Southern Hemisphere observers. Click on the image to enlarge. Created using my LookingUp program.
02/23/2021 – Ephemeris – The Perseverance rover landed on Mars taking video all the way down
Note: There was a news conference at JPL, Monday at 2 pm EST where videos of the parts of the landing were shown. Most hadn’t made it to the https://mars.nasa.gov website by Monday night. The news conference with the videos can be found on NASA TV, NASA’s YouTube channel and other sites.
This is Ephemeris for Tuesday, February 23rd. Today the Sun will be up for 10 hours and 52 minutes, setting at 6:22, and it will rise tomorrow at 7:28. The Moon, halfway from first quarter to full, will set at 6:15 tomorrow morning.
It looks like the Perseverance Rover was gently lowered to a flat spot in Jezero crater on Mars about a kilometer or two from the edge of the river delta it was aiming to be near. It is in the midst of checkouts and the unfolding of its masts and its various appendages. For the third time the Mars Reconnaissance Orbiter was able to take a picture of the entry craft on its parachute seen above the delta, as it had with Curiosity and the Phoenix lander before all the while performing its communication relay duties. A few images have come back from Percy, as the Rover is nicknamed as I record this Sunday night. By Monday Percy should have sent back more images and perhaps parts of the landing video.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A frame from the video looking down at the Perseverance rover from the Sky Crane. In the video as the rover neared the ground it was enveloped by a cloud of dust, so the support lines simply disappeared into the cloud of dust that enveloped the rover. Click on the image to enlarge. Credit NASA/JPL.
The Perseverance rover on the parachute over Jezero crater from the Mars Reconnaissance Orbiter. The circle on the image is the point where the rover landed. Click on the image to enlarge. Credit NASA/JPL-Caltech/University of Arizona.
02/19/2021 – Ephemeris – Let’s look at the first quarter Moon tonight
This is Ephemeris for Friday, February 19th. Today the Sun will be up for 10 hours and 40 minutes, setting at 6:17, and it will rise tomorrow at 7:34. The Moon, at first quarter today, will set at 2:32 tomorrow morning.
I love a first quarter Moon. The terminator or sunrise line cuts the Moon in half. Lots of craters are easily seen due to the long shadows cast by their crater walls. Best seen in a small telescope or strong pair of binoculars is a three crater chain just below left of the center of the Moon. The top and largest crater is Ptolemaeus. Below and connected to it is Alphonsus. A bit below Alphonsus is Arzachel. Alphonsus is the interesting one. In the pre-Apollo days amateur and some professional astronomers saw glows or mists in Alphonsus. In 1958 a Russian astronomer obtained spectra of one such mist. In 1965 the last Ranger mission to impact the Moon was sent to Alphonsus, but it didn’t find anything unusual.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The first quarter Moon tonight at 8 pm, February 19, 2021, as it might be seen in binoculars. Created using Stellarium.
A telescopic like view of the Moon via the Virtual Moon Atlas pointing out the craters discussed in the text.
Ranger 9 Image of Alphonsus #1. Credit NASA/JPL.
Left: The Ranger spacecraft. Right: The floor of the crater Alphonsus form Ranger 9. Only the last 3 spacecraft were successful. They transmitted images all the way down as they crashed into the Moon. Credit NASA/JPL.
02/18/2021 – Ephemeris – The Perseverance Rover will land on Mars this afternoon
This is Ephemeris for Thursday, February 18th. Today the Sun will be up for 10 hours and 37 minutes, setting at 6:15, and it will rise tomorrow at 7:36. The Moon, 1 day before first quarter, will set at 1:30 tomorrow morning.
Later this afternoon the Perseverance Rover will land in Jezero crater on Mars. NASA will have a live Internet feed from the Jet Propulsion Laboratory starting at 2:15 pm EST (19:15 UTC). Atmospheric entry will be at 3:48 pm EST (20:48 UTC), landing at 3:55 pm EST (20:55 UTC). This is Earth received time. The events actually happened 11 minutes 22 seconds earlier on Mars. Though cameras on the spacecraft will be recording the landing activity it will not be sent to Earth in real time due to the weak signal during entry. The spacecraft will be sending tones only for specific events during what is called EDL, Entry, Descent and Landing or “Seven Minutes of Terror”. If all goes well the first images will be taken and sent of its surroundings. And in the next weeks we’ll get an actual replay sent back of the landing with color and sound. It will be so cool!
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Links
NASA on YouTube: https://www.youtube.com/results?search_query=nasa
NASA TV: https://www.nasa.gov/multimedia/nasatv/#public
Graphic of the Entry, Descent and Landing of the Perseverance Rover. Click on the image to enlarge. Credit: NASA/JPL.
Perseverance drilling for a sample in Jezero crater. Artist drawing – NASA/JPL
02/17/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Ash Wednesday, Wednesday, February 17th. Today the Sun will be up for 10 hours and 34 minutes, setting at 6:14, and it will rise tomorrow at 7:38. The Moon, 2 days before first quarter, will set at 12:27 tomorrow morning.
Let’s search for the naked-eye planets for this week. Unfortunately the only one you’ll find is Mars. The other four are hanging out in the direction of the Sun and won’t be seen until spring. They’ll be first seen in the morning sky. Mars can be found high in the southwest and above the waxing crescent Moon at 8 pm tonight. They will be even closer Thursday night. Mars is increasing its speed eastward through the constellation of Aries the ram, which it’s two thirds the way through, and will set at 1:32 am. Of the outer planets Mars is the fastest, being the nearest to the Sun, and the Earth, so unlike Jupiter, Saturn and the stars which rise and set about four minutes earlier each night, Mars sets less than a minute earlier each night now.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Mars and the Moon in the southwestern sky at 8 pm tonight, February 17, 2021. Created using Stellarium.
The Moon as it might appear tonight at 8 pm, February 17, 2021. Created using Stellarium.
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on February 17, 2021. The night ends on the left with sunrise on the 18th. There is a planet traffic jam in the morning and the labels for Jupiter and Mercury overlap. Unfortunately these planets rise too soon before the Sun to be seen for us up north. It is a great sight for Southern Hemisphere observers. Click on the image to enlarge. Created using my LookingUp program.
