04/30/2021 – Ephemeris – Previewing May skies

This is Bob Moler with Ephemeris for Arbor Day, Friday, April 30th. Today the Sun will be up for 14 hours and 13 minutes, setting at 8:46, and it will rise tomorrow at 6:32. The Moon, 3 days before last quarter, will rise at 1:34 tomorrow morning.

The month of May starts tomorrow, when spring really gets going. Daylight hours in the Interlochen/Traverse City area will increase from 14 hours and 15 minutes tomorrow to 15 hours 19 minutes on the 31st. The altitude, or angle, of the Sun above the southern horizon at local noon will ascend from 61 degrees now to 67 degrees at month’s end. The altitude of the Sun in the Straits area will be a degree lower than that, but your daylight hours will be a few minutes longer. Local apparent noon this month, when the Sun passes due south, will be about 1:38 p.m. This is the month of the Eta Aquariid meteor shower which will reach its peak next week Thursday morning. There will be about a 2-hour viewing period starting at 3:15 am. We will get a chance to see the beginning of a lunar eclipse near sunrise on Wednesday the 26th.

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

Addendum

May Evening Star Chart

Star Chart for May 2021 (11 p.m. EDT May 15, 2021). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 5 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Note the chart times of 11 p.m. and 5 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, or 28 minutes. 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 for weekly positions.

May Morning Star Chart

Star Chart for May mornings 2021 (5 a.m. EDT May 15, 2020). Created using my LookingUp program. Click on image to enlarge.

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.
• Leaky dipper drips on Leo
• Follow the arc of the handle of the Big Dipper to the star Arcturus, and
• Extend like a spike to Spica,
• EaqR is the radiant of the Aquariid meteor shower that peaks on the 5th.  Best viewing is before the peak this year due to the bright Moon.

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2021-05-01	4h40m	5h24m	22h02m	22h47m	22h47m	1h35m	0.67
2021-05-02	4h38m	5h23m	22h04m	22h49m	22h49m	2h32m	0.57
2021-05-03	4h36m	5h21m	22h05m	22h51m	22h51m	3h17m	0.46
2021-05-04	4h33m	5h19m	22h07m	22h53m	22h53m	3h52m	0.36
2021-05-05	4h31m	5h17m	22h09m	22h55m	22h55m	4h20m	0.27
2021-05-06	4h29m	5h16m	22h10m	22h57m	22h57m	4h29m	0.18
2021-05-07	4h27m	5h14m	22h12m	22h59m	22h59m	4h27m	0.11
2021-05-08	4h25m	5h12m	22h13m	23h01m	23h01m	4h25m	0.06
2021-05-09	4h23m	5h11m	22h15m	23h03m	23h03m	4h23m	0.02
2021-05-10	4h21m	5h09m	22h16m	23h05m	23h05m	4h21m	0
2021-05-11	4h19m	5h07m	22h18m	23h07m	23h07m	4h19m	0
2021-05-12	4h17m	5h06m	22h19m	23h09m	23h09m	4h17m	0.02
2021-05-13	4h15m	5h04m	22h21m	23h11m	23h11m	4h15m	0.05
2021-05-14	4h13m	5h03m	22h23m	23h13m	–	4h13m	0.1
2021-05-15	4h11m	5h01m	22h24m	23h15m	0h07m	4h11m	0.17
2021-05-16	4h09m	5h00m	22h26m	23h17m	1h00m	4h09m	0.25
2021-05-17	4h07m	4h58m	22h27m	23h19m	1h46m	4h07m	0.34
2021-05-18	4h05m	4h57m	22h28m	23h21m	2h25m	4h05m	0.44
2021-05-19	4h03m	4h56m	22h30m	23h23m	2h58m	4h03m	0.54
2021-05-20	4h01m	4h54m	22h31m	23h24m	3h26m	4h01m	0.65
2021-05-21	4h00m	4h53m	22h33m	23h26m	3h51m	4h00m	0.76
2021-05-22	3h58m	4h52m	22h34m	23h28m	–	–	0.85
2021-05-23	3h56m	4h51m	22h36m	23h30m	–	–	0.92
2021-05-24	3h54m	4h49m	22h37m	23h32m	–	–	0.98
2021-05-25	3h53m	4h48m	22h38m	23h34m	–	–	1
2021-05-26	3h51m	4h47m	22h40m	23h36m	–	–	0.99
2021-05-27	3h49m	4h46m	22h41m	23h38m	–	–	0.95
2021-05-28	3h48m	4h45m	22h42m	23h39m	23h39m	–	0.89
2021-05-29	3h46m	4h44m	22h43m	23h41m	23h41m	0h19m	0.81
2021-05-30	3h45m	4h43m	22h45m	23h43m	23h43m	1h11m	0.72
2021-05-31	3h44m	4h42m	22h46m	23h44m	23h44m	1h52m	0.61

The twilight calendar was generated using Cartes du Ciel (Sky Charts), with some corrections.

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

May  1  Sa            Venus: 9.4° E
     1  Sa   5:37 am  Moon South Dec.: 25.6° S
     3  Mo   1:02 pm  Moon-Saturn: 4.4° N
     3  Mo   3:50 pm  Last Quarter
     3  Mo  11:01 pm  Mercury-Pleiades: 2.2° S
     4  Tu   5:00 pm  Moon-Jupiter: 4.9° N
     4  Tu   9:30 pm  Eta Aquariid Shower: ZHR = 60
    11  Tu   3:00 pm  New Moon
    11  Tu   5:54 pm  Moon Apogee: 406500 km
    13  Th   6:29 am  Moon Ascending Node
    13  Th   1:59 pm  Moon-Mercury: 2.4° N
    15  Sa   6:25 pm  Moon North Dec.: 25.6° N
    16  Su  12:47 am  Moon-Mars: 1.6° S
    17  Mo   1:59 am  Mercury Elongation: 22° E
    17  Mo   9:08 pm  Moon-Beehive: 3.1° S
    19  We   3:13 pm  First Quarter
    25  Tu   9:52 pm  Moon Perigee: 357300 km
    26  We   7:14 am  Full Moon
    26  We   7:19 am  Total Lunar Eclipse (Start is visible here)
    26  We   3:38 pm  Moon Descending Node
    28  Fr   3:21 pm  Moon South Dec.: 25.6° S
    28  Fr  11:01 pm  Mercury-Venus: 0.4° N
    30  Su   9:22 pm  Moon-Saturn: 4.3° N
    31  Mo   7:39 am  Mars-Pollux: 5.3° S
Jun  1  Tu            Venus: 17.5° E

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
May, 2021    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat  1| 06:32a  08:48p  14:15 | 10:00p  05:20a |      Rise 02:32a   70%|
+------+-----------------------+----------------+-----------------------+
|Sun  2| 06:30a  08:49p  14:18 | 10:02p  05:18a |      Rise 03:17a   59%|
|Mon  3| 06:29a  08:50p  14:21 | 10:03p  05:16a |L Qtr Rise 03:52a   48%|
|Tue  4| 06:28a  08:51p  14:23 | 10:05p  05:14a |      Rise 04:20a   38%|
|Wed  5| 06:26a  08:53p  14:26 | 10:06p  05:13a |      Rise 04:44a   28%|
|Thu  6| 06:25a  08:54p  14:28 | 10:08p  05:11a |      Rise 05:04a   20%|
|Fri  7| 06:24a  08:55p  14:31 | 10:09p  05:09a |      Rise 05:24a   13%|
|Sat  8| 06:22a  08:56p  14:33 | 10:11p  05:08a |      Rise 05:43a    7%|
+------+-----------------------+----------------+-----------------------+
|Sun  9| 06:21a  08:57p  14:36 | 10:13p  05:06a |      Rise 06:03a    3%|
|Mon 10| 06:20a  08:58p  14:38 | 10:14p  05:04a |      Rise 06:25a    1%|
|Tue 11| 06:18a  09:00p  14:41 | 10:16p  05:03a |New   Set  09:03p    0%|
|Wed 12| 06:17a  09:01p  14:43 | 10:17p  05:01a |      Set  10:06p    1%|
|Thu 13| 06:16a  09:02p  14:45 | 10:19p  05:00a |      Set  11:08p    4%|
|Fri 14| 06:15a  09:03p  14:48 | 10:20p  04:58a |      Set  12:07a    9%|
|Sat 15| 06:14a  09:04p  14:50 | 10:22p  04:57a |      Set  01:00a   15%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 06:13a  09:05p  14:52 | 10:23p  04:55a |      Set  01:46a   23%|
|Mon 17| 06:12a  09:06p  14:54 | 10:25p  04:54a |      Set  02:25a   32%|
|Tue 18| 06:11a  09:08p  14:56 | 10:26p  04:52a |      Set  02:57a   42%|
|Wed 19| 06:10a  09:09p  14:59 | 10:28p  04:51a |F Qtr Set  03:26a   52%|
|Thu 20| 06:09a  09:10p  15:01 | 10:29p  04:50a |      Set  03:51a   63%|
|Fri 21| 06:08a  09:11p  15:03 | 10:30p  04:48a |      Set  04:14a   73%|
|Sat 22| 06:07a  09:12p  15:04 | 10:32p  04:47a |      Set  04:38a   83%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 06:06a  09:13p  15:06 | 10:33p  04:46a |      Set  05:04a   91%|
|Mon 24| 06:05a  09:14p  15:08 | 10:35p  04:45a |      Set  05:33a   97%|
|Tue 25| 06:04a  09:15p  15:10 | 10:36p  04:44a |      Set  06:09a  100%|
|Wed 26| 06:04a  09:16p  15:12 | 10:37p  04:42a |Full  Rise 09:57p  100%|
|Thu 27| 06:03a  09:17p  15:13 | 10:39p  04:41a |      Rise 11:14p   96%|
|Fri 28| 06:02a  09:18p  15:15 | 10:40p  04:40a |      Rise 12:19a   91%|
|Sat 29| 06:01a  09:19p  15:17 | 10:41p  04:39a |      Rise 01:11a   83%|
+------+-----------------------+----------------+-----------------------+
|Sun 30| 06:01a  09:19p  15:18 | 10:42p  04:38a |      Rise 01:52a   74%|
|Mon 31| 06:00a  09:20p  15:19 | 10:43p  04:38a |      Rise 02:23a   64%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

04/29/2021 – Ephemeris – A star cluster that seems out of place

This is Bob Moler with Ephemeris for Thursday, April 29th. Today the Sun will be up for 14 hours and 10 minutes, setting at 8:45, and it will rise tomorrow at 6:33. The Moon, 3 days past full, will rise at 12:25 tomorrow morning.

Looking to the southeast these nights one can find the dim constellation of Coma Berenices, or Berenice’s hair. It’s located near the bottom of a triangle between Leo, Boötes the Big Dipper. It’s best seen on a moonless night as a sprinkling of faint stars that look like strands of hair. It is a star cluster some 271 light years away, the second-closest star cluster to the Earth, after the Hyades that marks the face of Taurus the bull, at about 160 light years. Coma Berenices is located at an odd spot for an open or galactic star cluster. It’s as far from the milky band as you can get. Most galactic star clusters are close or in that band. However, due to its closeness Coma Berenices is north of the solar system, as we both orbit the center of the Milky Way.

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

Addendum

Coma Berenices finder chart. Created using Stellarium.

Coma Berenices and galactic coordinated showing how close to the galactic pole it is. Created using Cartes du Ciel

04/28/2021 – Ephemeris – Searching for the naked-eye planets for this week

This is Ephemeris for Wednesday, April 28th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:44, and it will rise tomorrow at 6:35. The Moon, 2 days past full, will rise at 11:06 this evening.

Let’s search for the naked-eye planets for this week. Unfortunately the only one you’ll find in the evening is Mars. It can be found in the west at 10 pm tonight, in the constellation of Gemini the twins. Tonight it’s just above Castor’s foot. Mars will set at 1:21 am. Both Venus and Mercury are now just east of the Sun and to close to it to be spotted. Venus will be setting 43 minutes after sunset, with Mercury setting 27 minutes later. We should start spotting Mercury next week. It will be late May or early June before Venus will be easily seen. Jupiter and Saturn, are west of the Sun in the morning twilight. Saturn will rise at 3:24 am, with Jupiter rising at 4:03 am. By 6 am they will be low in the southeast. Jupiter, on the left, is the brighter of the two.

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

Venus and Mercury marginally visible over a Lake Michigan horizon 16 minutes after sunset at 9 pm tonight April 28, 2021. Venus will be 4 degrees altitude, Mercury will be 7 degrees altitude.

Mars finder animation for 10 pm tonight, April 28, 2021. Created using Stellarium and GIMP.

The waning gibbous Moon as it might be seen in binoculars or small telescope at midnight overnight April 29, 2021. Created using Stellarium.

Jupiter and Saturn in the morning twilight of 6 am tomorrow morning, April 29, 2021. Created using Stellarium.

Saturn and Jupiter as seen in a small telescope at the same magnification. Apparent diameters: Saturn, 16.65″, rings, 38.78″; Jupiter, 37.26″. Mars is too far away to make out detail on its surface, except maybe a polar cap. Its apparent diameter is 4.67″. Venus’ apparent diameter is 9.81″ and will be added next week. Mercury’s apparent diameter is 6.2″. The cutoff for whether to show a planet here is an apparent diameter of 10″ or greater. The ” symbol means seconds of arc (1/3600th of a degree). Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on April 28, 2021. The night ends on the left with sunrise on the 29th. Click on the image to enlarge. Created using my LookingUp program.

04/27/2021 – Ephemeris – What is the opposite of the Harvest Moon effect?

This is Bob Moler with Ephemeris for Tuesday, April 27th. Today the Sun will be up for 14 hours and 4 minutes, setting at 8:43, and it will rise tomorrow at 6:36. The Moon, 1 day past full, will rise at 9:43 this evening.

Let’s think back to last fall and the Harvest Moon. The big deal about the Harvest Moon is the Moon lingers, rising or being bright in twilight to help illuminate the harvesters of old by effective lengthening the effects of daylight. The spring bright Moon after full moon rises much later night to night. Six months ago the difference in the rise times of the Moon between the full moon and the next day was 20 minutes. Today the Moon will rise 96 minutes later than it did yesterday. The reason is the beside moving eastward, it is also moving southward to where the Sun was in late fall. So it rises much later each night than it did after full moon last fall. As it is the dark skies are moving to later and later in the evening due to the spring season and daylight time.

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

Addendum

The motion of the moon near the Harvest Moon as it rises from night to night. This is looking east at where the Moon will rise, and we’re able to see below the horizon. The celestial equator, a projection of the Earth’s equator on the sky cross the horizon at an angle equal to 90 minus one’s latitude. Around my location that’s 45.5 degrees. The Moon will rise parallel to the celestial equator. Its daily orbital motion is at the shallow angle of 5 degrees. So the advance in rise times starts off at 20 minutes later each night, rather than the average 50 minutes.

How the Moon’s path near a spring full moon affects its rise time interval. Note the scale is not the same as the top image. Created using Cartes du Ciel (Sky Charts).

04/26/2021 – Ephemeris – There’s a full supermoon tonight

This is Ephemeris for Monday, April 26th. Today the Sun will be up for 14 hours and 2 minutes, setting at 8:41, and it will rise tomorrow at 6:38. The Moon, at full today, will rise at 8:19 this evening.

The full moon tonight is the full Pink Moon, and a supermoon. As down as I am about full moons due to the fact that they light up the sky and flood out the dimmer objects in the sky, I once in a while stop and view it. The time of the full moon is 11:31 tonight, so when it rises tonight we will be looking at the moon from very nearly the direction of the Sun, so there will be few shadows to be had. The crater Tycho is near the bottom or south end of the moon and has long rays of tiny ejecta craters. The full moon is the best time to see these rays, which are easily visible in binoculars, through which Tycho itself looks like a bright dot. In telescopes Tycho looks like a small bright crater with a dark ring around it. The full moon is super bright. It’s daytime over there.

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

Addendum

The full Moon 7 hours before it was officially full. The contrast was greatly enhanced to bring out Tycho’s ray system. The crater Tycho is at the south part of the Moon and appears bright with a dark ring around it. Credit Bob Moler.

Tycho and Kepler. Artist for Tycho: Eduard Ender (1822-1883). Artist for Kepler, unknown. Source: Wikipedia

Tycho Brahe and Johannes Kepler are inexorably linked in astronomical history. Tycho was famously stingy with the results of his observations. It was only after his death that Kepler was able to have access to them. Mars was the planet that was hardest to model in both the Ptolemaic geocentric and Copernican heliocentric universes, since both assumed the planetary orbits were circular. So both resorted to epicycles in an attempt to tweak their models in an attempt to fit with observational reality.

Both Tycho and Kepler have craters named for them on the Moon. Tycho gets a splashy crater on the southern part of the Moon. Kepler, however, gets a small crater on the plains of Oceanus Procellarum west of the crater Copernicus on the left side of the Moon, as we see it

04/23/2021 – Ephemeris – The gibbous Moon tonight

This is Ephemeris for Friday, April 23rd. Today the Sun will be up for 13 hours and 53 minutes, setting at 8:38, and it will rise tomorrow at 6:43. The Moon, halfway from first quarter to full, will set at 5:49 tomorrow morning.

The Moon tonight is bright. The sunrise line or terminator on the Moon is crossing the large gray plain called Oceanus Procellarum, the largest of the Moon’s seas. These seas were figments of the first telescopic observer’s imagination. They are really huge impact basins into which interior lava flowed. On the upper left edge of the moon near the terminator is a bright spot visible in binoculars. In a telescope it is a crater called Aristarchus. It is a fairly new crater, probably 450 million years old. As a rule the brighter the crater the newer it is. Aristarchus is the brightest spot on the moon when it is seen during a full moon. Over the years visual astronomers have seen hazes and bright spots from time to time in and near Aristarchus.

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

Addendum

The Moon as it might be seen in a small telescope tonight, April 23, 2021 at 10 pm. Created using Stellarium.

The impact crater Aristarchus, in the center, is 24 miles or 40 kilometers in diameter and approximately 450 million years old. Credit: Lunar and Planetary Institute.

04/22/2021 – Ephemeris – Earth Day

This is Bob Moler with Ephemeris for Earth Day, Thursday, April 22nd. Today the Sun will be up for 13 hours and 50 minutes, setting at 8:37, and it will rise tomorrow at 6:44. The Moon, 2 days past first quarter, will set at 5:24 tomorrow morning.

The Earth is unique in the solar system. Actually every planet is unique, as we’ve found out with our spacecraft that have at least flown by every planet of the solar system, plus the dwarf planets Pluto and Ceres. But the Earth uniquely supports life as we know it. It’s the only one that we know of. It is imperative that we colonize the Moon, Mars and asteroids and live off the land, so no single disaster can wipe the human race out. However, we need to take care of the Earth, to understand and get a grip on what we’re doing to Earth’s climate. We must think of the Earth as a spaceship with both renewable resources and limited ones. Our journey is long, and the supplies will have to last. So support your local planet!

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

Addendum

The Earth from the DSCOVR satellite orbiting the Sun-Earth L1 point The image was taken two days ago. Credit NOAA.

04/21/2021 – Ephemeris – Let’s search for the naked-eye planets for this week

This is Ephemeris for Wednesday, April 21st. Today the Sun will be up for 13 hours and 47 minutes, setting at 8:35, and it will rise tomorrow at 6:46. The Moon, 1 day past first quarter, will set at 4:56 tomorrow morning.

Let’s search for the naked-eye planets for this week. Unfortunately the only one you’ll find in the evening is Mars. It can be found in the west at 10 pm tonight, between the constellations of Taurus the bull below and Gemini the twins above. Tonight it’s just off Castor’s big toe. Mars will set at 1:30 am. Venus is now just east of the Sun, setting 31 minutes after sunset. It will be late May or early June before it will be easily spotted in the evening twilight. Mercury is between the Sun and Venus. Saturn and Jupiter are at a far enough angle from the Sun to be spotted in the morning twilight. Saturn will rise at 3:51 am, with Jupiter rising at 4:28 am. By 6 am they will be low in the southeast.

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

Addendum

Mars and the Moon with the fleeing stars of winter tonight at 10 pm, April 21, 2021. Created using Stellarium.

The moon as it might appear tonight, April 21, 2021. Created using Stellarium.

Jupiter and Saturn in the morning twilight tomorrow morning, April 22, 2021. Created using Stellarium.

Saturn and Jupiter as seen in a small telescope at the same magnification. Apparent diameters: Saturn, 16.46″, rings, 38.36″; Jupiter, 36.55″. Mars is too far away to make out detail on its surface, except maybe a polar cap. Its apparent diameter is 4.81″. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on April 21, 2021. The night ends on the left with sunrise on the 22nd. Click on the image to enlarge. Created using my LookingUp program.

04/20/2021 – Ephemeris – SpaceX gets NASA contract for Human Landing System for the Artemis (Moon) Program

This is Bob Moler with Ephemeris for Tuesday, April 20th. Today the Sun will be up for 13 hours and 44 minutes, setting at 8:34, and it will rise tomorrow at 6:47. The Moon, at first quarter today, will set at 4:24 tomorrow morning.

Late last week NASA announced that it had selected SpaceX to provide the Human Lander System for the Artemis program. That lander is the lunar variant of the Starship SpaceX is currently testing near Boca Chica, Texas, just north of the mouth of the Rio Grande. A Starship consists of two stages: a booster called Super Heavy and the Starship upper stage. The Super Heavy returns to the launch site, while the Starship must be refueled several times in orbit to be able to head on out to the Moon. The astronauts would be launched as planned in an Orion capsule with the Space Launch System, then transfer the astronauts to the Starship waiting in lunar orbit or from the Lunar Gateway also in lunar orbit for the trip down to the lunar surface.

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

Addendum

SpaceX’s updated concept of their Starship lunar lander as of 04/16/2021. Credit: SpaceX.

NASA’s Source Selection Document (the rationale for their selection): https://www.nasa.gov/sites/default/files/atoms/files/option-a-source-selection-statement-final.pdf

04/19/2021 – Ephemeris – The Moon tonight, Yutu the Jade Rabbit

This is Ephemeris for Monday, April 19th. Today the Sun will be up for 13 hours and 42 minutes, setting at 8:33, and it will rise tomorrow at 6:49. The Moon, 1 day before first quarter, will set at 3:47 tomorrow morning.

Let’s take a look at the Moon tonight. Binoculars or a small telescope will be handy for seeing the lunar features. The Moon will be at actual first quarter at 3 am tomorrow morning so the terminator or in this case sunrise line on the Moon will cut it nearly in half. To the naked eye the face of the Man in the Moon isn’t yet noticeable, but the top part of the upside down Chinese rabbit Yutu can be glimpsed. His ears are the seas of Fertility and Nectar, his head is the Sea of Tranquility, and the top part of his body is the Sea of Serenity. The lower part of his body and his arms pulverizing medicine with a mortar and pestle will have to wait until the Moon is nearer full. Yutu is the pet rabbit of the Chinese Moon goddess Chang’e.

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

Addendum

The Moon as it should appear at 10 pm tonight, April 19, 2021. Can you see the rabbit’s head? Created using Stellarium.

Yutu, the Jade Rabbit pounding medicine, as he appears in the lunar seas on a full moon. Rotated to fit tonight’s moon orientation. Via Wikipedia, no source provided.