Morning Planets Mon Feb 24 2020

Just jumped outside to get a quick snap of the southwestern horizon. Looking for the morning planets through urban clutter and trees.

NOTE: Having trouble seeing details in the photos? Right click on the photo. Select “View Photo”. Click on photo to enlarge. Guy Ottewell was the first one I’ve seen point out this method and he has a few others if that doesn’t work.

Labeled image of southeastern horizon 5:45am EST 2/24/2020, 50 minutes before sunrise. Two brightest dots are Jupiter and Mars. Lines show the “Teaspoon” group of stars (above Jupiter) and the “Teapot” outlined with darker lines where the camera sees the stars and thinner lines where the stars are lost in the glow of twilight. Mars is just above the Teapot.
Canon XS on tripod, 18mm zoom lens at f/5.6, 10 seconds, ISO-800.
Zoom lens at 55mm, f5.6, 2.5 seconds at ISO-800.
Slightly out of focus to show Mars’ color better.
Jupiter is bright dot on the left, Mars is to the upper right, behind the tree.
Sky map from MobileObservatory for this morning’s southeastern sky. Horizon at bottom, top is 20 degrees (about two fist widths held at arm’s length) above the horizon. Saturn was hiding in the trees in my photos.

Go out some morning before sunrise and find these bright planets. They’ll be around for many weeks. Jupiter and Saturn will get a bit higher in the sky. Mars will pass by Jupiter and Saturn in the last third of March.

Moon and Jupiter Morning Feb 20 2020

I saw the crescent Moon peeking through the trees this morning. I went to the local middle school (no students – school vacation week) so take some snapshots with the Canon XS. Photos taken 40 to 50 minutes before sunrise, in twilight skies. If you want to see Jupiter, Saturn and Mars, go out a bit earlier and find a clear horizon to the southwest. Jupiter was easy to see even with twilight, although harder to find later, about 30 minutes before sunrise.

Update: Upon further review, Saturn is to the upper left of the Moon – dimmed by the cloud band.

Crescent Moon with Jupiter to its upper right.
Canon XS 2 second exposure at f7.1, ISO 200 with zoom lens at 55mm.
Moon with zoom lens at 250mm, 1/10 second, f/7.1, ISO 200.
Note the craters just visible on the terminator.
Cropped from larger photo.
250mm zoom lens photo of Jupiter, enhanced to show hints of its moons. Callisto on the left, Ganymede on the right. On the right near Jupiter looks like a fuzzy out of focus dot is because they are Europa and Io very close together in this photo.
1/10 second f7.1 ISO 200, cropped from larger photo.
Jupiter’s moons this morning from the app at Sky and Telescope.
Bonus! Photo of wave clouds formed as the turbulent air over us was made bumpy after passing over mountains upwind of us.

Sahara Dust Event in Puerto Rico Feb 20 2020

San Juan is getting dusted with the sands of the Sahara Desert today.

This morning visibility was down to 7 miles in a place where the visibility is 10 miles or more unless it’s raining. Click here to follow the link to the weather observation at San Juan International Airport.

If you are coming here to look for information about Sahara Dust – leave a comment or a question and I’ll try to add more information to help. (And, my apologies for the gross ads they insert here because I won’t pay for a ad-less version of the site.)

Helpful links:

US Navy Research Laboratory models dust transport.

Path the air took to get to Puerto Rico – I ran this yesterday at the READY trajectory calculation site:

Satellite data are processed to spot drier air and dust. However, I think the latest incarnation of the algorithm they are using overstates the area affected by dust or dry air from the Sahara.

The United States National Weather Service Office in San Juan is on top of the situation. Here’s a excerpt from their technical discussion:

.SHORT TERM...Today through Saturday...

A broad surface high pressure over the eastern Atlantic will promote moderate to fresh trade winds today. Areas of low level moisture embedded in the trade winds will reach the islands from time to time through the short term period. This will be enough to trigger diurnally induced afternoon showers over portions of the interior and west PR as well as from streamers developing off the USVI.
However, the overall moisture content decreases from 1.30 inches early this morning to just under an inch of precipitable water during the next couple of days. This is due to drier air moving in from the east with Saharan dust. Although not a strong SAL event, hazy skies are expected. Winds will gradually decrease on Friday and Saturday, and turn more from the southeast as an area of low pressure develops over the western Atlantic and an associated frontal boundary stalls to the north of the region during the weekend.

Moon Engages in a Cover-up Tuesday Morning

Take a look out Monday morning to find the moon at the same time it will be covered up on Tuesday. This way, you’ll know if you’ll be able to find it Tuesday morning around the time when Mars will be covered by the moon and, later, when Mars will appear to pop out from behind the moon.

Click here for a link to a good article and times for the cover-up and unveiling.

Or get up early Tuesday morning before sunrise (6:46am in the New York City metro area) when the moon and Mars will be less than a degree apart. Follow them until Mars disappears behind the moon, which will happen about 7:35am in the NYC area. If you can keep tracking the moon, watch for Mars to appear from behind the moon a little after 9am.

Shoot the Moon – Feb 3, 2020

A warm front came through today, giving an afternoon and evening of clear, stable skies. Get out there this evening! Even binoculars will show this at least this much detail.

Just a shot from the Canon XS on a tripod. The large crater near the middle of curving line where the Sun is rising on the Moon is Copernicus.

1/1250 sec. f/7.1 with 250mm zoom lens at ISO 400
Moon simulation. Go to https://svs.gsfc.nasa.gov/4768 for the full picture.

February Freeze – don't bet on it

Looking for the February freeze after the really warm January? It seems like we’ve had a few winters in the northeast corridor of the United States that got going only in late winter. It seems unlikely for this February. Several predictors at NOAA’s Climate Prediction Center are pointing toward warmer than normal for each week of the month.

For technical details, see the discussion document linked here. Click on ‘discussion’ in the sidebar. My favorite part:

The CPC Week 3-4 Outlook indicates high probabilities 
for above normal temperatures over the eastern CONUS and some enhanced 
probabilities of below normal temperatures over the Northwest. 
 
With the variable circulation pattern predicted through February, the 
updated temperature outlook represents a significant change from the 
previous February outlook, released in mid-January.

The links that popped up about the rapid update to this forecast caught my attention and the discussion quoted above shows why the climate center needed to change the previous outlook calling for a larger area of likely below normal temperatures.

Of course, note that a 40% chance of above normal on average for the month means a 60% chance of near or below normal for a monthly temperature average. Although, the 70% chance of above normal for the second half of February is pretty impressive for that far out.

Heads UP! February 2020

Moon Over Mars  The biggest event for February is one most of us won’t see. The Moon slides in front of Mars on the morning of the 11th.  Usually the Moon is a great pointer toward fainter objects.  This occultation of Mars by the Moon occurs after Sunrise on the 11th.  Will we be able to use the Moon, a thin crescent, to find Mars in the morning sunshine?  I’ll have a separate post on this closer to the event.

Pop-Up Planetary Event  Mercury strays into the evening sky in one of its best appearances of the year.  Already out in the evening sky as the month begins, Mercury is low to the right of brilliant Venus. Venus, at magnitude -4.1, sets an example, soaring higher, enticing magnitude -1 Mercury to show itself after sunset at the beginning of the month. Mercury will only go 18 degrees out from the Sun, as compared to Venus’ 43 degrees. About 45 minutes after sunset, look toward the lower right of Venus, towards where the Sun had set, to spot the speedy messenger of the gods.

Mercury reaches greatest elongation from the Sun on the 11th. By then, at magnitude -0.3, it’s already only half as bright as in early February. Starting on the 22nd, Mercury is only visible in the Solar and Heliospheric Observatory’s C3 camera, shuttling well north of the Sun on its way to its next delivery in the morning sky in March. [Link to Naval Research Lab map of planets transiting through the C3 camera]

Venus is starting to look less round and more gibbous, 63%-lit by month’s end. Mercury’s phase decreases faster, half-lit by the 10th. Both Venus and Mercury appear larger than Mars.  Venus is about Saturn’s size.

If you missed the Venus/Neptune conjunction in January, get a good star chart and try for Neptune near 4th magnitude Phi in Aquarius on the 10th, between Venus and Mercury. Uranus is up in the star-poor area between Aries, Pisces and Cetus all evening, starved for attention.

I haven’t seen Comet PANSTARRS C/2017 T2 yet, even though it’s up in our northern skies all night.  In February, this magnitude +9 wisp of dust, rock and snow is going to hang just above Cassiopeia.  T2 will be highest after sunset. Try for it with binoculars in a dark sky as it brightens until May.

[chart with panstarrs at midmonth]

Morning Sky Low Down  In the meantime, the morning sky is hopping with Jupiter and Saturn straining to join Mars just before sunrise. They are strung out low in the southeast, as if groggy from being awakened so early in the morning. Mars is 55 degrees out from the Sun, with Jupiter and Saturn trailing at 36 and 26 degrees elongation, respectively. Look for magnitude

-1.9 Jupiter with Mars right ahead at magnitude +1.3 and Saturn left behind at magnitude +0.6.

Mars should be more colorful than the giants that trail it, but I haven’t been impressed that it looks really red yet. Mars will gain about a half magnitude per month until October, when it will be brilliant. Barring dust storms, the red planet should live up to its colorful reputation as it gets brighter.

Loony Facts If you have a clear southeastern horizon, follow the waning Moon as it checks off visiting Jupiter and Saturn on the 19th and 20th. The Moon reaches perigee on the 10th, just 30 hours after Full Moon. Perigee near a New or Full Moon date makes for higher than normal tides for a few days following the dates of Full Moon. The Full Moons for the next three months will be even closer than February’s.

The International Space Station’s visible overflights are in the evening through the 10th, and in the morning from the 19th.

February 29th marks Leap Year Day, an extra day that keeps the calendar aligned with celestial milestones during our annual trips around the Sun. The last year that was evenly divisible by four but was without a Leap Year Day was 1900. Years divisible by 100 aren’t leap years, unless they are divisible by 400, like 2000 was. These exceptions are built into the Gregorian Calendar rules to keep our calendar even more precisely in sync with the stars. A bit more about this in a few days.