When the moon is bright, the sky is clear, and the wind is calm the moon’s reflection makes a path on the water.
In Sweden where this photo was taken the word for the moon’s path is mångata or “moon street.”
In English we have a name for it, though the word is rarely used: Moonglade.
(photo from Wikimedia Commons; click on the caption to see the original)
Wednesday, 29 January 2020:
Chances are it won’t happen but …
Tonight at around 6:39pm two defunct satellites that are still in orbit have a 1% (or less) chance of colliding 900km (560 miles) above Pittsburgh. They’ll be traveling toward each other at 32,880 mph!
If they don’t collide, everyone who has anything to do with satellites will breathe a sigh of relief because there will be that much less out-of-control space junk for their own satellites to hit.
If they do collide they won’t hurt us. At best we’ll see a few shooting stars as the bits burn up in Earth’s atmosphere. But we probably won’t see anything because Pittsburgh’s cloud cover will be 40% at that point. Check out the Clear Dark Sky chart for the forecast (screenshot below).
Here’s the original collision prediction from LeoLabs, an outfit in California that tracks space junk and potential collisions.
2/ On Jan 29 at 23:39:35 UTC, these two objects will pass close by one another at a relative velocity of 14.7 km/s (900km directly above Pittsburgh, PA). Our latest metrics on the event show a predicted miss distance of between 15-30 meters. pic.twitter.com/Hlb1KeQ50U
— LeoLabs, Inc. (@LeoLabs_Space) January 27, 2020
4/ Events like this highlight the need for responsible, timely deorbiting of satellites for space sustainability moving forward. We will continue to monitor this event through the coming days and provide updates as available.
— LeoLabs, Inc. (@LeoLabs_Space) January 27, 2020
See KDKA’s announcement with video.
And here’s a more in depth article from Forbes Magazine.
In the meantime, LeoLabs revised their estimate to a pass distance of 13-87 meters and a 1 in 1000 chance of collision.
I’ll bet we won’t see any stars tonight.
(screenshot of space junk collision from PBS Be Smart video; click on the caption to see the original video)
UPDATE on 31 January 2020: No, they didn’t hit but they came mighty close. Analysis by LeoLabs at The IRAS / GGSE 4 Close Approach.
What do these photos and video have in common?
humming sound of wind in the wires (turn up speakers)
Answer: All three indicate the presence of — or potential for — a von Kármán vortex street.
When you’re in the neighborhood, this street is a fluid dynamic place. Learn more in this vintage article as we go Walking Down Vortex Street. (click the link)
(photos NASA and Wikimedia Commons; click on the captions to see the originals. video by Megan Lewis on YouTube)
Now that climate change has really settled in there are loads of free fun winter activities that we can’t do in Pittsburgh. I was reminded of this when I heard that the Beaver County Snow Shovel Riding Championship was postponed last Saturday. Last year it was eventually canceled. As the Beaver County Times wrote last month:
The Beaver County Snow Shovel Riding Championship returns in 2020. That comes with the major assumption that sufficient snow rests on the 165-foot hill at Old Economy Park, just off Route 989 in Economy, on Jan. 11 or the makeup date of Jan. 18.
Beaver County Times, Let it snow, if shovel riding championship is to return
Last Saturday, 11 January 2020, was so hot that it broke a 130-year record. At Pittsburgh International Airport, nine miles from that Beaver County hillside, it was 71 degrees F. Of course there was no snow.
Other winter fun we’re missing includes building snowmen, making snow angels, and cross country skiing. These still might happen for a day or two if we get one big snowfall.
But some winter fun is just plain dangerous in today’s world. Ice fishermen used to count on our frozen lakes but these days the ice is missing or very thin. Unsafe!
To emphasize this dilemma, the Great Lakes were virtually ice free on January 12.
No winter fun.
(photos from Wikimedia Commons; map from U.S. National Ice Center; click on the captions to see the originals)
11 January 2020
Winter has a beauty all its own but we’re missing it in Pittsburgh this year. Today our high temperature will be 70oF.
Here’s some of what we’ll never see in today’s hot weather.
Pittsburgh is not alone in feeling the heat. Here’s today’s temperature forecast for the continental U.S. It looks like a Polar Vortex doesn’t it? High winds are on the way!
(photos from Wikimedia Commons and Kate St. John, map from the National Weather Service; click on the captions to see the originals)
If you live in Pittsburgh — or Alaska — you can expect a hot wet year in 2020.
In late December National Weather Service Climate Prediction Center published U.S. seasonal outlook maps for 2020’s temperature and precipitation, one map per quarter.
For temperature, the redder the color the more likely it will be hotter than normal. For precipitation, green means it’s likely to be wetter. Pittsburgh is high in both categories, hot and wet. So is Alaska, especially in temperature.
Watch the year heat up.
(images from the National Weather Service Climate Prediction Center, Monthly & Seasonal Outlook Maps)
At the end of The Inferno, set in the year 1300, Dante and his guide Virgil escape from Hell climbing upward to reach the Earth. They’ve almost emerged when Dante looks through the opening ahead and sees the heavens above.
… we climbed up, he first and I behind him,
— The Inferno by Dante Alighieri, translation by Robert & Jean Hollander
far enough to see, through a round opening,
a few of those fair things the heavens bear.
Then we came forth, to see again the stars.
The heavens are still wondrous but most of us miss it. So much electric light floods the sky that we cannot see the stars. No Milky Way (above), no meteor showers (below).
This 7-minute video gives a glimpse of what we’re missing.
To see the stars as Dante saw them we have to visit remote locations where the sky is dark. Click on the Milky Way photo at Tenerife (top) to see the sky in full screen splendor.
“Then we came forth, to see again the stars.”
p.s. This week we learned of an unexpected threat to viewing the stars: Thousands of tiny new satellites, launched by Elon Musk’s SpaceX, will obscure and confuse the astronomers’ view.
p.p.s. Stelle, meaning stars, is literally the last word in each of the three cantiche of Dante’s Divine Comedy: Inferno, Purgatorio and Paradiso.
(photos from Carl Jones on Flickr and Wikimedia Commons; click on the captions to see the originals. video by Peaceful Cuisine on YouTube)
On rare occasions, winter weather and the sea conspire to make ice balls that stack on the beach when they roll ashore. This ball ice, about the size of softballs, covered Stroomi Beach at the Baltic Sea in Estonia in December 2014.
Ball ice is so rare that it made the news last month in Alaska and Finland. Similar to hail, it forms in bays where the water is relatively calm and just cold enough to make ice. A “seed” of ice or grit starts the process, then wind and gentle waves keep turning the floating ball as it grows.
Sometimes two cool things happen at once. In this tweet from NWS APRFC, a field of ice balls in Alaska acquired pointy hats when snow or rime accumulated on one side.
Interesting formation of ice on the banks of the Wulik River near Kivalina. We suspect a combination of strong waves and super cold water created these ice balls. pic.twitter.com/oIM19Jle2N
— NWS APRFC (@NWSAPRFC) November 6, 2019
The prettiest ball ice by far were the thousands of white balls covering a beach on Hailuoto Island, Finland in early November. Ranging in size from golf balls to soccer balls, they made international news in photos by Risto Matilla. Island resident Ritva Rundgren filmed them for her Mrs. Santa Claus Finland blog.
Read more about Finland’s ice eggs and see a video of ice balls at Lake Michigan in this article from ScienceAlert.
(photo from Wikimedia Commons; click on the caption to see the original. Video embedded from Mrs. Santa Claus Finland)
Winter Solstice: 21 December 2019
Today the sun will pause at 11:19pm Eastern Time and begin to move north again — or so it will seem to us earthbound humans.
The far north will be dark but not inky black everywhere. At Kotzebue, Alaska, 26 miles north of the Arctic Circle, the sun will rise at 12:56pm and set 1 hour and 43 minutes later, similar to the solstice photo above, taken at Bering Land Bridge NP. Kotzebue is the furthest north I’ve ever been though I didn’t get off the plane..
Here in the Lower 48 we’ll have lingering sunsets …
… and the days will get longer tomorrow.
Soon the birds will think about spring for reasons described in this vintage article: In Response To Daylight.
(photos by Bering Land Bridge National Preserve, Kate St. John, and Alan Wolf on Flickr, Creative Commons licenses; click on the captions to see the originals)
If you don’t like snow, here’s some that you’ll never see in Pittsburgh.
These snow formations, called penitente, are found at elevations above 13,000 feet in the Dry Andes of Chile and Argentina. They form when the snow vaporizes — directly from solid to gas — in the cold dry wind. A feedback loop of sublimation and ablation creates snow peaks as tall as 16 feet.
Penitente are named for their resemblance to kneeling penitents or the hoods worn during Spanish Holy Week. They even resemble this statue of Saint Bernadette at the grotto at Nevers.
Sometimes a snow field will reach across the road …
… so people get out of their cars to look at it. This one is at Agua Negra Pass on the border of Chile and Argentina, elevation 15,682 ft.
The “penitent” snow creates an otherworldly scene. Click on the photo below for a panoramic view at night.
(photos from Wikimedia Commons; click on the captions to see the originals)
