January 3rd is one of my favorite days of the year in astronomy, because it's the day that the northern hemisphere has its latest sunrise of the winter. This morning in Chicago, the sun rose at 7:19 (though it rose behind a thick rainy overcast), just a few seconds later than it rose yesterday. But tomorrow it will rise just a few seconds earlier, then a few more, until by the end of January it'll rise more than a minute earlier each day.
Meanwhile, thanks to the eccentricity of our orbit around the sun, sunsets have gotten later since the first week of December. It's noticeable now; today's sunset at 16:33 is 14 minutes later than the earliest sunset on December 7th. A week from now sunset is at 16:40; a week later, at 16:48.
By January 31st we will see more clearly that the dark days of northern hemisphere winter are ending. Sunrise at 7:04 and sunset at 17:04 gives us 10 full hours of sunlight, 47 minutes more than we'll get today.
So even though the 115th Congress opened today in Washington, with the House Republicans proposing to geld their own ethics watchdog (and why would they want to do that, hmmm?), at least things will literally get more sunny throughout the country every day for the next six months.
The 2017 Chicago sunrise chart is now available. Share and enjoy.
For those of us in the northern hemisphere in places that observe daylight savings time on U.S. rules—that is, for most of the U.S. and Canada—this morning's sunrise was (or will be, west of the Rockies) the latest sunrise until 6 November 2027.
I've got to say, the sun rising around 7:30 has not helped my mornings. Tonight we return to standard time, putting tomorrow's sunrise at 6:30, and making it easier to get out of bed Monday morning.
Of course, from Decmeber 1st to February 4th, the sun will rise after 7 here in Chicago. And by this time next week we'll have less than 10 hours of daylight.
At least I'm not in places along the western edge of a time zone, like Lafayette Landing, Mich., where the sun didn't rise until 8:48 local time this morning. I'd bet they've been ready for a change for weeks now.
The Chicago sunrise chart for 2016-17 is up, just a few weeks late. (Look, I've been busy.)
In the last 40 years, astronomers have gathered more and more evidence that our moon came out of a scarcely-imaginable collision between a baby (100-million-year-old) Earth and another proto-planet named Theia. (Watch this video for a good explanation.) Just two weeks ago, astronomers at UCLA announced a clarification: Theia didn't hit Earth in a glancing blow, as previously thought. Instead, the two planets hit head-on:
“We don’t see any difference between the Earth’s and the moon’s oxygen isotopes; they’re indistinguishable,” said Edward Young, lead author of the new study and a UCLA professor of geochemistry and cosmochemistry.
The fact that oxygen in rocks on the Earth and our moon share chemical signatures was very telling, Young said. Had Earth and Theia collided in a glancing side blow, the vast majority of the moon would have been made mainly of Theia, and the Earth and moon should have different oxygen isotopes. A head-on collision, however, likely would have resulted in similar chemical composition of both Earth and the moon.
“Theia was thoroughly mixed into both the Earth and the moon, and evenly dispersed between them,” Young said. “This explains why we don’t see a different signature of Theia in the moon versus the Earth.”
So why am I reviewing catastrophic astronomical events? I'm reading Neal Stephenson's latest novel, Seveneaves, which posits (in its opening paragraph) the collision between our moon and what is probably a small black hole. Stephenson imagines what would happen from a serious, scientific perspective.
Seveneves isn't what you would call a character piece. I'm 45% through it, according to my Kindle, and thoroughly fascinated. But Stephenson is almost the anti-Ishiguro.
Another aside: I have to see the tidal bore in the Bay of Fundy someday. It just sounds so cool—especially in context.
This means I have some time to digest this over the weekend:
I might have a chance to read this weekend. Perhaps.
Here's the semi-annual Chicago sunrise chart. I'm posting it as a regular post in addition to posting it as a permanent page, to maintain deep-linking archiving. The previous post was here.
In just a few hours we'll see the latest sunrise of winter, until the days just before the change back to Standard Time in November. That will bring us something really rare: the latest sunrise in Chicago until November 2027, at 7:29am on November 6th. Thank leap years and orbital eccentricity for that. This statement holds true in all parts of the U.S. and Canada that observe daylight saving time until the first Sunday in November. The worst place to be that morning will be in the U.P. of Michigan, where the sun won't rise until after 8:30am. That's almost British.
||Latest sunrise until Oct 28th
||Earliest sunrise until Apr 17th
Earliest sunset until Oct 24th
||Daylight saving time begins
Latest sunrise until Oct 16th
Earliest sunset until Sep 18th
||7am sunrise, 7pm sunset
|| Equinox 23:30 CDT
||6:30am sunrise (again)
||Earliest sunrise of the year
|| Solstice 17:34 CDT
||Latest sunset of the year
||Equinox, 9:21 CDT
||Latest sunrise until 6 Nov 2027 (!)
Latest sunset until Feb 27th
||Standard time returns
Earliest sunrise until Feb 26th
||Earliest sunset of the year
||Solstice, 04:44 CST
You can get sunrise information for your location at wx-now.com.
...this app might be fun. CityLab explains:
Floating in space among the stars and planets are more than 2,250 satellites and “space junk” traveling at up to 18,000 miles an hour. Some are large enough to be seen with the naked eye—though you’d have to first figure out which ones are within your line of sight.
Luckily, there’s a map for that now, by Patricio Gonzalez Vivo, a graphics engineer at Mapzen who has a knack for turning pure data into mesmerizing visuals (like this one of New York City). His latest project, Line of Sight, traces the orbital path of more than a thousand of those satellites and predicts their current location using open-source data from tracking sites like CelesTrak andSatNogs. Plug in your address (or choose one of the pre-selected cities) to see if there are any satellites—shown as yellow dots—nearby. Or zoom out to watch all the satellites orbit the Earth at once in a dazzling visualization.
His city visualizer is also really cool.
A G3-class solar storm (i.e., a big one) is predicted to hit the earth tonight, generating category 7 aurorae, which are rarely seen on earth:
Auroral activity will be high(++). Weather permitting, highly active auroral displays will be visible overhead from Inuvik, Yellowknife, Rankin and Igaluit, to Portland OR, Cheyenne, Lincoln, Springfield, and New York City, and visible low on the horizon as far south as Carson City, Oklahoma City, and Raleigh.
Here's the prediction map from the University of Alaska at Fairbanks:
But here's the observed aurora right now:
So, while the aurora isn't yet visible in Chicago, the solar storm might propel enough material into our ionosphere that we could see some auroral displays in a few hours—or tomorrow. The prediction for Tuesday calls for displays overhead central Wisconsin which would be visible down to St. Louis, weather permitting.
The only place in Chicago dark enough to see them is the lakefront. Parker and I might have to walk over there tomorrow evening.
Updates as events warrant...
If you live in the parts of the U.S. and Canada that observe Daylight Saving Time, don't forget to move your clocks back an hour tonight. It couldn't come soon enough, though this is the soonest it can come under the 2007 changes to DST observance.
This morning's 7:22 sunrise in Chicago is the latest we'll have to endure until next November 1st, but tonight's 5:47 sunset is the latest we'll get to have until March 6th. Tomorrow the sun rises at 6:23 and sets at 4:45, as our available daylight shrinks from 10 hours, 24 minutes today down to 9 hours, 7 minutes on December 21st.
I'm not a fan of the 2007 changes. I like switching to DST in the spring and switching back in the fall, but I also believe that mid-October (or even the end of September as they do in Europe) makes a lot more sense. At least mornings aren't so gloomy in the fall. (Not a lot we can do about the post-7am sunrises from December 2nd through February 5th, but we expect those two months to be gloomy.)
Of course, I'm not in Chicago at the moment, and it's plenty sunny here...