Astronomy

For the rest of the month look in the western sky about an hour after sunset for Comet Tsuchinshan-Atlas, also called “A3”. You’ll see a fuzzy circle with a long tail. You’ll get a better view with binoculars, but you can see the comet with the naked eye.

The planet Jupiter rises a few hours after sunset and on Sunday the 20th you can look for it near the Moon. On Tuesday the 22nd if you stay up late look for the planet Mars below the Moon, which rises a little after 10:00. The next night the Moon will be to the left of Mars. And get up early on Monday the 21st and Tuesday the 22nd and look in the southern sky for the Orionid Meteor Shower.

Birds

Many kinds of waterfowl follow the St. Croix River on their way south. Look for Mallard and Wood Ducks, Red-breasted, Common, and Hooded Mergansers, and Canada Geese, among others!

Mammals

Raccoons prepare for winter in several ways. During the summer and fall they eat a lot to build up body fat which will help them survive when food is scarce. They also grow a thicker coat of fur to help keep them warm. And they find a sheltered place to sleep such as a hollow tree or an underground den abandoned by some other animal. They sometimes share dens with other raccoons so they can share body heat. Raccoons are not true hibernators but when it gets really cold they enter a state called “torpor” in which they have a lower body temperature and slower heart rate, both of which help them conserve energy. It takes raccoons an hour or so to come out of torpor, often by violently shaking and contracting muscles to warm up and wake up. They may remain in a state of torpor for just one night, several days, or weeks, depending on the weather conditions and temperature. But even if they only go into torpor for one night, the energy they save is more than the extra energy it takes them to wake up.

Insects

Bees will remain active on sunny days through fall, coming out of their nests or hives to visit whatever plants remain in bloom. And you might see a few Painted Ladies on the wing – I’ve seen one as late as October 25th! Finally, be careful not to step on Woolly Bear Caterpillars when you’re out hiking. The woolly bears are looking for sheltered places to curl up for the winter; next spring they’ll metamorphose into Isabella Tiger Moths. Folklore has it that the wider the rusty-orange band on the middle of the woolly bear, the milder the winter. Longer black segments on the ends of the caterpillar are said to forecast a more severe winter. Fact or fiction? Note the relative widths of the bands on any woolly bears you see this fall, and then watch to see what kind of winter we have.

Plants

Cattails have gotten fluffy; within the fluff are the plant’s slender, dark brown seeds. And milkweed seed pods have lost their green summer color and turned brown. They have started to open and release hundreds of milkweed seeds, each with its own fluffy little parachute.

Trees

This week’s featured oak is the Northern Red Oak. Like all red oaks, it has pointed lobes on its leaves. The Northern Red Oak is easy to distinguish from the Black Oak and the Pin Oak because the spaces between the lobes, or “sinuses”, are shallow, only extending about halfway to the mid-rib. The acorns take two years to mature, and the caps cover only the upper quarter of the nut. Northern Red Oaks like moist soils and can live for 100 to 150 years. Northern Red Oaks grow up to 70 feet in height.

Another deciduous tree you might see is Ironwood. They ‘re not very tall, reaching a height of 20 to 40 feet, but their wood is very strong, and in the past was used to make tent stakes and tool handles. The bark of young Ironwoods is smooth and reddish-brown in color; more mature trees have furrowed gray bark. Ironwood is a member of the birch family, and the double-toothed leaf looks a lot like a birch leaf. The seeds mature in a cluster of flattened nutlets that resemble hops. Another name for Ironwood is “Hop Hornbeam”.

Weather observations

Here are some weather observations for this week from past years.

Saturday, October 19	2000: record high of 84°
Friday, October 18	2021: temperature in the 70s; 2011: temperature in the 40s through the day
Sunday, October 20	2021: Rain and thunder through afternoon; 2020: record snowfall of 7.9 inches
Monday, October 21	2002: Record 0.4” snow
Tuesday, October 22	2013: frosty, with temperature in the 20s in the morning
Wednesday, October 23	1995: record rainfall of 1.01”
Thursday, October 24	2010: thunderstorm

Photo/Image credits

All photos copyright Nina Manzi, except:

• Keith Henjum: Hooded Mergansers, Raccoons
• Dean Lokken: Geese in flight, Mallard Duck
• Gary Sater: Red-breasted Mergansers