Long and sparkly, the winter night sky is a spectacle — inviting us to wrap up, go outside and gaze up at planets, stars, airplanes, a sudden meteor and the parade of satellites.
“Winter skies are dark, because the Earth is still leaning away from the sun. So what we see is brighter,” says Don Jolley of DarkSky West Marin, a community-led initiative to enact light restrictions and preserve the night sky. Without fog, “skies tend to be clear and really crisp.”
What are all those bright objects overhead? Here’s an identification guide.
It doesn’t twinkle? Planet
Seen with the naked eye, planets and stars both appear as pinpoints of light. But planets generally don’t flicker. That’s because planets are closer than stars, so their beams of light are less influenced by our turbulent atmosphere than the beam of light from a much more distant star.
In late January and early February, we’re most likely to see either Venus or Jupiter. Both can be strikingly bright, easily visible to the unaided eye. Jupiter is four times and Venus 19 times as brilliant as Sirius, the next brightest star after our sun.
Look to the east at nightfall to spot Jupiter, the largest planet in the solar system. Jupiter is bright because of its sheer size. And it reflects 34% of the sunlight that hits it.
Venus reigns as the “morning star,” visible in the southeast before dawn. While smaller than Jupiter, it’s easy to spot because it’s the shiniest planet in the solar system. It is covered in clouds, so it reflects more than 75% of the sunlight that strikes it.
The moon, the brightest and largest object in our night sky, isn’t technically a planet. That’s because it orbits around the Earth, not the sun. But take a moment to appreciate the moon’s critical role: It moderates our planet’s wobble on its axis, creating a relatively stable climate.
January’s “wolf moon,” named by Celtic and Old English traditions for the howling of hungry wolves in the winter, reaches peak illumination on Thursday, Jan. 25. The full moon of February is known as the snow moon. Because there wasn’t much to eat at this time of year, some cultures also called it the hunger moon.
It twinkles and may change color? Star
Out in airless space, stars never twinkle. But our atmosphere is turbulent. Tiny differences in the density and temperature of air cause light to bend and distort. Astronomers call that “atmospheric scintillation.”
Because the winter air is so clear, we’re able to perceive star colors better than in other times of the year, says Jolley. In the constellation Orion, look for the red star Betelgeuse, which is Orion’s right shoulder, and the blue star Rigel, Orion’s left foot.
Our galaxy, the Milky Way, is almost directly overhead, from southeast to northwest.
Stars show off some special geometry on winter nights. Look for the Winter Hexagon, made up of seven bright stars with one more as its hub. You can see it in the east-southeast, about halfway up the sky at nightfall. It encircles the constellation Orion.
First find Sirius, whose name means “glowing” in Greek — it’s the brightest star in the night sky. If this star were placed next to our sun, Sirius would outshine it more than 20 times over, according to NASA. Because Sirius is low in the sky, we see it through many atmospheric layers, causing it to twinkle and change colors.
Then sweep clockwise to Procyon, the Gemini twins Pollux and Castor, Capella, Aldebaran and down to Rigel, Orion’s bright, blue-white foot. The hexagon’s hub is Betelgeuse.
It moves quickly, sometimes with flashing lights? Airplane.
Airplanes can be confusing. They may appear to be stationary for a while, like a planet or star, when they fly directly towards you. But at some point, the aircraft will appear to veer sideways or upwards as it passes by.
Another clue: Planes travel quickly, at a steady rate.
It you see any blinking lights, that’s likely an airplane. An airplane’s collision avoidance lights flash quickly. You may also see the red and green navigation lights on its wingtips.
It twinkles, but it’s not distant? Drone.
A drone also uses anti-collision blinking lights — but its flight altitude is typically much lower than that of an airplane. Drones generally fly below 400 feet, as per FAA regulations.
Drones use their lights to improve nighttime visibility, making the device visible to other aircraft and easier to spot in the dark. The lights, also regulated by the FAA, must be visible for at least three miles.
These lights are not just for show; they serve a purpose. Red lights typically indicate the front of the drone, helping the pilot maintain orientation. Green lights usually indicate the rear. White lights can be used for illumination. If you see blue lights blinking along with red ones, it may be a police drone, useful for surveillance, search and rescue missions and other tasks.
They may hover or suddenly change direction, making quick, sharp movements, which is not typical for traditional aircraft.
Additionally, listen for a distinct buzzing or humming noise produced by the drone’s motors and propellers.
It moves slowly and steadily, with no flashing lights? Satellite.
Manmade satellites may seem too small and far away to see. But most are a lot closer than you might think. Many are also big and shiny, reflecting sunlight, so they can be brighter than many stars. There are presently more than 7,500 active satellites circling Earth.
They look like slowly and steadily moving stars. While low-altitude satellites seem to move at about the same speed as an airplane, they do not have flashing lights.
Satellites, which are silent, typically take about two minutes to cross the sky from one horizon to another. A satellite’s speed depends on how high it is orbiting.
The best example of a bright satellite is the International Space Station (ISS), which outshines the stars as it serenely and smoothly slides across the sky. Born 25 years ago, ISS was originally just a big steel can, built and launched by Russia but paid for by the United States. The addition of a second module, delivered by the Space Shuttle Endeavour, increased the size of ISS to more than the length of a football field.
It’s remarkable to think that there are human beings living there.
How do you know when to see the ISS pass overhead? NASA has a great tool to help. Sign up to the Spot the Station program to see a map-based feature that tracks when the station is flying over you.
But the ISS isn’t the only satellite to see. If you spot a chain of tiny dots of light moving across the sky in a straight line, that’s Starlink. It is Elon Musk’s plan to surround the planet with a latticework of mass-produced satellites to provide cheap, global wireless internet.
The Starlink satellites follow a shared trajectory, from west to east, before entering their assigned orbital slots.
While astronomers hate the Starlink trains for cluttering the night sky, they’re an astonishing sight. To learn exactly when a Starlink train will be visible from your precise location, visit the Find Starlink website (or the Find Starlink Satellites app) and just enter your location. It prioritizes the bright passes of newly launched satellites and gives a live map of where they are now.
It’s super fast, with a tapering path? Meteor.
You know meteors, also called “shooting stars.” The Holy Grail for skywatchers, meteors are easy to discern from other sky objects. They fly much faster than planes and satellites. They can be colorful, especially if they flare when hitting the Earth’s atmosphere. Their path is tapered, starting thin and ending thin.
It’s an amber orb. Or a silent and dim flying triangle. Or hovering diamond-shaped clusters: UFOs?
These are among the descriptions of UFOs made from Californians to the National UFO Reporting Center, a database of alleged sightings. Since its founding in 1995, the Center has collected 16,158 reports from our state.
Last July, a driver in the coastal town of Davenport reported an orb “in the rear view mirror… slowly behind us and to our left…It came forward towards us and paralleled our car.” In early September, a “cigar-shaped object” was reported in Fairfax, with “many blinking white lights, with some stationary. It moved slowly.” Later that month, an Oakland resident reported a “cylinder-shaped, highly reflective object silently traveling, not quite overhead, SE to SW.”
Of course, the vast majority of UFO reports can be explained. It’s likely they don’t really exist.
Or do they? The truth is out there, up in the night sky.
Source: www.mercurynews.com