As Bakersfield College begins its spring semester, I’m eager to teach students astronomy in the planetarium.
My previous column addressed how the official dates of the seasons are determined by the position of the sun with respect to the celestial equator. I also noted that the meteorological definition of a region’s seasons can be very different than the astronomical definition. As I did yardwork the previous weekend with temperatures reaching 70 degrees, I wondered if our winter had already come and gone in those few weeks in December!
Looking for comet ZTF
At the end of the month, we may be able to see a comet become a naked-eye object as it moves across the northern sky. Comet ZTF (C/2022 E3) was first detected last March by the Zwicky Transient Facility as it moved toward the inner solar system.
The Zwicky Transient Facility scans the entire northern sky every two nights using the P48 telescope at Palomar Observatory in Southern California to find new objects such as near-Earth objects, comets, supernovae, etc. Comet ZTF reached its closest distance to the sun on Thursday and will pass closest to Earth on Feb. 2 at a distance of 26 million miles.
Depending on how much activity it continues to have, there may be enough dust in its tail and coma (a cloud around the nucleus) to reflect a sufficient amount of sunlight for us to see without binoculars. Comets are notoriously unpredictable in the amount of gas and dust erupting as they pass near the sun.
Comet ZTF is going to follow a path between the Big and Little Dippers (Ursa Major and Ursa Minor) at the end of the month. On Jan. 27 and 28, it will be next to the bowl of the Little Dipper and on Jan. 31 it will be a fist-width away from Polaris at the end of the handle of the Little Dipper (or the tail of Ursa Minor). Those with a dark sky might be able to see a fuzzy object without binoculars but those in town will need to use the binoculars. Although the comet will be circumpolar (always above the horizon) by then, it will be placed higher in the sky after midnight.
In the night sky
Mercury has now left our evening sky, so we no longer have the entire grand parade of planets stretching across the sky, but what’s left is still quite fine. Low in the southwest shortly after sunset, you’ll see Venus blazing away in the twilight glow. Next to the left comes Saturn, the dimmest of the planets in tonight’s sky. Venus has been drawing ever closer to Saturn on our sky.
On Jan. 22, Venus and Saturn will be right next to each other about a pinky width at arm’s length apart from each other. After that, Venus will be the higher of the two.
Farther up in the southwest is bright Jupiter, outshone only by Venus in this evening’s sky and by the waxing crescent moon next week. Above Jupiter is the familiar Great Square of the constellation Pegasus. Between Jupiter and Pegasus is the string of stars for Pisces but city dwellers will have a hard time finding those dim stars because of our light pollution.
High up in the southeast shortly after sunset is bright orange-red Mars, about midway between the head of Taurus and the Pleiades at Taurus’ shoulder. Over the past few months, Mars has been retrograding — moving backward or westward back toward the Pleiades as Earth has caught up to and passed Mars in our faster orbit around the sun. Tonight Mars stops its retrograde motion and will head back to the head of Taurus, reaching the first horn in mid-February.
The night after Venus and Saturn’s conjunction, on Jan. 23, a thin waxing crescent moon will be to the left of Venus. A fatter crescent moon will be next to Jupiter two nights later on Jan. 25. The moon will be at first-quarter phase on the night of Jan. 28 and at the end of the month on Jan. 30, the moon will do a repeat performance of its December occultation of Mars. This time around, it will be a waxing gibbous phase that covers up Mars. Mars won’t be as bright as it was in December, but it will still be plenty bright enough to see it wink out behind the moon between 8:45 and 9:18 p.m.
