February Astronomy: Comet ZTF Has a Rendezvous With Planet … – Coachella Valley Independent
Evenings in February feature a striking array of three bright planets: Venus, Jupiter and Mars. (Saturn disappears into bright twilight within first few days.) The length of the three-planet lineup shrinks from 93° on Feb. 1 to 68° on the 28th.
In the year’s brightest planet pairing, Venus will pass 0.5° to the north (right) of Jupiter on March 1. Follow the pair for several evenings before and after, to watch for daily changes. On Feb. 19 and March 11—10 days before and after their March 1 conjunction—Venus and Jupiter are 10° apart. Five days out, on Feb. 24 and Mar. 6, they’re separated by 5°.
Binoculars provide fine views of the moon, pairings of planets (such as Venus-Jupiter around March 1), star clusters (such as the Pleiades and Hyades in Taurus, the Great Nebula in Orion’s Sword, and Andromeda Galaxy) and even an occasional comet. Comet ZTF (C/2022 E3)—discovered in March 2022 by the Zwicky Transient Facility at Palomar Observatory—was predicted to reach magnitude 5.4 in late January and early February. It will pass closest to Earth, at a distance of 26 million miles, on Feb. 1.
The comet appears about 10° from Polaris on the night of Jan. 29 (on a line from the North Star toward the Pointer Stars of the Big Dipper) and the evening of Jan. 30 (on a line from the North Star toward Omicron in Ursa Major, marking the nose of the Great Bear on detailed star maps). For six nights, from Jan. 29-Feb. 3, the comet shifts more than 6° daily, moving toward Capella. On night of Feb. 1, Comet ZTF, plying the wilderness of the faint constellation Camelopardalis, the Giraffe, is just east of the midpoint between Polaris and Capella. On the evening of Feb. 5, the comet passes within 1.6° to the west of Capella. Moving through the nearby compact isosceles triangle called the Kids, by the next evening, Feb. 6, ZTF passes only 0.2° west of Zeta Aurigae, one of the baby goats. By the evening of Feb. 8, in a moonless sky, the comet, now moving less than 4° per day, has passed within 0.7° west of Iota Aurigae, the 2.7-magnitude star nearly halfway from Capella toward Aldebaran. On the night of Feb. 10-11, the fading comet, moving 3° per day, will pass about 1° east of Mars. On the next night, Feb. 11, ZTF passes the descending node of its orbit and plunges through the ecliptic, the plane of Earth’s orbit, from north to south. On evening of Feb. 14, the comet passes 1.5° east of Aldebaran. By now, the comet has “slowed” to 1.9° per day, and is expected to have faded to 7th magnitude.
Follow the moon in evening sky from Feb. 1-6 and 20-28 and observe its gatherings with planets and bright zodiacal stars: Pollux and Castor in Gemini, near a waxing gibbous moon on the evenings of Feb. 2 and 3; and Regulus, heart of Leo, near the moon, just past full, from nightfall until dawn on nights of Feb. 5 and 6. Try to see zodiacal light—dust in the plane of the solar system—in dark, moonless sky at end of evening twilight Feb. 8-20.
The moon returns to early evening sky on Feb. 20. The best view of the young moon in the contiguous 48 states is right here in the Southwest, where the moon sets longest after sunset. A very thin crescent may be seen with the unaided eye in excellent sky conditions.
Venus pairs up with an easier crescent moon, low in the western sky at dusk, on Feb. 21; and Jupiter, within 2° of an even fatter crescent moon, on the next evening, Feb. 22. The gatherings with the two brightest planets, 8° or 7° apart those evenings, will present an excellent photo-op!
On the evening of Feb. 26, the nearly first quarter (half-full) moon will lie in Taurus, between two clusters of stars, the Hyades and Pleiades, and not far from Aldebaran. On Feb. 27 during the 9 p.m. hour, the southern edge of the moon will miss Mars by little more than one moon-diameter. Seen from the Arctic, the moon will occult Mars.
Follow the moon in the morning sky from Feb. 4-18, and catch it near Regulus on Feb. 6, Spica in Virgo on Feb. 11, and Antares in Scorpius on Feb. 14.
Regulus is at opposition on night of Feb. 18-19. As the Earth passes between the sun and Regulus, the star appears 180° from the sun. Spaceship Earth is then moving away from a point 4° south of the Pleiades in evening sky, and toward a point 3° west of the head of Scorpius in morning sky.
Don’t miss the monthly conjunctions of moon and Venus; during the current evening apparition of Venus, the best of these will occur on June 21. In coming months, watch Venus chase Mars through the evening zodiacal constellations until Venus gives up the pursuit. Watch for these planets’ conjunctions with Pleiades, Aldebaran and Beta in Taurus; Pollux and Castor in Gemini; Beehive in Cancer; and Regulus in Leo.
When will Venus finally catch up to and pass Mars? With Pollux and Castor, watch for three events for each planet: (1) When the planet forms an isosceles triangle with the “Twin” stars. (2) When the planet passes closest to Pollux. (3) When Castor, Pollux and the planet lie in a straight line. For Mars, the three Gemini events will occur April 22-May 16; for Venus, May 21-June 1. All these events will be illustrated in Sky Calendar.
Illustrations of many of the events described here, including nightly views leading up to the conjunction of Venus and Jupiter, appear on the February 2023 Sky Calendar. Subscriptions and a sample issue are available at www.abramsplanetarium.org/skycalendar.
Robert Victor originated the Abrams Planetarium monthly Sky Calendar in October 1968 and still produces issues occasionally, including the February 2023 edition. He enjoys being outdoors sharing the wonders of the night sky. Robert Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.
