Surface details stand out on the innermost planet in this view from NASA’s orbiting MESSENGER spacecraft.
One of the sky’s most familiar constellations rules February’s sky from dusk until after midnight local time. Orion the Hunter appears at its highest in the south just as evening twilight fades to darkness, when it stands about halfway to the zenith from mid-northern latitudes. The night sky’s brightest star, Sirius in the constellation Canis Major the Big Dog, trails about an hour behind the Hunter.
Saturday, February 23
A pair of fine binocular objects shows up nicely on evenings this week. The open star clusters M46 and M47 reside about a degree apart in the northwestern corner of the constellation Puppis the Stern. The two lie about 12° east-northeast of magnitude –1.5 Sirius, the night sky’s brightest star. The western cluster, M47, glows at 4th magnitude and appears as a fuzzy patch sprinkled with several pinpoint stars. Sixth-magnitude M46 shows up as a hazy collection of faint stars that is hard to resolve under most conditions. Although it contains nearly twice as many stars as M47, M46 appears fainter and fuzzier because it lies some three times farther from Earth.
Sunday, February 24
Mars continues to shine brightly on February evenings. Look for the Red Planet halfway to the zenith in the west-southwest as darkness falls. The orange-colored world glows at magnitude 1.1 against the dimmer stars of Aries the Ram. A telescope shows the planet’s 5″-diameter disk, but you likely won’t see any surface details.
Monday, February 25
This week offers skygazers an excellent chance to see the zodiacal light. From the Northern Hemisphere, late winter and early spring are great times to observe this elusive glow after sunset. It appears slightly fainter than the Milky Way, so you’ll need a clear moonless sky and an observing site located far from the city. Look for the cone-shaped glow, which has a broad base and points nearly straight up from the western horizon, after the last vestiges of twilight have faded away. The Moon stays out of the early evening sky through March 7.
The inner planet puts on its best evening show of 2019 in late February, when the tiny planet appears highest at dusk.
Last Quarter Moon occurs at 6:28 a.m. EST. You can find the half-lit orb rising in the east-southeast around 1 a.m. local time; it hangs about 30° above the southern horizon during twilight. The Moon spends the morning hours lurking near the border between the constellations Scorpius and Ophiuchus.
Mercury climbs to its maximum altitude in the evening sky tonight, when it lies some 11° above the western horizon 30 minutes after sunset. This peak coincides with the planet reaching its greatest elongation from the Sun. Mercury shines at magnitude –0.5, so it should be easy to spot in the deepening twilight. If you can’t see it with your naked eye, binoculars will show it easily. Target the planet through a telescope and you will see a 7″-diameter disk that appears half-lit.
Wednesday, February 27
The waning crescent Moon passes 2° north of Jupiter in a dramatic conjunction this morning. The two objects rise around 2 a.m. local time and climb nearly 25° high by the first hint of twilight. Jupiter gleams at magnitude –2.0 and appears conspicuous just below the Moon throughout the early morning hours.
The shadows of the Galilean moons regularly cross Jupiter’s disk. Viewers in western North America can see Europa’s shadow on the gas giant’s cloud tops the morning of February 28. In this image, the Hubble Space Telescope captured Ganymede’s shadow silhouetted against the Great Red Spot.
With the glare of the Moon now out of the way, Jupiter stands out even better against the background stars of Ophiuchus. If you target the planet through a telescope, you’ll easily see two dark cloud belts that run parallel to each other across the gas giant’s 36″-diameter disk. Small instruments also reveal Jupiter’s four bright Galilean moons. This morning, viewers across western North America get a bonus because the giant world appears to have a “black eye.” It is actually the dark shadow of the moon Europa, which crosses Jupiter’s northern hemisphere from 3:11 to 5:32 a.m. PST.
Friday, March 1
The waning crescent Moon dips lower with each passing day, and this morning, it pairs up with Saturn. Both objects clear the southeastern horizon by 4 a.m. local time and make a pretty sight an hour later, particularly if you view them under a dark sky with the glorious central regions of the Milky Way to their right and above.
The variable star Algol in Perseus reaches minimum brightness at 7:19 p.m. EST, when it shines at magnitude 3.4. If you start viewing as soon as darkness falls, you can watch it more than triple in brightness (to magnitude 2.1) over the course of about five hours. This eclipsing binary star runs through a cycle from minimum to maximum and back every 2.87 days. Algol appears high in the west after sunset and sinks slowly toward the northwestern horizon after midnight.
Saturday, March 2
If you’ve watched the waning crescent Moon these past few mornings, you no doubt saw a brilliant point of light poking above the horizon shortly after 4:30 a.m. local time. This is Venus, which shines at magnitude –4.1 against the background stars on the Sagittarius-Capricornus border. (The planet crosses from the former to the latter constellation today.) This morning, the slender crescent Moon appears less than 5° to Venus’ right. If you target Venus through a telescope, you’ll see a disk that spans 15″ and appears nearly three-quarters lit.
Sunday, March 3
Although Uranus reached opposition and peak visibility in October, it remains a tempting target. The outer planet appears nearly 30° high in the west after darkness falls and doesn’t set until nearly 10 p.m. local time. The magnitude 5.9 world lies in the southwestern corner of Aries the Ram, some 2.2° northeast of the 4th-magnitude star Omicron (ο) Piscium. Although Uranus shines brightly enough to glimpse with the naked eye under a dark sky, use binoculars to locate it initially. A telescope reveals Uranus’ disk, which spans 3.4″ and shows a distinct blue-green hue.
