The innermost solar system planet MERCURY starts off 2025 in the morning sky located in Ophiuchus, just after Greatest Elongation West (GEW) on December 25. Mercury plunges into the Sun for superior conjunction on February 9, not visible in the sky. Mercury and Saturn will meet up in the evening sky on February 25. Mercury will be shining at -1.2 magnitude but Saturn will be low on the horizon. On March 8, Mercury reaches Greatest Elongation East (GEE) (19 deg.) setting ~1.8 hours after the Sun. Because Mercury's orbital period is 87.96 days, each year this swiftly moving planet will generally cross between the Earth and Sun three times. On March 24, Mercury reaches inferior conjunction for the first time in 2025. It reemerges into the morning sky in April, reaching Greatest Elongation West (GEW), 27.4 deg. west from the Sun on April 21, poorly placed for northern observers. On May 30, Mercury will reach superior conjunction again. Returning to the evening sky, the swift-footed planet returns to the evening sky reaching GEE (23 deg.) away from the Sun on July 4, near the Beehive cluster (M-44) in Cancer. Mercury reaches inferior conjunction again on August 1, returning to the morning sky later in the month. On August 19, Mercury reaches GEW and will be 18.6 deg. away from the Sun, again near the Beehive cluster. It will be easier to see at this time for northern observers. Mercury reaches superior conjunction again on September 13. In the evening of October 21, Mercury has a conjunction with Mars, when the two planets are 2 deg. apart, however, again poorly located for the north. Mercury reaches GEE (23.9 deg.) away from the Sun on October 29. On November 12, Mercury passes Mars again as it returns to the Sun. This time Mercury will pass 1.2 deg. S. of Mars. The planet then reaches inferior conjunction on November 20. After emerging in the morning sky, Mercury will be well seen from the northern hemisphere. On December 7, Mercury reaches GEW, 20.7 deg. away from the Sun.

Earth's "sister" planet, VENUS opens the year in in the constellation of Aquarius, well placed for northern observers. Venus will join up with Saturn for a conjunction on January 20, when the two planets are 2.2 deg. apart. Venus will be brilliant, shining at -4.6 while Saturn will be a mere 1.1 magnitude. Venus will reach Greatest Illuminated Extent (GIE) on February 14, shining at -4.9 magnitude. Venus reaches inferior conjunction on March 23, passing 8.1 degrees north of the Sun. This will be observable, but Astra advises caution and observing experience to enjoy this spectacle. Take care whenever observing near the Sun. Soon Venus will be shining in the morning sky. On April 27, Venus will once again reach GIE, shining brightly in the constellation of Pisces. Venus will meet up with Saturn on April 28, a sight for southern hemisphere based observers. Five days later, on May 3, Venus and Neptune (mag. 7.9) join up but this is a telescopic observation. Venus is at Greatest Elongation West (GEW) on June 1, when it is 45.9 degrees away from the Sun. On June 4, Venus meets up with Uranus, passing 2.4 degrees south of the 5.8-magnitude gas giant. The best planetary conjunction of the year will occur when Venus and Jupiter meet up in the morning sky on August 12, when the two brightest planets in the sky pass a mere 52' apart in the constellation of Gemini. Venus will be -4.0 magnitude with a 13.5" gibbous disk while Jupiter shines at -1.9 magnitude with a 33" disk. On September 19, Venus and the Moon treat observers in northern Canada to an occultation when the waning Moon meets up with our sister planet. The bright star Regulus (Alpha Leonis) will be nearby. All three will fit in a low power eyepiece and binoculars should provide an excellent view.

MARS begins 2025 shining brightly at -1.2 mag., in the constellation of Gemini. On January 12, Mars will be at closest approach when it is as close as it will get to planet Earth. At this time, the disk will be 14.5" and the planet will shine at -1.8 magnitude. On January 16, 2025, Mars will be at opposition from the Sun as viewed from the Earth. Opposition occurs when the planet is in the constellation of Gemini. Now the planet will be "up" all night rising as the Sun sets, just like the full Moon. But just as soon as Mars and Earth reach opposition, their orbits quickly find Earth racing away from Mars. The first lunar occultation after opposition occurs on February 9, when a growing gibbous Moon covers the planet. This may be observed from northern latitudes from Scotland to the Korean peninsula. At this time the disk will be 97% illuminated. In February 2025, Mars' brightness fades from -1.0 magnitude to -0.25 magnitude as Earth speeds away. During the month of March, Mars' magnitude drops even more, shining at about +0.5 magnitude mid-month. As the month ends, Mars passes Kappa Geminorum, a fourth-magnitude star, and on April 2, 2025 a conjunction between Kappa Gem, Pollux and Mars will occur. Mars re-enters the constellation of Cancer on April 12. On April 14, Mars reaches aphelion as Spring is moving toward Summer in the northern hemisphere. On April 21 Eastern Quadrature or 90 degrees East of the Sun, shining at +.78 magnitude. On May 6 Mars, now magnitude +1.0, passes 0.6 degrees north of the star cluster Praesepe, or the Beehive Cluster (M44 or NGC 2632). Mars enters Leo around 0hr UT of May 26. Mars passes within a degree north of Alpha Leonis or Regulus on June 17th. On June 30, another lunar occultation of Mars takes place, when a waxing crescent Moon occults the planet. This event will be visible from the South Pacific Ocean and northeastern South America. On May 30, Mars will be at Solstice when Summer begins in the North and Winter begins South. Unfortunately, the disk of Mars will be only 5" Mars enters Virgo on July 28 the same day Mars is occulted by the waxing crescent Moon for the last time during this apparition that can only be seen from a small area of Antarctica. On July 31, Mars shines at +1.5 magnitude and sets in the northern summer twilight. In the middle of September 2025, Mars is lost to observers in the northern hemisphere. Mars enters Libra on October 4, passing by one of my favorite double stars, Zubenelgenubi also known as Alpha Librae. On October 21, Mercury passes two degrees south of Mars, the last planetary conjunction of this apparition, but it occurs during daylight hours in North America. Mars enters Scorpius on November 3, to catch up to Mercury when it passes 2 degrees North. Mars spends a few days in Scorpius then passes through Ophiuchus, landing in Sagittarius on December 10, 2025. Mars will still be there on January 09, 2026 when it reaches conjunction with the Sun.

The solar system's behemoth planet is the gas giant JUPITER. Jupiter may be the amateurs' favorite planet, as it is observable for 12 months every 13-month period. Its superfast rotation speed, that makes a revolution every 9h 51m, allows observers to study its many features: belts, festoons, giant storms and many other effects that one can't really predict. Jupiter's four largest moons, are called the "Galilean Moons" after their discoverer. In order of closeness to Jupiter, they are Io, Europa, Ganymede, and Callisto. They transit the disk of Jupiter leaving super round black shadows that crawl across the disc. The planet is a favorite target for astrophotographers. As the year opens, Jupiter shines from in the constellation Taurus, beaming at -2.7 magnitude. It is moving retrograde toward the horns of the Bull. Jupiter will resume prograde motion of February 4. Jupiter has been a beacon in the northern night sky, but it will return to conjunction with the Sun on June 24, afterward returning to the morning sky. A fabulous morning conjunction with Venus (described above) will be a real treat for early morning observers on August 12. On November 12, the giant planet will once again reach a stationary point and begin retrograde motion in the constellation of Gemini. Jupiter will rise earlier and earlier until it once again reaches opposition on January 10, 2026.

The last planet to be discussed is the ringed-wonder, gas giant SATURN. The rings are made of ice, dust, and rock orbiting the planet at various distances. This is somewhat like the ridges on a vinyl record album. There is one large gap near the center of them, dividing them into two pieces called "The Cassini Division." This gap can be seen with small telescopes; there are other gaps that can be seen with larger amateur instruments on a clear night. Saturn opens 2025 in Aquarius, shining in the evening sky. On January 4, Saturn's occultation by the Moon will not be visible from North America. On January 20, Saturn meets up with Venus (described above), passing 2.2 degrees above the ringed wonder. On February 1, a lunar occultation is visible from parts of SE Asia, China, Japan, and E. Russia. Saturn reaches conjunction with the Sun on March 12, returning to the morning sky by April. Saturn reaches opposition on September 21 shining at +0.6 mag. The rings will be tilted at a shallow angle. and the disk will be 19.45";. Saturn will reach its second stationary point and begin prograde motion on November 29. At the end of December, Saturn will still be prominent in the evening sky, setting before mid-night.

Eclipses for 2025

In 2025 there are two partial solar eclipses and two total lunar eclipses. This is the least number of eclipses that can occur in one year. The first eclipse of the year is a total lunar eclipse on March 14. The entire eclipse will occur when the moon is over the Americas, with North America winning the totality prize. The full eclipse lasts six hours, with totality beginning at 6:26 UT, morning in the Americas. The first solar eclipse is a partial eclipse that occurs on March 29. This eclipse will be visible from northeast USA and Canada, Europe, northwest Africa, and northern Russia. This eclipse will favor the western coasts of Europe and northern Africa with 93 percent of the Sun's disk covered. On September 7, a total lunar eclipse will occur beginning at 15:28 UT, this time favoring the Eastern hemisphere: Europe (partial), Africa, Middle East, India, Asia, Australia, and New Zealand. The last eclipse for 2025 is an partial solar eclipse on September 21, 2025 visible from South America and Antarctica. The moon will cover 85% of the Sun's disk at greatest eclipse. For more information on lunar and solar eclipses, check out Astra's Guide to Eclipses at: http://www.astras-stargate.com/eclipse-home.html

Remember more details on these and other celestial observations are available at What's Up in the Night Sky? every month at Astra's Stargate!

--See You Under the Stars!
Astra for Astra's Almanac