The innermost solar system planet MERCURY starts off 2024 in Ophiuchus, heading for Greatest Elongation West (GEW) that occurs on January 12, (-0.2 mag), when it is 24 deg. away from the Sun. Located in the morning sky, Mercury overtakes Mars, the two planets are closest on January 27. This conjunction may be observed with care as the Sun rises one hour after them. Mercury plunges into the Sun for superior conjunction on February 28, not visible in the sky. Mercury and Saturn will meet up behind the Sun in a conjunction that will not be observable. Mercury will return to the evening sky, giving northern observers the best evening apparition of 2024. On March 24, Mercury reaches Greatest Elongation East (GEE) (19 deg.) setting ~1.5 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 April 11, Mercury reaches inferior conjunction for the first time in 2024. It reemerges into the morning sky later in the month and will favor southern observers at that time. Mercury reaches GEW (26 deg.) again on May 9. On June 4, Mercury has a close conjunction with Jupiter, when the two planets are a mere 7' apart. It will be easier to find the two from the southern hemisphere, as the two planets rise less than an hour before the Sun. On June 14, Mercury will reach superior conjunction again. Returning to the evening sky, the swift-footed planet meets up with the Moon and the Beehive cluster (M-44) in Taurus on July 7. Mercury reaches inferior conjunction again on August 19, returning to the morning sky by the end of the month. This will be the best time for northern observers to see Mercury in the morning during 2024. On September 5, Mercury reaches GEW and will be 18 deg. away from the Sun. On September 9, Mercury comes within .5 deg of the first-magnitude star, Regulus, Alpha Leonis. Mercury reaches superior conjunction again on September 30. Mercury returns to the evening sky in October reaching GEE (23 deg.) away from the Sun on November 16. The planet then reaches inferior conjunction on December 6. After emerging in the morning sky, Mercury will be well seen from the northern hemisphere. On December 25, Mercury reaches GEW, 22 deg. away from the Sun.

Earth's "sister" planet, VENUS opens the year in in the constellation of Scorpius low on the horizon for northern observers. For the past few years, Venus has been favoring the northern hemisphere observers, but this year Venus will favor observers in the southern hemisphere. Venus catches up with Mars for a close conjunction on February 22. Venus will join up with Saturn for a conjunction on March 22, when the two planets are .3 deg. apart. Venus will meet Neptune on April 3, the two passing less 16' apart. This event will best be observed from the southern hemisphere. On April 7, Venus and the Moon will challenge observers to an occultation visible in eastern Polynesia, Galapagos Is., parts of south and east N America, S. Greenland, Iceland, Azores, and Ireland. Venus reaches superior conjunction on June 4, at that time it will actually be occulted by the Sun. On June 17, Venus meets up with Mercury, but this conjunction is too close to the Sun to be observed. Venus reemerges in the evening sky, but will still challenge northern observers. Venus will be 1.1 deg. north of the bright star Regulus on August 4. The Moon will be 1.7 deg. north of Venus the next day. The southern hemisphere observers have a much better view of these conjunctions. This holds true for the occultation of Venus by the Moon on September 5, this will only be visible for places in the extreme south.

MARS begins 2024 at 1.4 mag., slipping into the constellation of Sagittarius from Scorpius. It reaches 20 deg. elongation away from the Sun, kicking off the 2024 - 2025 apparition. The first Mars event of the year comes on January 27 when Mars is in conjunction with Mercury. Observing this conjunction will be a challenge as they rise less than an hour before the Sun. This conjunction is the first of six close conjunctions between Mars and the other planets in the solar system. In mid-February, Mars slips into the constellation of Capricornus, just in time to meet up with Venus on February 22. The bright inner planet has been moving toward Mars across the sky as it races back to the Sun. This time, Venus and Mars are separated by 0.6 degrees. Venus is -3.9 mag. but Mars is still shining at mag. 1.3 with a tiny 4.2" disk. This conjunction is best observed from the southern hemisphere, of course. Just after Equinox (March 20), Mars slips into Aquarius with plenty of time for it to catch up with Saturn on April 11. Unhappily for northern observers, Mars rises just a little over an hour before the Sun. But the red planet will pull away from the Sun and rise higher in the sky, leaving Saturn behind as it slips into Pisces a week or so later. Mars in Pisces will pass underneath the Circlet, a popular asterism in this constellation. The brightest star in the Circlet is Gamma Piscis and is only 3.7 mag. On April 21, Mars presents its maximum southern aspect, showing off its south pole at 25.7 degrees. Sadly, the entire martian disk is a mere 4.6", so even southern observers might not be checking out the pole on that date. On April 29, Mars (mag. 1.1 ) catches up with Neptune (mag. 7.9), marking the closest conjunction in the series when the two are separated by 0.04 deg. As far as disk size goes, Mars wins because Neptune shows only a 2.2" disk.

On May 5, Mars will be occulted by a 26-day old moon visible from the E. edge of Africa, Madagascar, Sri Lanka, SE Asia, NW Indonesia, Philippines, E. China, Japan, and the extreme SE of Russia. Mars will be at perihelion (closest position to the Sun) on May 8, still in Pisces and rising only 1.5 hours before the Sun. (Much earlier at southern latitudes!) In June, Mars moves into Aries, the red planet now positioned at Solstice, marking Summer in the South and Winter in the North (June 7). The martian disk is now 5.2" in diameter. In July, Mars begins to rise for high northern latitudes. Mars enters Taurus this month, passing below Uranus on July 15, the two planets are .6 deg. apart on that date. Mars has reached .9 magnitude, but Uranus will probably require a telescope at magnitude 5.7. Also in July, Mars passes ~5 deg. below the Pleiades open star cluster (M-45.) On August 5, Mars passes 5-degrees above the bright star Aldebaran, usually considered the eye of the bull. Compare the reddish Aldebaran (Alpha Tauri) to the disk of Mars. On August 6, Mars disk will be 6.0", marking the beginning of the 2024-2025 opposition for observers. Mars finally catches up to Jupiter, passing the gas giant by .3 degrees on August 14. Unlike the perihelic oppositions of Mars, this time Mars presents no challenge to the king of the night. Jupiter is brilliant at -2.2 magnitude while Mars appears as a reddish first-magnitude star. Mars is still feisty, though, it whizzes past the club of Orion, daring the giant to take a swing. On September 3, Mars is 16-degrees above Alpha Orionis, the famous bright star known as Betelgeuse. What an opportunity this is to compare the appearance of Mars and Betelgeuse, will they be nearly the same brightness at .7 mag? Guess we must go to the field to find out! In the northern high latitudes, Mars is now rising around 1 am. Mars slips into Gemini on September 6. On September 8-9, it makes a close pass below the open star cluster M-35.

As October begins, Earth observers should see a large northern polar cap, although the disk is still quite small at 7.5", now it begins to grow steadily. Earth is preparing to pass the red planet! On October 14, Mars is at Western Quadrature that occurs when the Earth Sun and Mars make a 90-degree angle in space. Mars, shining at .73 magnitude has begun rising before midnight. Mars moves into Cancer on October 30 reaching 0.0 magnitude on November 6. On November 12, Mars reaches Equinox marking Northern Spring and Southern Autumn. At this point, that northern polar cap is breaking up. On December 7, Mars reaches its first stationary point and begins to move in retrograde motion. Even though Mars appears to be retreating, it will remain in Cancer for this opposition. On December 18, Mars (-1.0 mag.) has a second lunar occultation, when the waning gibbous Moon passes in front of the red planet. The occultation will be visible from NE & N Russia, N Alaska, N Canada, Greenland, NW Europe, and NW tip of Africa. Opposition occurs on January 16, 2025.

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 super fast 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 sets long after midnight in the constellation Aries, beaming at -2.6 magnitude. It is now moving in prograde motion through the constellation. Jupiter will be in conjunction with Uranus on April 20, when they shine in the twilight evening sky. Jupiter moves into the constellation of Taurus near the end of April. Jupiter will disappear from the evening sky, reaching conjunction with the Sun on May 18. On May 23, Jupiter and Venus will meet up for a conjunction that will be too close to the Sun to be seen. On June 4, Jupiter and Mercury meet up for a conjunction in the early morning sky. This close conjunction is reported in the Mercury section of this article. On August 14, Jupiter and Mars meet up as described in the Mars section of this article. On October 9, Jupiter reaches its first stationary point and begins retrograde motion. Now dominating the evening sky, Jupiter will be at opposition on December 7, 2023. It will shine brilliantly at -2.8 when the disk will be 100-percent illuminated. The giant planet will present a large disk at 48.2". When Jupiter is near opposition, it is a good time to look for transits of its moons.

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 2024 in Aquarius, shining low in the evening sky. Saturn is in conjunction with the Sun on February 28, returning to the evening sky around the middle of March. On April 11, it joins Mars in a close conjunction, 0.5 deg. apart at 13 UT. In May 2024, Saturn begins a series of occultations with the Moon. On May 3, Saturn will be .8 deg. N. of the Moon for the far southern regions, Antarctica, SE Australasia, SW Polynesia, SE Melanesia. On May 31, Saturn will be .4 deg. N. of the Moon, with occultation in southern S. America, S. Georgia, Ascension Is., and parts of of Africa. This year, Saturn's rings become even more closed, so that they will become edge-on by March 2025. On June 27, Saturn is .08 deg. S. of the Moon with an occultation visible from E. Australia, SE Melanesia, Polynesia, south and central N. America. Saturn reaches its first stationary point on June 30, moving retrograde thereafter. Another lunar occultation occurs on July 24, visible from E. Africa, Madagascar, most of S. Asia, NW Indonesia, most of China and Mongolia, Japan and SE Russia. Another lunar occultation occurs on July 21, visible from N. half of S. America, Galapagos Is., south C. America, Cape Verde Is., Azores, NW Africa, and most of Europe. Saturn reaches opposition on September 8 shining at +0.6 mag. The rings will be tilted at 3.3 deg. and the disk will be 19.2". A lunar occultation occurs again on September 17, visible from N. Australia, Melanesia, S. and E Micronesia, NW Polynesia, central western N. America. Saturn's next lunar occultation occurs on October 14, visible from Ascension Is., S and E Africa, Madagascar, SE Arabian Peninsula, most of S. Asia, China, and Mongolia. On November 11, a lunar occultation will be visible from E. Polynesia, Galapagos Is., NW S. America, C. America, Caribbean, SE U.S.A., W. Azores. Saturn will arrive at its second stationary point on November 16, then resume its prograde motion through Aquarius. On December 8, Saturn will reach its final lunar occultation of the year, an event visible from Indonesia, Philippines, NW edge of Australia, NW Micronesia, and most of the Aleutian Is. At the end of December, Saturn will still be prominent in the evening sky, shining as the brightest "star" in Aquarius.

Eclipses for 2024

In 2024 there are two solar eclipses and two lunar eclipses. The first eclipse of the year is a lunar eclipse that occurs March 25. It is a deep penumbral eclipse. The entire eclipse will occur when the moon is over the Americas. Penumbral eclipses are notoriously hard to observe, but with the entire Moon in the Earth's penumbra, it will be worth a try if it is clear. The first solar eclipse is a total eclipse that occurs on April 8. This eclipse starts in Mexico by the resort city, Mazatlan, the path moves upwards and crosses North America at a diagonal that ends in Newfoundland. Moving through the Sierra Madras, greatest eclipse is over Nazas, Mexico and will last for 4 minutes and 38 seconds. The eclipse path enters the United States of America at Piedras Negras, Texas. Some large cities in Texas are treated to totality: Waco, San Antonio, and Dallas among others. The path crosses a corner of Oklahoma, Arkansas, Missouri, Illinois, Indiana, Ohio, a small piece of Pennsylvania, New York, Vermont, and Maine. It enters Canada, leaving the mainland and crossing over to Newfoundland. Astra's Stargate has an entire webpage devoted to the April 8, 2024 eclipse. On September 18, a partial lunar eclipse will occur, partial because a small portion of the lunar limb will dip into the Earth's Umbra. The eclipse will be fully visible from West Europe and Africa, Eastern N. America and South America. The last eclipse for 2024 is an annular solar eclipse on October 2, 2024 visible from Chile and Argentina. The moon will cover 93% of the Sun's disk for 7 min 25 seconds at greatest eclipse far away from land in the south Pacific Ocean. Astra's Stargate has a 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