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This is the Griffith Observatory Sky Report for the period between January 1 and January 31, 2025. Here are the events happening in the sky of southern California.
Mercury rises in the east-southeast at 5:28 a.m., PST, on the 1st, and the sun rises at 6:59 a.m., PST, one hour 31 minutes later. The disk of Mercury is 78-percent illuminated and 5.8 arcseconds wide. A telescope with a magnification of 150x is needed. On the 14th, Mercury rises in the east-southeast at 6:02 a.m., PST, and the sun rises at 6:59 a.m., PST, 57 minutes later. The disk of Mercury is 91-percent illuminated and 5.1 arcseconds wide. After the 14th, Mercury is close to the sun, and it is not safe to observe. Do not observe any planet when it comes close to the sun, for the danger to the eyes is great.
Venus sets in the west-southwest at 8:38 p.m., PST, on the 1st, and the sun sets at 4:55 p.m., PST. The disk of Venus is 55-percent illuminated and 22 arcseconds wide. On the 31st, the sun sets at 5:23 p.m., PST, and Venus sets due west at 9:00 p.m., PST, with a disk that is 38-percent illuminated and 32 arcseconds wide. A magnification of 100x will show the disk. On the 3rd, Venus is four degrees west of the crescent moon. On the 18th, Venus is two degrees north of Saturn.
Mars transitions from Cancer the Crab to Gemini the Twins on the 12th. On the 1st, Mars rises in the east-northeast at 6:12 p.m., PST, and on the 31st, Mars rises in the east-northeast at 3:19 p.m., PST, with a disk that is 99-percent illuminated and 14 arcseconds wide. A magnification of 150x will be needed to see anything on its disk.
Mars will be closest to the earth on the 12th. The difference in dates between closest to earth and opposition is due to the eccentricity of the orbit of Mars. On the 12th, Mars will be a few thousand miles closer to earth than on the 16th. This is not enough to change the size of its disk as seen through a telescope. Griffith Observatory will host neither a public event nor a web broadcast.
The Moon occults Mars on Monday the 13th, when the moon passes in front of Mars from 5:51 p.m., PST, to 6:46 p.m., PST. Griffith Observatory will host a web broadcast but no public event.
Mars opposition will occur on the 16th, when Mars is 59.7 million miles or 0.642825 astronomical units (AU) from the earth. Opposition occurs when an outer planet is opposite the sun in the sky. This is one of the more distant oppositions, which can vary from 34.6 million miles when Mars is at perihelion to 63 million miles at when Mars is at aphelion. During this opposition, the disk of Mars is only 14 arcseconds in width. A telescope capable of magnification of 150x is needed to see features on such a small disk. After the 16th, Mars will slowly move away from the earth and will decrease in size. Griffith Observatory will host neither a public event nor a web broadcast.
Jupiter is in Taurus the Bull. On the 1st, Jupiter sets in the west-northwest at 5:01 a.m., PST, with a disk that is 47 arcseconds wide. On the 31st, Jupiter sets in the west-northwest at 2:55 a.m., PST, with a disk that is 44 arcseconds wide. A telescope capable of magnification 50x will show the Red Spot, and the four bright Galilean moons can be seen moving back and forth, across and behind Jupiter.
Saturn is in Aquarius the Water Bearer. On the 1st, Saturn sets in the west at 9:53 p.m., PST. On the 31st, Saturn sets in the west at 8:08 p.m., PST, with a disk that is 16 arcseconds wide. The rings and Saturn’s largest moon Titan may be seen with a telescope capable of magnification 50x.
Uranus is in Aries the Ram. On the 1st, Uranus sets in the west-northwest at 3:28 a.m., PST. On the 31st, the planet sets in the west-northwest at 1:29 a.m., PST. On the 15th, Uranus is at Right Ascension 3h 24m 11s with a declination of +18° 22ʹ 28ʺ. The disk of Uranus is 3.7 arcseconds wide, and so a telescope with a magnification of 150x is needed.
Neptune is in Pisces the Fishes. On the 1st, Neptune sets in the west at 10:54 p.m., PST. On the 31st, Neptune sets in the West at 8:59 p.m., PST. On the 15th, Neptune is at Right Ascension 23h 53m 0s with a declination of -2° 8ʹ 57ʺ. The disk of Neptune is only 2.3 arcseconds wide, and so a telescope with a magnification of 150x is needed to show the disk.
The moon will be at first quarter on the 6th, full on the 13th, last quarter on the 21st, and new on the 29th.
SPECIAL EVENTS
In the major lunar standstill of 2024-2025, in January, northernmost moon occurs on the 11th, when the moon is two days from full phase. The moon rises in Los Angeles at 2:47 p.m., PST. The Observatory will not host a livestream broadcast or a public event. On the morning of the 12th, the moon sets at 5:12 a.m., PST. Griffith Observatory will not host a public event. For details on the major lunar standstill, please visit the website at https://griffithobservatory.org/extreme-moon-the-major-lunar-standstills-of-2024-2025/
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