What's Up In January

By Bernie Reim

​     The month of January is named for the Roman god Janus, who faces both forward and backward at the same time. Janus is the god of beginnings and transitions. As we welcome in the New Year and the first full month of winter, let us reflect on what the past year has taught us and look forward to all the new things that 2025 will teach us if we can remain open-minded enough.
    The days are already getting longer since the winter solstice, but this is a very slow process at first. We are only gaining about one minute per day until the middle of this month. The sun is setting a little later than at the solstice, but the sun is also still rising later each morning until the ninth. For us at this latitude of the Portland area that will be 7 :14 am. This happens because the earth is tilted at 23.5 degrees to the ecliptic plane and we orbit the sun in an elliptical shape and not a perfect circle.
      Despite the long and cold nights, this will be a great month to enjoy and learn more about several interesting celestial events. Four of the five brightest planets will be nicely aligned along the ecliptic and visible in the evening sky. Only Mercury is too close to the sun now and it will make a morning appearance until the middle of the month. Mars will reach opposition on the 16th when it will be at its best in 26 months. Venus and Saturn will have a close conjunction in the evening sky on the 17th, the moon will have two nice conjunctions with Venus this month. We will be closest to the sun on Saturday morning the 4th at 91.4 million miles instead of our average of 93 million miles, which is called one astronomical unit. The moon will not interfere with the Quadrantid Meteor shower this month which has a very short peak on Friday morning, January 3. Then the best highlight of all this month will be the full moon occulting or covering up Mars on the evening of Monday the 13th which will be visible for everyone in the contiguous United States, much of southern and eastern Canada, Mexico, and West Africa.
     

We begin the planetary parade in the western sky right after sunset with Venus nice and high and bright in Aquarius the water-bearer. It is still getting higher and brighter each evening as it is catching up with Earth in its faster orbit around the sun. It starts the month like a waning gibbous moon at 55% illuminated by the sun and will finish this month considerably larger and shaped like a waning crescent moon only 39% illuminated by the sun.
     Keep watching our brightest planet as it is rapidly catching up with Saturn, also in Aquarius. They will be just two and a quarter degrees apart on the evenings of the 17th and 18th. Notice that Venus will be nearly 200 times brighter than Saturn. Also look for the slight difference in color since Saturn will appear more golden than bright white Venus. Then Venus will keep traveling higher into Pisces and get even brighter as Saturn appears to sink lower and get a little fainter as it is getting farther away from earth at nearly one billion miles away. Venus will encounter a thin waxing crescent moon on the 3rd, the night of the Quadrantids, and it will once again encounter a thin waxing crescent moon one hour after sunset on the last day of this month. You could even try to see Venus in the daytime with a pair of binoculars since it will be so close to the moon on those two days.
     Then we travel eastward through Pisces the Fish and Aries the Ram to get to Jupiter in Taurus the Bull. Before we get there be aware that we are passing right by Neptune in Pisces and Uranus in Aries. Those two planets are not visible without a good pair of binoculars or a small telescope. So not only are 4 of the 5 brightest planets visible at the same time in the evening sky for the whole month of January and February, the remaining two planets out of our family of 7 planets outside of Earth are also visible now and next month. Only Mercury will be missing from this fairly rare great arc of all of our other family of planets nicely aligned in our evening sky for another month and a half. Mercury will join the group in late February as an evening planet, but we will have lost Saturn by then.
       You will get a good sense of the path of the ecliptic plane of our solar system as you follow all of these planets over the next month and a half. When the moon in different phases points out and joins these planets that will make this important path that the defines the shape of solar system as a disk or giant frisbee in the sky even more obvious. Also notice how the angle of this path gets a little steeper in relation to the horizon over the next month and a half. It is always at its most shallow in December at the winter solstice and then gets steeper and steeper until the sun reaches Gemini on June 21 at the summer solstice.
     We will start losing this great parade of planets by the middle of February as they start dropping out one by one. Saturn will be the first to exit this great celestial play now taking place in our evening sky. Then we lose Neptune in early March followed by Mercury and Venus in mid-March. Then we lose Uranus in April and Jupiter in May. That will leave only Mars, which will hang around our evening sky until next summer in August.
     Jupiter is still nice and high and bright in Taurus since it was at opposition on December 7. The king of the planets is still in its westward or retrograde motion now towards Aldebaran, a red giant star marking the eye of the bull perpetually charging the mighty hunter Orion but never catching him.
      We now end our trip along the ecliptic as we encounter Mars in the constellation of Cancer the crab. The red planet began its retrograde loop near the Beehive star cluster on December 7, the same day that Jupiter reached opposition. It is now in retrograde motion looping back into Gemini where it was in November. Watch as Mars nicely aligns with Castor and Pollux by the middle of the month, the two brightest stars in Gemini the Twins. Castor is the upper star and is the mortal twin and Pollux is the one closer to Mars and it is the immortal twin. Notice the slightly orange color of Pollux since it is also a red giant star like Aldebaran.
      Mars will reach opposition, which is always the mid-point of the retrograde loop of a superior planet, on January 16. This will not be a particularly high or close opposition, but it will offer us the best views of Mars until its next opposition in 26 months. Mars will reach minus 1.4 magnitude, which is the same brightness as the brightest star in our sky, Sirius in Canis Major, about 30 degrees to the right and below Mars in the winter hexagon. That is still about 20 times fainter than Venus, which now shines at minus 4.8 magnitude. If you have access to a small telescope you can see some of the dark markings and polar ice caps along with some of the tenuous atmosphere.
     We will finally get a good meteor shower that the nearly full moon will not interfere with. That shower is called the Quadrantids, named after an obsolete constellation called Quadrans Muralis, near the Big Dipper. The problem is that it has a very narrow peak, only about 6 hours, and that will happen around 10 am on Friday morning the 3rd our time. Alaska and the west coast are better placed for catching more of these meteors just before their dawn. It would still  be worth your while to see as many as you can here if it is clear that Friday morning before dawn.  
      One of only two of our best meteor showers each year, the Quadrantids are caused by leftover debris from an asteroid named 2003EH1. The other shower is the Geminids that we just had on December 13 that is caused by an asteroid named 3200 Phaethon. Both of them are probably nuclei of extinct comets since an asteroid would not normally leave a trail of debris behind it as it orbits the sun. You can expect up to 100 meteors per hour from a dark sky site for this shower if you catch the peak just right before sunrise on the 3rd. These meteors will be slightly denser than comet dust and they will enter our atmosphere at 91,000 miles per hour, faster than most of the other 10 or so good meteor showers that we encounter each year. They also create bright fireballs. By comparison, the earth orbits the sun at 67,000 mph.
     The best major highlight of this first month of the new year will be a fairly rare occultation of Mars by the full moon. That event will start at 9 pm on Monday the 13th. Mars and the full moon will rise very close to each other right at sunset, since they are both at opposition now, which means that they are opposite the earth from the sun. Then watch closely as the full moon gets closer and closer to Mars until it passes right in front of Mars based on our line of sight. That will take 29 seconds to completely cover Mars, so this is the best part of this event.  You will need a good pair of binoculars or a small telescope to see this since the moon will be so much brighter than Mars that you can’t really see this with the naked eye.
     It will take just over an hour for the moon to once again reveal Mars to us in all of it brilliant orange glory, the best and brightest that our intriguing and mysterious planet will appear for another 26 months. Make sure not to miss this and photograph it if it is clear.
Jan. 1. On this day in 1801 Giuseppe Piazzi discovered the first and largest asteroid, Ceres. It is 600 miles in diameter and is now considered a dwarf planet along with Pluto.
Jan.3. The Quadrantid meteor shower reaches its very shallow peak this Friday morning before sunrise. You can expect up to 100 meteors per hour since there will be no moon to interfere.
Jan. 4. Earth passed through perihelion, the closest distance it will reach to the sun for the year.  That is around 91.5 million miles. Our average distance to the sun is 93,000,000 miles. Saturn is near the moon this evening in the south-southwest.
Jan.6. First quarter moon is at 6:58 p.m. EST.
Jan. 7. On this day in 1609 Galileo discovered 3 of the 4 largest moons of Jupiter, Callisto, Europa, and Io. He would discover Ganymede, the largest moon in our solar system at 3200 miles in diameter 6 days later.
Jan. 8. Stephen Hawking was born on this day in 1942.
Jan. 9. The waxing gibbous moon visits the Pleiades, an open star cluster with about 500 stars riding on the back of Taurus the Bull. It is about 400 light years away, which is when Galileo first pointed the first telescope ever made by modern humans up to the sky enabling him to make many astounding and earth-shaking discoveries that many did not believe even though they could see them with their own eyes.
Jan.10. Robert Woodrow Wilson was born on this day in 1936. He won the Nobel Prize in physics along with Arno Penzias in 1978 for their discovery of the original cosmic background radiation from the Big Bang in 1964 using a radio telescope in NJ while working for Bell Labs.
Jan. 13. Full moon is at 5:27 p.m. EST. This is also called the Wolf Moon. The moon will occult Mars tonight starting at 9 pm.
Jan.14. The Huygens probe landed on Titan, the largest moon of Saturn and the second largest moon in our solar system on this day in 2005. This is the only moon of nearly 300 known moons in our solar system that has an atmosphere.
Jan. 16. Jill Tarter was born on this day in 1944. She is an American astronomer that used to head the SETI project. The Search for Extraterrestrial Intelligence.
Jan. 17. Venus and Saturn form a close conjunction in Aquarius one hour after sunset tonight.
Jan. 19. New Horizons was launched to Pluto on this day in 2006, the same year that Pluto was demoted to a dwarf planet or an icy dwarf or just the largest Kuiper Belt object. It arrived at Pluto on July 14 of 2015.
Jan.21 Last quarter moon is at 3:32 p.m.
Jan.25. Joseph-Louis Lagrange was born on this day in 1736 in Turin, Italy. The 5 Lagrangian points of any 2-body system where the gravitational forces balance out are name after him. The James Webb Space Telescope along with several other useful space telescopes are orbiting the L2 point about one million miles from Earth beyond the moon right now.
Jan.29. New moon is at 7:37 a.m.
Jan.30. Saturn and the moon form another nice conjunction in Aquarius with brilliant Venus right above them in Pisces.