What’s Happening in the Sky: October 2022 – YubaNet

Jupiter and Saturn all night long, Mars begins its retrograde motion, and Orionid meteors reach their climax!

The giant planets Jupiter and Saturn can be seen all night in October. Early in the evening, you’ll find them in the southeast, slowly moving west with the stars throughout the night. They form a triangle with the bright star Fomalhaut.

Sky chart showing Jupiter and Saturn early evening in October. The planets form a triangle with the bright star Fomalhaut. Credit: NASA/JPL-Caltech attributed to him: NASA / JPL-Caltech / NASA / JPL-Caltech

Observing this trio, notice how the planets shine with constant light, while the star shines. This can be an easy way to tell if what you’re looking for is a planet or a star.

Mars has been steadily making its way eastward throughout the year as it normally does, relative to the background stars. But at the end of October, Mars stopped this apparent motion, and then seemed to reverse course. For the next three months, from November to late January, Mars moves westward each night. Then towards the end of January, it reverses direction again and continues its journey east.

The sky chart shows the path of Mars over several months in 2022 and 2023, as it enters, and then exits, in retrograde motion. Mars seems to change the direction of its movement in the sky because the Earth passes the red planet, which is moving slower in its orbit. Credit: NASA/JPL-Caltech attributed to him: NASA / JPL-Caltech / NASA / JPL-Caltech

This is called the retrograde motion of Mars. It happens about every two years, and it threw early watchers an episode. It seems that Mars is changing its direction is an illusion caused by the motions of our planet in its orbit, passing through the red planet in its orbit.

See, Earth and Mars are on these roughly circular paths around the Sun, like cars on a racetrack, and Earth is on the faster inner track. About every 26 months, we pass Mars, which is moving slower in its orbit. During that period when we are passing through Mars, and before we go around the bend in our orbit to get away from it, we see Mars in retrograde, and it seems to change direction, even though it is still moving forward in its orbit.

So observe Mars over the next few months, as it appears to reverse course. Notice how its position relative to Betelgeuse, Aldebaran, and Pleiades changes over the course of the weeks, and you’ll witness what was once a source of intense curiosity for astronomers, but which we now know is just a sign of two planets passing through at night.

The Orionid meteor is active throughout October and November, peaking on the night of October 20. It is a moderate shower, usually producing 10-20 meteors per hour at its peak, under clear and dark skies. This year, the moon will be 20% full on peak nights. So it will interfere a bit when it rises a couple of hours before dawn, but it shouldn’t spoil the view completely.

The shower’s name comes from the fact that you can trace the tracks of its meteors to an area in the sky near Orion. These meteorites are fragments of dust left behind by Comet Halley in a path that extends along its orbit. They tend to be bright and fast-moving, often leaving static traces that can glow in the sky for a few seconds after you pass them.

No special equipment is needed to monitor meteor showers. Just make sure you’re warm enough, and look from a safe, dark place away from bright lights. Then all you have to do is search and enjoy the show.

Stay up-to-date with all NASA missions to explore the Solar System and beyond at nasa.gov. I’m Preston Deshes of NASA’s Jet Propulsion Laboratory, and this is what happened this month.

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