Ursid Meteor Shower

If you’re seeking for a celestial treat this winter, watch for the Ursid meteor shower, which is predicted to peak on December 23. The Ursids are tiny meteor showers that occur every year around the winter solstice as the Earth passes through the debris left by comet 8P/Tuttle.

The Ursids are not as stunning as the Geminids, which lit the sky earlier this month, but they nonetheless provide us with the opportunity to watch some shooting stars in the cool night sky. Under optimum conditions, the Ursids generate roughly five to ten meteors each hour.

Why is it caused?

The Ursids meteor shower is caused by the comet 8P/Tuttle. On January 9, 1790, Pierre Mechain found it from Paris, France. Mechain, a Messier collaborator, identified seven comets that bear his name. However, he identified two additional comets that do not. One, subsequently dubbed Comet Encke after Johann Encke, who computed its orbit, is responsible for the early November Southern Taurids meteor shower. This is the second comet Mechain discovered that does not carry his name, 8P/Tuttle.

The meteor shower outbursts have nothing to do with the years when the comet passes through the inner solar system. This is because the comet’s material forms its own course and trails behind the comet. When the comet passed through the inner solar system in 2007, there was enormous expectation of a shower outburst that December. But nothing happened. And meteor shower outbursts are not uncommon when the comet is distant from Earth.

The comet is still traveling away from Earth and the sun in 2023. But it doesn’t stop its stuff from coming in and colliding with Earth in late December.

Where to see the Ursid Meteor Shower?

To observe the Ursids, you must choose a dark and clear location away from city lights. The greatest time to search for meteors is in the early morning hours of December 22 and 23, before daybreak. The meteors will appear to emanate from the circumpolar constellation Ursa Minor, often known as the Little Bear or the Little Dipper, which is visible all night in the northern hemisphere. To find the constellation, utilize a sky map app on your phone or just look for the big star Polaris, which marks the end of the Little Dipper’s handle.

Because of the Christmas season, this low-key meteor shower, which always peaks around the solstice, is generally neglected. Its hourly rate is lower than the Geminid shower, which peaks a week earlier. The Ursids are worth a look in 2023, with several hours of darkness before daybreak!

This comet’s arrival in 1790 offered an estimated orbit, which Mechain computed. There were insufficient data points to suggest that the comet will ever return. But it happened. Horace Tuttle of Harvard University College spotted it up in the dusk sky 68 years later, on January 5, 1858. It was studied for many months and an orbit with a return date of 13.7 years was estimated. Tuttle connected it to Mechain’s comet found in 1790, and it became known as periodic Comet Tuttle. Because it was not detected as a periodic comet from Mechain’s orbit, it is not known as periodic Comet Mechain-Tuttle. As a result of the revised naming regulations implemented in 1995, the official name of this comet is 8P/Tuttle.

Comet 8P/Tuttle approaches the sun as closely as the planet Earth does, then orbits Saturn. Its trajectory is inclined to the Earth’s orbit, and we intercept the material as it descends from above. The comet’s most recent journey to the inner solar system was in August 2021.

The meteor shower outbursts are unrelated to the years when the comet visits the inner solar system. That is because the stream of material from the comet creates its own path, and lags behind the comet. In 2007, when the comet visited the inner solar system, there was great anticipation of a shower outburst that December. But none transpired. And it is not unusual for the meteor shower outbursts to occur when the comet is far from Earth.

This year, 2023, the comet is still moving out, away from Earth and the sun. But that does not prevent its material from moving in and intersecting Earth in late December.