Are We in for a Leonid Outburst Friday Night?

The November Leonid meteors may produce a surprise outburst this weekend.

If forecasters are right, a notorious meteor shower may put on a surprise showing soon, right after its expected peak. The meteor shower in question is the November Leonids. Most years, the Leonids are really nothing to wake up early for, producing an average hourly rate of 10 meteors an hour, barely double the background sporadic rate. But every 33 years or so, the Leonids are the source of great storms of meteors, as the Earth plows headlong into the stream of debris laid down by comet 55P/Tempel-Tuttle on its 33-year orbit around the Sun.

The orbit of Comet 55P/Tempel-Tuttle. Credit: NASA/JPL.

The Shower in 2022

Now, 2022 isn’t an expected storm year per se: the last great outburst from the Leonids ran from 1998 to 2000, and isn’t expected again until around 2033. In 2022, the formal peak for the shower arrives on Thursday, November 17th at around ~16:00 Universal Time (UT) with a paltry Zenithal Hourly Rate of 10. The fact that this occurs just one day after Last Quarter Moon (also in the constellation Leo) doesn’t help matters much.

The 2022 Outburst

So far, not much to brave the cold for. A prediction made by meteor stream modeling, however, shows something interesting: In 2022, the Earth may encounter a centuries-old Leonid stream on the morning of Saturday, November 19th. This stream was laid down in 1733, and could provide a good encore showing for the 2022 Leonids, approaching 200 meteors per hour. Not a true storm, but a decent showing all the same… think of the December Geminids on a good year. The peak could be short and swift, running from 1:00 to 1:30 AM EST (Eastern Time) or 6:00-6:30 UT favoring eastern North America.

Looking eastward on the morning of November 19th. Credit: Stellarium.

How (and When) to Watch

If skies are clear, the best strategy is to simply stand out and watch at the appointed time. The Leonids tend to be swift-moving, and the radiant sits in the center of the Sickle of Leo Asterism, assuring that the shower isn’t very apparent until after local midnight when the radiant has risen high in the sky. The Moon will have moved off a bit, and will have slimmed down to a 22% illuminated waning crescent by Saturday morning, another plus.

A 4-hour exposure of Leonids taken in 1998 from the Modra Observatory all-sky camera. Juraj Toth/Wikimedia Commons.

Of course, use of the words ‘Leonids’ and ‘outburst’ in the same sentence always gives us pause. Just how dense the 1733 stream actually is is anyone’s guess. The Leonids produced some of the truly epic meteor storms in history, notably in 1833 and more recently in 1966. We witnessed a fine display of the 1998 Leonids from the dark sky deserts of Kuwait, with rates approaching 1,000 per hour near storm levels towards dawn.

Pickering’s 1923 depiction of an earlier Leonid storm over Niagara Falls, New York. Credit: Public Domain.

One thing is for certain: you’ll see zero meteors if you sleep in. We’re over the half-way mark now to 2032-2033, and the next possible ‘storm years’ for the Leonid meteors.

If skies are clear, be vigilant this coming Saturday morning, and watch for a possible meteor stream that has been laying in wait for centuries to ambush the Earth.