Quadrantid Meteor Shower

The first meteor shower of 2015 is the annual Quadrantid meteor shower. The Quadrantids are a reliable shower, producing 60-120 ZHR, one to two meteors per minute. The Quadrantids are named for the obsolete constellation Quadrans Muralis, now part of the constellation Boötes.

Leonids in Orion
A pair of Leonid meteors streak through Orion
Unlike other showers where activity can occur for days or even weeks, the Quadrantids have a sharp peak, activity falls off rapidly on the preceding and following nights, or even a few hours away from the peak. Thus it is important to observe the Quadrantids quite near the peak prediction.

This year’s peak is calculated for January 4th at 08:00UT, this would be January 3rd at 22:00HST for observers in the islands. For northern observers the radiant is circumpolar, thus the shower is observable all night long. Given our 20° latitude here in Hawaii the radiant does not rise until 01:30HST, thus observations must wait until well into the morning hours. A 28% illuminated moon will rise about 02:13 to create some interference in observing the shower. Thus for island observers the predawn hours of January 4th is when you want to observe this meteor shower, this will be several hours after the predicted peak.

The 08h UT timing for the peak will be too late even in the extreme west of mainland Europe while North American observers are in a better position. The λ⊙ = 283.16° maximum timing is based on the best-observed return of the shower ever analysed, from IMO data collected in 1992, as confirmed by radio results in most years since 1996. Typically, the peak is normally short-lived, so can be easily missed in just a few hours of poor northern-winter weather, which may be why the ZHR level apparently fluctuates from year to year. Model calculations of Vaubaillon provide indications that the peak may occur earlier and may show a maximum between January 3, 22h, and January 4, 2hUT. This timing would be optimal for European longitudes. An added level of complexity comes from the fact mass-sorting of particles across the meteoroid stream related to the comet 96P/Machholz and the minor planet 2003 EH1 may make fainter objects (radio and telescopic meteors) reach maximum up to 14 hours before the brighter (visual and photographic) ones, so observers should be alert throughout the shower. – IMO 2016 Meteor Shower Calendar

Watching meteors requires no more equipment than your eyes and a dark sky, and can be enjoyable for just about anyone.

A Still-Growing El Niño Set to Bear Down on US

JPL press release

The current strong El Niño brewing in the Pacific Ocean shows no signs of waning, as seen in the latest satellite image from the U.S./European Ocean Surface Topography Mission (OSTM)/Jason-2 mission.

El Nino 2015
The latest satellite image of Pacific sea surface heights compared with 1997. Credit: NASA/JPL-Caltech
El Niño 2015 has already created weather chaos around the world. Over the next few months, forecasters expect the United States to feel its impacts as well.

The latest Jason-2 image bears a striking resemblance to one from December 1997, by Jason-2’s predecessor, the NASA/Centre National d’Etudes Spatiales (CNES) Topex/Poseidon mission, during the last large El Niño event. Both reflect the classic pattern of a fully developed El Niño. The images can be viewed at: http://sealevel.jpl.nasa.gov/elnino2015/index.html

The images show nearly identical, unusually high sea surface heights along the equator in the central and eastern Pacific: the signature of a big and powerful El Niño. Higher-than-normal sea surface heights are an indication that a thick layer of warm water is present.

Continue reading “A Still-Growing El Niño Set to Bear Down on US”

Mercury at Maximum Elongation

Today Mercury will be at maximum eastern elongation, as high in the evening sky as it will appear for this current apparition. After today the planet will slide back into the sunset, passing through inferior conjunction on January 14th to reappear in the dawn around the beginning of February.

Continue reading “Mercury at Maximum Elongation”

Winter is Here

Today marks the beginning of winter. While snow and ice can appear on the summit of Mauna Kea any time during the year, the most severe weather usually occurs during winter storms. We all look forward to the beautiful sight of Mauna Kea with her white coat. Of course this comes at a price, days of difficult access to the summit facilities, or no access at all. The loss of observing nights due to ice and clouds is most common from January to March.

Iced
The emergency evacuation vehicle covered with ice