Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.

Back On-Sky

The storm that deposited a heavy layer of ice on Mauna Kea has kept Keck Observatory shuttered for a week now. The last night we observed was New Year’s Day. Despite clear skies, there was just too much ice on the domes that could come crashing in on the telescope if we attempted to open. For a few days the Keck II dome was frozen in place by a pile of solid ice against the lower skirt.

We just got word that day crew, with a little solar help, has cleared the worst of the ice from the domes and we will be observing tonight.

Heavy Ice
Ice on the Keck 2 dome ladders after the New Year’s storm of 2015

Somebody left the seat up!

This photo is getting a little comment, no surprise, it is hilarious. When I stopped at park two to look around I had no idea and when I saw it I broke out laughing. Alone on the side of an ice covered mountain, laughing loudly with no one to hear but the wind…

A Cold Outhouse
Somebody left the door open on the outhouse…

Mercury and Venus

Over the next week Mercury and Venus will rendezvous in the sunset. This evening will see the two separated by 48′, well under one degree. This will close to about 38′ on the evening of January 10th, just a little over the width of a full Moon apart. Both objects are fairly bright, with Venus shining at -3.9 magnitude and Mercury at -0.7. Bright enough to be quite obvious, the pair will be 17° above the horizon at sunset.

A Failed Attempt at the Summit

The instruments were warming up. Liquid nitrogen exhausted, cooling interrupted by loss of power, the cryogenic dewars had begun to warm. Recovering instruments takes many days of vacuum pumps and re-cooling to restore function if cooling has been loss. Other problems caused by the storm and power outages plagued the summit, some systems not responding to remote queries.

Keck Under Ice
Keck Observatory covered in heavy ice
On Friday, the crew had abandoned early in the day in the face of deteriorating weather conditions. With the storm raging, no one had made it to the summit on Saturday. We all watched as remote weather instruments reported sustained winds of over 100mph and gusts as high as 134mph. With the wind came freezing fog, a thick coating of ice forming on every surface. The snowplow crews did not even try Saturday, it was just too dangerous.

Sunday offered at least a hope of making it to the summit. The storm had abated and beautiful sunny skies appeared over the summit. We readied for an attempt at the summit of Mauna Kea. As the engineer on call I would join the support techs at the summit. Maybe we could salvage something from the chaos.

Continue reading “A Failed Attempt at the Summit”

Earth at Perihelion

Today the Earth is closest to the Sun, a point called perihelion. We will be about 147,099,000km (91,403,000miles) from the Sun. Compare this to the 152,096,000km (94,508,000miles) we will be at aphelion on July 6th, a difference of about 4,996,000km (3,104,000miles) occurs throughout one orbit.

It may seem odd that we are actually at the closest for the middle of northern winter, you just have to remember that proximity to the Sun is not the cause of the seasons. The seasons are caused by the axial tilt of the Earth, creating short and long days throughout the year, with a resulting change in the angle and intensity of the sunlight.

2015 Solstices and Equinoxes
  UT HST
Perihelion Jan 4 08:59UT Jan 3 22:59HST
Vernal Equinox Mar 20 22:45UT Mar 20 12:45HST
Summer Solstice Jun 21 16:38UT Jun 21 06:38HST
Apehelion Jul 6 12:59UT Jul 6 02:59HST
Autumnal Equinox Sep 23 08:20UT Sep 22 22:20HST
Winter Solstice Dec 22 04:48UT Dec 21 18:48HST
 
Source: NASA Sky Calendar

 

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. For 2015 the peak is predicted for January 4th around 02:00UT, or January 3rd at 16:00HST on this side of the globe, mid-afternoon. The shower radiant in Boötes does not rise until around 2am local time. Combine the light of a full moon and poor timing and you quickly see that observing conditions are less than ideal for observing this year’s shower.

Watching meteors requires no more equipment than your eyes and a dark sky, and can be enjoyable for just about anyone. Set the alarm early? Probably not this year.