This evening a pretty crescent Moon will be just over 4° from the Pleiades star cluster. The Moon will be just 19% illuminated, a pretty companion for the bright star cluster. The pair will set after 10pm allowing plenty of time to appreciate.
The Moon, Venus and Jupiter
While Jupiter and Venus are now drawing apart after their rendezvous a few days ago one more pretty dance will liven the evening sky. With the two only 10° apart a crescent Moon will slide between them. The 11% illuminated Moon will make a nice match for the two brilliant planets, creating a lovely trio in the evening sky.
Tomorrow night the Moon will have moved to the other side of Venus, still quite close at about 4° separation, creating another pretty view.
Mauna Loa Messier Marathon
I was determined to get out and use the telescope during the March new Moon, but had planned to go observing with the guys at Hale Pohaku on Mauna Kea. At the last minute I decided to accept an invitation from the Hilo group to observe from Mauna Loa instead. The guys planned on running a Messier Marathon, something I have enjoyed many times before.
Our usual observing location is Hale Pohaku, at 9,000ft on the south side of Mauna Kea. Hale Pohaku is a great observing site, high enough to be above the clouds, but well below the summit where thin air, wind and frigid temperatures can be miserable. It is impossible to do a complete Messier Marathon from Hale Pohaku, the bulk of Mauna Kea blocks too much of the northern sky making a few objects, most notably M52, difficult to impossible.
Uranus at Superior Conjunction
Postcard from the Summit – Installing TBAD
Hanging 60ft over the concrete below… fun!
I spent the day drilling and tapping holes into the side of the Keck 2 secondary assembly at the front of the telescope. This is to install two pieces of steel that will serve as a mount for an electronic module behind the secondary mirror. The only way to do this is to climb out onto the secondary assembly. Not a job for anyone that has a problem with heights.
Mind you I am tied to the telescope with safety straps and a full harness. While a fall would not be fatal, it would be an experience in hurt, slammed up against the steel when the straps catch the fall.
The system I am installing is TBAD. I will have to write more about it later, a quick description for now. TBAD is a method of detecting aircraft in front of the telescope, intended to shutter the AO laser before we illuminate an aircraft. It will use a directional antenna to receive transponder transmissions from the aircraft. Of course, the antenna needs to be mounted to the telescope along with the receiver electronics. Thus today’s work.
When you read this I will probably be back at it. Today I will be pulling the cable for the system to the secondary. This is done using our JLG man-lift, a hydraulically powered basket/crane that can access much of the telescope. I think I remember how to drive it…
New Moon
The Reef Has Eyes
Mercury at Inferior Conjunction
Today the planet Mercury passes through inferior conjunction, passing between the Sun and the Earth. In a week or so the planet will again be visible in the dawn sky, climbing higher each day. Maximum elongation will occur April 18th.
Postcard from the Reef – Gaudy
Camouflage color schemes make sense, bright colors can be evolutionarily useful. Sometimes the color schemes exhibited by reef fish just seem weird…
A Great White at O’oma
Three days after we dove the site, a great white shark attacks a diver at the same site. The man was skin diving and spear fishing at O’oma, what the surfers call Pine Trees. The diver was not injured, the shark attempted to steal his catch and from the story might have escalated the attack if the diver had not gotten out of the water. Sounds like there were some photos taken of the shark from shore, but none seem to have surfaced yet.
Interestingly, the diver described the shark as injured, perhaps a reason the shark was attempting to grab an easy meal on the reef instead of the usual pelagic prey?