Postcard from the Reef – Redstripe Pipefish

A close relative of seahorses, pipefish are usually found sheltering in crevices or small caves. They are not uncommon sights for anyone who makes a habit of investigating the nooks and crannies of the reef…

Redstripe Pipefish
Redstripe Pipefish (Dunckerocampus baldwini) at the rear of an alcove at Hoover’s Towers

Postcard from the Summit – Mirror in the Hall

The radio call goes out… “Mirror in the hall, mirror in the hall!” Everyone gets out of the way as a mirror segment is rolled down the central hallway. It is being moved to the coating facility where it will be cleaned, stripped and re-coated with a layer of fresh aluminum.

Segment in the Hallway
The team moving a mirror segment from the telescope to the coating facility

Mercury at Maximum Elongation

Today Mercury reaches maximum elongation, the furthest point it will reach from the Sun in the sky and the highest it will be above the sunset this apparition. The planet is easily visible as a bright, starlike object about 15° above the setting Sun as the sky grows dark. Over the next couple weeks Mercury will slide back into the sunset, heading for inferior conjunction on Jul 28.

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Postcard from the Reef – Rosy Phyllidia

A nice day for a dive, and a new species of nudibrach for me. At first I thought it might simply be a juvenile P. varicosa, but there were no yellow pertuberances. Getting back I hit the books, no doubt, P. rosans. New species! This fellow was in a cave at Puako I have entered a dozen times. Even in a place I have often explored I can find something new…

Rosy Phyllidia
A Rosy Phyllidia (Phyllidiella rosans) in a cave at 25′ depth, Puako

The Moon and Saturn

Saturn, the Moon and Spica will form a trio high in the sky at sunset tonight. The three will be within 7° of each other. The gibbous Moon will be 62% illuminated. Saturn will be shining at 0.4 magnitude while Spica is very close to 1.0 magnitude. Look for the planet Mars 25° west of Saturn at about the same brightness.

Postcard from the Reef – Spanish Dancer

What is that? That is too big to be a nudibranch, but that is what it looked like. I could only see part of the beast looking into the cave crevice. Fortunately it turned out to be somewhat photophobic, the bright light flushed it out of the crevice into the cave…

Spanish Dancer
Spanish Dancer (Hexabranchus sanguineus)
A Spanish Dancer!

I make a point to look for nudibranchs, pretty critters that are wonderfully photogenic. Looking into the nooks and crannies of the reef for nudibranchs also tends to turn up other tiny surprises.

This was not small!

While the typical nudibranch is one or two inches long, this fellow was the size of a dinnerplate! Adding to the wonder was the dance. As soon as the animal left the crevice it swam across the cave. I flashed Mark to get his attention, he was ready to leave the cave. I suspect he is glad he came back. Deb also wondered what we were still doing in the cave and came in to check on us. Thus we all got a good look at the dance.

After a few photos… OK, a lot of photos, I shepherded the fellow back into his crevice. Once I withdrew the light he settled down to stay in the darkness.

Spanish Dancer
Spanish Dancer (Hexabranchus sanguineus) swimming in a cave at the Dotti’s Reef dive site north of Honokohau