Star names are sometimes simple, as with Vega, and sometimes total mouthfuls, like Betelgeuse. Others are just plain backward. To learn why, you might want to first go outside and look up.

One of the smallest constellations is reaching its highest point in the southern sky at around midnight local daylight time this week: Delphinus, the Dolphin. It certainly attracted the attention of ancient watchers of the sky, for despite its tiny size and the fact that it only consists of faint stars, theyre so closely spaced that they are easily seen on dark, clear nights. Here you will find a small diamond with perhaps one or two stars below it. There is something especially cute about it, positioned out in the dark just east of the bright summer Milky Way.

They first appeared in the Palermo Star Catalogue in 1814, but nobody seemed to have a clue as to their origin.

The English Astronomer Thomas Webb finally solved the mystery by reversing their letters, revealing the name of Nicolaus Venator, the Latinized form of Niccolo Cacciatore, the valued assistant and eventual successor of Palermo Observatorys Director Giuseppe Piazzi. But to this day nobody knows for sure whether it was Piazzi or Cacciatore himself who ultimately christened these two stars.

During the 1960s and 70s, one of the most popular people ever to lecture at New Yorks Hayden Planetarium was Dr. Fred Hess, affectionately known to some as the "Elmer Gantry of astronomy." Whenever he gave a tour of the summer night sky, Hess would entertain his audiences by telling the story of Sualocin and Rotanev. He then would embellish the tale by stating that he was always jealous of Cacciatore and decided on his own in tongue in cheek fashion to name the two other stars in the Delphinus diamond.

For the star Gamma Delphini, he assigned the name "Derf," which is "Fred" spelled backwards. And since the well-known astrophotographer Robert Little was one of his best friends, Dr. Hess referred to the star formally known as Eta Delphini as "Bob," which was "Bob" (a palindrome) spelled backwards.

Of course, the "Derf and Bob" monikers rarely got much beyond the confines of the Hayden Sky Theater. But it was much different story in the late 1960s when, during NASAs Apollo program, three reversed names that started out as a prank were unknowingly assigned to three stars.

The Apollo spacecraft that took men to the Moon were designed to operate under inertial guidance, with gyroscopes keeping them pointed in the right direction. But because the gyroscopes tended to drift, the Apollo astronauts had to periodically recalibrate the system by sighting on known stars. There were 37 in all.

Astronauts Virgil Grissom, Roger Chaffee and Edward White, were to be the crew on the very first Apollo flight.

While training in celestial navigation, Grissom, as a practical joke, quietly incorporated three new names onto NASAs star list: Dnoces (which was really Iota Ursae Majoris or Talitha), Navi (Epsilon Cassiopeiae) and Regor (Gamma Velorum or Suhail).

In later missions these three maverick stars were accorded the same respect as celebrated ones like Sirius, Vega and Aldebaran. They even innocently turned up on some star maps that were published during the late 1960s and 1970s.

But what did they stand for?

Dnoces is "second" spelled backwards, a reference to Astronaut White (Edward White, II, who was also the second man to walk in space). Navi was Grissoms middle name (Ivan) spelled backward. Regor was Chaffees first name in reverse.

Today, the names are classified by most reference sources as "disused or never really used." Sadly, Grissom had no idea that his celestial jest would turn into a memorial to himself and his crewmates. All three perished in a fire that enveloped the Apollo command module on January 27, 1967.