by Greg Mayer
On Sept. 6, NASA launched the Lunar Atmosphere and Dust Environment Explorer (LADEE) towards the moon, where it will go into orbit to gather data on the thin lunar atmosphere. But along with the rocket, a frog, apparently resting on the rocket or launch pad, was taken spaceward, before being thrown free.
NASA’s dry caption is priceless:
A still camera on a sound trigger captured this intriguing photo of an airborne frog as NASA’s LADEE spacecraft lifts off from Pad 0B at Wallops Flight Facility in Virginia. The photo team confirms the frog is real and was captured in a single frame by one of the remote cameras used to photograph the launch. The condition of the frog, however, is uncertain.
The photo reminded me immediately of a famous biogeographic experiment performed by Thomas Barbour (1884-1946) and Philip Darlington (1904-1983), who differed over the importance of land bridges (favored by Barbour) versus overwater dispersal (favored by Darlington) in the distribution of animals on islands. The experiment and its results are handed down from one generation of graduate students to the next by a well-known oral tradition at the Museum of Comparative Zoology, but the only published account I know of is by Bob O’Hara (1988):
A how-possibly experiment performed by Philip Darlington and Thomas Barbour at the Museum of Comparative Zoology has become legendary. Darlington and Barbour were disputing the possibility of frogs being dispersed in the West Indies by hurricanes. Darlington, who believed such dispersal was possible, took a bucket of live frogs up to the roof of the Museum, and, with Barbour standing on the lawn below, proceeded to throw the frogs to the ground, one by one. As each one hit the ground, Barbour examined it and called up “That one’s dead,” “So’s that one,” and so on. But after a few minutes, much to Barbour’s disappointment, the frogs all revived and started to hop away. Darlington had thus shown that hurricane dispersal was possible, or at least had removed one of Barbour’s objections to it, namely that it would be too rough on the frogs.
To Bob’s account I would add that the MCZ is 5 stories tall, which gives you some idea how far the frogs fell in their journey to the courtyard below. Bob used the experiment to illustrate his notion of a “how possibly” experiment, which demonstrates the possibility, though not the actual occurrence, of a phenomenon.
I thought of the experiment because I wondered about the “uncertain” fate of the frog. The frog appears to be outside the plume of hot gas escaping form the rocket engine. If so, and if the clear air around it has not been super-heated, the frog could well survive the fall. Many tree frogs are adept at jumping long distances, bodies flattened and limbs spread, so that they reach a terminal velocity more dependent on aerial friction than gravity. The so-called “flying frogs” are ones that have gotten very good at this, usually with both morphological and behavioral specialiazations (see Wallace’s flying frog, an apt example for Wallace Year).
I’m not sure about the identity of the frog. My guess is that it’s a tree frog of some sort. [Note: I’d originally guessed it was a Cuban tree frog (Osteopilus septentrionalis), a large, introduced species in Florida, but that’s before I realized the rocket was launched from a facility at Wallops Island, Virginia, on the Delmarva Peninsula, and not from NASA’s more usual Florida launchpads.]
O’Hara, R.J. 1988. Homage to Clio, or, toward an historical philosophy for evolutionary biology. Systematic Zoology 37:142–155. pdf