feature. The Enceladus Life Finder mission was first proposed in 2015 for
Discovery Mission 13 funding, but it was not selected. If selected at another future opportunity, the ELF mission would search for
biosignature and
biomolecules in the geysers of Enceladus. The south polar jets loft water, salts and
organic molecules dozens of miles over the moon's surface from an underground regional ocean. The hypothesis is that the water is warmed by thermal vents similar to features found deep in Earth's oceans. ELF's instruments would measure
amino acids — the building blocks of
proteins — analyze
fatty acids, and determine whether
methane (CH4) found in the plumes could have been produced by living
organisms.
Cassini also detected sodium and potassium at a concentration implying a salty liquid ocean.
Mission concept where the geysers are located. The Enceladus Life Finder (ELF) mission would pursue the implications of
Cassini orbiter's 2005 discoveries of active jetting from, and existence of an ocean within, Enceladus. The mission concept would have the ELF orbiter fly 8 to 10 times through plumes of water launched above the south pole of Enceladus over a period of 3 years. The Principal Investigator is
Jonathan Lunine of
Cornell University in Ithaca, New York.
Objectives The goals of the mission are derived directly from the most recent decadal survey: first, to determine primordial sources of
organics and the sites of
organic synthesis today; and second, to determine if there are current
habitats in Enceladus where the conditions for
life could exist today, and if life exists there now. To achieve these goals, the ELF mission has three objectives: • To measure abundances of a carefully selected set of neutral species, some of which were detected by
Cassini, to ascertain whether the organics and volatiles coming from Enceladus have been thermally altered over time. • To determine the details of the interior marine environment —
pH,
oxidation state, available chemical energy, and temperature — that permit characterization of the life-carrying capacity of the interior. • To look for indications that organics are the result of biological processes through three independent types of chemical measurements that are widely recognized as diagnostic of life. ==Proposed scientific payload==